Hello all! I am a new member and have been slowing preparing to build up my 99 rs. I am looking at dropping a turbo on my 420a but the issue is coming towards the after market catback exhaust.
The issue I am having is that I want to prepare for the turbo system but am not sure if I should hold off putting the exhaust on until the turbo system is ready to go. I don't want to buy parts twice if I don't have too. Will this cat back work without the added back pressure for velocity from the turbo?
#136939, "RE: Aftermarket Exhaust" In response to Reply # 0
First, pay attention to what section you are posting in. Familiarize yourself with the forum layout and introduce yourself in the appropriate section.
Hold off on the exhaust until you install the Turbo kit. The only significant change by installing one now will be the sound. Plenty of people have installed 3" systems while non Turbo. Might kill some low end power though. Up to you how you want to allocate your funds. 2.5" systems work on Turbo applications just fine.
#136944, "RE: Aftermarket Exhaust" In response to Reply # 1
Sorry about that. Didn't understand the forum setup until after I had posted. Thanks for the response. Right now I have an aem short ram intake as my only other mod on the car right now. Wouldn't the power loss in the low end still be negligible? I still don't completely understand the whole theory about how forced induction systems work. To my understanding right now even with out a turbo the short ram should still be providing enough velocity to compensate for the pressure/velocity difference. Is there something that I am missing?
#136945, "RE: Aftermarket Exhaust" In response to Reply # 2
Intakes are not providing velocity. All it is doing is allowing the engine to breathe better. Think of breathing through a straw. Then give yourself a larger diameter straw. Feel the difference? Rather simple analogy there, but you get the point.
It will break down the fundamentals very well and you will be better off than many other "tuners" that slap an ebay turbo kit on their car. I have a copy that is old and re-read many many times for years as I have referenced it often.
Mods for the your non-turbo setup do not provide any significant dollar to HP increase. So the bottom line is if you want to go turbo, save the money and put it toward buying or piecing your kit together.
#136946, "RE: Aftermarket Exhaust" In response to Reply # 3
Ok, that makes more sense. I had assumed that the engine breathing better would have also produced more exhaust gases. All though since you pointed that out it doesn't make that much more sense. Thanks for the book recommendation. I am ordering it as soon as I get off work.
I had previously talked with other DSM owners around my area and they had suggested going with the 16b?. I was looking at dropping in a Greddy 20g and only running at about 6 psi on stock internals and only 2.0l of displacement. Thats why I was looking at the 3" setup for the exhaust.
Would it still be any recommended to go with the 2.5"?
#136947, "RE: Aftermarket Exhaust" In response to Reply # 4
If you are new to all this (i'm relatively new myself), your best bet and simplest install by far will be to install an off-the-shelf turbo kit (Star or HRC). If you go this route, the downpipe will be setup for 2.5" exhaust so unless you plan on fabricating a 3" downpipe from the turbo to your 3" catback exhaust, you probably won't see much benefit from getting a 3" catback. It's also more of a challenge to route the thicker 3" piping (may not be able to go above the rear axle).
Anyone know anyone who can help me tune this in the Pittsburgh area (Greensburg)?
#136950, "RE: Aftermarket Exhaust" In response to Reply # 6
The only issue for the off the shelf kits is the cost otherwise I would just do that.. I am shooting for 1300 and 2000 max. I would like to at least piece together a stage 2 system. I will start looking at 2.5" setup then. Would there be any other potential issues with piecing together a turbo kit to match the exhaust setup?
#136954, "RE: Aftermarket Exhaust" In response to Reply # 7
Originally posted by romulusdsm The only issue for the off the shelf kits is the cost otherwise I would just do that.. I am shooting for 1300 and 2000 max. I would like to at least piece together a stage 2 system. I will start looking at 2.5" setup then. Would there be any other potential issues with piecing together a turbo kit to match the exhaust setup?
I think you are focusing too much on little details at this point. All off the shelf 3" exhausts have a neck-down at the point where it bolts to the factory catalytic converter so it will mate to OEM midpipe/downpipe sections. So with that in mind, an off the shelf turbo kit with a pre-fab downpipe will bolt on as long as it was designed around your intended platform.
As for piecing together a kit, you need a DP fabbed for you at a local place or if you know a welder, otherwise look for a used kit that includes the DP for a 420a Eclipse.
#136964, "RE: Aftermarket Exhaust" In response to Reply # 9
I will probably have a Star Downpipe for sale one I get my 3" DP made. Note that this has a 5-bolt t3/t4 flange.
Before you start piecing together a kit though, you need to decide a few things... First thing should be a power (HP/TQ) goal. Then based on that, you can determine which turbos are potential options. The turbo will then determine what type of wastegate (if not included internally), exhaust manifold, downpipe flange, and intercooler pipping size you will need. After that, most of the other items you need should work with any system (ie. fuel pump, injectors, fuel management, intercooler, blowoff valve, etc.).
Anyone know anyone who can help me tune this in the Pittsburgh area (Greensburg)?