Hey guys,
I'm in a mental battle between installing the JDM 4-1 header or leaving what I have. Currently I have a Comptech 4-2-1 with the collector size changed to 2.5". This goes into a 2.5 Catco cat then runs into a 2 1/4" exhaust straight through. (all bottleneck have been removed) I like the performance of what I have now. Made a big difference switching to a 2.5" collector.

I have in my possesion a JDM 4-1 header w/ heat shield which I bought for pennies. Should I swap out the comptech header in place of the JDM 4-1? The Comptech header is lighter btw and nothing is wrong with it.

Would I see a performance gain? I saw the results of the great header test and the stock comptech performed better than an unmodified JDM 4-1.

Should I have the welds grinded away on the JDM header? (Kinda like what D did to his)
I also noticed that the JDM primaries are not mandrel bent, these are crush bent (not krinkle bent).

The issue I'm having is, there was all this hype about how great a header the JDM is but looking at the quality of a mass produced piece scares me alittle. The COmptech header has smooth bends while the welds on the JDM looks sloppy and the bends aren't as smooth.

Any suggestions?

Oh ..... will the JDM header fit with the existing header braket? Would I need to change the inlet of the CAT when using it as well?

Thanks ...... I'll stop whinning now.

-nick

 

JDM 4-1 is ugly, but it works. Very robust construction

Comptech welds don't look so hot either IMO.

 

Keep your comptech.

 

You will probably not see any differences between the JDM 4-1 and the comptech. Keep the comptech....lighter, better ground clearance, and lazy factor should convince you to keep it on.

 

keep the comptech if you don't plan on modding your R any further than IHE...
if you are going further then the JDM might come in handy...
btw...shocks are still available


[Modified by BlueR, 3:03 PM 5/31/2002]

 

Both are good. I only got the JDM 4-1 Type R headers because I wanted the top heat shield incase cops ask me to lift my hood.

 

I mean if you already have the JDM might aswell test it out and see if you like it or not, but honestly you'll probably end up sticking with the comptech.

 

Keep the Comptech and sell me the JDM.

 

OEM JDM 4-1

What's your HP with your current set-up?

 

Current horsepower ...... don't know for sure.

My old motor (which was strong as hell) with Comptech Header (original collector), Comptech Exhaust, stock cat, Pullies, AEM CAI - pulled a 179.xx to the wheels.

Here is the link:
http://b16a.com/dynocenter/home.html

Thats doesn't count though!

Maybe I should try the JDM for a month and see what all the hype is about.

Can I still use the stock header bracket? Anyone?

-Nick


[Modified by Nick248, 2:23 PM 5/31/2002]

 

Nope, should be fine without it, though.

Give the JDM a try.

 

Yeah keep us posted...

 

look closely at the JDM 4-1 collector, it is far from being anywhere near 2.5 inches, I think it is barely over 2 inches, maybe 2.2 max when you account for the double and triple pipes inside the collector. Keep the Comptech it should out flow the unmodified 4-1 easily, and I am willing to bet mid range is slightly better.

Joey

 

the collector is 2.5", the anti reversion chamber(which you can cut out) inside the 2.5" collector is 2.38".
drawing:
( ( ) )
outer is actual collector(2.5") and inner is anti-reversion chamber(2.38")

 

Most of the hype about the jdm 4-1 is the big collector...you already have put a big collector on the Comptech soo... what's the point?

 

Will it help out performance to cut it out? How far do u cut in to?

 

i hear.. 1-2 whp? estimates from people... talk to david from SMSP about it. i think he could give you a better figure.

 

Install the JDM with heatshields, or sell both and get a Hytech...

 

Get a Spoon header I got my used one from Mike(IPS) today and the collector on that biatch is massive

 

Install the JDM and sell the Comptech!!!

 

I assume any muffler shop can cut the anti-reversion chamber out correct?

Should I still grind the excess welds inside the primaries? Does that yeild anything or are folks just being ****?

Hopefully ... my car will be running soon so I can test out the JDM.

I'll keep you guys posted.

-NIck

 

keep the what j00 have on the car and sell me the heat sheild for the jdm... i would have to say dyno wid the comptech and the again wid the jdm and see what the dyno tells j00. i'd personally go wid the jdm.

 

I second the post about talking to Dave @SMS...I took my JDM 4-1 to him and he cut out the ant-reversion chamber and ground down the welds. I never had it on the car beforehand, but I am betting that it will be worth the amount that I paid him to do it. Next I will be taking my Type One B-pipe to him for modifications.

However, since you are in the tri-state, don't know if it's worth it to you to suffer the shipping charges or the drive down to F-burg.

 

If your going to mod the header thats one thing.Stock for stock you can't beat the comptech,did better than the JDM 4-1 on the typeR.If you have a fully worked motor you want to get a 4-1,but if your going to totaly mod your motor than you wouldn't want to JDM anyway.

 

how do you go about cut out the anti reversion camber?