mglobe

I don't have the knowledge or skills needed to comment on how complicated it is, but I can't imagine it being a good idea either from a financial or technical point of view. If you get to that point, it's probably better to either retire the 4S to the street, or swap it out for a C2. Because of this potential crossroad in the future, I personally think it's probably best to go slow on how much you put in to a C4. The PSS9/10 setup with sways and control arms is about as far as I would go with it. It would be a change that would leave the car enjoyable to drive on the street, and perform better on the track. Past that, and you will turn the car you love into the car you hate (at least hate on the street).

Hardback

Well put Van, thanks for reposting.

Rob996

Carey, I experienced the same quandary with my 996 C4, as i was getting faster and more experienced
on the track it became clear to either change cars or start making incremental modifications to my C4.
Before i go any further, and many people have stated this, but SEAT TIME, SEAT TIME, is the biggest investment you need to make....

I wanted to achieve a certain balance between an enjoyable car to drive on the street and a competent track car that performs well..After spending over 2 years of DE events with the car completely stock. I made the following modifications in this order... Its important to understand the car and your own skills before masking them with upgrades that will inherently make you faster, but not more skilled.

1. Alignment with more negative camber(limited with stock suspension)
2. Second set of lightweight wheels with MPSC's
2. Pagid Yellow pads
3. Fabspeed exhaust ( OE mufflers broken baffles)
4. X-74 suspension kit.

The suspension was the best upgrade by far.. not only did it stiffen up the car, and reduce body roll, but changed the way the car rotates around the corners.. This suspension lowers the car a lot, i now have to be careful with ramps and driveways.. It feels comfortable for the street making it a great compromise upgrade...

Winter list are roll bar, harness and seats...

Good luck, its addictive..

himself

I agree with some of what Van's article says, specifically that seat time should not be in the equation because that has nothing to do with the car itself. I think the real question is: what would a good driver do to your car so they could get more out of it?

WRT acceleration, IMO there is no real bang-for-the-buck engine modification for the 996. Everything is many bucks for little bang, unless you toss your entire 401K at it. You could need to spend $15K-25K at your car in order to get another 100 HP. But even then, you still won't be able to use it at the track properly without the other components working in concert. So I think acceleration is a red herring for track mods - particularly with a 996.

Also, the stock 996 engine is quite good at the track. Relatively quick revving and plenty of grunt. The real weak link at the track is the suspension. The parts are too soft and cushy for hard core track use. That is, you lose time under braking due to slow weight transfer and you have a delayed usage of the engine's capabilities (can't get to gas) because the car takes too long to take a set in a corner. Overall, you might loose .5 second (or more) per corner because of a sloppy suspension. You will get the same result if you have 300 HP, 500 HP, or 1000 HP.

So, IMO, the best bang-for-the-buck modification is suspension. I would put that at a 5 on the "Van-scale" and move acceleration down to 3, maybe even 2. I would leave braking at 4, because it is braking technique that really makes a car go fast - not the gas pedal. But there are no real bang-for-the-buck mods for the braking system except pads. You won't be getting serious improvements with 6-pot calipers. The stock setup works pretty well.

As for suspension, you can easily get another 2-3 seconds per lap with a good suspension. If you get set of PSS9/10s and new sway bars, you will be out around $3,500 with install and alignment for those precious 2-3 seconds. [You would have to put in a $15,000 supercharger to get that kind of improvement based on acceleration alone.] So, suspension yields about 1 second per $1,000.

The next thing you should consider is seats, harnesses, roll bar. Although these fit in the "safety" category, they have the added benefit of getting you (at least) another second per lap just by being planted to the seat. This will set you back another $2-3K depending on equipment used. So, seats etc yield about .5 second per $1,000.

