New Horsepower/Torque Curve Shape Rules

#17

If I had any want to bring a car to miller you better bet it will have 150/165. Using a dyno is a great tool, but should NEVER be used for a final say in anything. You have tire pressures set for the rules, but what about the way you strap it down? You can easily have 3-4hp in the way you strap if down.

Rulers do not lie. Whistlers are very consistent.

Also what about the guy with 162hp having to add 140lbs now that car is legal with the HP rules but NON COMPLIANT with the ballast rules of no more ballast than 125lbs. :huh:

#18

I’m not crazy about potentially having to add an additional 140 lbs of ballast after I already have 70 lbs and barely make the 2700 weight minimum.
I don’t think we should be penalized with weight for having a legally built motor that meets the factory specifications. Weight penalties should start ABOVE the 168 HP factory spec. not at 155.9. Those of us with recently built motors are being unfairly penalized by this new rule.
I think this rule is trying to fix something that isn’t broken.

#19

I cant speak for the rules people, but the intent, if I follow, is a cost effective spec class.

Just because you can be 100% legal, spend many many MANY thousands of $$$$ on a motor, doesn’t make it a healthy spec class long term. One shouldn’t have to show up with more than a healthy stock motor, and be competitive by the spirit of any stock limited class.

That is the intent I got from reading the new rules.

What is the eventual cost of a competitive E30 car, if “its legal” with money thrown at the problem? I believe there are more people unable/willing to keep up with the budget war, than are.

That is the long term intent that I see going on here, and I see a healthier long-term E30 presence from it.

I 'spose for much else, you’ll have to reach out to the people that make the rules.

PS: I suppose the joke at the end of the day, is that I’m seeing high 14xhp cars win races cleanly occasionally, so what’s that say about spending more than Pick & Pull wants for a motor and a few gaskets?

Save your $ for BBQ and beer after the race, it lasts longer than the race does. :slight_smile: :slight_smile:

#20

If I’m not mistaken, that factory 168hp spec is at the crank and not the wheels. Allowing for driveline losses and the increases of a more free flowing exhaust, 155.9 at the wheels seems reasonable. It only represents about 7-8 % loss from the crank to the wheels.

#21

[quote]
How do you define “match?” The shape of the line/curve could be identical while have absolute values that are greater than those shown on the representative curve.[/quote]

Well, umm, no they couldn’t. HP = (TQ * RPM)/5280. So a torque curve that is consistently higher than stock, matches the shape of the stock curve, and reaches a peak torque that is 7-10% higher than “average”, will also generate 7-10% more HP. You can only bump the peak torque and keep the HP down by changing the shape of the curve. Course who’s to say what kind of template will be used to judge a “match”.

#22

The rules sounds about right after having Fish build me a legal motor and dynoing it on a Dynojet.

#23

Finally, a Dynojet data point :slight_smile:
Chris, mind sharing where your dyno numbers shook out? Thanks!
-Vic

#24

Old original motor that came in my car. Ran it till I overheated it and hurt a couple of the cylinders:

I don’t think I have the dyno from my new engine uploaded, but I can upload it tonight. The advantage of Dynojets is that you can get the actual dyno run files and plot them in their free software.

#25

Awesome. Thanks!
-Vic

#26

Its in the appendix in the new rules.

IIRC.

#27

I’m happy about it. The whole point of this series is cheap and equal. 170+ whp E30s aren’t cheap or equal.

#28

[quote=“victorhall” post=73464]Finally, a Dynojet data point :slight_smile:
Chris, mind sharing where your dyno numbers shook out? Thanks!
-Vic[/quote]

Sorry it took an extra night. Here are my dyno plots:

Old Motor (original motor that came in my E30 with 180,000 miles before odometer died):

New Motor (built by Fish):

Comparison:

#29

Well it looks like torque numbers aren’t an issue. Please excuse me while I go build a torque monster motor with only 155 peak HP.

If peak torque numbers aren’t addressed this HP rule will be useless.

#30

Your engine is running too lean. Something is wrong with engine management. Compare the A/F to the plot below. I don’t know what the best acheivable A/F for us looks like but I can give a ballpark. Stating the obvious, it’s hard to control our A/F, but I think the objective should be to spend as much time around 13 as possible. The engine will always go rich between 4500 and 5200 because, so the unconfirmed lore goes, the DME is dialing back timing to avoid engine knock.

The engine in my dyno chart below was a fresh build by Chuck Baader. New .020 over pistons, new cam, and new spark plugs. With my old engine management parts we got a little over 150hp. By replacing a lot of engine management parts we got to the below chart as our best of the day of prob 15runs. Only later did I understand that long term fuel trim will defeat this idea of swapping out parts and comparing dyno runs.

I ran this engine starting Aug10 until I came home with my two Metric Mechanic bottom ends 5 months later. Altho the MM bottom ends were not .020 over I was curious as to how they would do (and bored) so I pulled Chuck’s motor and replaced it with an MM motor. Chuck’s bottom end is now a spare.

If I was still obsessed with engine performance I’d try to find a way to get the mixture a bit more rich in the upper rpm. I have an A/F meter on my dash and this is a comfort. I check it every once and now while on the track to make sure that nothing is crazy.

#31

[quote=“Ranger” post=73510]Your engine is running too lean. Something is wrong with engine management. Compare the A/F to the plot below. I don’t know what the best acheivable A/F for us looks like but I can give a ballpark. Stating the obvious, it’s hard to control our A/F, but I think the objective should be to spend as much time around 13 as possible. The engine will always go rich between 4500 and 5200 because, so the unconfirmed lore goes, the DME is dialing back timing to avoid engine knock.

The engine in my dyno chart below was a fresh build by Chuck Baader. New .020 over pistons, new cam, and new spark plugs. With my old engine management parts we got a little over 150hp. By replacing a lot of engine management parts we got to the below chart as our best of the day of prob 15runs. Only later did I understand that long term fuel trim will defeat this idea of swapping out parts and comparing dyno runs.

I ran this engine starting Aug10 until I came home with my two Metric Mechanic bottom ends 5 months later. Altho the MM bottom ends were not .020 over I was curious as to how they would do (and bored) so I pulled Chuck’s motor and replaced it with an MM motor. Chuck’s bottom end is now a spare.

If I was still obsessed with engine performance I’d try to find a way to get the mixture a bit more rich in the upper rpm. I have an A/F meter on my dash and this is a comfort. I check it every once and now while on the track to make sure that nothing is crazy.[/quote]

There was no Air Fuel hookup for my new engine run. That is why it is so flat and at 14.7:1. Theoretically we should want our AFR to be 13:1 the entire time, but the fact that we can’t tune our ECUs, it is doubtful anyone will achieve that. I have not changed out any sensor on my motor ever. I am using all the original sensors that came on my original motor, and that is probably why the two plots line up so closely minus the hp/torque delta of all the new parts in the engine.

#32

Getting engine management cooperating as best it can is very important. Dyno runs w/o A/F info are ok if the result is terrific. But if the result is less than terrific one is left wondering how much A/F is contributing to the problem.

#33

And another data point. 1987 'is bone stock. Injectors cleaned and flowed. Newish plugs, new wires, cap, & rotors.

[attachment=1981]E30Aug2013.jpg[/attachment]

#34

RRhodes, the HP and TQ scales don’t match.

#35

Sorry I don’t follow. TQ scale is on the left edge of the graph, HP is on the right.

#36

The scale should be the same left and right. Otherwise the shape of the curve isn’t accurately reflected.