Ebanks

You may have seen in the main section about our dyno tuning session with my car last night. The car made 865 RWHP corrected, which was a bit lower than anticipated, but we also didn't run full boost (still 4psi to go, with gains of 20-30 RWHP per psi in this boost range).

Anyways, after taking some things apart to inspect what restrictions we may have been having at the point we were at we found that since the throttle cable on the new intake manifold setup was not exactly how it should have been the throttle plate was only opening up about 80-85% of the way. My question is how big of a difference do you think that will make in my dyno numbers?

I doubt it is directly related (ie since it will open 15-20% more then it will make 15-20% more power) although that would be nice So how much do you think this will actually effect the power?

BTW, we also realized that we need to play with cam timing quite a bit from where we have it, but that is beside the point right now.

-Ethan

Lex Luthor

Eth, that's a tough one. I don't think there's any way to estimate how much more you'll gain with full throttle opening, there's just too many variables - i.e. the butterfly in the t-body could have been close enough to fully open parallel with incoming air enough that it didn't kill off too much cfm of airflow, but the throttle angle could have been off enough for your Speed Pro to dial back enough fuel and timing that it would make a big difference on the top end, unless you're running set tables for your timing advance and pulse width/ duty cycles that you weren't relying on a TPS signal to determine how much to give. What did Larry say? Regardless, you're gonna dyno it again anyway i'm sure, so why wade knee-deep in conjecture when you'll have the data soon enough? Your setup should definitely be getting you to the 'magic mark,' how much more atmosphere do you intend to run above the 26psi? Will you be staying around 30 pounds for the next pull or heading all the way to 38? This is on 116 octane? I'm assuming you're running the PG now, figuring you're at 4500-5000 stall with that '88.
- Jon

Ebanks

Jon-

It is all pretty much guessing at this point I am just impatient (to an extent I guess). I am actually running the SP400 trans now, I sold the PG for something more streetable. It is around a 4k stall w/ lockup.

The timing advance is set tables, the fuel is self corrected off the wideband to whatever we set it at (11:1 is what we are doing now for safety). On a lower boost setting it we did add some timing into to see how it would do and it gained nearly 60 RWHP at the same boost level, but when we started turning up the boost we pulled it all back out to be safe.

We will know soon enough I guess, I am just thinking outloud a lot now that I have new things to think about since this is the first time my car has ran in a while I personally think adjusting the cam timing will net me more power than fixing that throttle plate will... Oh well, once again, all just conjecture right now, so I will stop thinking outloud

-Ethan

Lex Luthor

You're moving the powerband downstairs? Not sure what your valvetrain setup is (fuly ported GE head w/ 5 angle, but what equipment, using the Crower Supra kit?), but where do you intend to shift at?

Ebanks

I wouldn't call it "downstairs" but we don't want to have to rev to 9k+. We want the shift point to be right at 8k-8.2k. The head is fine to probably 10k, but the strongest rods on the market are only rated 200hp per rod at the motor, and we are already going to be well past that... So we don't want to push it and be well past that AND have them revving 9k. Remember, rods have to stop 2 times per revolution and completely change direction, we are just trying to minimize the risk of me shelling a rod since no one makes one strong enough!

-Ethan

Lex Luthor

All makes sense, you're using the Pauter rods now instead of the Crower?

Camshaft

The way I look at it is, hold your hand over your mouth and breath through your fingers. Now go run. Easier to breath with it off, right? Why do you think that porting and polishing the head makes such a difference.

Ebanks

Yes, it is Pauter Rods now.

Camshaft- good point.

-Ethan

sc300tt

Well, since boost is simply the engines inability to ingest air, at a given boost level, you won't be making any more power, as that boost is measured in the intake manifold, which is post throttle body. This is why contrary to popular belief, an aftermarket intake manifold will not make any more HP if the stock one can mantain a given PSI. We have dyno tested this with a Supra making 780rwhp swapping intakes on the dyno. Now as far as cylinder balance, that can be a different story, but that is more related to a safety issue, rather than making raw power.

Now, if you change the runner length, this can affect power levels, depending on which level harmonics it is now tuned to.

But if you didn't see the boost drop off, you aren't going to make any more power with a larger throttle body opening, as it is not a restriction.

Ebanks

Maybe that is why it was having trouble boosting above 32-33psi ish then

On that pass it got to just between 33 and 34 psi, and would not go any higher, so perhaps now that that restriction is cleared up we can actually get that 38ish psi we want.

-Ethan

Camshaft

Airflow is everything. That rough cast aluminum on the inside of the intake, the heads, the 3 degree valve job, throttle plate, everything. Everything adds up to restriction, if you are looking into things that small. Why do you think KN makes tons of money....