I am working on my new GS-R project car, and currently have an AEM CAI, DC Sports 4-1 header, GReddy Cat-Back exhuast, AEM Cam Gears, and Unorthodox Racing Underdrive pulleys. I plan to add a Rev Hard turbo kit, AEM fuel system (pump, regulator, rails, etc.) and an MSD Ignition system. My question is, does anybody here believe that the Thermal exhaust system will be more effective with the turbo set-up than the GReddy? I'm very pleased with the GReddy system I have now, but I've heard that with a turbo set-up, the Thermal is better. Can anybody here agree/disagree with that? Also, to help get more power out of the turbo, should I get some lower compression pistons, and if so, what kind do you recommend? Thanks.

Ben

 

The reason for the Thermal is because people get the 3" variety for quicker spool times and better flow of the turbos. There are smaller Thermal exhausts, but no need to buy if your turbo. Greddy as of yet didnt come out with their 3" exhaust for our cars, atleast I dont think they are out yet--correct me if im wrong.
As far as the pistons, its all in tuning. Some people run a little higher compression and lower boost--but with more chance of detonating without the greatest tuning. With lower compression slugs you can run more boost have a chance to detonate a lil more without much tuning. BUT tuning is everything with turbos, people blew their **** up with very, very low boost. Tuning, tuning, tuning.
Also if your gonna do lower compression pistons, might as well just build the motor since its all apart.

 

I never really felt the true potential of my car untill I upgraded to the thermal. Ben, did you look at all the pics I sent you?

art

 

Art, what did you have before?

I have a greddy evo, and it just "feels" restricted...like it wants to breath...and especially if I am not in the perfect gear, it seems like it takes forever for the turbo to spool.

-> Hoping that thermal 3" stealth option and 3" downpipe are a noticeable difference for me.

 

the greddy evo isnt so bad it goes from a 60mm to a 70mm. but nothing beats the thermal

 

I had the APEX N1 which I liked because it was sooo quiet. But now I have the thermal and I really like it, even tho it is kinda loud. But its not a nasty raspy loud but a deep tone and at WOT it sounds mean!!

art

 

Go custom! Find a shop to do a 3" SS mandrel bent exhaust. I got a 3" SS custom all the way back to a SS magnaflow... for $380! You can't go wrong and the looks is better than that of a Thermal and you can put your choice of muffler.

Nick

 

A custom SS 3" Mandrel bent exhaust will cost you tons of $$$, as compared to buy a manufactered exhaust system from thermal. Thermal gets

 

Tons of $$$ for a custom??? Don't think so unless you look like prey to them and are easy enough to get suckered but in no way a custom should cost more.

Nick

 

Wow you got a great deal for $380 dollars because I know it would take at least 3 hours to do the piping from cat back. Was it tig weld or mig weld? Big difference.


[Modified by ekb18c, 3:56 PM 12/27/2001]


[Modified by ekb18c, 3:57 PM 12/27/2001]

 

It's mig welded, but again for 380 I couldn't go wrong and like I said looks a hell of alot better (muffler wise) to that of a thermal. But hey man it's his money to spend, I just offered my suggestion.

Nick

 

See the only reason why i said custom exhaust will cost more is because I was assume it would be tig weld. Tig weld wont rust as easy as compared to mig weld. I have had people with custom mig weld exhaust come to me after 1 year or 2 and say their whole exhuast rusted, so they end up doing it again.
What im saying is do it right the first time so you wont have to do it again.

 

Just paint the welds...every couple of oil changes, just scrape and repaint.

Works great.

 

is the 3" thermal louder than the 2.25"?

the 2.25 is awfully loud on my lude. i can't imagine it being any louder and not killing birds, insects, small children, and most small mammals that were in the path of it's grating low frequency rumbling.

 

From what you guys say, I'll probably upgrade to the Thermal. My GReddy EVO also feels like it's trying to breathe, but that's because it probalby is trying to breath. And yes, I did look at the pics you got for me, thanks a bunch. I should seriously consider just making a completely new motor since I'll have to take it out to put in the lower compression pistons. I want to run about 10 lbs of boost, which I should be able to do, but will I need forged connecting rods and a forged crank? Once I have everything on the car, I'm going to have it tuned to prevent detonation and such. I would like to get to the low 12's, does this sound reasonable with the setup I have now. Other mods I have now include Unorthodox Racing pulley set, AEM Cam gears, and MSD ignition, and a new AEM fuel system (rail, regulator, pump, etc.) Thanks.

Ben