3.2 turbo upgrades "While in there"

pirin911 · 10-23-2009, 01:25 PM

Hi:

I have been reading and learning from all of you for more than 10 years. My car is a 1985 Carrera cabriolet and converted to turbo 7 years ago with a Protomotive on the side kit (J-pipe), intercooled at 0.7 Bar with no issues, until now. It recently started to smoke on deceleration badly, so I am in the process of buying parts for the dissasembly (to correct oil leaks also) and rebuild the heads (valve guides).

I am planning on doing these "while you are in there":
1) Change bearings (crankshaft, rods and intermediate shaft)
2) Put GT2 Evo camshafts (if they can be used in the 3.2)
3) Lower the compression a bit by means of cylinder base gaskets and turbo head gaskets (like the Protomotive Stage 2).
4) Eliminate the intercooler and run water/methanol injection because I need the AC back. Here in Puerto Rico is very hot and rainy.
5) Put a high flow fuel pump.
6) Change from Dilavar to steel.

So the question is: If I lower the compression to about 8.8:1 and run water/methanol, no intercooler, can I run about 0.8 Bar for very short runs? I don't track the car and it sees full boost for very short periods (seconds). Do I need to remap the chip? Can I use shims under the cylinders to lower the compression (like air cooled VW guys do)? I think that I read in one forum that Supertec or other company sells these shims to lower compression?

Thanks in advance for your attention, and here is the obligatory photo.

Francisco

911st · 10-23-2009, 05:30 PM

Any chance you can post some pictures of the "on the side" kit?

Check the condition of your pistons first. If shot might want to to with custom J&E turbo pistons. If needed, your cylinder can be opened up to a 3.4 and re-plated. If the pistons are still usable, I would machine the tops for lower compression before I would stretch the motor. Or, get a factory 3.4 Turbo piston set.

Nothing wrong with your cams.

Do you still have the stock 915 transmission? If so you might want to just do a good low pressure turbo build without the inter-cooler or maybe a water to air inter-cooler and put the water radiator in the left front fender. A 915 is not going to handle the kind of HP you are talking.

Might want to change to turbo exhaust valves.

88-diamondblue · 10-23-2009, 09:42 PM

While you are in there replace the stock rod bolts with ARP rod bolts. This is a known weak point on Carrera engines that have been modified. Check with John Dougherty at Dougherty Racing Cams for the right cam for what you want out of the engine. He posts here as Camgrinder and does great work. It's a great time rebuilding these engines

rubenmad · 10-24-2009, 06:27 AM

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sjf911 · sjf911's Garage

0.7 bar sounds like a lot of boost on a stock 3.2 with only intercooling. Did you lower compression? Do you know what kind of timing map changes that Promotive made? Do you know your advance and AFR's at peak boost?

juan ruiz · juan ruiz's Garage

Whats our Budget ?

Based on that I can give you some ideas

Things that come to mind, change the rod bolts, the OEM rod will hold pretty good at pretty high power I ran stock rods for a very long time, never had a problem, May want to fresh your cylinder heads especially inspect the condition of the valve guides,

the EVO GT 2 cams are an awesome cam very aggressive on mid to top range BUT it depends on the turbo, you can ask John Dougherty and I'm sure he can suggest something that may work better for what you are trying to accomplish.

Fuel pump is all good or install two bosh pumps you may want to look into bigger fuel lines and Injectors and the list goes on.

Regarding the chip you will need to have that taken care too, after a while is a huge pain and thats why so many people move to stand alone systems

pirin911 · 10-24-2009, 03:40 PM

Hi:

Thanks guys for your replies and suggestions.

911st: Yes, I have the stock 915 and will check everything on the engine to see if it is on spec. Here is a picture of the system. It use the stock HE and in place of the catalytic goes the J-pipe.

sjf911: 0.7 is supposed to be OK with the stock 3.2 compression and intercooler. To go 0.85 Bar then you have to lower compression and change to a high flow fuel pump as stated by Protomotive. Haven't taken the car to a dyno, so don't know the AFR. The chip came with the kit, so I suppose it should be mapped for the kit. Juan Ruiz knows best.

Juan: The primary reason for the rebuild is due to worn valve guides (I think) and some oil leaks, because the car smoke on deceleration only. Don't have oil in the HE's. Yes, was thinking about the rod bolts. Thanks.

If I just can stay with 0.7 bar and water/methanol and no intercooler that would be OK for me, but boost is ssssoooooooo addicted.

Thanks again for the answers,
Francisco

sjf911 · sjf911's Garage

I am running the same compression of 9.5:1 JE with 3.2 heads (twin plugged) and intake but GSF headers. I have run only 0.5 bar with both an intercooler and methanol injection. I would be very interested in knowing if anyone has an ignition map of yours or similar conversion at these higher boost levels. I also wonder how the JE pison design with deep valve pockets effects detonation risk compared to the stock 3.2 pistons of the same compression.

911st · 08:55 PM

Thanks for the pic!

Where dose the turbo drain to?

Dose it or can it use the stock muffler?

Can I see a picture of the inter-cooler?

This keeps the stock heater blower I suspect.

pirin911 · 10-25-2009, 05:04 PM

Hi:

911st: The turbo drains to the lower valve cover by gravity. Yes, it uses the stock muffler. In my case I have a Borla that replaced the factory unit. The non-intercooled kit maintains the engine blower. Here is a picture of the intercooler.

sjf911: Do you changed the fuel mixture to run the methanol or just worked with the size of the injection jet? The only map I have is in the DME.

Juan Ruiz: Do the GT2 Evo cams loose some low end in the powerband? Can they be used with the Garret turbo that came with the kit or do I need a bigger turbo?

As always, thanks.
Francisco

sjf911 · sjf911's Garage

I can adjust my fuel tables to account for the methanol. Using a wide band AFR gauge is critical in monitoring and tuning these engines.

911st · 10-25-2009, 06:08 PM

Thanks for the info.

I like the intercooler. Is that from Protomotove?

When you say stock muffler you mean the stock 3.2 muffler would bolt up?

pirin911 · 10-26-2009, 11:39 AM

Hi 911st:

The intercooler is not from Protomotive. It was custom made. Yes, the stock 3.2 muffler bolts up. There is an aditional segment of pipe not featured in the picture that goes between the turbo and the muffler. On the turbo side is bolted with a ring (see photo) and on the muffler side it has the 3 bolt flange for the stock muffler.

Joe V · 10-26-2009, 07:15 PM

Hola Pirin!

Little off topic, but I wanted to tell you that I attended El Colegio 20 years ago. There was a gorgeous young lady that had a red Carrera coupe that lived in Mayaguez Terrace. I don't know which was more appealing: her or the car. Maybe both!

Is El Garabato still the place to go for cheap beer?

Nice car, by the way. Dale duro!

pirin911 · 10-27-2009, 04:28 PM

Hola Joe:

Saludos. El garabato is no longer there. It was closed some years ago. But there is still La Casita, Los Balcones, Blues Cafe (not so cheap), Tertulia. Me too attended El Colegio also about 26 years ago for ten long years to complete a MS. Oh well......
Thanks and nice to hear from you and dandole duro always (a la cerveza)

Francisco

spence88mph · 10-27-2009, 05:15 PM

Hey dude, my next rebuild will be some 3.3 pistons and cylinders, I've also been told to do some turbo oil squirter mod but not sure what's involved. My car is still running fine with .5bar but I want to rebuild for more power. As you said boost is addictive! I drove a stock 3.2 well chip and muffler the other day, nearly fell asleep behind the wheel!