Just found my first dyno on the LNF when it was new and stock, then dyno'd it again two weeks ago. I was shocked when my new DP and exhaust was put on and the whp went DOWN!!!!! Just goes to prove that all those people that said the stock exhaust system including DP is as good as anything aftermarket were correct. It's a shame people\companies are posting power numbers of 12-15 whp for DP's and 5-8 whp for 3"exhaust systems, that showed a power loss on my TC!!!!

Some companies say 15 whp\tq for their DP..... MY Ass!!!!! Maybe 2 or 3 crank hp at best.

The only gain was from the tune. I wish I had listened to all those that said the stock DP and exhaust system is good to about 315-320 whp.

 

Which exhaust do you have?

Kevin

 

assuming the hahn or custom

 

dude... you need a tune to see any gains... our pcm are dumb they adjust to always give the same hp. and dynos are not always correct...

 

Yea, bigger exhaust isnt necessarily a good thing. We saw this on the CSRT's when people put on a catless turboback exhaust. The only real restriction on the CSRT is the DP. Putting anything else on doesnt net any gain whatsoever.

^^Most of this is due to the PCM pulling timing.

Its probly the same with with the SS/TC. Try only the DP as a mod, not a full exhaust. See what numbers you run then.

 

well my car dynod 14whp and 14wtq + with vibrant header downpipe .... s/c

 

SC is different. Turbo's need a certain amount of back pressure, otherwise the previously stated can happen.

 

Why in the world would a turbo need backpressure? Wouldn't a higher differential pressure make the turbo spool faster?

 

I think the stock tiny turbo on these cars will max out before the stock exhaust becomes a restriction.

 

dont feel bad i added a GMPP Manifold, 3"DP, GMPP catback, tune and a meth kit and lost 18whp!!! (from257whp to 239whp)Funny thing is it ran better than when i dyno'd 18whp less, i chalk it up to dyno discrepancies and colder weather then after i did my mods.

Different dynos' different days, different #'s...first dyno on my car was a high reading one the second a lower reading one

 

Correct-a-mondo.

 

was your car dynoed on the same dyno at the same shop?

 

I do agree a tune will be needed when you start removing cats and decreasing backpressue in the exhaust system.

But the stock stuff is pretty damn good!

 

However, now that my tune is back in place things are coming around nicely....282 whp and 329 wtq on 91 octane and : 287 whp\337 wtq on 93-97 octane........ W\Just the tune, DP, exhaust.

I'm just 11-13 whp and 10-12 wtq shy of my buddy that has one more BIG mod over me: An upgraded IC. That's next for me. Should be good for 300 whp, then the clutch comes.

Dynojet dyno (eddy current type) most accurate dyno on the planet. I've had high hp 2006 GTO, 2006 C6 Z06, all done on the same dyno. I've run all these cars (except the SS\TC) on a chasis dyno and mustang dyno, but I will stick with the dynojet. Mustang dynos tend to read a little low.

 

the thread title says all u need to know...............tune ftw

 

You should let me have a crack at it. Bet I can make more power than you do with the BSR Tune. Look at what I did for Nick's car, you were there. Whaddya say?

And people think I'm full of crap when I tell them their 3" and intake will do nothing good for their car.

BEST MODS TO DATE: INTERCOOLER/CHARGE PIPING/Catless DP all from Synapse............and they don't pay me money, they're just the ONLY mods I've seen that gained anything. And by anything I still mean not by much.

 

with out a tune all your mods will be useless... research it man.. i agree tune FTW!!

 

If the turbo is blowing air faster than it can suck, you will lose power. Lack of back pressure.

 

turbo + "backpressure" = ALWAYS BAD!!

"Backpressure" beign a good thing is such a ******* misnomer. What is actually happening when a smaller pipe makes better power than a larger is the inertia of the coulumn of gasses helps scavenge the cylinder that's on blowdown.
The "backpressure" in that case is actually lower since faster moving gas has a lower pressure. Only when the velocity begins to exceed about 350ft/sec does the pipe begine to restric flow

 

sound clip please..and what exhaust?

 

i got the same exhaust setup as sportredss but i plan on getting a turbo swap so 3 inch is a must

 

That is why you need to get these cars tuned....

The ECM will drop boost/ timing/ whatever to keep power realatively close to 260/260..... c'mon guys... the first mod on the LNF should be a TUNE!

 

This doesn't make sense to me though. If you were talking about a car not being able to get to its potential because of a hotside that was too small, that is one thing. (That is, one side of the turbo being a restriction to the other side.)

But how can a compressor outrun itself?

 

I got a lot of respect for you bud, but this is the most rediculous comment I've ever heard. It's the PCM, not the exhaust. If there is anything wrong, it would be a stock wastegate problem experiencing boost creep from the big ass 3" exhaust, and that doesn't sound like the problem at all.

and then you go and post this. Sucking a blowing is a compressor problem, not a turbine/exhaust problem. Sounds like the little crap turbo on the new newer cars could benefit from a bit bigger compressor cover.