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Exhausted Tuner
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Discussion Starter #1
Had a chance to do some tuning with a 2005 Pontiac GTO A4

Modifications:
K&N CAI
MagnaFlow cat-back
Kook's 1 3/4" LT headers
MagnaFlow Metallic cat mid-pipes

BLUE "BEFORE" Dyno - Stock Tune (K&N CAI) 91 Octane

RED "AFTER" Dyno - Custom Tune (K&N CAI, MagnaFlow cat-back, Kook's 1 3/4" LT headers, MagnaFlow LT header Metallic cat mid-pipes) Street Tune 91 Octane



Before: 346 / 343
After: 368 / 365

27 Max RWHP increase
26 Max RWTQ increase

22 Peak RWHP increase
22 Peak RWTQ increase

Weather: 76-78* F / 28% Humidity

Richard
 

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solid gains, congrats. i enjoyed watching that car on the dyno.
 

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Su Sussudio
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sorry to hijack, but im a newb and i dont understand the fact that the original dyno shows the normal availability of high torque throughout all rpms, but when mods are added, and sometimes with a tune, all the low-end torque+power dissapears on the graph and is replaced with high end torque+power. isn't this only good for rolling races? and isnt it worse for initial acceleration from a dig? somebody please explain. thanks
 

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Slow LS2
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Those are some nice #'s, I cant wait to get there wednsday and have ole Betsy tuned. :gears:
 

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Thanks for the awesome tune. I love the new exhaust note and extra power. Now I look for excuses to drive her. The magnaflow cat-backs are the perfect setup IMHO. Time to take it to the track!
 

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Exhausted Tuner
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Discussion Starter #8
mooninitesunite said:
sorry to hijack, but im a newb and i dont understand the fact that the original dyno shows the normal availability of high torque throughout all rpms, but when mods are added, and sometimes with a tune, all the low-end torque+power dissapears on the graph and is replaced with high end torque+power. isn't this only good for rolling races? and isnt it worse for initial acceleration from a dig? somebody please explain. thanks
????? The graph shows power increases over stock EVERYWHERE ....
 

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Is 27 rwhp with longtube back exhaust and a tune good?

I would've imagined you could pickup almost that much without a tune? Granted I dont know a lot about the GTOs yet, but 27 seems a little low. What IS impressive though is the fact that the power is picked up everywhere, not just uptop.
 

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Exhausted Tuner
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Discussion Starter #10 (Edited)
FloydSummerOf68 said:
Is 27 rwhp with longtube back exhaust and a tune good?

I would've imagined you could pickup almost that much without a tune? Granted I dont know a lot about the GTOs yet, but 27 seems a little low. What IS impressive though is the fact that the power is picked up everywhere, not just uptop.
For a street tune 91 Octane car, I feel that this number is right on par.

Here is a chart that shows the car stock with CAI (Blue), the car with CAI with LT's, high flow cats and cat-back with the stock tune (Red) and the same tuned (Green)

 

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Stand Back - I Spray!
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FloydSummerOf68 said:
Is 27 rwhp with longtube back exhaust and a tune good?

I would've imagined you could pickup almost that much without a tune? Granted I dont know a lot about the GTOs yet, but 27 seems a little low. What IS impressive though is the fact that the power is picked up everywhere, not just uptop.
Actually......it's very good. Quite often long tubes don't get you much without a tune. I did long tubes with no tune on my '99 Corvette and only picked up 9 rwhp. Tuning is definitely key in many cases.

And to Btlfed1500......:hail: your tuning abilities!
 

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He started with a very healthy LS2 A4 GTO.

I made 38 rwhp from headers and a tune on my GTO but I started much lower. My car only made 320 rwhp running pig rich from the factory. With headers and a tune power jumped to 358 rwhp.

He is making over 360 rwhp in an A4 which is really good.
 

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Oh ok, being an A4 does help the argument a little, I missed that part originally.

I guess the factory exhaust on these cars is pretty good stock considering I was told 10-20 rwhp could be picked up by a tune alone, so that would make the full exhaust be worth around 15 hp (which is quite ridiculous)

Those are really awesome numbers for an auto though, still not awesome gains in my eyes, but definatley very very strong overall numbers.
 

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FloydSummerOf68 said:
Oh ok, being an A4 does help the argument a little, I missed that part originally.

I guess the factory exhaust on these cars is pretty good stock considering I was told 10-20 rwhp could be picked up by a tune alone, so that would make the full exhaust be worth around 15 hp (which is quite ridiculous)

Those are really awesome numbers for an auto though, still not awesome gains in my eyes, but definatley very very strong overall numbers.
I can tell you that although the numbers seem low the difference in performance on the road is much greater. The car pulls much harder now and really gets with the program much better. I really don't care what the dyno says it was worth every penny.
 

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Trust me, I, more than anyone, hate dyno numbers...I live by track numbers showing the true benefit of mods.

