Not only that, but the fastest P2 race trap speed was 167.5 mph versus 166.1 for FB. Oops!Originally Posted by Jnovak
Not only that, but the fastest P2 race trap speed was 167.5 mph versus 166.1 for FB. Oops!
Stan Clayton
Stohr Cars
FB Daytona Speed Trap Speeds?
Hey Stan, I thought the Fastest FB trap speed at Daytona was a 169.xx.
Doug
Is Coop running Jake's Stohr?
Jason Bell doing 169 mph. I think I can hear him with a sinister laugh every time he pulls out on a straight stretch all the way up here in Michigan.Very impressive.
Last edited by Gearslingr; 12.08.15 at 1:51 AM.
Lawrence spared no expense on his engines. It had 4 weekends on it.....but it was one of the best.......so no...... Alex didn't have a better engine this year. I have the dyno sheets.
The ad hoc committee task....as I understood it....was to cap speeds where they are....not slow them down. This does more than that.
No one has done dyno on the kaw with the 37.5 flaired in restrictor....only the gsxr. Therefore, the process of getting an adjustment done will require someone dynoing a kaw and gsxr side by side on the same dyno. We already have that data for flat plate restrictors.....and was used as a basis for my request. According to George Dean again, same size flat plat restrictor on both engines takes the same percentage off both....which doesn't get them anywhere nearly close enough. I doubt it will be any different with faired in restrictors......higher hp for a given size...yes......minimal change in power difference with same size on both. Until I see a dyno run that says otherwise, my conclusion seems logical.
If the crb wants track data, then that will take months. Meanwhile the season will be half over.
Biggest question is: if data shows an adjustment is needed will they make the gsxr larger or the kaw smaller......slowing us even more.
Jerry
Page 2 Stan of the FB/F1000 shows 166.436.....same conclusion/point.Not only that, but the fastest P2 race trap speed was 167.5 mph versus 166.1 for FB. Oops!
Curious if the timing beacons were in the same positions for both classes? Maybe I imagined it, but I seem to recall a discussion somewhere on here about the timing beacons for speeds located at different places relative to the s/f line for different classes.
A full bodied car with similar frontal area should be faster in a straight line than an open wheel car.....way less drag.Not only that, but the fastest P2 race trap speed was 167.5 mph versus 166.1 for FB. Oops!
I believe that is why the lap times were that close. I didn't see that at other tracks during the season......but I will check the lap records at all the tracks we ran this year.
Jerry
The Kawi comes with 47mm TB, the GSXR 44mm. Both going to a 37.5 is a much larger change to the Kawi. It's a difference of 36.3% in cross section area to the Kawi and 27.4% difference to the Suzuki.
FB Qual 1 at Daytona Trap Speed
Jason Bell hit a 169.193 S/F Speed on lap 10 of Day 1 Qual.
http://cdn.growassets.net/user_files...pdf?1442865108
I don't know if he was in tow or not with that, but it's haulin anyways.
Doug
I'm pretty sure it's the other way around. Full bodied cars have more drag. The difference in lap times (at least for p1) comes from the downforce. My best top speed was 165 with a $30k 1615cc Hayabusa (running perfectly, but grossly over restricted)
I don't like this rule change but I think FB will still be quicker than P2. The real question is how this will affect the Kawi
"If you're not driving on the edge you're taking up too much space.... "
Proceedure please.
Can someone please post the proper procedure to officially write a letter to the SCCA voicing our opinion to this ?
Letter to the CRB
The process is to send a letter to the CRB and the process is on the SCCA web site here
http://www.scca.com/pages/cars-and-rules
The CRB has 2 BoD liaison so they also have visibility to all letter regardless of them being tech bulletins or rule changes.
David
PS - all letter both for and against are in the CRB meeting minutes and the letter that is directly associated with the change is listed in the tech bulletins. Not all letters on the subject have been processed through the system due to the date they were received.
JP
You are an awesome dude but on this one you are wrong. A closed wheel design has inherently less drag than an open wheel car. I'd be happy to point you to many articles written on this very subject and supporting data to go along with it.
You only need to look at how hard F1 and Indy car try to redirect the turbulent bubble from the tires to see this in real life.
The FB with a 37.5 restrictor will be considerably slower than a P2 car. Daytona is a terrible example to use.
At this point I've already lost one car sale this year over the restrictor threat and I know another car builder that is likely in the same position.
Gary Hickman
Edge Engineering Inc
FB #76
For those of you that couldn't make the Daytona Runoffs. Yes it is true Bell did hit 169 but I can tell you this, they had all the D/F out of that car. I was pitted right next to them in the garages. They took the entire diffuser and cut it into what was nothing more than a decoration. They had all the wing out of the car. We know where Bell ended up, spinning in the grass=lack of grip.
