Big Boy

Agree to disagree. Slightly shifting the powerband higher using cams would be a way to make power at higher revs. I understand your argument about the head not being designed for that but there are certain thing that can be done to improve it. A Turbo is going to be pushing a lot of air at that point.

FYI 8500 is not my target for peak power. 8500 is where I want my "safe" operating conditions to extend to.

M-Tuned

iTrader: (6)

Call it what you want.. I would be within 10-15 hp of peak power until 8200rpm and still making good steam. I needed the extra gear as a shift to 5th just slowed the car down to much.

EDIT: Just found this chart. Ignore the red line as this was playing with a Nitrous controller, but the Blue shows me revving to 7700ish and still a pretty good amount of hoursepower. This chart is with a T3/T4 54 Trim Turbo and a 1994 head at the time. I eventually got a T3/T4 50 Trim and some more guts and used to rev the motor higher and higher. The 50 trim turbo responded much better than the 54 trim

patsmx5

iTrader: (16)

350HP 500 HP
You made peak power before 7K and it started dropping after that.
You didn't rev to 8500 or 8200.

But yeah when you find the 500 HP plot with it holding power flat to 8200 I'd like to see it. Till then....

Braineack

iTrader: (62)

perspective?

Big Boy

sorry miss-post

Braineack

iTrader: (62)

that wouldn't change the dynos

what both plots are missing is a good intake manifold and cams....

Markp's setup was: Built bottom end, shim under buckets, titanium retainers, and dual springs with 70# pressure seated 180# open. T3/T4 50 trim.


and I guess I'm confused, when someone says they hold power to redline, I assume TQ not HP.

patsmx5

iTrader: (16)

Yeah, holding power (HP) and torque are two different things. Personally, I hate how BP's stop building power so soon. Takes off around 3500 and builds good till 5500, then flat, then down. As we all are becoming aware of, it seems the factory intake manifold is the "major" restriction to top end power. I'd be happy if I had 90% torque to 7K and it fell off after that. Kinda like Paul's doing.

Braineack

iTrader: (62)

pauls gains say a lot...only change here was the IM, 70mm TB, and some fueling.




FM saw the same gain when developing the IM themselves:





The "power" doesn't level off, it keeps climbing. I'd say this would give you a better chance of peaking HP at 8-8.5K

patsmx5

iTrader: (16)

I like paul's dyno graph. I just wonder what my 99' w/ all my headwork would do with a badass intake manifold. And boost.

Braineack

iTrader: (62)

his curve is pretty stellar, I hope mine looks as good.

l_bader

No, I did not use aftermarket cams, though they *might* have brought additional life (and possibly a longer torque curve) to the engine. However, the benefit vs cost wouldn't be seen once the engine was under boost. - As with Braineack, I see a need for a better flowing intake to see better HP-for-$$$ gains.

As to Road Racing, that is exactly what I have been building the car for. Daily-Driver/Road-Race/Time-Trial hybrid as it were. - Yet I am running a quick spooling turbo, factory 5-speed and have *never* run out of revs in a corner. - If I even think I'll need more tach, I'll shift (up or down appropriately) *prior* to getting into the curve...

By swapping the rear diff to a 3.63, I have a gear limited top speed north of 160mph, boost from 2500 to redline and can cruise at 120mph at under 6K.

To give an idea, here's the dyno plot at only 7psi:

M-Tuned

iTrader: (6)

That is my car with a stock 95 Escort GT Motor (Same as Miata BP), 50 Trim Turbo and FM/BEGi Intake Manifold with 70mm Tb. Funny as my dyno charts start to show up Looks like I pulled that one to 7700-7750 RPM and was still climbing.