3k Hotbox Experiment

[vagen]

I am going to try a little experiment on my 3k. I will swap the standard gasket for a sheet of stainless steel sealed with exhaust rated RTV. The idea is two fold one the exhaust will no longer directly contact the intake and two the flow in the manifold might be less turbulent.

 

BTW: this is on a twin outlet exhaust mani.

 

Am I mad for even trying this?

[irokin]

Unless you've ported manifold and head to perfection, you're wasting your time. Bum dyno might tell you otherwise but its purely placebo.

[vagen]

I doubt my butt dyno will be able to tell anything as I have never driven this car in anger. I'll skip this if it is of no benefit.

[Taz_Rx]

If the whole point is just to improve exhaust flow then don't bother.

Just get yourself a set of decent tuned length extractors and you'll be set. End of story. :y:

[Felix]

tuned length extractors

 

That term amuses me. Tuned for what? Unless they are designed with the aid of an engine dyno they are not going to be perfectly tuned to the engine combo. That said any reasonable quality extractors are going to be an improvement over a crappily designed exhaust manifold.

 

I guess you could always port the manifold and get a set of larger diameter secondary pipes made up that run into a collector sized to suit the exhaust you are going to run. Not ideal but will be an improvement. A set of off the shelf extractors would be easier.

 

Your car is LHD isn't it? Might be worth asking on a US starlet forum about sourcing some.

Edited June 26, 2009 by Felix

[philbey]

Yeh, you won't see bugger all change. Just put a set of extractors on it!

[vagen]

I can get extractors but they are not common here and have to be shipped in from Austrailia. I was hoping the SS pannel would offer a slightly cooler intake charge and any improvement in exhaust flow would be lucky coincidence.

[coln72]

It wont cost much - so why not. Tried all sorts of things when I was competing with a 3k as I thought that even if it made 1% improvement, it was better than before.

[philbey]

A thin sheet of stainless with a couple of standard gaskets would be best then. The metal-metal conduction will cause the biggest increase in charge temperature, as you will heat up the manifold through contact. If you can get a high temp asbestos or similar gasket in there as well that will keep it right down.

[rob83ke70]

a couple of bhp gain is more noticable and worth it in a 72hp engine than say a 500+ hp engine...

 

just my 2c. And yes, I'd be the sort of person that would try something like that, not a lot of money, and time spent is ok because I'm assuming you, like me, love working on your corolla?

 

Robert.

[towe001]

One thing you'll be losing out on is fuel vaporization but depending on the climate you live in would depend on if its a good thing or an iffy thing

[vagen]

I live in the south and this car is used for track only so cold weather is not an issue. BTW anyone know why SS is a good heat shield? Its because it's greedy about the energy applied to it. SS will not transmit anywhere as much heat as aluminum. the SS cost me nothing and the plate is there to stay. If it gains me power good will it cost power I highly doubt it.

 

 

 

BTW: I priced a set of extractors here $300usd and a 3-6 week wait. I'll go free and here now over twice what I paid for the car and forever to get here.

Edited June 26, 2009 by vagen

[parrot]

Presumably any EFFECTIVE method of reducing heat to the inlet manifold without reduction of inlet charge / exhaust gas flow has to be worth a try.

 

I say go for it.

[philbey]

Sure, Stainless steel has a low thermal conductivity, but it still conducts much more heat than a fibrous paper gasket.

[vagen]

the way this thing was designed the exhaust blew directly on the manifold (it even has a heat sink to grab exhaust heat)so placing a bit of stainless in the way will help lower intake charge temps. One more thing I'm using .0625 inch SS which coincidentally is the same thickness as the gasket and stacking extra material in that gap will misalign the manifold causing problems with alignment of ports bolts lots of things.