Power: 993 headers? MAF conversion?
 

I am not expecting big power increases but it would be nice to optimize the stock engine and improve the throttle response as much as possible without spending tons of cash.

Beyond the normal mods (cat and muffler deletes, RS flywheel, chip, K&N) I have read about using original 993 exhaust manifolds and MAF conversion kits.

From an earlier post: True or false? Are they are direct bolt-on that retain the heat?

What about MAF kits? I have never liked anything from Autothoirty. Are there other options? Even if MAF kits only add 5hp peak they should improve part-throttle response.

Thoughts :confused:

THe search function is your friend:) What is your budget? The mods you mention above - have you done them already?

Drive a 993. You'll be underwhelmed by the power.
Get rid of about 300 pounds out of your 964 and you'll notice a huge difference...for free!

911 and 964 heads have a bolt pattern that is no compatible w/ the right side 993 header. You can cut and reweld the header flange to fit, but then the next problem is the orientation of the collector.....

essentially you have a series of solvable problems but in summation, it's a lot of work.

I used B&B headers on my 964 engine and currently on a 993(993 heads have dual pattern studs so any exhaust can be used) most of those racing 964 in PCA use something similar.

B&B retains heat, it's not as good as stock but is ok for most purposes(not ski trips), us a lightweight dual in dual out mufler for Flowmaster, Magna flow et al and a couple od 2.5" ss U's adda dash of welding skill and you have a nice efficient exhaust.

Don't expect miricles in the power department. The cams and intake are going to be the new choke point.

I do agree that lightening(exhaust is included in that category) is the first best option.

We just dynoed a 1994 964 with our (Vitesse) MAF conversion. The power curve looks great with a crisp response. We got 257.8 rwhp and 238.3rwtq on 93 octane. I'm sure the owner of the car will elaborate with more details.
The car has the stock header, cat-bypass and a single muffler, light flywheel.

The Vitesse kit includes our software, which is written to support Air Mass. There will be a product announcement shortly with a RennList promotional offer. Stay tuned.

The car John is speaking of is mine. And I have to say WOW.
I had a MFI car before this one and I have been trying to get that same fast throttle response for this car.
I went though three chips , to get to the point where I am happy and I am very happy now.

The day I picked it up, before we did the final tune on the dyno. I was driving home and a new 07 M3 came up to play. Now on the track these cars will walk away when we get to the straights ,330 HP right.

This time he could not walk away, with several tries.
The response was very smooth and clean all the way though. And fast, it really gets up there fast.

John , and I spent a few hours today running the car on the dyno , till he got the maps tuned correctly for the 964. We did over 25 pulls till he was happy with the AFR and the safety of the MAF.

Below is a copy of the run that the car was programmed with and is in the Car now. I drove around Atlanta for about two hours tonight getting use to my new car.
You can't beat this bang for the buck!!
I would not write this if I was not happy with it and think that John did a complete and safe job with his product. I look forward to the next DE to really see how it runs now.

If you are in Atlanta and would like to see for your self , Pm me .

http://mail.google.com/a/og-energy.c...65f48be986835f

Derek,
Could you elaborate on which chips you tried and maybe a brief description of their characteristics? I will be getting a chip for my 964 motor w/ 993 HE, lightweight flywheel, to put into my 81' SC.

Bill,
What differences in sound have you heard between the Flowmaster, MagnaFlow, and any other co.'s when used with 993 HE?

For those unfamiliar with John at Vitesse, he has been making chips, MAF conversions (and Turbos..) for the 944 Turbo crowd for several years. He is generally regarded as the god of software tuning over there...
John, I'll be calling you for this conversion soon - I just picked up a 964...

I can only found info about a kit for the pre-89 on the Vitesse website. How soon will the 964-kit be ready and will the price be the same as for the pre -89 kit? Does anyone know?

Derek,

Recalling all you went through with this car in the early go, it's good to hear your perserverance has turned all around. Congratulations to both you and John!

Now you know the question I must ask...:D...any stalling issues with the lwt flywheel/clutch?

MitchB, thank you for the kind words. Congratulations on your new purchase, the 964 is a fun car. I'm considering getting one myself, a ride in Derek's car is all it took :). The crisp response is a joy, the lightweight flywheel is a good addition. Over the past few years, I have been driving turbo and supercharged cars, it was nice to feel the crisp response of the 964.

The MAF kit will be added to the website shortly, however the kit is available now. We also offer a MAF kit for forced induction 964 (turbo or supercharged). We are working on a 964TT conversion now, more details and pictures as soon as possible.

We will be offering some more goodies for the 964, in addition to the MAF we will be offering a PiggyBack to give you access to fuel and ignition as well as data logging. I will be making a announcement shortly, Rennlisters will get a promotional discount, please stay tuned.

Noah,
John worked on that to make sure that there was no stalling. I did every thing I could to make it stall with John recording the data and making the adjustments. Still no stalling, and I ran the A/C for about two hours in traffic yesterday too.

The first chip I had was the stock.. would not like the Lwt flywheel, and cat bypass

The second a custom made in Conn, I will not say more but it was not a good chip at all, I return it in a few days.
Third was the Cintex Chip, over all the chip worked well, It took care of the Lwt flywheel, and the cat bypass. It was slow below 4000 , then really opened up.

John,

I am very interested to hear the details of your 964 kit. Will it include a new chip or some other type of signal modfier? Will you retain the factory airbox or do you use and open K&N cone?

If you are doing a custom chip maybe you can bump the idle 150-200rpm to help the guys with light weight flywheels?

What did the car make before your MAF kit?

Keep us updated :)

Fast4525,
Same as with all of the MAF kits that we provide, we rewrite the software to support true Air Mass, the 964 is no exception. We do not rely on a signal massager to convert the MAF signal to look like a AFM so the DME understands it. Our DME software is designed to work with Air Mass (MAF). For more general details, check out these 2 links:

Vitesse 911/964 MAF

Vitesse MAF FAQ

For the 964 we provide the MAF sensor, wiring/connector, J&N cone filter, support bracket and our software. As an option, you can get our PiggyBack which will give you control over fuel and ignition.

For the 964, we can provide the MAF as a stealth kit where the MAF attaches (via an adapter) to the factory air box. However, the factory air box will need minor modifications, as it has a lip where the AFM attches.

At the moment, we support a lightweight flywheel. I would like to thank Derek for trying his best to get the car to stall while I was monitoring the data. As far as I know, the lightweight flywheel is not a problem.