Author Topic: GM performance exhaust???? (Read 7661 times)

MeatHead · « **on:** April 15, 2011, 10:32:07 AM »

Hello,
I'm considering a GM cat back performance exhaust for my 2.4. I found a few for great prices! Does anyone have any info on them? I've heard they are made by Borla. Any performance gains? Do they sound good? I don't want a loud exhaust, just a little deeper would be nice.

elff · « **Reply #1 on:** April 15, 2011, 10:41:26 AM »

They are a 2.5" pipe and are made by Borla.
You might want to compare and contrast the cost, with one from SOLO.

I'm not sure if the 2.4 ECM will learn out any gains you will get from an exhaust, [The 2.0 stock tune does this] but look and sound are always a nice upgrade to our cars.

Uranium-238 · « **Reply #2 on:** April 15, 2011, 12:20:31 PM »

Aren't those the ones that caused a drop in power?

Critterman · « **Reply #3 on:** April 15, 2011, 12:29:54 PM »

From experience I can tell you that all that happens when you change the exhaust is it gets louder. Find someone with a GXP that has gotten a solo exhaust and difuser. Make them an offer on the stock difuser and exhaust. You should get a good deal.

After hundreds of dollars on the dyno, before and after every change made to my car before I decided I was going to quit wasting money and actually get some power - the best bang for the dollar is a tune, period. Everything else is eye candy.

LatinVenom · « **Reply #4 on:** April 15, 2011, 08:34:37 PM »

A tune for sure is the must have, but also a long tube header, high flow cat will wake the LE5 to about 200 BHP.

Critterman · « **Reply #5 on:** April 16, 2011, 02:25:22 PM »

I don't know where you came up with those figures, LV, but I can tell you that with all of the above I never saw gains anywhere near that.

Graywolf · « **Reply #6 on:** April 16, 2011, 05:16:59 PM »

Stop , do not buy GM performance exhaust, complete waste of money. I threw the one I had in the Garbage. It sounds the same as the stock exhaust and gives no increase in performance.

LatinVenom · « **Reply #7 on:** April 16, 2011, 05:49:24 PM »

Critterman,
Back in 2005 2006 when we all had the LE5 there were a lot of Dyno's made.
I also said crank horse power and not at the wheels.
So starting with 177 then the tune/long tube header and high flow cat was about an additional 23 more crank HP.
Some folks even got more. I believe Gizmo was about 215 crank HP.

Critterman · « **Reply #8 on:** April 16, 2011, 06:37:50 PM »

LV I went to the same dyno 12 times, stock, and after every mod i made on the car, and I never saw anywhere near that until the DDM stage I.

A dyno run without a starting point is worthless to show gain, and everything effects the output. Heat, humidity, air pressure, operator, actually he makes the most difference in the way he has the dyno set up.

SKY888 · « **Reply #9 on:** April 16, 2011, 06:50:05 PM »

A friend of mine upgraded his exhaust, headers, hi flow cat and was tuned at SMG.

Only received 12 bhp.........

Gentleman Jack · « **Reply #10 on:** April 17, 2011, 12:46:41 AM »

How does one calibrate / test a dyno? Is it like calibrating a scale?

cruiservic · « **Reply #11 on:** April 17, 2011, 01:29:57 AM »

What is the difference between stage 1, II and III? I understand that adding the tune makes a big difference, is that stage 1 or II? I want to get the GM Tune and Solo high flow long cat and exhaust pipes. Would that set-up get me to 300hp? I am still new to this and want to get started when I get back in June, but I will need your expert advice so I do not screw things up and waste money for nothing. So, I do read your posts as a student learning the Sol from all of you.

SKY888 · « **Reply #12 on:** April 17, 2011, 08:02:19 AM »

Quote from: cruiservic on April 17, 2011, 01:29:57 AM

What is the difference between stage 1, II and III? I understand that adding the tune makes a big difference, is that stage 1 or II? I want to get the GM Tune and Solo high flow long cat and exhaust pipes. Would that set-up get me to 300hp? I am still new to this and want to get started when I get back in June, but I will need your expert advice so I do not screw things up and waste money for nothing. So, I do read your posts as a student learning the Sol from all of you.

what's your car? gxp or 2.4?

they are talking about a 2.4 engine here.....

cai/headers/exhaust/tune......will not get you to 300hp on a 2.4 engine.

you need SC or TC

Rogue · « **Reply #13 on:** April 17, 2011, 08:12:12 AM »

His Avatar shows a GXP coupe, so he's already turbocharged. The GMPP tune along with a hi flow cat and free flowing exhaust would put him at about 300 crank HP, maybe a bit more. If warranty is not an issue than there are numerous other tunes and turbo upgrades that will up the output quite a bit higher. The real question to ask here is if he's looking for 300 crank HP or 300 RWHP.

