Poll results & how to control power in FB engines

[Jnovak]

Interesting results from the 2 polls I put up. Not what I expected. The results are over 3 to 1 in favor of restricting power to the current levels and over 3 to 1 who think the FB class will be better with engine power restriction to current levels.

I guess that it must be time to start a discussion on how to control FB engine HP to approximately the current level.

I personally am not in favor of the proposal to homologate engines as this will be difficult to implement and very expensive. Perhaps the best solution is to run some form of inlet restriction. My personal race and dyno experience is with IIRs. These are sharp edged orifices that fit between the manifold and the head or between the throttle body and the intake manifold.

On our F600 development with Suzuki and Honda engines we had great results with making these 2 very different engines produce within about 1 to 2 hp on a chassis dyno on the same day, operator, tires etc.

We have also raced cars with no adjustments other than fuel pressure. The Honda and the Suzuki both picked up a whole 1 hp with many hours of testing and programming with a Power Commander on the dyno.

So my suggestionn is that we try restrictors on the dyno to see what happens.

I volunteer to make restrictors for anyone who wants to do dyno work. I would do it myself except we will not be dynoing for some time.

Anyone with other thoughts on the subject?

Thanks ... Jay Novak

[RobLav]

Anyone with other thoughts on the subject?

Sure - restrict to 220 HP, so that when SCCA merges FB into FA, we'll more immediately be competitive.

I guess that it must be time to start a discussion on how to control FB engine HP to approximately the current level.

The current level is at least 200 HP.

[Wren]

No one has hit the track with an engine making more than the 07-09 GSXR 1000. Now is the time to do it.

[RobLav]

Mine will in two and a half weeks. Jesse finished my pan, and it arrives Friday.

[Jnovak]

As I stated in my first post on this thread, I was very surprised at the results that seem to indicate that a majority of poll responders want to restrict the engines in FB.

The reason I was surprised is that I thought that most racers in the FB community would want the next generation of engines into the class for several reasons. So all that said and after MUCH thought on the subject. I think it is too early in the life of the class to restrict the power of our engines. I think we need one more new generation of engines for this class to stabilize. The supply of engines is getting tighter and new parts are very expensive to purchase (I know this for a fact). Suzuki will be out with their new engine next year and probably Yamaha too. I suggest that we not push this restriction proposal to the CRB at this point in time and to that end I have sent my letter to the CRB (#8090) requesting that the next generation of production motorcycles be allowed for use in FB without restriction at this time.

Thanks ... Jay Novak

[starkejt]

Can we wait until your car has produced 200 hp for a complete lap, perhaps even reliably for a race distance, before we assert that 200 hp is the current level of the class?

[Jnovak]

Our motor was just on the dyno so I know how much power it had and it is a long way from 200 hp and it is not above that number for certain.

Thanks ... Jay Novak

[starkejt]

Our motor was just on the dyno so I know how much power it had and it is a long way from 200 hp and it is not above that number for certain.

Thanks ... Jay Novak

Sorry, I should have quoted Rob to be clearer. Wasn't talking about yours.

[Northwind]

Rob goes blasting past pit lane and all he can see is the other teams crews and they all look just like this

[Wren]

The reason I was surprised is that I thought that most racers in the FB community would want the next generation of engines into the class for several reasons.

Restricting the power still lets them in. It just lets them in without obsoleting the current engines or making these cars faster than it makes sense for them to be. Keeping the revs down should help the engines last longer as well.

Nothing good is going to come from making these cars as fast as Atlantics. Can anyone think of something positive that could come from this?

Personally, I am surprised at the number of FB cars that have been bought and then parked or sold immediately. I believe that the ultimate performance capability of these cars is scaring people away.

[John Mosteller]

As I stated in my first post on this thread, I was very surprised at the results that seem to indicate that a majority of poll responders want to restrict the engines in FB.

