I am running a LS/VTEC in a 94 4dr teg. with pr3 11:3:1 pistons. I am buying a header and exaust next week. Should I get a 4-1 header or 4-2-1 header? whats the pros and cons? also what kinda exaust should I get , I am going n/a all motor. 2 1/4" or 2 1/2" which company u recommend?

Thanks !

 

I like the 4-2-1 header design myself. Comptech is a good choice. Which exhaust will depend on how much you like to be heard. Some of the fave exhausts out are really loud. I have an A'pexi WS and it's only slightly louder than stock until Vtec then it's loud.

 

JDM ITR header 2.5 cat 2.5 mandrel bent B pipe with no resonators and the stock ITR muffler

 

TimoneX, isn't the A'pexi WS pretty restictive for your setup?

 

We shall have to see. It didn't seem to hurt me much w/ the ITR pistons. I won't go to a loud grapefruit launcher style exhaust just to pick up a couple ponies. I think the Comptech header will hurt me more than the exhaust at this point. I'm waiting to see more results on the Comptech knock-off...er race header. One of those may be in my future.

 

Wait, I'm confused....

you have a 2L GSR, right? Well, how are you running ITR Pistons? Is it stroked instead of bored?

With a 2L, aggressive cams, and decent pistons I would think that a 2.5" straight though exhaust would give you more than a couple HP over a 2.25" chambered exhaust....... I would expect it to be in the double digits.

But I totaly hear you on the "Grapefruit Launchers", that's why I'm probably going to save up and wait for a Hytech for my set up.

 

I dyno'd 198 w/ ITR pistons using the Comptech header and WS exhaust. I've since had the block sleeved to 85mm, installed JE pistons, and a couple other goodies. I'm in the process of re-assembling it now. I'm still in need of injectors and my Hondata S200 is still running the base map I got w/ it, so after I get it back together and broken in I need to get it tuned(other side of MI). Compression will be just over 12.5:1, so I won't be able to get on it till I get it tuned or detonation will be a part of the equation. I'm sure a re-design of my entire exhaust system will be in my future, just not for awhile. Meanwhile I like the A'pexi cat back just fine.

 

Ok, I got it.

Yeah, I'm sure the WS will be fine. But with your new set up, I bet there would be a big difference from your WS and a good 2.5" straight through exhaust (like Hytech or SMSP).

Keep me posted on your dyno numbers.

I'm running:

97 GSR
- 84mm GE Sleeves
- Skunk2 Stage 2 Cams & Gears
- 11.8:1 Wiseco
- JDM DC 4-1 Header
- Hondata Stage 2
- Eagle Rods
- Portflow springs and retainers
- 440cc injectors
(still running stock cat & cat-back)

And I'm getting my bent valves fixed and a Portflow Port & Polish this month.

After that, a cat & cat-back will be next. But I won't be able to affored the Hytech for a while, I don't want to settle for a "Grapefruit Launcher" exhaust, and I'm afraid a WS or SP will be too restrictive and I won't be happy with it.

I'd be interested to see you numbers with you new setup using your WS exhaust compared to your new exhaust down the road.

 

No doubt the Hytech or SMSP would help, they're just really tough on the wallet and I doubt they'd do much w/o a header replacement as well.

What happened to your valves? Floated or timing belt break/slip?

 

Yeah, I hear ya..... those exhaust are pricy.

What happend to my valves:

Well, I'm not entirely sure. I had the motor built by ImportBuilders. When I got the motor, the cams were set at 0,0. And after I swapped in the engine, I babyed it around to break it in, then took it down to Steve Sakai (sgt) to get it dyno/hondata tuned.

It was maxing out at almost 150/120 to the wheels. I know that my stock cat & cat-back are were chocking the motor a quit a bit, but Steve still felt the engine should be making more power (and I was figuring 170-180plus even with my stock exhaust). So, steve did a Compression test (Ok, at about 240-250 on all of them... can't remember exact numbers) & and leakdown test (NOT OK, 10%,15%,20%,10% leak).

Steve determined that it was bent valves. I'm not 100% sure how he could tell that was it. But he seems to really know his stuff, so I trust him. Steve said that because of how Sk2 S2 cam line up with Sk2 Gears (or their lack of lining up), even at 0,0 their could be a 1/2-1 degree off. So it is possible that they could have actaully been at +1 Intake, -1 Exhaust event though the gears read 0,0 And this could have caused valve-to-valve interferance, resulting in the bent valves.

I talked to Jeff at ImportBuilders and he dissagrees with the fact that the Skunk2 Stage 2's can have valve-to-valve interferance while set at 0,0.

So steve, set the exhaust at +4, and the intake at 0, just to make sure there is no risk of interferance again until I get them fixed.

Right now, I don't really car how they got bent, as long as they get fixed and that helps my HP numbers climb to a respectable position.

I'm just waiting on the Head from Portflow. Then I'll be taking my car back down to Steve and basically swaping heads with him (and replacing the bent valves, and upgrading the intake valves to ITRs). And the Head should be back anyday now.

 

Bummer. Hope you get it all sorted out though bro.