911SC (with CIS to EFI) Turbo Conversion

[MichiganMat]

awesome site, thanks for sharing. Finally some decent, much-needed, porsche parts without the luxury tax! Where have you been all my life!!@#@%

[ohecht]

I thought his prices were suspiciously reasonable. Pretty cost-effective for turboing a 3.2, but buying so many parts together definitely takes some of the fun out of it!

[89turbocabmike]

I too was surprised at the low prices but his ebay rating is excellent. He also has a crank trigger assembly.

[ohecht]

What else would you need for crank-fired ignition besides the sensor itself and the coil packs?

Olivier

[RickM]

This guy seems to have a home run business. I think an Email is in order.

[ohecht]

Maybe Wayne would be interested in carrying some of his stuff?

[Lukesportsman]

I have purchased a few items from him. Very fast service, good communication and a quality product. I never heard of him before Ebay but decided to give him a chance...he came through.

Yes, it is nice to see high performance Porsche parts minus the premium.

Maybe we are seeing a change in ideas. Since the factory is moving away in support, the hobbiest will be taking over in the air cooled camps for performance. As it has been discussed here, there is an inbalance between the cars restoration costs and finished vehicle value. Much of these import tuners could/can make parts in limited quantity for our needs. We simply have to let them know that there is an audience.

[cowtown]

Originally posted by Lukesportsman
Yes, it is nice to see high performance Porsche parts minus the premium.

I agree, but the cynical business-guy side of me says that, as soon as he realizes how much he could charge, he will. Capitalism-gotta love it.

[tbitz]

Just to redirect this thread back on topic. (Turbo conversion for the 911). There is another thread for the 930.....

Although I had a used T04B turbo with a V1/V2 compressor I decided to hold off on starting this conversion until I got the turbo I wanted.

Well guess what the UPS man droped off today


It's a T04E with the 54 trim compressor, which I believe is the best fit for the 3.0L engine based on compressor maps. The turbine side is T3 with a stage 3 turbine. The A/R is 0.63 on the hot side.

I'm hoping this will give a quick spool with good efficiency. I will use an external wastegate, to keep the T3 from chocking the engine at higher power.

Let the conversion begin.....

[ohecht]

Tony,

Can you explain exactly how the external wastegate is better to avoid choking? I knew they were usually smoother, but wouldn't the flow through the turbine blades be about the same regardless of how the bled off pressure is vented? Or will you also bleed the waste right to the atmosphere?

Olivier

[tbitz]

I figure since I will be running low amounts of boost, at higher rpms a smaller percentage of the exhaust needs to flow through the turbine to drive the compressor. The rest needs to be bypassed. This is the job of the wastegate.

On a T3 turbine the internal wastegate output is a 20mm diameter hole on the housing. The external wastegate I have has a 35mm diameter, so the bypass can happen with less backpressure to the engine. Also since it will be venting to the atmosphere there will be less backpressure.

The above is based on my observations and how I see things working. I'm not a turbo expert, so take what I say for what it is worth.

A smart a$$ would say, don't bother with external wastegates, higher efficiency T04E compressors, intercoolers, and tuned exhaust. If you want more power just crank up the boost. He would be right. You want more power you simply crank up the boost. I, however, want create more power with the least amount of strain on the engine. (ie: create power to the wheels efficiently).

[beepbeep]

Nice turbo! What propted you to choose TD04E? Is it a hybrid of T3 turbine and TD04E compressor?

Expect really fast spoolup, T3 turbines aren't big. Good thinking on external WG and low boost.

Are you going to use OEM exchangers or custom headers?

[tbitz]

It a T04E not TD04E. Yes it is a hybrid T04E/T3.

Look at the posts in this thread. Some analysis was done to determine the best compressor. The T04E with a 54 trim compressor seems to be the best fit for the 3.0L in my opinion.

The turbine is a stage 3 which is almost the same exhaust diameter as a T4 "O" trim. Major diameter is less, which means less rotational inertial, thus better spool up.

Again, this is all based on theory.

I have original porsche backdated headers on my setup.

[tbitz]

Here are specs on the turbines:


I wish I could make an educated guess as to the proper A/R for the turbine housing. I'm just guessing a 0.63 is a good start.

[tsuter]

If that is really a T3 turbine mated to a T4 compressor then it is called a T3/T04E hybrid.
You can choose the hot side in different trims (48/63) as well as the compressor side.

The T3/T4 hybrids have appeared for the sport compact racing where their 1.8-2.4 liter motors exhaust just couldn't drive a normal T4 turbine but the peeps wanted high flow and boost compressors i.e., T4...compressors

Hence the smaller T3 turbine has been mated to the larger T4 compressor.

http://64.49.247.187/index.asp?PageAction=VIEWPROD&ProdID=101

I would suspect that a T3 turbine on a 3.0 liter or larger motor is going to see premature failure.

[ohecht]

Tony, would such a setup result in the wastegate being open almost all the time and venting unmuffled exhaust to the atmosphere? I am just wondering about the effect the noise, etc. may have on the kit for certain people in certain areas, etc.

Olivier

[ohecht]

Tony,

I am looking to get an EFI and ignition solution before any turbo project, and I am bouncing between your approach and other aftermarket fuel and spark management systems.

I have a few more questions after visiting the Megasquirt site:

- Do your kits to date use the MAP sensor on the board that is suitable for boosted applications? Or will this be an upgrade for those who may turbocharge in the future?

- What are the best options with your kits you see for controlling ignition on NA cars that may be turbocharged (and twin-plugged) in the future? One of the Megasquirt add-ons, or a stand-alone aftermarket ignition kit like Electromotive's? I have always felt my ignition is "sloppy" (the dist cap rotates a few degrees even when clipped down, and I would probably eventually twin plug and need something more than the stock distributor).

Thanks,

Olivier

[tbitz]

Originally posted by tsuter

.....I would suspect that a T3 turbine on a 3.0 liter or larger motor is going to see premature failure.

Why would a T3 turbine be less reliable than a T4?

[tbitz]

Originally posted by ohecht
Tony, would such a setup result in the wastegate being open almost all the time and venting unmuffled exhaust to the atmosphere? I am just wondering about the effect the noise, etc. may have on the kit for certain people in certain areas, etc.

Olivier

Don't know until I try it.

[tbitz]

Originally posted by ohecht
Tony,

I am looking to get an EFI and ignition solution before any turbo project, and I am bouncing between your approach and other aftermarket fuel and spark management systems.

I have a few more questions after visiting the Megasquirt site:

- Do your kits to date use the MAP sensor on the board that is suitable for boosted applications? Or will this be an upgrade for those who may turbocharge in the future?

- What are the best options with your kits you see for controlling ignition on NA cars that may be turbocharged (and twin-plugged) in the future? One of the Megasquirt add-ons, or a stand-alone aftermarket ignition kit like Electromotive's? I have always felt my ignition is "sloppy" (the dist cap rotates a few degrees even when clipped down, and I would probably eventually twin plug and need something more than the stock distributor).

Thanks,

Olivier

My CIS to EFI kit uses the +2.5bar (absolute) MAP sensor which is plenty good for turbo.

I looking at having MegaSquirt also control timing in conjunction with the distributor. This has already been done by other MegaSquirters.