Planning a 3.2 Turbo Conversion

[lr172]

I am planning a turbo conversion for my “new” ’88 3.2 Carrera. I have read many threads on this forum as I attempt to educate myself. I am a decent wrench and have experience rebuilding Chevy’s. I have begun planning and was hoping to get some guidance from the experts during my planning phase. I am not looking to go crazy, just some additional ponies to help the car reach it’s potential. I am planning to start with no intercooler and a boost of .5 bar. I would like to someday add an intercooler and bump the boost to .7. The car has 125K miles and has never had a rebuild. The PPI indicated strong compression (175-180) and reasonable leak down (6-8%). Based upon inspection, They indicated the valve guides have moderate wear and the head studs are intact. I plan to do a top end rebuild this winter or next. This is a street car and likely won’t see the track, although I could see myself doing DE’s.

I will be leaving the stock exhaust headers and will likely fabricate a J Pipe to feed the turbo. What size pipe is recommended here (2.5”?)

I have the opportunity to purchase a used turbo from a member here on the board. It is a Garrett T3/T4 (T04E) unit. The Specs are:

Hot: .63 AR, 76 trim
Cold: 60 AR, 60 Trim

Based upon what I learned from the Garret site about sizing, my application (350-400 HP) seems to fit well on the Compressor map for a street application, which is what I am looking for. I am willing to sacrifice a little top end pull in exchange for having the turbo come on early in the RPMs. I am looking for something that will both begin to boost early, as well as to produce a decent amount of it’s boost early in the RPM range, even if the engine flattens out a little at the top end. Being a street car, I have more use for the mid-range. What do you guys think of this turbo for my application? Will it meet my goals?

This is a standard journal bearing turbo. It appears from reading the Garrett site that running pressures over 40 PSI, that a restrictor may be required to reduce flow in the turbo. Have you guys run restrictors in your setups? Do you guys recommend a -3 line for this feed? I also noticed that most of you ran -10 lines from the turbo to the oil drain plug on the case. Is -10 necessary over a -8? It’s tight in there and a -8 would be easier to make work.

I will either buy a muffler from Ben or Brian or fabricate something with a Dynomax Ultraflow. The consensus seems that Ben and Brian’s sound great. I am assuming that I want 3” after the turbo, with the Wide band 02 at this point as well. Any opinions here?

I have read that the Tial 44 W/G flows as well as the 46 and costs less. Does anyone think I’ll have problems with the 44? Given that I am fabricating my options are open.

It seems the BOV’s have springs as well. Do I match the BOV spring to the one on the Wastegate?

Can someone tell me the recommended pipe size for the charge pipe? Is this 3” or something less? I will either buy an aluminum kit or fabricate it from 18 GA aluminized steel. Unfortunately, I am not set up to weld aluminum, only steel.

I will be using the BEGI FPR. Do I need to use the check valve in this application? I also saw a post where someone recommended a check valve on the wastegate. Is this required or typical?

Last, my cylinders are Alusil (10 fins). It seems from my research that several folks have done this without problems. I plan to keep the boost moderate and hope to avoid problems with the cast pistons. My research on the Chevy side taught me that cast or Hyper pistons do fine under relatively high pressure. However, the forged can handle a fair amount of detonation without destruction that that cast cannot. I hope that a mild boost will keep me away from detonation and avoid this problem. Any thoughts here?

Thanks in advance for any help and support you can provide. Once I collect all of the parts and begin the installation, I will start another thread to document the process.

[gsmith660]

You are doing what I plan for the near future I have a 2.7 and am running .5 boost now the 3.2 has a turbo bottom end so it is suited for turbo apps. already there is alot of expert help to be had on this forum and they have all been very helpful. What are your plans for fuel control? Get something versatile you will be rewarded, I used the Bitz system and it ran out of the box and is upgradeable to a 12x12 fuel map. Keep an ear out on the used parts forum and nice intercoolers come available from time to time. Good luck and I am subscribed to watch your results. Here are a couple pics of my motor for viewing. Oh and I used -4 for supply oil with the stock oil pickup on the back of the motor and used -12 to drain back to a sump plate that Ben made.

[911st]

It might be easier to stay with factory components where you can. I have seen stock 930 J pipes for around $100 from time to time. A K27-7200 is targeted right at your stated goal and it would allow you to use a standard aftermarket 930 muffler. There is also a bracket that supports the turbo's weight.

Or you could get a 60-1 or 62-1 that will bolt up to the J pipe and fab you own straight through muffler.

Double check with someone that knows turbos about your hot side. I am not sure but the size you note might be small. The good thing if if you go with a Turbonetics turbo you can order a different AR housing for not much an just swap it out.

Get in touch with 911chips.com. I hear he may be supporting Turbo Chips.

I would be cautious about using a smaller WG. Especially if you are going to use a small hot side on the turbo.

