ketel

Gang,

I'd like to get an unscientific poll going of what people on this board consider the first, simple, and most bang-for-the-buck performance mods a 964 owner should consider for a fairly dead-stock 964.

I have had my '89 C4 for nearly 13 years and 80k miles. She's been great companion but I am now leaning toward putting her out to pasture as far as a day-to-day workhorse vehicle and turning her slowly into a track-only car for club events, etc. This will be a gradual process as I have not yet picked her replacement for the daily-drive duties, so I need her to be street legal for a while longer. That said, I am looking at starting the mod process bit by bit to boost her performance.

So far, I have kept her stock with the exception of the air-box mod (a crude application of a hole saw to 'open' up the contricted airbox for more airflow that I learned from the '101 Projects' book) and a K&N filter.

In my shoes, what would you do and in what order? Chip? Bypass pipe? throttle body? Big Red brake upgrade? etc?

all thoughtful suggestions welcome.

ketel

1990-964

Hey Ketel,

The mods you mentioined are fine to do but consider suspension first. The 964 in stock form has more than enough power to overwhelm the stock setup, especially on with 80,000k on the clock. Try researching quality suspension upgrades and a good set of wheels and tires. IMO 17" is the way to go, do some more homework on that topic too. Once you have a ride that can really handle then a move to more power and better brakes would be more prudent. This is just my 2cents, but almost anything we do to these cars is very expensive so I feel that approaching things in a logical progression makes plenty of sense. Good Luck

ketel

Thanks, for the record, I already have 17" S-03s on her and I did upgrade her to the Carrera Cup wheels some time ago. [Okay, not exactly dead stock, but close.]

Cosmetically, I also added the aero mirrors. So, essentially she looks like a '94, but mechanically she is still intact.

As to suspension, what is your opinion of a camber/strut brace as a first step in improving her suspension/handling? That's about a $200 upgrade from what I am seeing.

ketel

wsybert

I am sure you will get a lot of responses here...
IMHO, I would start with the suspension. Dampers and Springs... PSS9 and JIC seem popular here. (not sure what everyone is using for the track. A search will provide you more answers.)
Probably upgrade the swaybars too and a strut brace.
I would stay away from the engine, unless you plan on doing serious modifications. Maybe a cup pipe and cat bypass. Porsche did it right, and it takes a good bit of $$ to extract noticeable power out of the engine.
Unless you are going to get serious about racing, I think the stock brakes are fine. Maybe upgrade the rears to the 4 pots. Just get a good set of pads for the track, and you will be fine. At least until you are too fast for the car. And keep the brake fluid fresh... good DOT 4, like Castrol SRF, Motul 600, and ATE 200.

The fun part, is taking it in steps. Add more as your skill improves.

My 0.02.

Bill

joey bagadonuts

Another vote for suspension. Make sure you get parts for an 89-90 964 ... the rears are different from the later model years.

Your rear brakes are the four-pot variety, so you should be fine, there. It was the 90-91 C2's which came with smaller rear calipers.

Next, you might want to lighten that car. There are plenty of threads covering that topic, so use the Search feature and enter words like "diet" and "weight".

Race buckets will keep you upright at the track, shed 60-80 lbs and can be used with stock seatbelts. If you get bitten by the track bug, consider getting a rollbar.

Before you head out, you will definitely need DOT4 (racing) brake fluid and racing brake pads. Don't skimp, here. Not being able to stop is a bad thing.

That should get your car set for the track. As for driver prep, you might consider reading up on high-performance driving technique. The "Speed Secrets" books by Ross Bentley are hard to beat. Also, make sure to get considerable in-car instruction in the early going.

Have fun and be safe!

kgorman

If you have not been on the track a lot, I would suggest, getting on the track a lot. With the car just the way it is.

Then I would change the suspension out *and* start removing weight, and get a good set of sways. Follow the "wringing out the c4" article (see here)

ketel

Joey B -

Just curious. I see you have a C2 as your race car, which replaced your C4. Any reason you left AWD for RWD?

As to driving, I actually have a bit of track experience (some TTs and Jim Russell courses), but your points are well-taken. I think it always behooves one to get in as much seat time as possible before fiddling with the car. Unless one is one of the most accomplished drivers out there, one will usually hit his/her limit long before a car like a 964 C4 will hit its. Ergo, I agree with the sentiment of taking the car as far as it can go in fairly stock form before sinking a ton into refinements.

