3.0" to 2.5" Exhaust - Bad flow characteristics?

[Notorious_V.I.C]

Have you tried contacting GHL? I was under the impression that it was a lifetime warranty on the product, not matter who the owner is...

EDIT: Nevermind, just read their website.... "GHL Motorsports, L.L.C. offers a Limited Lifetime Warranty to the original purchaser of all non-race application products."

Yep, that would be nice if they offered it but they dont. Taking the S pipe off and re-installing it would be a pain.

 

[yashart@work]

The Greddy SP2 looks good to me, I'll have to do a search to see if there are any pictures of it posted on the car and before. Anyone know or have heard how it sounds?

The Greddy SP2 looks and sounds amazing, and it sounds even better in conjunction with a 2.5" downpipe. THe only downside is that it is 60mm (2.36")


Oh, and about my decision.... I picked up a full 3" GHL turboback exhaust. I am going to weld in another resonator (maybe even 2) to help quiet it down.

 

[Notorious_V.I.C]

Damn! So the whole Greddy SP2 Cat-back is 2.36" !?!

 

[yashart@work]

Damn! So the whole Greddy SP2 Cat-back is 2.36" !?!

yuppers!

 

[msp35]

I read their warranty but, there are places that actually have good customer service (unlike MAM). If you were to contact them in a professional, and respectful manor then I'm sure they'd work something out for you. Atleast I would think they'd sell you a replacement at a deep discount.
If not then can't you have it rewelded and add a flexpipe afterwards. I can tell you that even if you put the flex @ the end of their dp it will hold up.

 

[Notorious_V.I.C]

I read their warranty but, there are places that actually have good customer service (unlike MAM). If you were to contact them in a professional, and respectful manor then I'm sure they'd work something out for you. Atleast I would think they'd sell you a replacement at a deep discount.
If not then can't you have it rewelded and add a flexpipe afterwards. I can tell you that even if you put the flex @ the end of their dp it will hold up.

I'm going to have get the portion cut off and have a new section re-welded and have a flex put in just like the one pictured from street unit below. I have also marked the area where it cracked. I'm also going get my mid pipe with the high-flow cat redone and make it 2.50" comming off the GHL S pipe

Well if I can get anyone to please post some real life pictures of the Greedy SP2 installed and before on the MSP that would be great. So far this is the only exhaust I like that has a stock muffler look to it.

 

[Notorious_V.I.C]

Thanks to MP3Architetic for the pictures he provided...Trying to get some under neath the car to see the bends and what it comes with (i.e. resonator if anything else)

 

[Striker187]

iirc, the greddy sp2 has two resonators. the bends follow the same path as the stock exhaust. you may wanna look into a magnaflow universal oval muffler. you could keep the stock look that way.

 

[yashart_mp3]

iirc, the greddy sp2 has two resonators. the bends follow the same path as the stock exhaust. you may wanna look into a magnaflow universal oval muffler. you could keep the stock look that way.

The 1st design had 2 resonators. It was sold that way for about a year. Now the Greddy is sold with 1 resonator.

 

[Jeff@Tri-Point]

Ill share what I know...

We did some dyno runs with a 3" thermal exhaust vs the stock exhaust. Only mod on the car was an Injen Intake...

These dyno runs were taken on a mustang type dyno, its acutally a clayton. So the HP #'s are going to be less and the torque #'s are going to be higher.

3" Thermal Cat-Back Exhaust w/ Stock Cats
Max Torque = 205.3 @ 5000 rpm
Max HP = 141 @ 5500 rpm

Stock Cat-back Exhaust w/ Stock Cats
Max Torque = 208 @ 4950 rpm
Max HP 143.6 @ 5700 rpm

3" Thermal Cat-Back Exhaust w/ No Cats 2.25" Mid Pipe
Max Torque = 222.3 @ 4700 rpm
Max HP = 154.4 @ 5850 rpm

Stock Cat-Back Exhaust w/ No Cats 2.25" Mid Pipe
Max Torque = 214.8 @ 5000 rpm
Max HP = 151.3 @ 6100 rpm

 

[sandspeed]

I have a GHL 3" full downpipe with the flex and highflow cat and the rest is custom 3" SS and a RSR gt muffler. It's a real "deep" loud but the gains are very noticable and my stock turbo spools super quick. I put the silncer back in the other day and now peace and quiet.

 

[Notorious_V.I.C]

Well I am looking for the mid section piece that comes off the Cat and then hooks up to the axle-back!