The reason I was surprised is that I thought that most racers in the FB community would want the next generation of engines into the class for several reasons. So all that said and after MUCH thought on the subject. I think it is too early in the life of the class to restrict the power of our engines. I think we need one more new generation of engines for this class to stabilize. The supply of engines is getting tighter and new parts are very expensive to purchase (I know this for a fact). Suzuki will be out with their new engine next year and probably Yamaha too. I suggest that we not push this restriction proposal to the CRB at this point in time and to that end I have sent my letter to the CRB (#8090) requesting that the next generation of production motorcycles be allowed for use in FB without restriction at this time.

IMHO now IS the time to restrict or don't ever restrict.

If we restrict to the current level the only competitors that have to go to the next generation engines are ones that need an engine now and can't find one.They can go to the new 200HP generation that restricted to 175HP should be very reliable.Unrestricted they may be less reliable than the current engines and probably will be as they are higher RPM. The other 50+ cars out there will still be able to compete.

If we allow the next generation with no restriction then all of the 50+ cars will have to switch over now if they expect to be competitive.How many will convert to FC or FF Honda rather than spend $25K+ to convert to a different engine knowing that this will be just the start as it might be only a few years down the road until it will have to be done again.

If we don't restrict now then there will be no reason to restrict the new 200HP engines as everybody will have one.Then it would be why restrict at this level when there is nothing out there to be afraid of.Lets wait until someone shows up with something first.Then we would be right where we are today.

I think restricting the new 200HP engines would only have a positive affect .None of these engines were designed to operate in cars that are twice the weight as the bike they came in.
IIR's will limit the maximum RPM and go a long way towards extending the longivity which would be a good thing.

This class already has a rep for fragile engines.The bugs have been worked out of the current engines and will probably have to be worked out on the new 200HP engines as well. We can try to get them to live on the edge or restrict them and maybe have some margin of reliability that might attract people to this class instead of scaring them off.

[Purple Frog]

I second what Mosteller wrote.

[RobLav]

Can we wait until your car has produced 200 hp for a complete lap, perhaps even reliably for a race distance, before we assert that 200 hp is the current level of the class?

But Josh, can we wait until a car has produced 200 hp for a complete lap, perhaps even reliably for a race distance, before discussing restrictors and making predictions that the sky is falling?

And John, please show the details of your $25K estimate to convert. My single engine package was much less than $10K outright (more like $9K): New engine with all electronics, BRD dry sump Citation type pan (more $$$ than normal) and stainless exhaust. This is my outright cost. For a conversion, you also have at least $3500 worth of stuff to sell. The difference IMO amounts to about $5500 - less than 1/4th of your estimate. That $5500 difference is getting pretty close to a full up Geartronics, which we've already fought at length about. I don't see it.

[Mike B]

Not that anyone cares what I think...
I've always felt that rules stability was the absolute most important factor in helping this class grow, even when it comes to electronic shifters and creative aero interpretation. No new rules or rule changes, period.
So, my initial thought was this was just one more thing to drive people away from the class. However, as Wren, JM, and Jay (sort of) have alluded to, restricting all engines to a given HP level now introduces a stability that the class wouldn't have had otherwise. If done correctly, it can be the best of both worlds: allow older engines to stay competitive and still allow people to experiment with new engines, all while keeping the HP war and escalating engine costs in check.
The way the Fastrack was written leaves too much to the imagination and just creates more doubt and questions (maybe that's the intent). The key will be crafting a rule that can be verified by an SCCA tech inspector and won't cost the competitor a significant amount. Unfortunately, Wren is also spot-on when he says that it's doubtful the SCCA could manage it.


I humbly suggest that we as a group take control of our class and begin the framework of a workable rule to present to the F/SRAC and/or the CRB.

[starkejt]

But Josh, can we wait until a car has produced 200 hp for a complete lap, perhaps even reliably for a race distance, before discussing restrictors and making predictions that the sky is falling?

I was only disputing your statement that the "current level is at least 200 hp." People can discuss and predict at their leisure.

[RobLav]

Hey Mike - we agree on some things! Mostly that we should take control of our own class and that rules stability is key. A 175HP limit restrictor though is not a compromise.

