IMF Exhaust

[Lextreme II]

Got a chance to examine IMF exhaust system for the 1uzfe. The qaulity is amazing. Stainless steel all over and it also comes with exhaust gaskets along with cat gaskets too. Here are some pictures of IMF headers. If you have any questions, please contact Chase for more details.

 

[spf_lexus]

Those are nice headers.... too bad like all the rest they dont fit LS

 

[Lextreme II]

With some mods it would. I was talking to Chase via emails. He stated that 1992 to 1994 SC fit without any issue. Perhaps we can use the SC400 engine mounts and see.

 

[spf_lexus]

I'm just curious about the driver side steering shaft... OEM routes around it and it's in a bad place for LS... willing to tinker tho

 

[ChronoJ1]

how was the fitment with the rest of the exhaust piping?

 

[Lextreme II]

I can not speak for the rest of the models. However, for the LS400 (95 California Version), you would need to modify or delete the cats.

 

[GS400CIVI]

will this fit the GS400?

 

[JBrady]

All models would require removal or relocation of the cats to fit.

David states that modification would be required for fitment in the LS400 and that would almost certainly apply to the GS400. It would be fun and interesting to see just how much "modifying" would be needed.

These are designed as a direct bolt in replacement for 1992-1995 SC400s and would fit in all SC400s as far as I am aware. They may even bolt up to the 96-00 exhaust. As I mentioned you must remove the cats to bolt these in. You could re-install the cats after the headers with some modification to the Y pipe. Ground clearance would probably suffer.

For the price it is hard to argue getting a set of stainless headers.

From a functional standpoint it would be very interesting and fun (at least for me) to test the various available options for the SC400s.

 

[GS400CIVI]

I actually just ordered a set of the S&S headers, hopefully they can get them to me quickly

 

[JBrady]

I actually just ordered a set of the S&S headers, hopefully they can get them to me quickly

Did you order direct or from a dealer? Did they say they were in stock? S&S ususally builds in batches of 20 sets.

The S&S work very well for the design limitations of the application. On a short duration camshaft design like we have the main thing is high flow high velocity. This enhances the entire RPM range.

 

[spf_lexus]

With a full tune from a standalone running 4.7L block 4.0 Heads, and procharged 7psi, any idea of what I could net from a set of S&S headers? Just curious as my stock restrictive headers get more restrictive every time I upgrade something lol. I would rather get a set of headers than increase my boost. I know the S&S model fits the LS, just need to relocate cats slightly furthur down but I know it fits... don't like the idea of IMF headers in that I will need to cut and weld to fit. Great quality nontheless, totally jealous.

 

[JBrady]

With a full tune from a standalone running 4.7L block 4.0 Heads, and procharged 7psi, any idea of what I could net from a set of S&S headers? Just curious as my stock restrictive headers get more restrictive every time I upgrade something lol. I would rather get a set of headers than increase my boost. I know the S&S model fits the LS, just need to relocate cats slightly furthur down but I know it fits... don't like the idea of IMF headers in that I will need to cut and weld to fit. Great quality nontheless, totally jealous.

I would love to see some dyno numbers on both IMF and S&S. Here is a GS430 with Vortech? at 6.5psi untuned (IIRC).

S&S gained a peak gains of 28rwhp and 24rwtq. BUT, if you look closely you will see mid range gains of 43rwhp and 34rwtq. If properly tuned who knows. Now this is on a 4.3 vvti which has stock manifolds very similar to the early LS and SC400s.
http://www.clublexus.com/forums/performance/184071-lms-sc-results-new-update-w-jbrady-headers-3.html

Something to keep in mind. These gains were with the STOCK Y pipe with 1.97" duals into a single 2.36" center. The S&S are designed to retain maximum low and mid range power with minimal top end restriction WHILE fitting in a stock GS with cats in stock location. All designs are compromises.

Again, it would be great fun to do a wide range of testing with different exhaust layouts. One thing is surprisingly clear... the stock Y system works WAY better than it looks. Stock manifolds look poor and work poorly.

 

[spf_lexus]

Thanks for the link Jbrady, the only stock part of my modded exhaust is the front y-pipe, I read enough of your posts to know it should probably be left alone. Now that I have a 4.7L w/ blower I might end up with a dual 2.5'' with a 3'' collector Y with a nozzle setup, but with a standard 4.0 the gains are nonexistent.

 

[mtnrat]

Just received my IMF headers from Chase. They look great and were shipped fast. Here they are with my other goodies.

 

[JBrady]

Just received my IMF headers from Chase. They look great and were shipped fast. Here they are with my other goodies.

Welcome to Lextreme.

Your parts collection is impressive. Have you decided on a hood yet?

Post some car pics of that mint 92 SC400 when you can.

Give some background on yourself and your plan. What is your end goal? That 122 should make for some serious torque.

 

[JBrady]

Thanks for the link Jbrady, the only stock part of my modded exhaust is the front y-pipe, I read enough of your posts to know it should probably be left alone. Now that I have a 4.7L w/ blower I might end up with a dual 2.5'' with a 3'' collector Y with a nozzle setup, but with a standard 4.0 the gains are nonexistent.

Yeah, with a 4.7 AND the blower you are getting to the point where a larger Y or H or X or duals... will actually be useful. The 4.7 should get you into boost RPMs fairly quickly. If you are still wanting more a torque converter will get that thing boosting NOW.

So, you have a modded Y pipe with stock other pipes? How would you like it to sound?

 

[mtnrat]

Welcome to Lextreme.

Your parts collection is impressive. Have you decided on a hood yet?

Post some car pics of that mint 92 SC400 when you can.

Give some background on yourself and your plan. What is your end goal? That 122 should make for some serious torque.

The M112 was milled down to fit under the stock hood, (lextreme treatment). So I don't need to change that.
I am just a bit of a car nut that feels that just about anything that is made needs modifications.
I want to keep the stock look of the car, but have a little unexpected extra when needed. I drive across BC frequently and feel extra passing punch and some more ponies to run with dogs is in order. So the end goal is to build a very drivable road car. I have pulleys for 10 and 12 lbs boost, and am also looking at water methanol injection.
After these mods I want to install a LSD and W58 swap.
Here is a recent pic. I now have 65,000 km (39,000 mi), on the car.