Dyno Numbers (2.80, 2lb, Port, etc...) untuned (LEAN!)

[Red99SVT]

You WILL pick up some power when you add some fuel when you are that lean. Let us know how it goes.

I am about to put a 2lb lower on my car with the 2.80 upper. How much boost do you see?

 

[nuxx]

Originally posted by Red99SVT
You WILL pick up some power when you add some fuel when you are that lean. Let us know how it goes.

I am about to put a 2lb lower on my car with the 2.80 upper. How much boost do you see?

Pegged

I'm still running the stock guage... I hate boost gauges, look tacky to me. I've tossed the idea back and forth, and just ended up deciding I don't want one. I don't plan on keeping the car longer than a year to a year and a half, and it will probably hurt the resale value if I put a gauge in.

When I dyno tuned last time, I saw 14 pounds on a warm day. On a cool day with the lower, I'm going to say 16-17lbs.
-Peter

 

[trey193]

Uptop the car isnt all that lean looks like 12.5-1 to me or a tad higher, I know several cars on here running over 13.1 with tunes for many many miles and these cars make tons of power and et and mph with the best of them. Not mentioning any names but 12.5-1 isnt on the edge by any means. Down low its lean but uptop I wouldnt worry about.

 

[garyhigh]

Originally posted by nuxx
Not true... look at my last dyno, I was really lean on the first run, after tunning and bringing the AF down, I picked up 20 or so RWHP.
-Peter

Oh it's true...it's DAMN true.

All parameters being equal (weather, timing, gas, etc.) I guarantee you will make less HP at 11.5:1 than 12.0:1.

 

[nuxx]

Originally posted by garyhigh
Oh it's true...it's DAMN true.

All parameters being equal (weather, timing, gas, etc.) I guarantee you will make less HP at 11.5:1 than 12.0:1.

Yeah I agree with you that if my AF was 12.0 and I lowered it to 11.x, I'd lose power...

... but if my AF starts at 14.5 and goes to 12.5, I'm sure I'll gain power if my AF is under 12 all the way...
-Peter

 

[SWEET03COBRA]

Well, when I was running lean and got my A/F back to a good 12.1 I lost about 15 across the board.

 

[Hermes]

garyhigh is correct. Unless there is a new corollary to the basic laws of physics the most hp is produced at 14.7:1 (since the gas is fully combusted in this perfectly matched a/f ratio) although this is a lab number only, not for the real world. A tune with your mods that goes from 11.8 to 12.1:1 will get you good power and has worked for a lot of members without a notable history of blowing up engines when running good, high octane (93) gas.

 

[Hermes]

nuxx, one item that I forgot is that you are getting to the reliability limits of the stock fuel system when you push past 500rwhp. My fuel system mods really paid unexpected dividends since it seems that the stock returnless fuel system allows a lot of variation in the amount of gas in the rails when you stress it. If you beef it up you lessen the chance of going lean and breaking because the fuel system isn't up to it. My driveability is still very good even with the larger injectors although there is some noticeable difference at idle.

 

[Hermes]

nuxx, one item that I forgot is that you are getting to the reliability limits of the stock fuel system when you push past 500rwhp. My fuel system mods really paid unexpected dividends since it seems that the stock returnless fuel system allows a lot of variation in the amount of gas in the rails when you stress it. If you beef it up you lessen the chance of going lean and breaking because the fuel system isn't up to it. My driveability is still very good even with the larger injectors although there is some noticeable difference at idle.

 

[nuxx]

I need to see what my tuner says in terms on the fuel system on Saturday... I know I'm getting close to the limit, but there seems to be people running 4lb / 2.80 combos with no problem.
-Peter