993TT headers?
 

Can anyone tell me whether 993TT headers would bolt straight onto 3.2 Carrera heads?

Or would I need to have the flanges rotated, like the 993 NA headers?

you could do that or if your pulling the heads for machine work, have them drilled for later exhaust flanges. Now you have a 3.2, which has the same oil tank layout as my 930, I think, dont know, but I believe that there may be trouble with trying to mount the twins on the sides of the motor because of the location of the oil tank. If you look at most of the twin turbo cars of our body style; they have the twins mounted in the bumper, usually with a pair of dump pipes right off the hot housing. If you want any more info on a set of manifolds let me know, I have some nice ideas because I think about them for my car.

You would need to have the flanges rotated.

Yep.

Sorry, what do you mean have my heads drilled for the later flanges? Why can't I just have the flanges rotated to suit the Carrera heads, instead of messing around with a whole top end R&R to make some headers fit?

I said you could rotate the flanges OR if you were taking the heads off for port or valve work you could drill them while they are off to match the newer bolt pattern. If you are going to do the flanges and want to use new one instead of reusing the old ones, I believe that Burns makes a real nice half in. thick set. :)

Cool, thanks for clarifying ;)

Now what do you think about turbo placement? Are the 95-97 twin manifolds good when taking into account the position of the oil tank? My friend Eddie B. makes a nasty set of twin turbo manifolds that locate the turbos in the rear bumper if you are interested and/or the turbos dont clear the tank.

Look at Brian's thread. Yes flip flanges. No they won't fit without converting oil tank to 964 location (72'). But they are very short and well made providing quick spool up.

M&K (Ben) does a good job at flipping.

A concern of mine is the proximity of the turbo to the valve cover.

Please everyone! Don't think I'm crazy (maybe a little bit) I am well aware of the fact that the flanges need to be flipped and that on an already together motor would be easier +less expensive than machining the heads for the flanges. I was just stating that if the heads were already off the car for other machine work that it may take less money than jigging the headers up to flip the flanges. I'm just thinking in terms of what I would do back when I sent my work out to Verden to get done.
ok? :D

I wasn't suggesting the least :D

I was just giving my experience and him some leads and pictures from Brian's thread on designing his TT system. Ben (MB911) already is setup for this and he doesn't charge that much anyway. Of course if you had the heads drilled for either stud you would keep future options well open I guess. Though it sounds that in this case, he didn't plan to tear the engine down.

I know- Im just bein a chooch

hehe, you guys are funny :D

As for turbo placement, I prefer side mounted units so I can run them into a Magnaflow dual inlet/outlet "X" style muffler. I MUST run a muffler as this will be my daily streeter too :confused:

I'm told the inlet to the oil tank can be relocated with some fancy wleding and the bottom of the oil tank can be slightly kicked outwards to make room for the turbo using a bracket. That's the path I'm *thinking* of taking.

As for oil drain. I *think* the 993tt headers will position the turbo's a bit higher than the sump drain plug, so that's where I'll drain both turbo's to, using a T at the sump drain point.

Just throwing some ideas in the air here... feel free to throw in your 2cents worth ;)

Here is a picture of Luke's 993tt exchangers with flipped flanges on the Evil Engine with K16 turbos. You can see the passenger's side is going to be a problem.


http://forums.pelicanparts.com/uploa...1173158379.jpg

http://forums.pelicanparts.com/uploa...1173158533.jpg

I dont know what I would do- screw it I would run twin open dump turbos and just tip-toe by the police. :)

You wouldn't have to tip toe... they'd hear you coming a mile away! :cool:

I'd probably go with a pair of GT28RS ball bearing turbo's to begin with (set to 0.7bar) because later down the track, I want to go with some 97mm or 98mm turbo P&C's. I'd like to have the HP growth capability there, so the GT28RS's would be ideal. I can get them for $2k for a pair. The K16's would be too small for what I want to achieve down the track.

Merv- thats why I want 600 horses, those cops dont stand a chance even if they do hear me, and I dont want to hear about the "motorola" cuz I have beaten that as well.

James- The 28rs would be nasty and two would be good for between 6 and 700 horsepower. Just be prepared to watch the exhaust wheels spin 2 minutes after you shut the motor down. Ball bearings kick a$$

I'd imagine a pair of GT28RS's on a high compression Carrera motor would spool extremely quick, even if boost is limited to only 0.7bar. It'd be an interesting setup. Go for it!

