is300 3uz headers

[Brad Bedell]

Just finishing these up:

All are within 1.5" of equal length. Still need to add some finishing touches and build mounts to fasten them to the transmission in order to reduce vibration cracking. Of course, build some heat shields for everything, but that's easy stuff. 1.5" primaries into a 2.25" collector then into a high flow cat. They should keep the exhaust clean while not robbing too much power.

 

[Chicken Wing]

Wow that looks great mate!
Im on the way through a similar project, give me an honest opinion though, do you think a low mount pair of turbos would work?

I've seen some conversions, and there looks to be a fair amount of room down there but im not exactly sure. Im only talking T25 or T28, relatively small frame turbos so I can keep them close to the block.

Do you think its possible?

Thanks in advance mate, keep up the good work!

 

[Brad Bedell]

I'd stay away from twin turbos. Way too much plumbing to fit in a tight quarters.

I mocked up a T60-1 with a T4 flange on the pass side just about a week ago. (actually, the manifolds are 80% finished) I was going to use a GT35 with the smaller compressor housing and a .82 a/r ratio. (should support about 600hp) I decided against it as I want to do one project at a time. For now, I'll keep the supercharger I have, but will be considering the turbo or maybe a twin charge at a later date.

Basic turbo setup: two log manifolds, route the left side across the top of the transmission to the right side. Turbo compressor pointed down and routed under the cross member up to the bumper. 3" intake runs between the engine mount and frame rail, right turn into the wheel well and up as high as possible to avoid water. I'd probably put some sort of water trap in it also to help reduce the potential of ingesting water on a bad day.


With a little frame notching, a larger turbo could be fitted down low. It just depends on how big you want to be. The alternate would be to mount the turbo up front of the engine and remove the fan shroud.

 

[cribbj]

Headers look nice Brad; it's good to see you back!

 

[JBrady]

Nice work... except for the collectors.

Brad, you have very good fabrication skills. Take the time to create some decent merge collectors. You will be glad you did.

 

[spf_lexus]

That collector is more of a work of art than anything else.

 

[Brad Bedell]

A merge into a cat(like my above setup) isn't going to make a bit of difference in power. Even if the merge was of proper volume, running it directly into a ceramic honeycomb wall isn't the greatest for velocity.

 

[Chicken Wing]

Basic turbo setup: two log manifolds, route the left side across the top of the transmission to the right side. Turbo compressor pointed down and routed under the cross member up to the bumper. 3" intake runs between the engine mount and frame rail, right turn into the wheel well and up as high as possible to avoid water. I'd probably put some sort of water trap in it also to help reduce the potential of ingesting water on a bad day.

Sounds excellent mate glad your seeing it through, get a couple of pictures of the turbo manifold up here when its done!
So the reason why youd want to put it on the passengers side is because of the steering column etc? We drive on the other side of the road, but our engines are the same, meaning the only difference is the steering column.

Anyway was just browsing and I found this from the guys at SteedSpeed, its for an M3, but i find the engineering work quite impressive.
Alternative to a log style?























Sorry if theres too many pics, i treid to get them to a small size though, hopefully it works for all.

 

[Brad Bedell]

Correct on the right side, but same concept really, you could just mount the turbo on the left side.

Oh my, that manifold is pure porn! I think I'd just stick with the weld-L bends since I don't have the available resources to do that at a reasonable price. But wow; just wow!

 

[JBrady]

A merge into a cat(like my above setup) isn't going to make a bit of difference in power. Even if the merge was of proper volume, running it directly into a ceramic honeycomb wall isn't the greatest for velocity.

Gotta disagree with you here. The merge maintains velocity into the cats core. The cat actually works like a one way check valve and enhances low RPM power be reducing reversion.

The collector style you have actually creates turbulence and aids in reversion. Its very similar to how water comes out of a "small" fawcet and splashes and doesn't drain as fast as it enters the sink due to turbulence.

