BSF

Hi Folks,

I'm planning to do a 964 ('90 C4) to 993TT conversion. Here's the skeleton plan:

1. Use factory 993TT exhaust headers
2. Use MAHLE OE-replacement 965 pistons and rings
3. BorgWarner turbos
4. Custom intercooler, air plumbing, intake, and muffler fabrications

My only remaining variable right now is the control system and fuel delivery system. Does anyone have thoughts on the following?

1. What are the capabilities of the factory fuel pump?
2. What size injectors are routinely used on 993TT's to reach the 500-hp level?
3. I'm torn between a modified 964 control system (such as Split-Second boxes or Protomotive recalibration software) versus a rip-out and replacement plan using 993TT wiring, ECU, and sensors. I like factory controls but it seems really expensive to buy all 993TT controls equip.
4. Along the lines of question 3, has anyone walked this path before and know of the easiest way to make a 964 controller capable of 500hp?
5. What about a 965 ECU? Would it work with all the 964 wiring and sensors?

Thanks in advance,
Brock Fraser

Carrera GT

I can barely begin to list all the obstacles and huge money-sinks facing this project.

The biggest single problem will be engine management electronics. I would suggest Garrett turbos. And, for my time and effort, I would look at a split left/right bank system rather than the 993 2-1-2. I'd give up on any thought of a/c or heat. I'd go for manual steering.

All that said, I'd find someone that's already done it and buy their car ... you'll save a year and $50K ... or just get a 993 Turbo, they're still significantly devalued and only just now climbing back to earlier averages.

Let me know if you want to pay me to do the work for the conversion ... I have a child to send through school ...

OldGuy

Adam where have you been I have missed your ....ah.....ah.... intellectual
humour! Still interested in our low cost Time Space Position information
transmitter for our track cars??

Carrera GT

Hey Paul, I'm more than interested. Let's get going on the project. PM or email me. Cheers,

OldGuy

I will --I am going to be spending alot of time on airplanes so I will
have alot of time to think about the project.

BSF

Carrera GT-
Interesting views, but I'm looking to build a $25k car, not a $50-60k car. I don't see having much money tied up in the project... I already have the 993TT exhaust manifolds, and I'm lucky enough to have free access to turbos. Intercooler and plumbing are cheap, becuase I'm going to fabricate that all myself. A friend works across town at Mahle, so there won't be much moo-lah in the pistons and rings either. The only real cash outlay is going to be the control system, hence my topic's questions. Speaking of staying on topic, does anyone else have any input?
Thanks for your time,
Brock

Geoffrey

Great project!!! Speaking from experience, here are my comments:

You will need 55lb/hr injectors (Bosch 280150403s would be my choice) However, they are peak and hold low impedence injectors and the factory 993 44lb/hr injectors are saturated high impedence injectors. This really only matters if you are planning to use the stock 993 ECU. Beyond about 550hp and you will need 72lb/hr injectors.

The only way to really ensure proper ECU calibration with a custom setup like you are talking about is to use an aftermarket ECU which can control all of the 993TT sensors. MoTeC or Autronics would be my choice and will need to be tuned on a dyno.

I am tuning a 964C4 with 993TT engine and Kevin's turbos controled by a MoTeC for another Rennlister in a few weeks. I've done a number of this type of system so it really isn't new stuff.

A 965 does not have an ECU, it is still CIS.

I'm partial to Kevin's turbos over Garretts and think they perform better and are more reliable.

I hope this helps.

BSF

Geoffrey-

Thanks for the input! If I go with aftermarket controls, I'll probably head for the Electromotive TEC-3 just because I have experience with Electromotive products, and with their new systems it cost-effectively incorporates a wide-band O2 sensor as well as multiple "general purpose outputs" that I can use for turbo control. Distributorless ignition is an attractive aspect too.

I was really preferring to use the OE system, however. Mostly because it's a real pain to have to re-wire and re-sensor the engine. The best option I have heard of so far is Protomotive's pressure-sensing conversion of the factory ECU, plus their chip calibration software. The biggest weaknesses I see are the retention of the OE ignition system and the lack of any turbo control output.

I have two new questions for you...