Josh - yes, I know.... I was merely reversing your logic. And as you say, people can discuss and predict at their leisure - and many predict that the sky will fall if this happens. I do not wish to pay for other people's security.

[starkejt]

many predict that the sky will fall if this happens.

One time I drank a fifth of cheap scotch and predicted I could take my pants off over my head. That didn't happen either.

[RobLav]

Josh - are you coming to NJMP? I've a bottle of some really good stuff. Besides, I have no idea if this thing will put out 200 reliable HP. Nevermind the fact that I'm a mediocre driver. Even with 200HP, I won't be up at the pointy end. I need all the help I can get!

[starkejt]

Josh - are you coming to NJMP? I've a bottle of some really good stuff.

The only event I would possibly go to there would be the F2KCS weekend, but I'm considering skipping that one and Lime Rock to work on the new car. I'm spread too thin.

[Wren]

But Josh, can we wait until a car has produced 200 hp for a complete lap, perhaps even reliably for a race distance, before discussing restrictors and making predictions that the sky is falling?

No one has made predictions that the sky is falling. We have had some personal insults but no predictions that the sky is falling.

There is a difference betwen questioning what good will come from the new engines, pointing out the negatives and saying that the sky is falling.

And John, please show the details of your $25K estimate to convert. My single engine package was much less than $10K outright (more like $9K): New engine with all electronics, BRD dry sump Citation type pan (more $$$ than normal) and stainless exhaust. This is my outright cost. For a conversion, you also have at least $3500 worth of stuff to sell. The difference IMO amounts to about $5500 - less than 1/4th of your estimate. That $5500 difference is getting pretty close to a full up Geartronics, which we've already fought at length about. I don't see it.

$25k is too high but $10k for a home conversion is a lot. Imagine if you had to pay someone to do that. If I was pioneering a new install, I would want at least 5 engines sitting there to consume. It took at lot more 07-08 GSXR engines to sort out the initial problems but it might take less than that since some of the knowledge from the old engines will apply to the new engines. None of this comes with any promise that it will actually work either. Don't count on being able to sell an uncompetitive engine for a reasonable price for very long either.

It is always interesting to see what people think a geartronics costs.

Hey Mike - we agree on some things! Mostly that we should take control of our own class and that rules stability is key. A 175HP limit restrictor though is not a compromise.

Josh - yes, I know.... I was merely reversing your logic. And as you say, people can discuss and predict at their leisure - and many predict that the sky will fall if this happens. I do not wish to pay for other people's security.

Class stability is an excellent compromise. We've known for years that the CRB was not going to let the engines escalate beyond current levels. Interesting that you think that allowing in an overdog engine would be rules stability, care to explain that one?

[Jnovak]

I have probably spent more time developing IIR restrictors on bike engines than anyone in the SCCA. I can tell you for a certainty that they do work. However what I also learned is: To keep different engines equal in power it is necessary to have significant levels of restriction on the most powerful engine. To get the Honda 600 and the GSXR 600 equal we had to knock about 20 hp off of the GSXR engine. For instance the GSXR engine made (unrestricted) about 125 hp and the Honda made about 110 hp (engine dyno). When both engines were restricted by the 32mm restrictor they both made about 103 hp on a chassis dyno. This data, while incomplete, is still clearly indicative that with the 32mm restrictor these 2 engines both flow about the same amount of air and thus make very similar levels of hp.

I suspect that the only way to keep the GSXR1000 at 170-175hp is to leave it alone and restrict the newer engines with a specific diameter of inlet restrictor. My 1st estimate is that it would take around a 38mm (+-) restrictor to knock 25 hp off of a 200 hp bike engine.

Obviously anything can be accomplished with enough work and $$$. My questions are: Who will do the testing? Who will validate the tests? Who will pay the bills? Who will manage the entire process? Who will have the absolute authority to make the decisions?

Then what happens with the followup? Someone builds a new and better car with a new restricted engine. The net result is that the car is 1 second a lap faster than the others. What happens then? I know, reduce the restrictor another mm until the new car is equal to the old cars.