Actually, I doubt the trouble to make equal length will gain anything especially at the RPMs of the stock ECU and the with the virtually no overlap cam profile. Streamlined flow is where its at under these conditions. With your supercharger you could probably go with larger pipe diameter (something I RARELY advise).

Anyway, just a suggestion.

 

[Brad Bedell]

What you're saying makes sense. We just didn't see more than 1hp difference on the motorcycles when we tried each collector. I suspect to get full gains from a proper collector, I should invest with Burns to help with tuning it; where does one stop? I also agree on the larger tube diameter. I was considering a 1.625ID tube. Part of the exhaust revision for me is to get the noise down just a bit in the car.

This would make a merge quite a bit easier; I'm waiting for the seller's response:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=150295630017

 

[JBrady]

What you're saying makes sense. We just didn't see more than 1hp difference on the motorcycles when we tried each collector. I suspect to get full gains from a proper collector, I should invest with Burns to help with tuning it; where does one stop? I also agree on the larger tube diameter. I was considering a 1.625ID tube. Part of the exhaust revision for me is to get the noise down just a bit in the car.

This would make a merge quite a bit easier; I'm waiting for the seller's response:
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=150295630017

I would suggest there is much more than a dyno 1hp but that is another discussion.

I don't think you need to try to engineer the "perfect" header as that is not possible as all designs are compromises.

IMO the collector is more important than the primary length especially on a muffled full street exhaust system. (something Vizard concures with)

Your near zero overlap Lexus camshafts make accoustically tuned lengths less important than velocity scavenging even if there were NO increase in peak power as (IMO) mid range IE power under the curve is where its at on street engines.

Your eBay find is worth considering but could also be made with a chop saw and some straight tube. Here is another option using formed collectors that is definitely worth a look.

http://www.coneeng.com/collectors.html

 

[JBrady]

Sounds excellent mate glad your seeing it through, get a couple of pictures of the turbo manifold up here when its done!
So the reason why youd want to put it on the passengers side is because of the steering column etc? We drive on the other side of the road, but our engines are the same, meaning the only difference is the steering column.

Anyway was just browsing and I found this from the guys at SteedSpeed, its for an M3, but i find the engineering work quite impressive.
Alternative to a log style?

Very cool execution. Not sure about the need for as would be lighter, cheaper, less heat retentive made from tubing.

That said something I have been mentally engineering for some time now would be similar but made from ceramic like the shuttle heat shields... a "casting" if you will with highly accurate formed runners and merges. Light weight and heat neutral (or close to it). Needs to be supported and protected from shock as well as supporting the weight and motion that an exhaust manifold would be. Turbine housings of the same material possibly cast into the unit.

 

[Brad Bedell]

Now, that's worth a find! Thanks for the link! I bet I can add something very similar to my current collector. I've got some long tips and snub clamp for the welding torch. Getting in there won't be too much of an issue.

 

[JBrady]

Brad, I am more concerned with the exterior shape of your collectors (which look like Stainless Works formed pieces).

Your picture shows the bulging outside edges which allow the gases to spin and/or turn back which destroys velocity and flow. I know I know you have already bought and built... not trying to detract from you excellent efforts... just wanting to give you thoughts now as they probably will be the same for some time once installed.

I also am not crazy about welding the cats to the collectors. V bands are expensive but a HUGE time and sanity saver come repair time.

 

[Brad Bedell]

While this isn't what I'd consider laboratory clean, it does show the difference and importance of back side shielding the inside of an exhaust pipe. Left is unshielded, right is. If you're short-cutting and not shielding the back side with stainless, you're creating turbulance in the exhaust AND won't get much more than 60% penetration. Other than too much heat, this is why many stainless welds break.

And yes, this means there are new collectors being built.

 

[JBrady]

Sweet.....

 

[Brad Bedell]

Just gotta bolt up the head flange to the spare head and weld up the last one. Then drill/tap a 1" piece of aluminum plate to weld the flange to the collector. Inside of the tubes have a nice radius and everything was smoothed out with a flapper wheel.