That said, always nice to get a bit more power.

Steven C.

+1 Suspension, seating, mufflers then motor. Not as sexy as reversing the order but MORE effective.

1990-964

Hi ketel,

I think that lowering your car would be a good first step. you cannot go wrong with the strut brace but I don't think it will give you much by itself assuming everthing else is stock. Think seriously about new dampers(shocks) and springs or a coilover kit like PSS9s or JIC. If you do choose the PSS9s don't be discouraged that no application exists for your car. They can be very easily adapted to work in the early style rear mount and do indeed work great. Do by all means get the brace but consider doing the suspension at the same time. It will be like having a new car. Keep us posted.

Darren

joey bagadonuts

First of all, I'd still be racing my C4 if it hadn't met its untimely demise a few years back. Yes, racing incident. But I had no issues with racing an awd car.

The main reason I opted for a C2 was because it was classed more fairly within NASA GTS racing. AWD cars carried a 10% weight penalty, so I could have the same dyno number as a C2 or M3 but needed to run a couple hundred pounds heavier.

For PCA racing, however, it was grouped in the highly-competitve F class and did just fine. There's a gent on the East Coast, Chris Reinsborough, who continues to campaigns his C4 in F and is often a podium finisher. And I believe, the awd weight penalty is no longer in effect with NASA, so I'd say there's really no downside with racing a C4.

And, of course if it rains, look out!

Ritter v4.0

Chip- no question

Seriously though, as stated above race brake pads/fluid, suspension, good tires and weight loss will take you a long way.

roketman

work on you !! improving your driving skills and understanding of how to is your best investment.

TR6

Lots of great input above so I'll add on my thoughts also.

One person said to take it on the track as it is and start gaining driving skills (DE). I agree with that, but first make sure your brake pads and fluid are fresh before you venture onto the track. Fresh ATE, Motul, or even SRF fluid. I would not even think about a big brake kit upgrade (Big Reds, etc). Not for a long time. The stock 964 brakes will take you a long way with good pads and fluid. You may want to think about PFC97 or equivalent brake pads for the track. You can keep them on for street too, but they tend to dust more and may squeal.

Next, suspension. As others have said, suspension is much more important than trying to gain some extra horsepower. I wouldn't go too nuts in this department though. A basic upgrade to Bilstein/H&R reds or the equivalent will transform the car. It sounds like you've already got some decent wheels/tires to DE with.

I would then recommend an exhaust bypass (secondary or primary). It adds only a few horsepower, but honestly the real gain is losing a little weight and mainly the big grin on your face when you mash down the go-pedal on the track and hear the throaty roar. Its addictive. Once you decide if you like that sound, next would be a cat bypass. Again, a little more hp and a little more noise and a little less weight.

Someone else mentioned seats. That's on my list for 2008. Track seats and harnesses. It reduces weight significantly and adds an element of safety. But it also will make you feel more connected with the car which translates to more proactive driver inputs on the track since you will better feel the car's attitude and movement.

Maybe a performance chip optimized for the exhaust bypasses (want to have some fun? ask for opinions on chips!). I bought a chip but I would rank it fairly low on the list of priorities.

Beyond those things, the options get much more expensive and the incremental returns get smaller. Light weight flywheel/clutch for example. Highly recommended for DE/track (I did it) but it will definitely lighten your checkbook. Wait til you need a clutch anyway to justify it.

kgorman

.

Best way to achieve more power is to reduce weight. There is about 300lbs to be lost on your c4. Ask me how I know. Reducing your weight by 300lbs is like getting an additional 50hp. The plus side is you also need to remove one of your mufflers in order to loose some of that weight, that with a cat bypass yields some more power yet. Plus you can sell all the stuff you remove. Do a search on my name, or 'diet' to see what I did. PM me if you want for the other mods I did. Garrett376 is another guy running a C4 on the track, so you can search on his username for loads of info.

donoman

My favorite mod has been suspension although I lost a little bit of ride quality.

Going to the track isn't only good for skills, but if you already have skills, going to the track (or autocross) allows you to meet people with the same car and the mods you are considering.