Myself, JRO, Mayer and others were pretty much stuck in the 155-160 range. Obviously we were all running a similar amount of D/F to get through the infield coarse.
Gary Hickman
Edge Engineering Inc
FB #76
drag
On an open wheel car, the wheel/tires are roughly 50% of the total drag. Closed wheel has way less drag because of that.
SO WE WILL BE SLOWER THAN P2.
P2 doesn't have the downforce your P1 car has. It is more in line with an FB.
Jerry
Wow Jay you are really going out on a limb here. Where would we suddenly get a 5HP gain in the Suzuki's in the time since Loshak did that 2:04 at RA?
If that engine builder exists I'd like to hire his services.
I tested the 42mm restrictor last year, the 37.5 will be a noticeable change.
Gary Hickman
Edge Engineering Inc
FB #76
Gary please tell us how much slower your FB will be with 5 less hp.
Of course FB can keep getting faster and then the class can be merged with FA
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
The one thing I think will make this possibly a very big and expensive decision by the CRB is that P1 and P2 don't have the restrictions on the ECU that FB does and as such getting the engines running with the restrictor might be problematic for some engines, if not all engines. The factory racing ECU are tuned around a given inlet package that this rule changes that in a dramatic way.
This may or may not be a good decision but it certainly needed some research to back it up. And that was not done.
One thing that the advisory committee for FB was able to determine, with certainty, was that different engines had very different responses to a given restrictor size and that was why the committee was forced to look at engine specific restrictors. This is a whole new game and no one really knows what is involved. At a minimum it should have had a 6 months implementation period.
FA
Jay,
At most tracks, FB lap records are about half way between FA and FC lap records.....and that is where we should be.
I can see limiting future speed increases.....by limiting newer engines.....but there is no need to slow the cars down.
Jerry
The winning P2 car at the Runoffs used a stock GSXR1000 motor with 37.5mm restrictors and a remapped stock ecu. The Kawasaki ecu can also be remapped.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Overall effect
Our cars will stay the same relative to each other.
We will be slower than P2 (same power...more drag)
The class looses some of its appeal by slowing it down.
Hp differences between engines is not addressed.
We will move closer to FC....not half way between FA and FC where we are now at most tracks.
Jerry
I'm not sure where you are getting this 5HP number, this doesn't jive with our dyno readings.
With a 42mm restrictor at WSIR I was 1.2 seconds slower than unrestricted. My guess is that with a 37.5mm restrictor my lap times will be 2 seconds slower possibly more. This would put me solidly in the FC times. I know WSIR like the back of my hand, these are legit times.
And by the way I had my double sided venturi smoother installed when we did this test, best case scenario.
At WSIR a well driven Atlantic car is 4 seconds quicker than me, so where is the creep we are talking about? At Daytona the well driven FA's were about 3 seconds quicker.
Nice job SCCA. I would have happily offered to test this before they pulled the trigger.
Last edited by ghickman; 12.08.15 at 12:07 PM.
Gary Hickman
Edge Engineering Inc
FB #76
Yep pretty much what I've been saying for over a year now.
Gary Hickman
Edge Engineering Inc
FB #76
Wow, guess I need to spend a bunch of money to convert my car to a honda or 06 GSXR. I wonder if any of the actual FB competitors/builders are for this rule change?
Charles
Yeah, I forgot to look at page two. Thanks for the catch. In any case, upthread somewhere someone makes the point that Daytona is an outlier with a heavy premium on outright speed. It will be interesting to see their respective times at Mid-Ohio. Same engine rules. Same restrictor sizes. Same weight.
The two results sheets I have list the "S/F Speed", so I'm guessing they taken at the same place.
Last edited by Stan Clayton; 12.08.15 at 12:34 PM. Reason: add top speed comment
Stan Clayton
Stohr Cars
These restrictors have been used in P2 cars for over 2 seasons and are very well developed. It is important to note that this type of restrictors are not true flat plat restrictors. While there is a true flat plate sandwiched in the middle of an upper and lower fairings. The top piece is any shaped air horn that you want and the bottom piece is a fairing into the throttle body. This effectively turns them into a Venturi type restrictor. The top and the bottom parts are free so there will be very little restriction and certainly less any true flat plate restrictor that could fit onto these motors. They also make the engine run much cleaner than with a true flat plate restrictor and can actually increase the peak torque.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
The 07-08 Suzuki was a game changer when it came out because it made about 15 hp more than any of the earlier bike motors. So you can spend a ton of money on an older unrestricted motor and still be at least 10hp down from either of the 2 competitive currently used motors with restrictors.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Say what?!