How does this all work? I have not heard a single person come up with a defined process on how to do this and manage it much less to make it fair to all involved.

I am not against the concept. I am against a process that cannot be properly implemented and managed.

Instead of complaining that we MUST have restricted new engines, present a process that will work fairly and properly. For example, I understand that Honda paid for significant dyno testing prior to getting the Honda engine approved for FF. I am sure that the cost involved was very significant and certainly way beyond what any individual would or could spend.

Another example, when we originally tried to get the 600cc bike engines approved for use in F500 we were told that dyno testing was a MUST to make this happen. I spent a very considerable sum of $$$ and also had contributions from several others to conduct over 3 days of engine dyno testing. Great, we learned a lot and I think we understood what it would take to get the power to the appropriate level.

SORRY JAY but that is not enough. Dyno testing does not mean anything at this time we need track testing and more track testing.

I am not trying to rehash an old story or offend anyone but that is what happend.
I see this same scenario happening again because there is ALWAYS someone who is not satisfied with the answers you give them.

Thanks ... Jay Novak

[Nicholas Belling]

Can we wait until your car has produced 200 hp for a complete lap, perhaps even reliably for a race distance, before we assert that 200 hp is the current level of the class?

Agreed. when we developed the new 09/10/11 suzuki dry sump and started testing we burned down a few motors on the dyno, and at the track until the package became proven and sorted. and it took half a year or more to sort through all the electronic issues.

A new engine is not going to come into the class overnight.. for sure. as well the costs associated I expect will be higher than people anticipate to develop reliability in a new package ! JR is proof of that from a 2 years ago at the runoffs..

their will be much more costs than just having the raw car conversion with a new motor sitting in a car ready to run on track for sure..

Look forward to seeing the new BMW / KAWI / SUZ run this year and see how it all pans out.

My thought is just maintain stock engines.. no modification / alterations beyond stock as delivered from manufacturer except open electronics up.. this allows the class to properly run these damn engines and bypass all the limp / safe /dealer mode operations that haunt these new engines.

Forget restrictors and trying to manage and enforce that. But defintiely work to have engine builders specify guidelines for new engines for scca tech to identify and measure and look at stock engines appropriately at the track or if a protest is done. Their are to many grey areas in service manuals that are up for interpretation.. If it doesnt say you can machine your head in the service manual, then you can't right ? or if tolerance specs are listed then can you ?

[RussMcB]

I think the class has the best chance of thriving if there are caps to keep engine competition close. Ideally, a low budget racer should have access to almost the same HP as rich racers. That's a recipe for inviting new people to the class and having the best drivers and chassis get the rewards they deserve. I don't think a class benefits if some people are able to spend less time on straights because they have more HP than competitors.

However, I sure would be disappointed if something were implemented now that penalized someone like Rob or JR. That could be like when Jeremy was screwed at the Runoffs years ago with his totally legal bike engine FC car.

Jay has offered to help test IIR's. Someone should work with him to prove/disprove their viability. I hope IIR's work because that would let racers keep their current power plants longer (no new engine mounts, harnesses, header, dry sumps, support systems, etc.).

I'm a big fan of F1000 cars. I hope the class becomes super popular.

[Jnovak]

OK, just for discussions sake, let's say restrictors are a good thing.

What is the process?

Thanks ... Jay Novak

[Mike B]

Rob,
This is a no-brainer for you. Jay has offered to make the restrictor for you and I’m pretty sure that George has a Kawasaki that he could readily dyno with the IIR. You could actually be ahead of the curve compared to everyone else. It also protects your investment next year when Yamaha or Honda come out with their Kawasaki-killer and might prevent you from throwing in the towel again. I don't see it as a penalty at all. I think we can all agree (except for Nicholas ) that some sort of restriction is a good thing. I think the stability it will bring to the class might help it grow despite other forces that are weakening it. It should be done soon.
Personally, I would like to see the HP restriction a little lower so I could go back to the more reliable R1 engine. It might even make the older Hondas and Kawasakis competitive and open up more engine options. Maybe Russ will come back!
The question mark is how to implement it. If done properly, I can’t see a big downside to it.

