Manifold and Throttle Body Question

[The_Plague]

Hi guys

I am looking to change my manifold and throttle body.
I was wondering if there are any advantages in doing so?
I am unsure whether the heads are rectangular or cathedral - they are Higgins heads with the stock manifold above them that has no modifications done to it.
The heads are 241's - I am just wondering are these rectangular port are cathedral port?
Should I go a 102mm throttle body or stick with a 90mm throttle body?
The car is twin turbo'd and makes just over 600rwhp if that makes any difference to considerations - I am unsure of the cam specifications and do not have them but it is a bit top endy.

Any recommendations are appreciated.

[whitels1ss]

Have you just bought this car with all this work done already?

If it's a twin turbo putting out over 600rwhp I think you need to be asking the engine builder exactly what is in the engine & exactly what is done to it.
After that, armed with that information, a very good tuner who you intend to get to do the work for this advice.

Has it got a stock or larger throttle body on it now?
How much boost is it running?
What is done to the bottom end of the engine?
Dyno sheets & graph of power?
etc, etc....

All I can answer for certain just now is that 241 heads are cathedral port.

[white lie]

I think Dave would have something to say about putting a FAST manifold on a TT car...his split like a banana on the first run.

Shaun's alloy would be where I'd be looking. One of these...but they don't come cheap. $5200

http://i235.photobucket.com/albums/ee264/mr_zogg/Mobile%20Uploads/FB_IMG_1442964659197_zpsflhevi4j.jpg

[duke5700]

No point having a larger throttle body than the charge pipes.

You really need more info on the engine package. Realistically the LS6 inlet manifold won't hold you back all that much. Plenty of cars 1000+ at the tyres with that manifold.

Holley to a hi rise etc that might be worth a look. You will need to modify the bonnet.

[The_Plague]

Have you just bought this car with all this work done already?

If it's a twin turbo putting out over 600rwhp I think you need to be asking the engine builder exactly what is in the engine & exactly what is done to it.
After that, armed with that information, a very good tuner who you intend to get to do the work for this advice.

Has it got a stock or larger throttle body on it now?
How much boost is it running?
What is done to the bottom end of the engine?
Dyno sheets & graph of power?
etc, etc....

All I can answer for certain just now is that 241 heads are cathedral port.

I had the work done to the car mate.
I have the Dyno graphs and can name the parts in it but do not have the cam specs.
The cam was done by Carline Maitland - the turbos in 2007 and further work in 2009.
Boost is handled by an Eboost 2 (from 2007) with 6 settings.
Max PSI run is 11, the 14 PSI option has never been used.
Throttle body is stock at the moment, manifold is also stock - it had a FAST one on it to begin with but it was ****ed and kept jamming up and not idling properly.

[The_Plague]

I think Dave would have something to say about putting a FAST manifold on a TT car...his split like a banana on the first run.

Shaun's alloy would be where I'd be looking. One of these...but they don't come cheap. $5200

http://i235.photobucket.com/albums/ee264/mr_zogg/Mobile%20Uploads/FB_IMG_1442964659197_zpsflhevi4j.jpg

That looks awesome mate but I don't think it would fit under the hood somehow.

Did it split because of the power of the engine or did it have more to do with it being made of everything except metal?

[white lie]

Pretty sure it does, it's not very high at all. He has spent a lot of time developing them. Every part is CNC'd, most of it 5 axis. No welds, fully bolt together with bungs and a burst panel at the back for sensors.
The runners extend in to the plenum so they're not super short.

Send him an email. He was promoting them a lot on Facebook but has taken the pics down for a while. Not sure why.

[white lie]

I'd change the throttle body as a start. Holley or something similar but I think you'll need a 3 bolt to 4 bolt adaptor.
Might be worth porting the snout of the stock manifold, not too sure

[The_Plague]

I'd change the throttle body as a start. Holley or something similar but I think you'll need a 3 bolt to 4 bolt adaptor.
Might be worth porting the snout of the stock manifold, not too sure

I see there are some Holley ones available that are similar to the one you posted above - however they re not getting good reviews and hood clearance seems to be an issue.

[white lie]

Yes, the Holley manifold is a lot taller and won't fit easily under the bonnet

[The_Plague]

I have a picture of the turbo piping and it is quiet large - but cannot attach it.
Unsure if this makes any difference.
Car will also be getting a catch can.

