Hollywood

One of my good friends locally makes custom turbo headers, said he would make me some headers for gs430. I read many pagers of the headers thread and there was discussion if the engine needed to be pulled or not to take them off. After viewing them last night, I currently do not see a problem with removing the stock headers, there seems to be ample room to get the front botls and if nessesay access the rear bolts from underneath if required.

Unless someone knows otherwise, feel free to share.

RRocket

Wow..you'd be a GS400/430 Hero if you got those headers made...and your bud could make a fair amount of $$$$ I'd suspect too....

Hollywood

He said he would make a few, but he's a 1 man crew, and has a full time job still. He uses his work shop to build them as they build large scale ventalation systems, but the manifold things are on the side.

Hollywood

I should clairify. We are talking about N/A headers, and it is premature at this point. I dont feel like pulling the engine to change and design headers if that's what it takes.

JPI Racing

Custom headers are not cheap. It can go up between $1200-$2000. You can get away without pulling the engine.
JPI

Hollywood

One of my best friends would be doing it so the markup for me is no that high.

But there must be so much power lost in the headers. DaveGS4 says there is only like 2 hp gained from swapping a cat back exhaust??? It really should be that way unless the cats are mega restrictive or the headers are so bad that you cant even see gains from a performance cat back.

Put it this way if you can make gains with replacing the intake (which I have read in these forums), and not from the exhaust then there is somthing seriously holding back the power between the exhaust side of the heads to y pipe. Judging by the pics I have seen in the big header thread, it looks like the headers are the culprit.

RMMGS4

iTrader: (5)

That is a good assumption, however if the design of intake , exhaust and header was already designed well from the factory, then your theory could be wrong. Also depending on who's post you read, the change in intake AND exhaust does yield an overall improvement. Too many people do exhaust first and don't do the intake as well, then they give credit to the intake when they add it later, as if the exhaust didn't contribute. The science of providing good breathing and exhaust doesn't really change here.

I discussed this exact question with Bruce Nomura and he said the factory header design was not that bad. He felt the installation of well designed headers can yield some improvement, but not as significant as one would think.

I'm not trying to disagree with you, I'm just telling you what I heard from a very reputable source. http://www.brucenomura.com/projectcars/lexus/martin/

If your bud is knowledgeable on exhaust design: equal tube lengths, collector length, proper scavanging, etc, and he cuts you a deal, it might be worth it to try so by all means go for it.

I'd really like to see a before and after dyno run to really quantify any improvement tho.

Good Luck

Hollywood

Thanks for the info, and dont worry about ediquette of disagreeing with me, that's what forums are all about.

But I personnally think the design of the stock headers are horrible.One of the worst I have ever seen as far as stock goes.

I have easy access to a mustang dyno so thats no problem.