hey, we dont want to rush this. i am very happy with waiting till the final tested product is ready. No rush here!

 

im in....im down for performance mods what so ever...PM SENT

 

Guru -

I'm assuming that you are well verse at making these headers with your statement. If that is the case, could you go ahead and make a couple for comparison purposes if it's that simple and you have the expertise and tools.

I think we'd all be grateful for some comparisons and competition.

 

Dan, by all means, if you can make a comparable design that fits in the stock location at the price that we are working with... GO FOR IT.

As Dave pointed out there have been several delays in even getting this approved from CL to be offered. I have been working to get this project to market for over 6 months so if anyone should be impatient it should be me. Nobody wants these more than I... that is WHY I have gone to this effort. At one time I had access to fabrication equipment and I built exhaust systems and intercooler systems for my own car as well as friends. I do not currently have that option.

As far as time goes... there are still unanswered questions regarding installation. A set of manifolds would allow a prototype to be built and tested. YES, I did speak to Marken at SRT and unfortunately they do not have any manifolds available. If ANYONE has a line on a set that would be a HUGE help.

DAN... maybe you can help here? Can you get me a set of manifolds? Even if you build you own you will need to remove the stockers. Let me borrow them for a couple weeks. What do you say?

Once we have something to work with, a car and/or manifolds, R&D time is expected at 6 weeks.

BTW, in conversation with the header craftsman I was informed that they have measured up to 12 inches of vacuum in the non firing runners when using a proper merge collector. Contrast this "vacuum cleaner" effect with the "pressurizing effect" the stock manifolds do to the other runners and you get a good idea on how effective these could be.

 

Keep up the good work JBrady. I wish I was located out there so I could lend you my car for a couple of weeks to get this going. Have you tried a few dismantling yards for these? I will check around here to see what I can come up with. What other cars have the same manifold? Sc430?LS430?.....
Lee

 

Lee,

I have asked a couple of people if they could cross reference the part numbers on the possible cars that could share this manifold. That list is:

98-00 LS400
98-00 GS400
98-00 SC400
01-04 GS430

Other possibilities include:

01-04 LS430
01-04 SC430

Wrecking yards may be a source but they have gotten expensive and usually do not want to sell parts off a usable engine. Check if you have the time but honestly I am not budgeted to buy stock parts for this project.

As far as the fitment list goes, the 92 SC400 needed a different exhaust manifold to fit than what came on the LS400 but I would guess that Lexus would have designed a universal manifold by 1998 since all the above 98-00 cars used the same engine. But, it would be nice to confirm with a part number check if any one has access that would be helpful information.

 

I will try and get VVt-i to come in and see if he could help you since he's a Lexus Master Tech working at our Local Dealer so he should have access to part no's.

 

I've spoken to VVT-i and he's gonna start to cross reference the numbers for you with Dealer's parts computer data base.

I'm sure he'll come in and let you know.

 

THANKS

 

You're welcome.

Just remember that when you're handing out discounts.......

 

I just the part# for all the ex. maniflod list above.
98-00 LS (LH) 17105-50090 and (RH) 17104-50090
98-00 GS400 (LH) 17105-50100 and (RH) 17104-50100
98-00 SC400 (LH) 17105-50110 and (RH) 17104-50110
01-04 LS430,SC430 and GS430 are the same (LH) 17105-50160 and (RH) 17104-50160
For some reason the 98-00 GS has 10 more hp than the LS ( 300 vs 290) by difference header designed. But the 01-04 they're used the same header, but computer tuned the LS to has 10 less hp. I hope this will help the project.

 

First of all, Thank You VVT-i for getting these numbers

Hmmm... this is curious.

On first glance this looks like they use different manifolds for all these cars... BUT... on second glance I am not so sure. From an engineering standpoint this would be stupid and the Japanese are many things but not stupid.

Oh, regarding the power differences... it is NOT in the exhaust manifold or tuning. It is in the MUCH more restrictive exhaust system of the SC and LS models. In the GS models the dual 50mm (also found on the LS and SC's) join into a 60mm single center resonator and pipe. The LS and SC's have a single 50mm center resonator (less than 2")


Now, back to the manifolds. Notice ALL the left hand manifolds are 17105-50xxx and ALL the right hand manifolds are part number 17104-50xxx. Now, either there are 4 separate designs or for the 98-00 cars Lexus used the part numbers for tracking purposes. Which part needed to be replaced on what car kind of thing.

So, I guess I may try to persuade my local dealer to let me visually check out the various parts (if they even stock them). I believe at the very least they will all have the same flange locations for the heads and catalysts.

 

The first 5 # is the pre-fixed# and designated to exhaust manifolds and then the last 5 # is the specific # for each car. They may be some differences designed of the manifolds for each car( 98-00 LS, GS, and SC), but the cylinder heads are still the same. I'm not sure about the 430.
I'm sure that the dealer will not stock the exhaust manifold because it's a rare part and we don't have any problem with the exhaust manifold leaks or cracked at all. I will find out about the PN# for the cylinder heads on all car listed above. If they are the same # then the exhaust ports and mounting bolts will be the same.

 

Have you checked junk yards? My local one has many sets of manifolds available. As for myself making them, sure, we engineer and make many products but we really only make stainless stuff for the most part on exhaust manifolds and number 2, I have no time. I have a dozen new products coming out this year and with all the everyday work we have like TT 350Z's, EVO's and STi's we are absolutely swamped. Since this project would be a personal one it gets last priority around here. I have absolutely no interest in making headers of this kind since my ideal design would ditch the cats, be equal length, be stainless, and cost a hell of a lot more than $600. I would have to sell at least 50 sets to be worth my time and I don't think I would have 50 people in this market segment to make them for. Let me know if you want the number for the salvage yard. Those crazy russians have EVERYTHING in stock. WHere do you think I got my LS430 calipers?

 

The insurance I'm sure took Mike's car by now. I doubt they'd let him remove anything.