Wow - I fly to the UK for work, land and log onto Apex and see this. Holy smokes....what happened to the 42mm restrictors that were tested? I thought the goal was to cap the speed, not slow us down.
Once again I find myself not understanding.....
I am not looking forward to going slower, let alone slower than P2. If I wanted to do that I would just sell my car and go to Formula 4. <sigh>
I think everyone is misunderstanding these restrictors. They are smaller but less restrictive than the flat plate restrictors used in our dyno testing over a year ago.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
Maybe you are forgetting who you are speaking to here. I know all this and what you just described is exactly what I had in the car last year when I tested the 42mm restrictor.
At Fontana and Thunderhill the best driven P2 car (Chris Farrell) turned almost identical times to me. So by sound logic if we put a 37.5mm restrictor in my car I WILL BE 2 seconds slower than him.
Ask Chris Farrell what his opinion of the 37.5 restrictor is. He tells me the engine is a dog and just quits pulling. If they didn't have fenders on them they'd be a horrible.
You keep using this P2 logic and it is flawed. The P2 is a full body car, better aero. I'll be right there with the well driven FC cars. Wonderful.
Gary Hickman
Edge Engineering Inc
FB #76
In addition to the full body, the top P2 cars are significantly narrower than most FBs.
Chris was using MUCH modified engines in his cars when they were DSR and or P1 so yes he now has a lot less power in P2. I am not using any P2 logic, I am using the P2 dyno curves that I have seen with the 37.5mm restrictors.
I think what you are saying is that you do not want restrictors used at all in FB no matter what the size is. Is that correct?
My logic is that the dyno data shows that the 37.5mm restrictor takes about 5 hp off the top end and adds 2 ft-lbs of torque to the peak torque. You state that this will add several seconds a lap to your lap times. Correct?
You should write a letter to the CRB recommending a size that will not slow the cars down because it seems that the CRB wants restrictors in the class.
PS: just a reminder. I was a member of the FB ad hoc committee that recommended the use of flat plate restrictors to the class last year. That was not approved at that time because the CRB thought that the engineering behind the size selection was too complex.
I am simply trying to explain how this type of restrictor is different from the flat plate restrictors are and how much power change is caused by their use.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
I read that as well. I was under the impression they were calculating speeds from a timing loop rather than radar and that the beginning/end of that timing loop distance relative to the start finish line varied throughout the event. Perhaps I am wrong about that. Just making the point that even though I am "anti-restrictor" I don't know that the P2 / FB top speeds in the race (no out of class draft) are necessarily a true apples to apples comparison.
5 hp less? at what rpm
That is an important question.
If the peek power is at a reduced rpm, it might extend engine life....as some have suggested.
BUT.... it didn't seem to be that way when we were testing flat plat restrictors. They still had to turn the same rpm to reach max power.......probably due to cam profiles and cam timing.
We really need to see the P2 dyno testing results.
Jerry
Given that the sheets specify that it was the 'start-finish' timing loop, in the absence of any contradictory information I presume it was the same loop for all classes. All the timing loops I've seen are embedded in the asphalt, so I'm not seeing how one varies the distance, or for what purpose...or even if it makes any difference.
And while I agree that top speed per se is not very important, it became a topic of discussion because several persons voiced concerns that restrictors would slow FBs 'down to P2 speeds', which at least at Daytona turned out to be not much of a handicap...if at all.
As to Gary's comment that 37.5mm restrictors will put him back in the FC ranks, I'm wondering "how?" After all, even with the restrictors an FB has superior aero to an FC, 20-30 more hosspressure, and weighs 200-ish pounds less than one. If that puts one back in the FC scrum it's not the engine's fault.
Stan Clayton
Stohr Cars
Jay
Jay,
LAST YEARS RESTRICTOR PROPOSAL was rejected because there was a ton of push back. Everyone in the class knows that. The reasons for the push back were:
1. the kaw guys didn't want to loose their advantage (whether real or perceived debate can wait)
2. the gsxr guys didn't think they should be restricted at all....because it would slow the cars down. (the hp drop on the gsxr was 7 to 8 with the 42 flat plate restrictor.)
The excuse may have been the "complicated engineering" involved in selecting restrictor sizes.....but it was just dyno results and a spread sheet.....not all that complicated.
NOW WE STILL HAVE A TON OF PUSH BACK.....because no one wants to slow the cars down.