[formulasuper]

I second what Mosteller wrote.

I'll third it.

[Wren]

Someone should probably pick up the phone and call George and ask him at least this:

1. Will IIR's work with the stock ecu on the GSXR1000 and the new Kawasaki at 175hp levels?

2. How much will it cost to do the dyno testing on a few(say 4) different restrictor sizes on these two engines?

[nulrich]

OK, just for discussions sake, let's say restrictors are a good thing.

What is the process?

I don't have a stake in FB, so here's the view of an outside observer.

Some people enjoy developing engines in the same way others enjoy developing chassis or aerodynamics, and FB has been a good class for single individuals looking to build a better car through their own ingenuity. I don't think you want to lose that.

That said, you don't want one of these new engines making existing cars obsolete or start an engine war that gives huge advantage to those with the most resources.

I also don't think SCCA has the resources or expertise to homologate and control engine horsepower, especially given the number of possible engines.

My suggestion is to select one size of IIR for all engines. There will be small differences between engines, but peak power will be very similar. It also allows engine builders and individuals to fine tune around the restrictor for small gains, just like you can fine tune your suspension or aero.

It certainly would be a lot easier to enforce than any of the alternatives.

I'd pick a restrictor size just big enough that it doesn't substantially effect current engines.

FWIW.

Nathan

[R. Pare]

Another question to get an answer to:

Will the implementation be a single restrictor diameter across the board for all engines, or tailored individually to exactly how the engine reacts on the dyno?

If a single diameter is mandated, and one particular engine somehow puts out, say, 180 HP instead of the desired 175, there will be a lot of squawking by those who don't already have that engine.

To me, the only "fair" way to do this is a single size across the board, even realizing that it may not give the desired results on all engines, current and future. It also would be the most economical and easiest for Tech to manage.

[John Mosteller]

And John, please show the details of your $25K estimate to convert. My single engine package was much less than $10K outright (more like $9K): New engine with all electronics, BRD dry sump Citation type pan (more $$$ than normal) and stainless exhaust. This is my outright cost. For a conversion, you also have at least $3500 worth of stuff to sell. The difference IMO amounts to about $5500 - less than 1/4th of your estimate. That $5500 difference is getting pretty close to a full up Geartronics, which we've already fought at length about. I don't see it.

Rob you may do it cheaper if you buy a new bike and part it out but that is not how the masses will buy. On the new engine thread it was posted that a new Kawasaki crate motor with electronics,oil system and fuel injection will be right at $10K. If one is serious about running nationals or a pro series with the costs of travel,entry fees etc. I think one would have to have a spare engine with dry sump pump and pan (in case you throw a rod and wipe out your pan or dry sump pump). If you are converting you will need a new exhaust system. I would guess a new custom stainless system will be well north of 1K.You will need a new airbox which I am guessing up to 1K for a custom airbox from Stohr or some other composite company.

10K crate engine,electronics,fuel injection oil system etc.
7K spare engine with dry sump pump and pan
1K+ custom exhaust
1K custom airbox

So 19K just in parts before you do any mods to the car that are required to install new engine.What if the chain on new engine ends up where a pickup point is and needs frame suspension redesign/fabrication. Different water line/oil line systems.I have over 2K in aeroquip fittings/lines for my water and oil.I think fabrication,possible body work mods etc. could easily run 5K.

Can someone do everthing themselves and do it cheaper? Sure if your time isn't worth much.

[Wren]

Correct. The only way to carry a spare engine is completely dressed with a pan and dry sump pump on it. Otherwise you spend all Saturday afternoon and all day Sunday at the runoffs prepping a new motor to go in the car and putting it in the car.

Counting that in the cost of conversion is tough though. Not everyone carries a spare. Conversion cost should be the cost to get one in the car. Anything to do with spares is bonus.

