GMs in IT

[joeg]

No love for Fieros, Citations or Chevettes?

[Ron Earp]

No love for Fieros, Citations or Chevettes?

Au Contraire, I love Fieros. I still think a full on 100% Megasquirted built to the max Fiero could do some damage in ITA. Still haven't seen a 100% build yet, or close to it.

Those other two, no, no love there despite the common DNA with the Fiero.

[chuck baader]

Look at the intake manifold/ports on the Fiero and you might change your mind. cB

[CRallo]

I like the ideas. Good thinking.

3.4 needs a torque adder? What else does? Where is the line drawn?

[TomL]

"Torque adder"? Is that still around? I'll say it again. Horsepower counts, torque doesn't. "Torque monster" is noting but a synonym for "revless wonder". I wonder why things like torque adders are still even discussed, much less used. Color me disappointed.

[JoshS]

"Torque adder"? Is that still around? I'll say it again. Horsepower counts, torque doesn't. "Torque monster" is noting but a synonym for "revless wonder". I wonder why things like torque adders are still even discussed, much less used. Color me disappointed.

Tom, I agree, but here's why it is part of the Process:

What really matters is not only peak HP, but also, the breadth of the peak part of the HP curve. Until we are all using CVT transmissions, we'll be spending some full-throttle time away from the HP peak. We need something to approximate how quickly HP falls off on either side of the peak to account for this. Neither displacement nor peak torque are exactly related to this, but on average are decent indicators of this breadth and are easily available to the ITAC.

[GKR_17]

Tom, I agree, but here's why it is part of the Process:

What really matters is not only peak HP, but also, the breadth of the peak part of the HP curve. Until we are all using CVT transmissions, we'll be spending some full-throttle time away from the HP peak. We need something to approximate how quickly HP falls off on either side of the peak to account for this. Neither displacement nor peak torque are exactly related to this, but on average are decent indicators of this breadth and are easily available to the ITAC.

You have to admit that is is completely bogus to have an adder for torque, but not account for the transmission. We have cars getting deductions for low torque that also have ridiculously good ratios in 6-speed boxes.

[Gary L]

Look at the intake manifold/ports on the Fiero and you might change your mind. cB

Put one on the track and you might change it back. I've posted this story on these pages before, but what the Hell...

In 2004 I took a nearly stock (I've owned it since new, so I know what's been monkeyed with and what hasn't) '88 Fiero GT to Hallett and did a few track days. The car had the muffler removed (converter still installed), was lowered an inch or two by chopping the stock springs, and had orange Koni street shocks front and rear. We mounted some used Hoosier SM's on 7" Kosei K1's, decambered it front & rear and went at it. We ended up 3.5 seconds off the ITA lap record, held at that time by Bob Stretch in the Nissan 240S. This was with nothing done to the engine - and I do mean nothing whatsoever; no chip, no headers, no tuning of any sort. Oh, yes... about the weight... we were 300 pounds (three hundred - it's not a typo) over current ITA minimum for the car. And remember, we're talking about a 2900+ lb car on used 205/50 15's!

I'm not saying it's an overdog in ITA, but I sure wouldn't dismiss it as an also-ran; in full prep and the right hands, the car is a potential front runner IMO.

[TomL]

Josh - I realize that high torque has sometimes been taken as an indicator of wide torque band. For a specific engine, I don't doubt that is the case. However, I have serious doubts that this is true across the huge variety of engines that are found in IT. Admittedly, I haven't seen a huge number of dyno sheets to confirm my impression, but I'll take that as true until I see otherwise.

Have you all done a systematic survey of all the data you have to demonstrate that peak torque is a reliable indicator of power band width? Is so, could I see it? I've been thinking about writing a paper on the whole torque vs. HP question, and would like to see what anyone else has discovered. Alternatively, could I get access to a selection of the dyno graphs the ITAC has so I could do my own analysis? This is a topic which has bothered me for years, and I'd like to see a definitive resolution.

Thanks

[Ron Earp]

3.4 needs a torque adder? What else does? Where is the line drawn?

Apparently it is a "We know it when we see it" thing. Empirically it is a "Domestic Penalty" - TR8 (ITS, maybe it has one, domestic motor), Mustang V8 in ITR (does have one), Camaro V8 in ITR (has one), Corvette (not classed but would probably have a torque adder in ITR) - all domestic powered cars with torque adders.

RX7s have no torque to speak of, but at 8000 RPM that twisting force makes a lot of horsepower, and horsepower tells us how much work we can do with the motor. There are many torqueless motors that perform just fine - Miatas, GSR, etc. because they produce good horsepower in the framework of the class they race. Their horsepower peaks are broad enough to get the job done.

Naturally I'd take a broader horsepower curver over a narrower horsepower curve as the area under the horsepower curve that is accessible with the gearbox is all that makes any difference. But in looking at a lot of dyno plots I'm not entirely convinced that 2V large displacement domestic engines are producing horsepower curves that are appreciably wider than small displacement imports. Especially when most of the import motors have four valve heads which provide for impressive breathing capability.

But besides all of that, those two GM cars should be in IT. Shame about the Camaro as it doesn't have disc brakes in the rear. Typically GM does ok on brakes but they left drums on the car until it got the more powerful 3.8L V6.

[Z3_GoCar]

Apparently it is a "We know it when we see it" thing. Empirically it is a "Domestic Penalty" - TR8 (ITS, maybe it has one, domestic motor), Mustang V8 in ITR (does have one), Camaro V8 in ITR (has one), Corvette (not classed but would probably have a torque adder in ITR) - all domestic powered cars with torque adders.

RX7s have no torque to speak of, but at 8000 RPM that twisting force makes a lot of horsepower, and horsepower tells us how much work we can do with the motor. There are many torqueless motors that perform just fine - Miatas, GSR, etc. because they produce good horsepower in the framework of the class they race. Their horsepower peaks are broad enough to get the job done.

Naturally I'd take a broader horsepower curver over a narrower horsepower curve as the area under the horsepower curve that is accessible with the gearbox is all that makes any difference. But in looking at a lot of dyno plots I'm not entirely convinced that 2V large displacement domestic engines are producing horsepower curves that are appreciably wider than small displacement imports. Especially when most of the import motors have four valve heads which provide for impressive breathing capability.

But besides all of that, those two GM cars should be in IT. Shame about the Camaro as it doesn't have disc brakes in the rear. Typically GM does ok on brakes but they left drums on the car until it got the more powerful 3.8L V6.

First I've heard of a "Domestic" penalty... My car's made in Greer South Carolina, this might explain a bunch.