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kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

The turbosmart boost tee arrived this week and I plan on upping the boost to euro level (about 9psi, yes?) on my 1982 931. Boost gauge is installed and showing a steady max boost around 6psi. Engine health is good.

Is there anything else I have to do for fueling or will the CIS/DITC compensate for the increased air?

The plan if anyone is interested.

Purchase car. Check.
Replace stuff that needs replacing. Check.
Drive the car for about a year and decide I like it. Check.
Think the engine should handle the extra stress of more boost. Check.
Add boost controller and raise to euro levels. Doing that now.
Drive all winter.
Add WI in summer. http://tinyurl.com/3bats95
Add a WB/IAT/EGT gauge. http://tinyurl.com/4xh4yy4
Raise boost a little more.
Call it a day.

Thanks,
Kevin
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1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

Nein37 · Joined: 29 Dec 2009 Posts: 513 Location: New London, CT

The CIS system will compensate just fine. Just keep your max boost at or below 10psi and you should be good. The only caveat... if your head gasket is near the end of its useful life the added boost may finally pop it.
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1981 931 CGT replica, OEM CGT intercooler, .8 BAR WG spring, GTS Headlights, Innovative Wide band A/F, A/C delete, 16" Fuchs, Weltmeister 200lb lowering springs, Bilstein HDs front, Koni Sport rears.

flosho · Posted: Fri Nov 04, 2011 11:19 pm Post subject:

I would move a wideband gauge up on your list. It's always good to have a wideband when you start modifying.

CIS uses the mechanical air meter to supply the extra fuel for now, so no need to worry as long as everything is up to par.

You'll really only want to bump the boost to 9-10psi without meth or an intercooler though.
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kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

Thanks guys. I'm going to keep the boost to reasonable levels, and I should have put the WB above the WI so I have a baseline to go by. I'd put the WB next but its pricey and the holidays are around the corner.

If the headgasket lets go then i'm thinking maybe this?

http://tinyurl.com/3subk9q
_________________
1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

Cedric · Joined: 27 Aug 2004 Posts: 2822 Location: Sweden

10 psi according to google convertor is 0.69 bar. That should be perfect. I have 0.7 bar s1 spring in my s2 engine (0.65 bar original)and it works fine (but if you check the boost tolerances they almost overlap between those two springs, not much difference), at least for full throttle track driving

. But please check it with WB, an innovate lm-2 is really cheap in the US. Could save you from a big bang, once you know that everything works you could be calm. Be aware that you should only use high octane fuel, or else it can become very expensive...

BTW i seem to remember that the DITC us box is more conservative with the ignition than the eurobox, that gives you even more margin

;;

edit: The importan question, did the us s2 get the same CR as the ROW? I thought so but now I got a bit unsure. Memory isnt something ive got a lot of

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1980 924 Turbo
www.instagram.com/garagecedric/

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

How many miles on the car? Wastegate might need attention. . .
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WeiBe (1987 924S 2.5t) - 931 S3

kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

So I got the turbosmart boost tee plumbed in today with minimum fuss. Lowest boost I can get with the it dialed all the way out is around 8 psi with a very brief spike to about 9-10psi. This is with the ball and spring still in the MBC. The car feels good, no odd sounds. Boost seems to come on a bit sooner but I can't really say, my butt-o-meter sucks. I will eventually pull the ball and spring out to see if I can get lower boost settings. Seems like a quality unit. FYI.

_________________
1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Nice job on the adapters. I wonder if you are spiking because of the kink in the factory line? Maybe you could use a spring to keep it from kinking?
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

flosho · Posted: Mon Nov 07, 2011 1:00 am Post subject:

How big are the ports on that MBC with regards to the inlet/outlets?

If it is a standard 1/8" barb style. You may have to drill the ends out to allow more air flow.

More than a few people have had to do that with a MBC. Our wastegate lines are HUGE compared to modern cars/MBC ports. Which could be the cause of the spiking.
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Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

kcoyle · Joined: 15 Jan 2011 Posts: 712 Location: Long Island, NY

Rasta,

The line isn't kinked, just looks that way from the photo.

Flosho,

Yea, the barb inlet side is silly small. The pic actually makes it look big.

Carrera,

I think I remember reading your thread, I'll look it up again this weekend.

KC
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1982 931- Stock with MBC at 8psi

Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

flosho · Posted: Mon Nov 07, 2011 8:41 am Post subject:

You definitely have to enlarge that hole.
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Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

Definately the port size I had and it didn't work. To little boost going through to the wastegate and causing to over boost.

I removed it out on the road, must of placed it on the inner wing, closed the bonnet and drove off!! Never seen it again!!
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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