$1k sounds really low for any exhaust that I would want to use.

[JerryH]

Nathan and Richard have stated the obvious. Use the same size restrictors on all engines.....sized to allow 08 gsxr power level.

Jay stated that the 600's had similar outputs with the same restrictor size....even though they started out way different. The 1000's should have a similar outcome.

If we dyno the 08 gsxr with various sizes restrictors until the power starts to drop, then use that size for all engines, that should do the trick. Minor differences will still exist....but small enough to live with.

Done this way, everyone can run the engine he chooses.....without forcing anyone to change just to stay competitive.

Jay and Rob.....I know you have significant money investing in adapting to newer engines......but this will not relegate you to being non competitive.....as doing nothing will do to many others.

Thanks,

Jerry

[Thomas Copeland]

At first I wasn't sure how I came down on this idea.

But after some thought I think I'm for the idea of some kind of HP restriction.

Perhaps 175 is the starting point (although I think I would like something more like 185-190). If that is, if it can actually be policed properly.

But at the same time we really do need to open up the electronics on these motors. It's stifing engine development.

With engines being restricted there is absolutely NO reason anymore to restrict ECU's.

[RobLav]

Ok.... I have emotionally ranted and raved too much. Not a good thing. Please understand my time and monetary commitment to building the best FB car I could. Having done this once before with a weaker engine package, I wanted to do it right. I feel that I am being cut off at the knees by my efforts. So I ask that you please try to understand where I am coming from. A few days have passed since the F/SRAC proposal, and time reduces emotions. Even though I don't agree with the proposal, I recognize now that they needed to do something to get this underlying issue satisfactorily resolved. My perspective is that we never resolved our philosophical differences, especially wrt restrictors, in our rules committee 5 or 6 years ago. Since we never resolved it then, it was eventually going to again rear its ugly head. It seems that now is the time to resolve it.

Given the limited number of our cars, that will be run in both Club and Pro, it seems to me that the more the rules diverge, then the less likely sufficient numbers will result. If we eventually end up in FA, then putting 175 HP restrictors on now will put us behind in development in order to be reasonably competitive in FA. My logic here is, of course, based on an assumption. But we have to make decisions based on uncertainties, so assumptions must be made. I do believe it is very important to not diverge the Club and Pro rules too far apart. We will not get the crossover.

The comical banter between Josh and I made me realize that all this ranting and accusations are non-productive. I admit guilt. If we are going to do restrictors, then it needs be a simply executed compromise. Simply executed in that EVERYBODY runs the same IIR (not SIR), and a compromise that the IIR is neither too big nor too small.

If we run restrictors, then we still need to be able quickly set up between Club and Pro. The use of the Factory Race ECU in Club will help in this regard (along with many other issues), and it will more align Club to Pro rules (less divergence between rules provides more opportunity for crossover). Concerning the restrictor size, I am wondering if a compromise exists. Too big or too small, and many will walk away and take their wallets with them. For instance, 175 HP limit, and I'm out (run FS and Pro). And it looks like that with 200+HP limit, then people on the other end of the spectrum will walk. Both sides can make the argument that new members will not join (new cars and drivers) because the rule doesn't fit, so I see that argument as moot on both sides.

Is 185-190 HP a reasonable compromise?

Also:
Yes, John, I know... most people do not do what I do and have done. Sometimes I forget that. I built my stainless exhaust and made my own new airbox and engine cover and engine sides. I made my own engine bay tube structure. I make all sorts of things - mostly on a table saw with a metal cutting blade. I think the realistic conversion cost is somewhere between your figure and mine. But that is up to each individual.


On edit, it seems Thomas and I are on exactly the same page.

[Ivinsea]

... no modification .... except open electronics up.. this allows the class to properly run these damn engines and bypass all the limp / safe /dealer mode operations that haunt these new engines.

This cannot be overstated.