VENTURI RESTRICTORS: I am obviously opposed to the 37.5mm restrictor.....but if an appropriate size can be agreed on, I am not opposed to using venturi restrictors..... but here are some things people need to know about them:
With any shaped venturi around the restrictor allowed......people will have to make or buy them.....and engine builders will start experimenting with different shapes, lengths, etc to find the best one. Flat plate restrictors avoided that....and seem to work fine. I know some tweaking of the mixture is needed....and George says it is easier to do with the venturi restrictors....but it can be done.
Last year, George said the tuning issues with flat plate restrictors were a problem when the restrictor was placed below the throttle body.....fuel was puddling on the plate.....but not much of a problem when mounted above the throttle body.....which Is why our committee decision was to put them above the throttle body. I have all those emails.
Jerry
The original proposal for P2 was also flat plate restrictors but after George tried to tune them the engines were not responding to map changes properly so he built some Venturi type restrictors and the engines ran much much better and had a little more peak torque. That is why the P2 sizes are smaller than the flat plate restrictors because the 37.5mm size produces about the same peak power but with more torque than the 42mm flat plate restrictors but the engines ran so much better. The CRB decided that this was the better way to go and they did this.
George said that the engine works much better than with the flat plate restrictors and you cannot trick the restrictors with an air horn like you could with the flat plate restrictors.
Another advantage is that you are wasting your time to rev the motor another thousand or more RPMs, they will rev but no more power. The P2 guys are having very good engine life.
Now, what will be the optimum final restrictor sizes? I do not know. Maybe it will be larger or different sizes for different engines. The CRB wanted to start both motors at the same size and I think that this is just the start of the process and not the end game.
I would also note that the CRB has been making numerous changes to various engine combinations in P2 with good results.
Thanks ... Jay Novak
313-445-4047
On my 54th year as an SCCA member
with a special thanks to every SCCA worker (NONE OF US WOULD RACE WITHOUT THE WORKERS)
And I think you are a pretty awesome dude also! You and Jerry are correct. Fenders make the car slicker and faster. Its the tunnels that slow me down (p1). My car wouldn't as fast in a straight line as a top FB (using the same engine) because of the mega downforce generated by the tunnels. P2 doesnt have tunnels so yes they would be quicker. They make a huge difference. We picked up a huge amount of top speed with the tunnel blocks but our over times were crap because, contrary to popular belief Daytona needs alot of downforce to put down a real fast lap. JR and myself learned that when we rented Daytona for test day. We trimmed the cars down to nothing and couldn't get around the track anywhere near where we needed to be. I was convinced the car had a serious problem. I felt like i was on ice. We tried everything but more downforce. Finally with less then an hour left in the day I told critter to put give me every bit of downforce I had. I ran 3 seconds quicker the first lap. JR did the same.
Anyway, we both win and set lap records with slowest straight line speed.
Ok, back on the topic, you are right, P2 will be quicker staight line speed: fenders and no tunnels.
I have no idea why they would slow down the 07/08 suzuki. Just when the class had so much traction. 20 cars at the run offs and they felt like they needed to mess with the class? Like I always said: a bunch of wannabe drivers with too much time on thier hands and a chip on their shoulder making rules that make no sense.
I personally think you should put some fenders and tunnels on the Phoenix and run P1. I honestly think that most FB guys are P1 guys at heart. The stohr WF1 is the funnest car in the world to drive. And I don't care what anyone says it isn't much more expensive to run.
Come to the dark side Gary..... (j/k)
Jay, you know ive grown to love you. You are defending this change saying it isn't a big deal (which I know you believe) but if it isn't why make the change at all?
Last edited by JohnPaul; 12.08.15 at 4:52 PM.
"If you're not driving on the edge you're taking up too much space.... "
does anyone have a picture or drawing of the venturi restrictors they can post.
Mike
I'll email you a picture of what I came up with last year. I did this before there was any wording in the rule that you could do this. I figured if it didn't say I couldn't then I could.
Gary Hickman
Edge Engineering Inc
FB #76
The short answer is NO.
My understanding was they wanted some restriction on the Gen4 Kawasaki. I believe this overall 37.5mm deal caught most if not all by surprise.
Gary Hickman
Edge Engineering Inc
FB #76
Speak for yourself, Gary, as Stohr supports this rule change. The dozen or more people who have called me to discuss buying an FB have virtually all expressed strong reservations about engine reliability and TBO in FB under the current rules, and this change will address that issue in a positive way.
Sure, everybody wants to go faster. I understand that. But when the cost of doing so starts to eat into sales and participation it's time for some considered changes IMO. I applaud the CRB for taking the bull by the horns and making what I consider a long overdue change.
Now, raise the minimum weight and we're set.
Stan Clayton
Stohr Cars
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