T28 with stock downpipe - can it reach full potential?

[Silversurfermd]

Reason I ask is because I have a 2.5in high flow cat coupled to HKS Ti which is 2.25in to 3in catback. I want an T28 but don't want to pinch off performance too much. I stupidly bought Apex N1 3in downpipe thinking it would match the HKS...it doesn't.

Should I cut/weld the transition out of the HKS to make a full turbo back 3in exhuast (loud and requires hacking my $$$ exhaust). Or keep the 2.25in stock DP with the T28 and sell the Apex DP? Is it worth it to port the T28 if I keep the stock DP? And is it necessary to port exhaust manifold to match ported T28?

Sorry for the newb questions...but hey, thats what this forum is all about right?

 

[pboglio]

Reason I ask is because I have a 2.5in high flow cat coupled to HKS Ti which is 2.25in to 3in catback. I want an T28 but don't want to pinch off performance too much. I stupidly bought Apex N1 3in downpipe thinking it would match the HKS...it doesn't.

Should I cut/weld the transition out of the HKS to make a full turbo back 3in exhuast (loud and requires hacking my $$$ exhaust). Or keep the 2.25in stock DP with the T28 and sell the Apex DP? Is it worth it to port the T28 if I keep the stock DP? And is it necessary to port exhaust manifold to match ported T28?

Sorry for the newb questions...but hey, thats what this forum is all about right?

A 2.5" downpipe works great with a 3" catback on a T28, even connected to a 2.5" high flow cat. Cut the 2.25" transition if you want but it I wouldn't bother on a T28.

Porting is worthwhile on a T28, you might pickup 5 h.p. based on what I've seen on my setup. It doesn't hurt any.

 

[Silversurfermd]

Thanks a lot. I read a lot of your posts on the subject and trust your input. Thanks for getting back to me...great guy!

-Mike

 

[embi24]

I Bought A Apexi Downpipe Also And Found Out It Didnt Bolt Up To My 3in Thermal Exhaust.. Apexi Dp Are Only For Apexi Exhaust Unless You Cut And Stuff.. I Had A Shop Do Like He Said Cut Out The Transition Or Ends And Get It Together, Its Worth Installing A Downpipe Because Your Getting More Airflow.

 

[DSMunknown]

Porting is worthwhile on a T28, you might pickup 5 h.p. based on what I've seen on my setup. It doesn't hurt any.

Hmmm. Not sure if I agree on it being "worthwhile".

Okay, I don't. Not trying to be a dick, but that gain doesn't inspire me to port.

 

[pboglio]

Hmmm. Not sure if I agree on it being "worthwhile".

Okay, I don't. Not trying to be a dick, but that gain doesn't inspire me to port.

Then don't port if you don't feel inspired to.

Look at it from a larger context, any one "free" mod that can give you 5 h.p. is a big deal if your trying to max out your current setup.

The guy who IS willing to port is probably the one who is going to be pulling 400 h.p. out of a T28 instead of 300 h.p.

 

[the_mork]

Reason I ask is because I have a 2.5in high flow cat coupled to HKS Ti which is 2.25in to 3in catback. I want an T28 but don't want to pinch off performance too much. I stupidly bought Apex N1 3in downpipe thinking it would match the HKS...it doesn't.

Should I cut/weld the transition out of the HKS to make a full turbo back 3in exhuast (loud and requires hacking my $$$ exhaust). Or keep the 2.25in stock DP with the T28 and sell the Apex DP? Is it worth it to port the T28 if I keep the stock DP? And is it necessary to port exhaust manifold to match ported T28?

Sorry for the newb questions...but hey, thats what this forum is all about right?

I'm running a 16g to completely stock exhaust, it still spools relatively quickly and blows away my t25 even with minimal fuel mods and low boost. Even worse than just the stock exhaust I had my o2 housing ported knowing full well that it would hinder performance until I picked up a larger exhaust. Running the stock downpipe for the time being shouldn't be an issue until you can sell your apex downpipe and get an hks one or get a shop to put something together.

 

[daren_p]

Sure the stocker can be run with the T28 but it will hurt top end performance & also some spool. A 3" turbo back even works great with a T25. When I was having a new flex section welded in my 3" downpipe, I installed the stocker to take the car to its winter storage location & with the evoIII I was running at the time there was a defently noticeable/big drop in performance (also went from a 3" HF to the stock CAT). Do you still want to run a cat?

 

[Silversurfermd]

***TIME WARP***

The short answer is yes I would still like to run a cat. But I think I found my solution. Hook my Apex N1 3'' DP to this: CATCO EVO 8/VIII 3" HIGH FLOW CAT CATALYTIC CONVERTER.

eBay Motors: CATCO EVO 8/VIII 3" HIGH FLOW CAT CATALYTIC CONVERTER (item 300259701047 end time Feb-14-09 20:34:42 PST)

This catalytic converter seems to have the same 2 bolt flange as the Apexi and keeps me within the federal law. Then I get a shop to weld a couple of flanges on a 3'' mandrel bend tube to the muffler of my HKS exhaust. Think it will fit/work?

Oh and an aside. I installed Apex ATS and saw a huge drop in decible. They say I won't loose much horsepower. Think this is true and do you think this affects spool?

 

[97GSTAUTO]

BTW. 3" exhausts are not loud. Our turbos quiet down the exhause alot compared to the same exhaust on a N/T. I run a 3" with no cat and its quieter than 99% of the honda exhausts or mufflers for that matter. But just to answer your questions. Yes. If it quiets down the exhaust then it decreases power in some way. Can you really notice the difference? Probably not. Does it effect spool? Yes. Will you notice? Probably not.