1. Have you applied turbo power to a 964C4 driveline before? Did anything break?
2. Have you heard of a way to safely disable the front wheel drive such that the car can be run on a 2wd chassis dyno?


Thanks,
Brock

Kevin

Brock;

We have talked before and my recommendation is to snag a '96 TT ECU, in fact Alain has one for sale. Buy the factory engine harness and away you go. I have a NEW DTA system for sale. Being that you have the '90 drivetrain, you will see the durability of the 993TT. You could put a cooler on the front pumpkin.

Kevin

By the way the stock 964 fuel pump believe it or not is standard issue in the 993TT!

BSF

Hey Kevin,

Yes, using a '96 ECU is certainly an option... in fact there is one being auctioned on Ebay right now that expires in about 2 days. My biggest concern is where to get the harness from and then what sensors would have to be purchased to mate with the new harness. (sensors that are not equivalent to what's on my engine) It seems really clean to use straight OE equipment, but I'm afraid of being pickpocketed to death at the dealer's parts counter if I cannot find all the right bits and pieces used. Lastly, I'm concerned about not having any adjustability. You know what turbos I'm planning to use on this, and I just don't know how well a non-adjustable OE cal is going to deal with that... even if I assume that the boost control will be strictly pneumatic or using an aftermarket boost controller. The boost vs engine speed relationship might be radically different than what a stock 400hp cal is used to dealing with.

Anyway... what is a DTA system? I don't know that abbreviation.

Thanks,
Brock

BSF

Oh yeah, and how do I get in touch with Alain?

I tried to look at the PM list, but the username list is disabled...

-Brock

Geoffrey

Regarding the Electromotive TEC III. There are other ECU choices out there that are in the same price range and are much better in terms of engine control. The Electromotive ignition uses GM wasted spark coil packs from the mid 80s and I believe the factory Porsche ignition system is much better. Also, while the Electromotive is sequential, it does not allow you to vary the fuel injection timing. It is set to end at TDC when you really can continue spraying fuel into the open inlet valve until BDC under turbo boost and until about 20 degrees BBDC under N/A conditions. Also, the wide band support is not native to the unit. It supports wide band with an external preprocessing box.

If I were to do twin plug, then I certainly would go with a distributorless system, probably incorporating a CDI/multi coil setup. If I stayed with single ignition, then I'd most definitely stay with the Porsche setup. It also has a hall sensor with a single tooth wheel inside that you can use for a cam sensor as long as you pin or weld the distributor advance.

I have not applied turbo power to the older 964 style AWD system so I cannot comment on its longevity. I believe Jean on the 964 turbo board has the setup in his turbo car and there are a few others.

I don't know of a way to disconnect the AWD to run on a 2WD dyno. I would seek out a Dynapack or Dyno Dynamics AWD dyno to do my tuning on. My opinion is that these are the only two dynos capable of doing a complete tuning job including maximizing timing at steady state.

If you did go with a recalibrated factory ECU from GIAC or Protomotive, you'll have to make sure the calibration is done for your setup. I also think the factory 44lb/hr injectors are maxed out at 500hp. The BSFC of the 911/993 engine is terrible compared to newer 4 valve pent roof heads and will require more fuel.

Jean

Brock,

As Geoffrey mentioned I have a 4WD 965, the car is CIS however has many modifications and dynoed 400 at the rear wheels. The 6 spd gearbox and tranny that I have are from the 993TT, and the car runs fabulously. My understanding is that the 993TT internals are more solid than say the 993 C4.
Geoffrey and Kevin are both extremely knowledgeable, I would follow their advise without hesitation. If you want to go EFI, I would listen carefully to Geoffrey's suggestions.

Good luck in your project.

Kevin, could you please PM me about your DTA for sale, any Motecs?

Jean

Ruf-Dan-Ruf

Not sure if this will help?

My RUF BTR-2 has a 964 computer. It has a wired inline Bosch Motronic electronic fuel injection and ignition system into a 964 loom.

It has x2 993 TT fuel pumps.

The gearbox and Diff are Ruf specials.

Not sure what the injectors are. I do have the fuel pressure for the rail ..... just not here, dooh, so not sure if 964 or 993 parts used here.

So my RUF is some C2 some 964 and some 993TT .... my cars mummy was a **** heh.