The complexities of stock ECU's and modfying harnesses to bypass traction control, anti-theft, limp home mode etc are only going to get worse. The BMW and Honda are apparently extremely difficult to defeat, and if the manufactuer does not offer a racing ECU, a standalone ECU will be essential. Maybe we do not want to open up to $15K Motecs, but allowing some kind of basic aftermarket ECU is essential.

[starkejt]

...The comical banter between Josh and I....

I'm fine with whatever as long as we don't restrict my comical banter to everyone else's level.

[stonebridge20]

I'm fine with whatever as long as we don't restrict my comical banter to everyone else's level.

Maybe you could be fitted with a single OUTLET restrictor to level the playing field?

[RobLav]

That was obtuse Josh! Where's the 090 to 180?

[starkejt]

Maybe you could be fitted with a single OUTLET restrictor to level the playing field?

[Jnovak]

I have spent a ton of time on the dyno and on the flow bench developing restrictors for the 600cc F600 engines and I have learned a few things that I want to share. Not in any order of importance.

1. in order to use the exact same restrictor in all engines including the current GSXR motors will require a significant reduction in HP for all engines including the GSXR engines. The current GSXR1000 engine is pretty optimized wrt it's entire configuration so ANY IIR restrictor implemented on a GSXR engine will result in a reduction in HP. Based on our work trying to equalize a couple of 600cc engines I expect that a minimalist restrictor diameter that would equalize all engines to a very similar power level would probably reduce the HP of the GSXR by a significant margin.
2. Here are some details (just talking peak power and round numbers for discussions sake) For 2 very different 600cc MC engines both engines completely unrestricted: The GSXR engine produced about 124 hp and the Honda produced about 112 hp.
3. Let's put 32mm IIR restrictors in both engines. The both now produce 103-104 HP (round numbers). This means that the 32mm restrictors reduced the power in the GSXR by about 16% and reduced the Honda power by about 7%.
4. Just for the sake of discussion let's apply those percentages to the current GSXR1000 engine at 180 hp and the Kawasaki ZX10R at 200 hp and here is what you get. The GSXR makes 167 hp and the Kawasaki makes 168 hp. Wow how interesting and amazing.
5. Now remember that if you want restrictors of the SAME SIZE ON ALL ENGINES the Suzuki must give up 13 hp to be the egual of the Kawasaki.
6. This is what physics tells us about applying the same sized restrictor to ALL ENGINES. If you want to keep the power level of the current Suzuki at the current level then you must not restrict it and you must have a slightly larger restrictor for the new Kawasaki.
7. Now you must make the clear decision: Either reduce the power of ALL ENGINES or selectively restrict the newer engines such that they have the power of the current engines. I do think that all 200 hp engines will react in a very similar manner with the same sized restrictor.

This is a very important philosophical decision that must be made and this makes the process more complex.

Tech point #2: While our experience is with only a couple of engines we have seen on the GSXR600 a problem with throttle response when putting the inlet restrictor inside the manifold boot. Throttle response at around 8000 RPM and up was much compromized with the restrictor sandwiched between the manifold and the throttle body. We do no know what caused this but I suspect that it has something to do with the proximity of the restrictor plate and the throttle blade. When the IIR was placed between the manifold and the cylinder head the throttle response was pretty normal.

Tech point #3: We were able to optimize BSFC (fuel mixture) with fuel pressure and without modifying the ECU in any way at all on the engine dyno. When we did a full day of chassis dyno testing using a Power Commander on both the Honda and the Suzuki they both only gained about 1 hp after several hours of adjustments.

Tech point #4: Will all 1000cc engines respond in a similar manner? I do not consider myself any kind of an expert on this business even though I have some experience. I will say that engines are air pumps and that if you have several modern 1000cc MC engines making 200 hp then I would bet that they are pumping very similar amounts of air. I thus expect that several 1000cc engines that make approximately 200 hp unrestricted will all make very similar HP with the same sized restrictors.

So make your choices. Restrict ALL engines to a lower than current level or restrict newer engines only to the level of current engines. Good luck on making this happen and making everyone happy.

Thanks ... Jay Novak

PS: I hope I got this all right, my brain is spinning.