I have considered doing a conversion myself but was thinking of a different approach. I was thinking of more copying the 944Turbo set up and do a suck through instead of a blow through system. My thought was to use the 944T injectors and fuel pressure reg. Then get a SW chip set up to support it. Not sure if there is an advantage to going this way but it is a more factory style approach. Even worked through how I would leave the air cleaner in its stock location like RUF did with its 3.6 kit.

When you do your top end something to consider is sending your cylinders to EBS in Reno and have them bored to a 3.4 and get some J&E Turbo pistons at about 8-8.5/1 CR.

[lr172]

Originally Posted by 911st

Double check with someone that knows turbos about your hot side. I am not sure but the size you note might be small. The good thing if if you go with a Turbonetics turbo you can order a different AR housing for not much an just swap it out.

THanks for the reply. I am still learning and have much to learn on the turbo selection process. Which part is too small? Is it AR or the trim?

[911st]

I am rusty on trim. Call Turbonetics as you are bassically talking about a 60-1 on a T3 frame so it will fit on a KKK mount I belive. It has been a while.

[griffx4]

Just completed the same on my 87 Carrera. Tons of information on this forum and plenty of folks out here to help.

I went with a "stock" 930 j-pipe and stock turbo. Plenty of used parts out there if you take your time to collect.

For the charge pipe I purchased a "kit" using 2.75 pipe. I actually bought more than I needed and if you are interested, would be willing to give you most of what you need for the cost of shipping (send me a PM if you are interested).

Ben at M&K Exhaust helped me out with fabrication of the AFM adapter as well as the BOV.

Also, you didn't mention in you post, but you will need to backdate your heat if you are interested in retaining it.

[911st]

So how dose it run?

[mb911]

they run awesome never had anyone say they were disappointed

[spence88mph]

+1 on the awesome, turns into a car you REALLY look forward to driving.

[Nashville84Cab]

Originally Posted by mb911

they run awesome never had anyone say they were disappointed

+1

You will have a much bigger smile when driving your turbo 3.2. The turbo really wakes up the car. And just for fyi, I used a GT30 (76R) with .63a/r since I wanted more mid-range power than top end. I essentially have little or no turbo lag.

Since you are in the planning stages, don't forget about the boost and AFR gauges. You may also want to consider better oil cooling and brake upgrades.

[spence88mph]

Stiffer rear torsions and/or coilovers on the back too unless you want to scrape your numberplate

[911st]

Originally Posted by Nashville84Cab

+1

You will have a much bigger smile when driving your turbo 3.2. The turbo really wakes up the car. And just for fyi, I used a GT30 (76R) with .63a/r since I wanted more mid-range power than top end. I essentially have little or no turbo lag.

Since you are in the planning stages, don't forget about the boost and AFR gauges. You may also want to consider better oil cooling and brake upgrades.

That is a good looking install!

What kind of HP are you pulling? Stock pistons? What else can you tell us?

[MikeD930]

For those of you who added a turbo to a 3.2, did you retain the stock fuel injectors? What are the stock injectors flow rate?

BTW, those with added turbos looks like it belongs there!

[911st]

Darrel,

The pic of how clean your install is has me dreaming of backdating to a 73RS with 400hp turbo hiding under the duck.

-I think the limit is about 400hp if I remember correctly. After that some go to 944Turbo injectors although there are other options.

Here is some Protomotove info: http://www.geocities.com/protomotive/911descr.htm

[lr172]

Does anyone have additional input on this particular turbo and whether or not it will meet the goals of spooling quickly and covering the mid-range well. Some have indicated it is too big and others too small.

[Nashville84Cab]

Thanks and compliments need to go to my buddy Carter Thompson (cturbo28) who did the install and fabrication. His work and attention to detail was superb.

I still have the stock pistons and stock fuel injectors (from 84 3.2). I can't remember the flow rate of the fuel injectors, but they should be good for at least Stage 1 and 2. I did get a bigger fuel pump to increase the fuel flow. I am using an aftermarket but a 930 fuel pump should be a direct replacement.

As far as HP, I really don't know and I don't really see a need to dyno (yet). I will later try to perform the iPhone "dyno" to get a ball park figure. Jerry Brinkley did see 320 at the wheels (~380 flywheel).

And perhaps these websites can help you select the correct turbo:

http://www.squirrelpf.com/turbocalc/

http://www.not2fast.com/turbo/glossary/turbo_calc.shtml

[juan ruiz]

3.2 - Factory 217hp- Added Turbo, .5 bar of non adjustable boost, re chipped, no intercooler, added fuel pressure regulator, aftermarket air filter will give you 320rwhp.

[spence88mph]

the bible:

http://www.geocities.com/protomotive/911descr.htm

[911st]

Darrel,

Do you have heat and how did you plumb that.

Did your guy fab all the tubing and intercooler?

If he ordered the IC can you tell from where?

Again, such a clean install.

Thx.

[911st]

Is there a source for a .5 bar spring for the Porsche 930 WG?