RE: intake manifolds

[andrew_lally]

do the red sti intake manifolds flow any better or offer any performance advantage ie larger throttle body???

anybody know???

cheers

andy

[wilky]

The red sti inlets were port matched and after a certain year were better insulated, although its always a good idea to put manifold spacers in to stop heatsoak. There is serveral schools of thought as to which manifold was the best. I personally prefere the phase one manifold with the larger plenum. One phase was known for higher torque. Someone will be able to give you a better heads up than that, but this should get the ball rolling!

Callum W

[lessels]

i have just painted my inlet manifold red on my xrturbo for sunday baldy and i think it is going to outperform i.e. blow your mr2 of the track mate,so in theory,yes the red inlet manifold is better lmao!!!

[Carl Davey]

I have a Phase 1.5 STi manifold here and also a standard WRX one. They are 100% identical, right down to the casting numebrs (AA910). I also have a Phase 2 STi inlet which isn't anything special and with the paint removed (as i have been doing today) could be overlooked for a UK one.

I did hear a while back certain STi Ver 2 RA's manifolds had their runner outlets CNC ported/polished. This theory was then put into doubt when i saw inside a manifold from a STi Ver 2 555 RA which looked as though someone had kicked a lump out of the mould before casting nevermind point it at any CNC equipment...

To answer your question i'd say no unless you find one of the fabled ones with ported/polished runners. Throttle body sizes are certainly identical at +/- 60mm.

[andrew_lally]

lessels you nutter ha ha ha.....few wee mods on the old rwd MR2 that might give you a little surprise mate!!!

and i believe "taking the conversation i had with your AL into consideration" my balls are much bigger than yours hahaha

duffus entry speeds supposed to be 20mph higher......oooooooooooooooooo

gonna be interesting....hope they dont cancel due to icy conditions!!!

take it easy lads

andy.........

[ken555]

<< I did hear a while back certain STi Ver 2 RA's manifolds had their runner outlets CNC ported/polished. This theory was then put into doubt when i saw inside a manifold from a STi Ver 2 555 RA which looked as though someone had kicked a lump out of the mould before casting nevermind point it at any CNC equipment. >>

HEY, I resemble that remark

Nothing that a Die Grinder couldn't cure.

[JohnSt]

Carl, you are absolutely correct, all PH1 the same except RA 5th inj. All Ph1.5 the same also. Same with ph2.

I think Wilky is Spouting Scoobynet Myth No. 10234 part A.

[WUZ]

Best manifold for flow is, without a doubt, the Phase 1 manifold (Pre97 cars)

Russell

[Kenny.S]

You could be onto something with regard to the RA manifolds Carl, i've got a normal phase1 wrx manifold in the shed and compared to the one on the car its rough as hell!

I had the manifold off the car when i did the fuel rail mod and the inside of the risers look much better finished, the outside looks better too, the casting is much smother.

A very hungover Kenny

[Carl Davey]

I'm sure they exist as the info came from a very reliable source. Certainly isn't the case for 95% of STi manifolds though. Like John says it's probably just STi Ver 2 RA's with the 5th injector - i don't remember yours having the injector Ken?

Grab a pic next time it's off Kenny.

[Kenny.S]

I removed it when i did the fuel rail mod, the PFC doesnt have an output for it anyway. Doesnt do much with the standard ecu either!

I've got a few ideas brewing just now, one of them being making a new manifold to allow me to fit an Sti8 ic. I'd like to use the original manifold as the risers are much better looking but if it all goes wrong i'll have screwed up a perfectly good Ra manifold. The wrx manifold will tidy up with a die grinder and some time, i could also use a set of you're spacers to help match it to the inlet ports.

I know i could use a phase 1.5 manifold but even that's a tight fit, this way hopefully ill be able to make it fit without bashing the hell out of the gearbox mount and the iscv can be mounted out the way.

Kenny

[Carl Davey]

Aye i read about your plans on 22B.com. Was that you that got the bargain STi 7/8 TMIC on eBay the other night? Even cheaper than my one but not much.

Manifold spacers are in stock. Will have some 25mm thick ones coming in over the next few weeks if you're considering going front-entry at some point?

[drb5]

No 5th injector!

IMHO i think to change manifolds etc, would be too much work for the STi8 IC.

[Kenny.S]

Maybe

I'm going to be offshore when it turns up though.

I figured i might as well just get one instead of thinking about it at least now ill be able to offer everything up and see how much room i need to make. If the worst comes to the worst and it doesnt happen i'm sure ill be able to sell it again.

With regard to the amount of work involved to fit an Sti8 ic, no such thing as too much work in my book My time is free and i've got the patience of a saint, the Sti8 tmic is more than adequate for the power i'm looking for.

Kenny

[drb5]

Fair enough. I just recall how much of a hassle it was to fit an 02 WRX IC to my old RA. And the fun you have with a hammer!

[wilky]

The, original manifold on my 95 STI RA was port matched, not very well, but port matched. Quality of the actual "bluprinting" of the STI suffered in 1995 when the process of turning a basic subaru into an STI was tansfered from STI to the subaru main factory in Japan. I am unsure of the name of the places.

Although the same spec, the workmanship was poorer and detail like port matching was largley ignored by the mass production punters.

Mind you the quality of the port matching would suggest that the STI place was a sausage factory as well!

Callum W