[white lie]

That looks awesome mate but I don't think it would fit under the hood somehow.

Did it split because of the power of the engine or did it have more to do with it being made of everything except metal?
Just saw the second part of your post. It split between the two layers. Wasn't exactly high boost from memory either. Should be a thread around about it, I'll have a look

[The_Plague]

I guess that's the danger of it being made of several composite pieces.
Watching the video on it they say the individual runners can be ported, but not being one solid machined / TIG welded piece may be an issue.

[The_Plague]

http://www.ls1.com.au/forum/showthread.php?137520-Lsx-102-wilson-manifold-split-under-boost-!!!&highlight=fast+manifold+split+boost

[white lie]

That's the one :)
Like a few replies in that thread, many people have run them on higher boost levels with no issues, it may have just been bad luck but certainly something to consider

[The_Plague]

An open question:

Is anyone here running a FAST manifold in either 92 or 102 spec and can comment on it?

Extensive Googling is not really turning up a whole lot.

There were more manifolds available for my stroked 308 in the year 2001...........

[BLACK 346]

An open question:

Is anyone here running a FAST manifold in either 92 or 102 spec and can comment on it?

Extensive Googling is not really turning up a whole lot.

There were more manifolds available for my stroked 308 in the year 2001...........

Fast 92 took me backwards on H+C LS1, that was going from ported LS6.

[whitels1ss]

An open question:

Is anyone here running a FAST manifold in either 92 or 102 spec and can comment on it?

Extensive Googling is not really turning up a whole lot.

There were more manifolds available for my stroked 308 in the year 2001...........

I think I have read somewhere about them splitting or cracking with boost put through them but can't find the threads where I read about it
I found a thread that might be worth a read for you though,
I didn't bother reading the entire thing but saw a couple of interesting comments on pages 3 & 4

http://www.ls1.com.au/forum/showthread.php?71618-guys-with-after-market-manifolds-help-please/page3

[duke5700]

There is a shauns custom alloy one for sale in the classifieds...

EDIT: Ignore me it suits LS7 heads.

[185iboy]

There's no real need to change the TB/intake manifold on a boosted ls. You won't gain peak power, it will help more off boost.

http://www.corvetteforum.com/forums/c6-forced-induction-nitrous/2634526-max-boost-through-a-fast-lsxr-102-a.html

[The_Plague]

Ordered a Fast 92 and throttle body.

Spoke to Fast in the USA (or Comp, as they may be) and, as stated on that forum, they have rammed 60 psi into various ones to test them - so I don't think 11 to 14psi will harm it.

[IJ.]

Till it backfires ;)

[The_Plague]

There's no real need to change the TB/intake manifold on a boosted ls. You won't gain peak power, it will help more off boost.

http://www.corvetteforum.com/forums/c6-forced-induction-nitrous/2634526-max-boost-through-a-fast-lsxr-102-a.html

That's a plus, it is an intolerable bitch at lower RPM so anything that will help there.

[The_Plague]

Till it backfires ;)

lol, at the frequency I drive the car IJ that may be many years from now.
There were actually less alloy ones available than you would hope for (at a moderate price anyway, I'm reluctant to drop thousands on a manifold and would more likely spend that on stroking etc) that would fit under the hood.
Plus I'm not a mechanical engineer and my method of figuring out what would fit may not be accurate..... (I measured the centre cardboard on a roll of paper towel to 50mm and sat it on top of the existing manifold and closed the hood then checked if it had contacted it - on the assumption that 50mm extra clearance was needed)

[IJ.]

lol, at the frequency I drive the car IJ that may be many years from now.
There were actually less alloy ones available than you would hope for (at a moderate price anyway, I'm reluctant to drop thousands on a manifold and would more likely spend that on stroking etc) that would fit under the hood.
Plus I'm not a mechanical engineer and my method of figuring out what would fit may not be accurate..... (I measured the centre cardboard on a roll of paper towel to 50mm and sat it on top of the existing manifold and closed the hood then checked if it had contacted it - on the assumption that 50mm extra clearance was needed)

Or it may happen the 2nd time you start the engine... ;)

"Murphy's Law"