Stock one that comes off the MSP. Anyone that has a stock MSP Exhaust pieces I'm looking to buy. Prefer Local...

 

[Earful]

As soon as I get my new exhaust system, I will be parting with these pieces...I am local too....

 

[yashart_mp3]

As soon as I get my new exhaust system, I will be parting with these pieces...I am local too....

What pieces? Greddy, GHL??

 

[Earful]

No... Yas....the stock catback MSP exhaust pieces only.

 

[terbow]

im guessing the stock stuff since hes replyinh to vic

edit, damn your fast fingers.

 

[yashart_mp3]

gotcha.... Hey, any of you guys know if Vibrant Intercooler cores are any good?

 

[Notorious_V.I.C]

No... Yas....the stock catback MSP exhaust pieces only.

Awsome! I need the cat-back minus the axle-back. I already have the OG MSP axle back.

So whats that pipe called then?

After I go back to stock exhaust i will have a full 3 inch Turbo-back up for grabs.

Full GHL downpipe, and 3inch cat-back with 5zigen. Only thing that needs to be done to the GHl is on the S Pipe needs a Flex welded into it and it perfect unless yous guys see something different.

 

[Greysave]

We're all forgetting Boehr's law for gases...basic chem right? (Although I didn't spell his name right, but I only got a B, so sue me) As gases cool, they expand in volume. To go from 2.5" to 3" is okay, that is how they build scavenger headers, they step them up as they go back because as the gas cools, it expands in volume, therefore to maintain exhaust gas velocity you should step up the pipe otherwise you will create pressure in the pipe. This is why personally I don't think you would see a significant hp increase by going with a 3" downpipe, the gases are so hot coming out of the turbo that they are thin and travel very fast, Corky Bell talks a bit about this, but this all really makes more of a difference on N/A cars where low end torque is an issue. On a turbo car, you shouldn't lose low end torque, because you are decreasing spool time and allowing some boost creep. You won't notice it at all. I have the CS S/J which is 2.4" ID, and it made a huge difference. I actually gained torque on the low end, but I run a cat, which many test have proven that you can make more torque with goo high flow cat than without. A lot of the Hot Rod/ Car Craft mags do these comparisons all the time 2.5 vs 3, cat vs no cat etc, and so far everything I've read from those tests have been right in line with what Corky rates hp to pipe diameter.

However, that all being said, I do think a diverged wastegate path is useful to decrease the turbulence of an internal wastegate. What would be interesting to do (and relatively easy) is to measure the temps along the GHL before the cat to see how far away from the turbo the gas starts cooling, then you can calculate volume, then in turn mach velocity. The GHL is diverged, so the main pipe is about 2.5" and the Wastegate pipe is probably 1.5" (which no backpressure at all on the WG is best - hence the reason the WRC cars just dump the waste gates about two feet from the turbo) and then the GHL becomes 3" about maybe 10" from the turbo flange, this is probably too close to step up to 3" anyways, it should run about 18" before the step (of course depends on temps) because of the different flow characteristics of the downpipes/exhausts, the temp step down/volume increase will happen at different points.

If I had the money, I'd go with the GHL downpipe but extend the WG path back to right before the cat and then dump it back in, and mate the GHL with the Vibrant without the resonator, but with the cat and muffler.

this is my plan, but I'm gonna have a hard time cutting up the GHL downpipe since it's so stupidly expensive. But oh well...

Britt

In fact, I'm so bored, I will measure the temps on my CS exhaust tonight just for curiosities sake, see where it starts to cool. Maybe I'll even plumb in my pressure gauge into the exaust to measure the backpressure.

How do you figure the exhaust is stupidly expensive? It is a full turbo back system, look them up on other cars, it even comes with a cat. A turbo back invidia costs much more then that for other cars, same thing goes for the apexi gt spec, and even turbo xs garbage. It comes with the s pipe down pipe cat and resinator, where would you get a better deal on all of that unless you found something custom for cheap?

 

[yashart_mp3]

How do you figure the exhaust is stupidly expensive? It is a full turbo back system, look them up on other cars, it even comes with a cat. A turbo back invidia costs much more then that for other cars, same thing goes for the apexi gt spec, and even turbo xs garbage. It comes with the s pipe down pipe cat and resinator, where would you get a better deal on all of that unless you found something custom for cheap?

He said downpipe.... I agree with him, the downpipe is stupidly expensive. Its $785, which does seem extremely expensive