Dyno Result for my GTS

[Dawgfan]

Went to the Dyno today for the NASA season. We had a 358 hp at the Rear Wheels and 438 at the Fly Wheel reading and I don't think that's to bad.

[panozracing]

Is that a sealed Panoz GTS engine? Is that with all the updates allowed?

Seems like too much drivetrain loss. I would expect the 440 FWHP but the RWHP should be around 400. Right? How was FWHP determined when you are using a chassis dyno?

Our motors are 500 FWHP checked on an engine dyno and 450 RWHP on a chassis dyno.

[Dawgfan]

My engine is from Elon, it is a 351 Winsor. The guy at the Dyno said you figure 20% to 25% for the FWHP. That is what I am basing this on.

[panozracing]

do you have all of the Panoz engine upgrades? Long tube headers, proform carb upgrades, cowl induction, etc.?

Panoz claims more HP. I would have expected about 400 RWHP from a Elan sealed motor?

[eric1h]

i swear we have a ton of drivetrain loss in these cars either from the rear end, tremec tranny or all of the above.

Still nice numbers comparable to what i'm running with The Panoz. Zooooooooom

[NZGTRA17]

For conversion from rear wheel hp to flywheel for Dynojet dyno's I use a conversion factor of x 1.17.

So on a Dynojet dyno if a sealed GTS engine is 440 flywheel hp it should be 375hp at the wheels.

What sort of dyno was it? What was the torque reading at the rear wheels? Likewise for your 427's Brian, what torque are they at the wheels when in 450 rwhp trim?

[jmimac351]

I'd think you can get from 358 to 375 by fiddling with jets and timing. That number sounds in the ballpark; dyno variations notwithstanding...

[panozracing]

Attached are the last dyno sessions we did with both 390 carb and the 650 carb. As you can see from one car to the other and from dyno to the other the results VARY. This really annoys me since my class in NASA is a dyno based racing league and I cannot tune with any kind of confidence. Could you imagine me dyno tuning the car in Florida, buying a special built carb to get as close as you can to the allowed limit and then go to nationals in Utah and their dyno reads illegal? Now what? When we got dyno checked in Ohio at nationals their dyno read 420 RWHP with the 390 carb which is 30 HP less than the "SAME" dyno in Florida.


390 CFM #4 DynoJet


390 CFM #23 DynoJet


650 CFM #4 DynoJet


650 CFM #4 Some other dyno (I forgot the brand)


390 CFM #4 Some other dyno (I forgot the brand)

[Dawgfan]

I will get the info on the Dyno today and also go over to Elon and talk to them and see what they have to say. This engine only has 6 to 7 hours on it, so I'm sure Elon will talk to me about it.

[David Eastman]

How about some photos of the new car.

[NZGTRA17]

Originally Posted by panozracing

Attached are the last dyno sessions we did with both 390 carb and the 650 carb. As you can see from one car to the other and from dyno to the other the results VARY. This really annoys me since my class in NASA is a dyno based racing league and I cannot tune with any kind of confidence. Could you imagine me dyno tuning the car in Florida, buying a special built carb to get as close as you can to the allowed limit and then go to nationals in Utah and their dyno reads illegal? Now what? When we got dyno checked in Ohio at nationals their dyno read 420 RWHP with the 390 carb which is 30 HP less than the "SAME" dyno in Florida.

Thanks Brian, very interesting. Yes it is pretty hard to run on the edge with inconsistencies like that. I guess all you can do is learn from year to year and anticipate the benefit offered by one dyno over another. The inconsistencies are the very reason I always use the same dyno every time I tune the car.

Love that 427 torque curve. I am guessing it would be pretty hard to harness that much torque with DOT's over an endurance race - even with the likes of 315's. Rear tyre heat/wear would definitely be more of an issue!!

Kel.

[Dawgfan]

Went to Elan and talked to a very impressive guy that showed me all around Elan. He says that my engine should at least make 400 hp at the rear wheels. Will start the weekend at R A and work on it as we go. The Elan pro says it could be the timing, fuel mixture or the jets in the carb. Will give update and pics when available.

[eric1h]

Originally Posted by Dawgfan

Went to Elan and talked to a very impressive guy that showed me all around Elan. He says that my engine should at least make 400 hp at the rear wheels. Will start the weekend at R A and work on it as we go. The Elan pro says it could be the timing, fuel mixture or the jets in the carb. Will give update and pics when available.

Do you have long tubes? i forget?

[Dawgfan]

I'm not sure. I will let everyone Sunday how we do. It will be and allways is a great weekend to load up on Sunday as good as you look unloading on Friday.

[NZGTRA17]

Originally Posted by Dawgfan

Went to Elan and talked to a very impressive guy that showed me all around Elan. He says that my engine should at least make 400 hp at the rear wheels. Will start the weekend at R A and work on it as we go. The Elan pro says it could be the timing, fuel mixture or the jets in the carb. Will give update and pics when available.

Getting an extra 42hp from timing and jetting is possible but the setup would have to be quite a way out now. Going from 302 to 347 my engine made 373hp / 368tq with the carb jetted to suit the 302. 1 size up on primary jets & 2 sizes up on mains and the 347 was up to 388hp / 392tq (with aircleaner fitted).

Some of the difference may be from a different type of dyno or something about the way the car was dynoed such as running the car without the air cleaner on, not properly up to temperature etc (my car picks up approx 15ftlbs of torque and 10hp at the wheels with the aircleaner & cold air tray fitted). I wouldnt sweat it, main thing will be that it pulls well on the track and has similar pace to other well sorted GTS's.

Kel.