930gt-40r, have you decided on a turbo yet? Is it a GT40R, as noted in your alias? I've heard someone used one of those on a 3.3 EFI turbo and made a tonne of power :cool: It has a 72lb compressor, which is good for ~612+ HP on an air-cooled Porsche motor :eek:

James,

If I were to repurchase today, I would go GT2560R (GT28R). I think these might be the hot ticket for quick spool and still head room for 600hp. They are the same chassis as the GT28RS and could be easily swapped later since turbos are a WEAR item. I was timid at the time because I hadn't planned to drop compression so I went small. I also got the dry housing so I wouldn't have to be concerned with water issue. Since, I've bought 91-92 P&C for a good deal. PM if your interested in a lead on them.

Make that a big clearance in the oil tank as turbos would function as nice oil preheaters. I'd be careful in any decrease in oil volume too with the added stress without the turbos oiling system. I'm debating on a C2 pump in the 3.2 to make sure oil flow is sufficient. It might prove a thousand dollars in vane, but/though not cheap insurance......I'd hate to find out otherwise.

The 993TT HE's have small collectors that certainly are not "Burns" fashion with only 1.5" orifice. If you get into a T3 size hot side, it might reduce velocity. I'd personally stay with a small/mid chassis with T25 flanges.

It's been discussed here before, but I'd still contemplate a low pressure minimal flow water circulation system to secure the BB's on shut down. Something simple from a boat, 944 or SC Ford. Use Al plumbing and it ought to radiate enough heat to not require a resovoir of any real volume. 5lbs including water.

Ben is the pipeline to fabricate some nice TIG'd sump plates with feedlines integrated into the Al design...might take a look, very clean versus a tapped pipe fitting.

Merv, how you liking the Spec Clutch now that's she broke in?

Hi Luke. The SPEC is alright... if I had to do it again, I would go for a Kennedy KEP G50 solution. The SPEC is still a b!tch in traffic and it takes an educated foot to take off without looking like a complete *****. I'd say 85% of the time I can engage it fairly smoothly, but if I'm in a rush and let it out too quickly, the car bucks viciously :mad: I'd recommend a Kennedy solution over the SPEC.

Mind you, the SPEC will hold anything you throw at it. I've run her up to 1.3bar and I get absolutely zero slipage :cool:

James, Luke is right, the GT28R's would be a very nice path to take. Are you intending to use external gates or integral? The GT28R's don't come externally gated. Only the GT28RS's do.

Merv- I aspire to a Gt-40r, Right now I have a "37R" which is really a dual ball bearing pt-67. Next year when I do JE's and LN cyls. I run a 40R and enjoy wheelspin.

LOL! You're absolutely nuts... but then again, aren't we all? :D :cool: ;)

I'm planning to use a pair of TiAL 38mm external gates, so I guess I'm limited to the GT28RS units, right?

How reliable are the integral gated turbo's? I hear they tend to introduce boost spikes at high boost levels? Not that I'm planning to run mega boost anyway... I plan to run at max, 1.0 - 1.1 bar when I eventually go with proper turbo P&C's & ARP studs etc.

What do you guru's think?

Yes we are Merv, like you didnt know that.

James,

If you already have the 38's, then by all means run them. I don't think anyone argues that external isn't the better option because you can properly size them and achieve greater flows and you have to assume a $400 WG is better than an internal in a $800 turbo. To make a blanket statement that internal won't vent off at high boosts is probably over simplifying and I would suggest its going to depend on the independent turbo design. Size is the issue and port flow in an internal WG with possibility of more turbulence in the exh housing.

And as you suggest, few of us are running "high" boost. Have you mapped out the piping, because ext. WG certainly makes things a lot tighter back there unless you plan to vent to atmosphere and HEAH why not :D

Your going to run an electronic boost controller anyway to improve boost control and help hold that gate shut without leakage in any case, correct?

That's right, Luke... I plan to eventually run an EBC, but for now, it's 100% bolt-on and I'm limiting boost to 0.7bar in the 38mm w/gates.

Just thought I'd revisit this thread.

Can the GT28R's be pre-ordered with the integral gate preset or pre-configured to whatever boost level is desired?

If I do all of this at the same time as slipping in some turbo P&C's, I'm thinking I might just get the GT28R's preset to 1.1bar. Also saves me from butchering nice 993TT headers for external gates.

Advice anyone?

I think you can order them and as far down as 5psi springs
28Rs will be lots of fun