SKY888 · « **Reply #14 on:** April 17, 2011, 08:17:06 AM »

yeah, that's what I thought....he has a gxp.

its a 2.4L thread/section........

it will just add confusion.....

elff · « **Reply #15 on:** April 17, 2011, 08:18:05 AM »

The gmpp tune would put him at 290 hp crank and about 265 at the wheels.
It is not tuned for exhaust or cat so adding those will still put you at the above numbers.
You need a custom tune to take advantage of additional hardware.

wspohn · « **Reply #16 on:** April 17, 2011, 01:52:21 PM »

Quote from: elff on April 17, 2011, 08:18:05 AM

The gmpp tune would put him at 290 hp crank and about 265 at the wheels.
It is not tuned for exhaust or cat so adding those will still put you at the above numbers.
You need a custom tune to take advantage of additional hardware.

Not necessarily. Other than some remaining torque management low down, the GMPP tune does allow mods to have effect on the ouput, so adding, for instance, a low restriction CAT, will indeed result in an increase in power without any retuning needed. In fact that would be the single best improvement for him to look at as it has more effect than the rest of the exhaust system.

Rogue · « **Reply #17 on:** April 17, 2011, 02:15:21 PM »

I agree. My wife and I both added hi flow cats to our GXP's after we had the GMPP installed and we both noticed a distinct "seat of the pants" improvement. I don't have any dyno numbers to back up my claim, but believe it to be true just the same. The cats we installed were the Solo hi flow 3", mated up to a 3" Magnaflow on GXPsy (auto) and a 3" Solo Mach Shorty on Rogue (5 spd).

elff · « **Reply #18 on:** April 17, 2011, 03:02:59 PM »

Quote from: wspohn on April 17, 2011, 01:52:21 PM

Not necessarily. Other than some remaining torque management low down, the GMPP tune does allow mods to have effect on the ouput, so adding, for instance, a low restriction CAT, will indeed result in an increase in power without any retuning needed. In fact that would be the single best improvement for him to look at as it has more effect than the rest of the exhaust system.

In theory, what you are saying is how everyone talked up the GMPP
In Realty that is not the case and we have facts to back up my statement. Kenny was one of the participants.

We Dyno'd 4 different GMPP tuned cars on the same day on the same dyno.
All 4 cars varied from stock everything to intakes, IC Pipes and exhausts.

All 4 cars, +/- 2hp +/- 3 Ft/lbs torque
Dyno Printouts were posted here and on SkyRoadster.com

Funny thing is, Kenny's, with Stock Intake, Stock IC Pipes, Stock Cat, Stock Exhaust had the highest number.

Sorry. The GMPP is a canned tune. You get 290hp at the crank and it is not optimized and does not take advantage of 3rd part add ons.

That being said. The GMPP tune is a good tune. The redline should have come with it stock.

Back On Topic,
I still recommend talking to solo and get a tune to take advantage of the Solo cat and exhaust.

If you want more power, you can work your way through the DDM supercharger stages as money allows.

Gentleman Jack · « **Reply #19 on:** April 17, 2011, 03:44:42 PM »

MODERATORS:

Can we separate out the GXP/RL info from this thread and put it in a new thread for CruiserVic, then we can keep this thread clean for MeatHead and his 2.4 exhaust questions.

MeatHead (by the way, one of my FAVORITE words...) the cheapest and best exhaust for you is going to be to put on someones GXP exhaust and rear valence as has already been mentioned. Someone may even have an extra one hanging in his garage as we speak.... but you wouldn't want to pay for the shipping

GJ

LatinVenom · « **Reply #20 on:** April 17, 2011, 05:28:18 PM »

I will try to find some of the earlier Dyno's and also Gizmo's, where it showed the improvement, before and after.

cruiservic · « **Reply #21 on:** April 18, 2011, 04:58:23 AM »

Hey, sorry guys, I missed the 2.4 connection discussion and did not mean to muddy the water with my questions. I will read more carefully next time. I just saw, 'talking about the tune,' and I had some questions. Thanks for your input.

J_Bond · « **Reply #22 on:** May 25, 2011, 01:13:53 AM »

Meathead, go to a DYNO-shop. get your Kappa on a dyno and use an HP-Tuner!!! I only have a K&N Cold air intake and my 2.4L made 200ft lbs of torque at the WHEELS. it made 206 peak! the pre-made tunes are good, but every car comes out of the factory a little different, so it's good to get a balanced AFR and push for as much power as you can without leaning out.

Also, reduce the weight of your car and especially reduce the rolling mass of your wheels and get some lightweight wheels and tires. Continental DWS tires are the lightest I have found. The lighter you are, the more 'effective' your horsepower is.

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Author Topic: GM performance exhaust???? (Read 7661 times)