Dyno results

[Rmag911]

Has anyone dyno'd their PFM? What kind of numbers did you achieve?

I noticed in my last test day that I would make up a ton of ground on FE2s by late braking and carrying more speed in corners, but couldn't narrow any gaps on straights. I would have thought the extra horsepower would've had me closing gaps on straights, but we maintained the same distance on each straight. So I am having the car taken to a dyno and am curious if anyone knows what "normal" is supposed to be. thanks.

[mikey]

Not sure but you can also do a compression check. Watch a YouTube on how to do it on rotary compression check. I used a regular tester and recorded with iPhone and then played back the gauge view in slow motion to determine needle peak reading.

does the engine cold start quickly or require longer spinning with the starter?

also are you sure you are on the gas as early as the FE2 cars?

[Rmag911]

Not sure but you can also do a compression check. Watch a YouTube on how to do it on rotary compression check. I used a regular tester and recorded with iPhone and then played back the gauge view in slow motion to determine needle peak reading.

does the engine cold start quickly or require longer spinning with the starter?

also are you sure you are on the gas as early as the FE2 cars?

Does not start up super quickly. Sometimes I need to hold the starter a bit to get it going. Give it a touch of gas too.

Good idea on compression check.

Def. on the gas as early. In fact, I turned into a long sweeper about 200 feet from the FE2 and caught up to its bumper through a long sweeper. I was clearly carrying more speed and I was nearly full throttle on that corner, so even if he was getting to full throttle significantly before me, I doubt that would translate to being faster on the straight under those conditions. Yet I didn't close the gap on the straight at all.

[David Ferguson]

Contact Worldspeed, I believe they ran their cars on their own dyno routinely to make sure they were in top condition.

https://www.worldspeed.com/

[Lotus7]

... I would have thought the extra horsepower would've had me closing gaps on straights, but we maintained the same distance on each straight....

you're presuming equal drag (aero and mechanical);
your PFM has bigger tires, bigger sidepods, bigger wings ...

[Rmag911]

you're presuming equal drag (aero and mechanical);
your PFM has bigger tires, bigger sidepods, bigger wings ...

Fair point. I figured the extra drag on the PFM would eat into some of the HP advantage, but I didn't think it would cancel out the entirety of the extra 70 or so hp the PFM has.

[mikey]

if your car doesn't fire right up, it's likely the apex seals are worn and you could be down on quite a bit of power.

other thought, do you know if you have the short or tall gear stack in the gearbox?

[Rmag911]

if your car doesn't fire right up, it's likely the apex seals are worn and you could be down on quite a bit of power.

other thought, do you know if you have the short or tall gear stack in the gearbox?

you’re right to consider the gearing. I was running a tall-ish stack on a short stack track, so I knew I was losing some time from that. Need to order a short stack. Do you swap 2-6 or just 3-6 for the short stack?

[CGOffroad]

I am an FE2 driver and I have been on track with PFM cars. I will throw out a couple of ideas that may lead you somewhere or nowhere.

What you describe about entering and exiting the corner in comparison to the FE2 is very much what I would expect. Comparing your PFM's performance in a drag race down the straight would be a much better comparison with Mike Sauce in his PFM. Someone can chime in and correct me if I am wrong on this, but rotaries get the high HP numbers because they are higher rev'ing engines. Rotaries don't have that great of torque. So, in your drag race scenario you are comparing a rotary to an inline 4. Every model car has a strength and a weakness. The torque and the ability of the FE2 to accelerate out of a corner is one of its strengths. So, I don't think you have discovered a need to put your car on a dyno. I think you have found a variation between two models of cars.

[Rmag911]

I am an FE2 driver and I have been on track with PFM cars. I will throw out a couple of ideas that may lead you somewhere or nowhere.

What you describe about entering and exiting the corner in comparison to the FE2 is very much what I would expect. Comparing your PFM's performance in a drag race down the straight would be a much better comparison with Mike Sauce in his PFM. Someone can chime in and correct me if I am wrong on this, but rotaries get the high HP numbers because they are higher rev'ing engines. Rotaries don't have that great of torque. So, in your drag race scenario you are comparing a rotary to an inline 4. Every model car has a strength and a weakness. The torque and the ability of the FE2 to accelerate out of a corner is one of its strengths. So, I don't think you have discovered a need to put your car on a dyno. I think you have found a variation between two models of cars.

Interesting. thanks for sharing.

[Lotus7]

you’re right to consider the gearing. I was running a tall-ish stack on a short stack track, so I knew I was losing some time from that. Need to order a short stack. Do you swap 2-6 or just 3-6 for the short stack?

it’s been 15+ years, but if I recall, the tall stack uses the short fourth for third, and adds 3 taller gears

[LarryWinkelman]

Check with Paul Ravaris. He had a PFM car listed for sale with 206 hp at the rear wheels.