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Join Date: May 2007
Location: Collegeville, PA
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Originally Posted by 911st View Post
What is the size of the turbo you have on it? That is, how big is the diameter of the intake wheel (inducer). You probably need at least 60mm and 62mm might about right.
This is a picture of YermanCars' headers with his old turbo on there. He's graciously agreed to hold onto them for me until next month when my cash flow is looking better. He confirmed that they're definitely not split. I just him a PM inquiring about the turbo.

Originally Posted by 911st View Post
Do a search of DonE's posts. There is a chart somewhere where that shows his HP at .8 bar and 1 bar.

Going to from 1 to 1.2 can make up to about 8% more HP.

However, you will probably need fire rings as the head starts to lift at those kind of pressures I hear.
From the research I've done, it looks like 1.2 BAR is the limit of the 911/930 engine without flame rings. In particular, I remember Goran (BeepBeep), responding to a Pelican who said something like, "As long as your AFRs are under control you can run as much boost as you like." Goran went onto explain that this was simply not the case and that things change after 1.2 BAR. Please let me know if I'm missing something here. If the consensus is that there is a material difference in engine wear between 1.0 and 1.2 BAR, then I'll play it conservatively. I'm planning the following to cool the intake change and mitigate detonation:

1. Water/methanol Injection
2. Water-to-air intercooler
3. Twin Plugs
4. Knock sensor

Originally Posted by spuggy View Post
SC and Carrera cams are identical profiles, just timed differently. Seem to recall 993 is almost identical profile as well (modulo ramps for the hydraulic tappets).

With EFI, you should be able to go more aggressive on the profile for better top-end breathing if you want. It won't hurt the low and mid-range as much as with CIS (where you don't have full control over the ignition and fuelling).
Hey Spuggy, thank you for this information! I did not realize that SC cams had the same profile as Carreras. I'd love to go after every last HP that my engine could put out, but realistically I need to stick within my budget or else I'll end up not finishing the project due to lack of funds, going into too much debt or have the wife leave me I'd shooting for the most HP I can afford at acceptable level of reliability. I'm seeing many guys on this 930 forum running SC cams, so this is encouraging. The other thing is that I'm trying to avoid having to tear down the engine at all. I know where that leads...

Originally Posted by WERK I View Post
I was able to find the T3 and T4 dimensions for you on the Garrett turbo site. If you have a T4 flange on your headers, I'm curious what turbo you have mounted. Visually, it doesn't seem to require that big of a flange.
Hi Dave - thanks for the info on Garret's T3 & T4 setup. As I mention at the top of this post to 911st, this is a picture from YermenCars of his headers that I'm buying along with his old turbo (which I'm not planning to buy). I've sent him a PM to inquire about turbo.
Andy - 1987 911 Carrera Coupe
Old 10-31-2010, 09:19 AM
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