Removing Engine Heat Shields

[Rikki]

Im getting a custom 4" to 3" downpipe made up at the moment (snakehead design) and have had the heat shields removed from the top of the exhaust manifold and turbo. Ive also noticed "most" tubby's with engine bay mods missing this bit.

All was well until I went into a local turbo conversion place and asked them something about by new HKS BOV. The engineer popped the engine cover up looked in and placed his hand on the plenum where the BOV fits onto and in doing so nearly burned his hand off. He then asked where the heat shield was and I said it was taken off. He explained thats all well and good on normal cars where the exhaust manifold sits on one side of the engine and the inlet piping on te other side but with the MR2 the air route goes over the top of the turbo and manifold so by removing the heat shields all the extremely heat from the turbo and exhaust rises up and cooks the air before it goes into the IC and the IC wont be able to cool it enough since its so !Removed! hot. He said on a warm day it will probably pink a lot and the performance will be way down.

It kinda makes sense to me with the engine bay layout but thought I'd ask / let other 2 tubby owners know what he said in case you want to rethink the heat shield removal like I have.

Cheers,

Rikki

[DeusMR2]

makes sense i suppose, but what doesnt make sense is the stupid bracket holding the intercooler to the engine. it acts like a huge heat sink and trasfers heat to the intercooler pipe..not good. gonna remove this soon!

[midmotorsteve]

Thats why you should wrap the manifold :-

[Rikki]

Thats why you should wrap the manifold :-

...and turbo and downpipe ? LOL

[pizza boy]

Rikkis 100% right about this I feel major torque in the first 10 min after temp is normal. Then after city traffic etc ...the torque has dropped noticably after a quick test thrashing. My temps will be waaay up @ 17psi so Im feeling it a lot. Think its also time for a cooling upgrade this summer will be cooking.

Wrapping the manifold, altho benificial, wont stop the turbo heat from hitting the inlet piping. A shield is whats really needed. But then..wont the turbo be running pretty damn hot with the heat trapped in the shield? Isnt the result the same?

[msherry21]

Just re-route the Air con into the engine bay, problem solved.

Hardcore budgeting!

[Rikki]

We carried out a scientific experiment last night.

Parked up with my car and MSherry's. Let them cool for 30 mins. Then went for a fairly normal drive around town. 30 mins later we parked up and popped the engine bay covers.

Mark has his sheilds in place and I have mine removed.

His turbo side inlet plenum was warm/hot and mine was f'ckin hot/roasting.

Next stop, heat shields back on!

R.

[msherry21]

who's Mark?

[Rikki]

Thats your evil twin LOL ;)

[pizza boy]

I think after your fingers were cooked you really couldnt feel much anyway. :)