Thats why I said that the amount of area that increased is impressive, but thats about it. (as far as dynos are concerned)

I'd like to see before and after ETs/MPH
 

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Su Sussudio
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Btlfed1500 said:
????? The graph shows power increases over stock EVERYWHERE ....
O WAIT...I was reading it wrong--i thought that the darker red+dark blue=new dyno, and light blue+ light red=old dyno. haha woops. :eek:
 

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Exhausted Tuner
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Discussion Starter #17
FloydSummerOf68 said:
Oh ok, being an A4 does help the argument a little, I missed that part originally.

I guess the factory exhaust on these cars is pretty good stock considering I was told 10-20 rwhp could be picked up by a tune alone, so that would make the full exhaust be worth around 15 hp (which is quite ridiculous)

Those are really awesome numbers for an auto though, still not awesome gains in my eyes, but definatley very very strong overall numbers.
What are you expectations? ... you do understand that power gains are NOT cumulative.

Think of it this way:
A bone stock vehicle may benefit 15 rwhp from a custom tune ... a stock a/f of 10.5:1 benfits from leaning to a 12.8:1 and additional timing to create this power.

A stock car with CAI may have either leaned or richened the stock tune in favor of power by nature of its design. This means a stock a/f of 10.5:1 may now be 11.5:1 with the cai. Now the tune will only be effectively changing a/f from 11.5:1 to 12.8:1 and not 10.5:1. The 1 point difference may equate to the tune netting less than 15 rwhp.

Is the tune any less effective?

I would say no. Complimenting modifications may help create conditions which help reach target a/f ratios thus making the tunes effect diminished only in the sence it had to make up for less variance.

In this particular case the car was already equiped with a CAI and stock with the cai it was running 10.7-10.8:1 a/f and not sub 10.0:1 ratios like some may have seen. The fact this car made a high baseline is testiment to the fact that the cai "benefited" the car and created a more desirable a/f. A tune on the stock car may have netted a 15 rwhp gain but a tune on the cai car with a better a/f may not see that 15 rwhp gain.

A 400 hp A4 car which ususally makes 330 rwhp bone stock makes nearly 370 rwhp with only bolt-ons and a tune does not seem unimpressive. Gains of 40 rwhp from a freer flowing intake, reduced back pressure and some additional scavenging with no modifications to internals seems a to me to be a good thing.
 

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Yes, I understand power gains are not cumulative and understand that I/E are the building blocks for making useable power with more intense modifications.

You had a high baseline dyno for an auto which could be a reason why I'm not impressed with your PEAK gains (I am impressed with the overall power increase).

27rwhp just seems a very weak gain on a dyno when I see cars with far smaller motors making the same increase (which equates to a FAR larger increase in relative power). A tuned stock motor will pick up (just for the sake of argument) 15rwhp and adding the longtubes, cats, and catback only pickup another 12rwhp when its tuned again (and yes I realize that the additional tune would not pick up power like the original and it would be more a tool for finetuning air/fuel)....that seems low to me. Like I said, this is probably due to the effectiveness of the stock exhaust being true dual with decent stock manifolds and probably flows enough air to be a pretty effective design.

Also, the baseline on that car is 346.xx rwhp...picking up 16 rwhp just from an intake would definatley be ridiculous if the baseline STOCK was 330...that would mean a filter and box picked up as much power as a set of longtubes (if not more) from this example.

I'm not trying to downplay your numbers, because dyno numbers mean nothing to me and dynos are only a tool for tuning, I was just thinking that 27rwhp seemed a little low, if its not, then thats cool and I'm glad you got the power you were looking for. The track is where its at, so thats all that really matters at the end of the day.
 

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Too Fast
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Btlfed1500 said:
Had a chance to do some tuning with a 2005 Pontiac GTO A4

Modifications:
K&N CAI
MagnaFlow cat-back
Kook's 1 3/4" LT headers
MagnaFlow Metallic cat mid-pipes

BLUE "BEFORE" Dyno - Stock Tune (K&N CAI) 91 Octane

RED "AFTER" Dyno - Custom Tune (K&N CAI, MagnaFlow cat-back, Kook's 1 3/4" LT headers, MagnaFlow LT header Metallic cat mid-pipes) Street Tune 91 Octane



Before: 346 / 343
After: 368 / 365

27 Max RWHP increase
26 Max RWTQ increase

22 Peak RWHP increase
22 Peak RWTQ increase

Weather: 76-78* F / 28% Humidity

Richard
you have a PM!
 

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Stand Back - I Spray!
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FloydSummerOf68 said:
blah blah blah.....
Dude....arguing with Richard (an extremely respected tuner in these parts) over gains from exhaust (his profession) and a tune (his specialty) when you weren't there and have no idea about the car he was tuning probably ain't gonna get you much respect here.......:nuts:
 
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