Next will be tires and brakes. I put these together because they are a system that needs to work together. If you have high grip tires, you need high friction brakes. If you have R-comps and stock pads you will ruin your pads in less than a day. On the other hand, if you have soft brake pads and street tires, you will get into ABS all the time. So, if you buy new stuff, you are looking at another $2K. Tires will be around $1250, and pads around $750. This should get you another couple seconds. Now, in the scheme of band-for-the-buck, tires are the actual cheapest way to go. But, you really shouldn't upgrade tires until you are fairly proficient. So on this criteria alone, this mod should be down the list. Also, although tires/brakes may yield 1-2 seconds per $1,000, they are a consumable that you will buy 2-3 times a year or more. So their effective bang-for-the-buck comes out to around .3-.5 second per $1,000.

Fiinally, you will be throwing thousands of dollars at tenths of a second with most other mods. Solid this and that, lightweight anything, titanium or carbon whatever, aero, etc is all expensive. So, these things come out to be .1-.2 per $1,000.

Probably the best thing you can do is put the car on a diet - which is free.

-td

Sneaky Pete

+1 on the brake and tire upgrade. Also would add bleeding the brakes (for upkeep and safety)

+10 for the suspension. I got Rob to get the X74 after Van and Ed got me into the X74. Haven't regretted a second on that one.

The last thing I'm working on is the seats and harness. Like others have said the motor is fine all by it self.

Surfer161

I am in same situation. C4S as DD and 5-8 track days per year. I was very unsatisfied with stock suspension. A set of PSS9s have helped a lot. I was advised to leave the control arms off until i was good enough to run with radically lowered and cambered setups. Turned out the stock hardware was able to adjust to a modest drop in the car (about 1" on 4 corners)

Surfer161

photo taken at watkins glen

balefire

Completely Agree.

Cheapest track / autox mods not already mentioned:
1) Diet - Lose the spare tire, floor mats, rear seats, washer fluid, and as much fuel as you can (free). (1 gallon fuel is about 6 lbs).
2) CG-Lock - 50 bucks and you will be secured to your seat
3) Ebay Bypass Pipes - 150 bucks and you will lose 50 lbs and gain a few hp

If you're willing to spend real money, bang for buck is always best with tires. I agree with staying away from race/R-compounds until your skills/equipment are improved. Instead I'd consider sticky "street" tires like Hankook RS3 or Dunlop Star Spec, etc. ($1k).

After sticky street tires, the best mod would have to be suspension.
One caveat re: x74 or m030 susp - its not adjustable.
The cheapest adjustable suspension mods are GT3 sways ($700) and koni yellow shocks ($1k). More popular is the aforementioned adjustable PSS9/10 coilovers ($2k) which have the additional benefit of lowering the CG and increasing camber.

gl!

Tbred911

so who has done the accusump.... I hear its a must for adding longevity to the motor... ?

himself

I think most that do oiling mods get the deep sump kit, extended oil pickup, and X51 oil pan.

-td

knfeparty

I would have to say that a good alignment and then swaybars are the cheapest and easiest to install mods for better trackability. The GMG setup is the cheapest adjustable swaybar kit out there and it utilizes the stock droplinks.

I would definitely stick with street tires for a bit. If you want to delve into R-comps, do it autocrossing first to learn how they behave. They are a lot of fun and can help you save unsprung weight with some lightweight wheels, but having to swap wheels is no fun at all.

The other MUST is brake fluid (you said you were using motul already so good on you) and track or dual-purpose pads. PAGIDs would be great; I have some ferodo ds2500s on my BMW that are fantastic street/track pads.

The body is going to dive/roll a bit unless you put a lot of cash into suspension, after which it won't be as comfortable on the street. Adjusting some adjustable swaybars for greater rear stiffness will really help the car rotate and it's an easy mod to install.

mglobe

I know of a few racers who have done accusump. I'm not sure I would call it a must, but if you are racing it's probably good insurance. I've never seen it done in a street car. One problem with accusump is that it's pretty large, and there are not that many places to put it. The SpecBox guys put theirs in the rear trunk. The one 996 accusump I've seen in person had it in the back seat area. Not something you want on a street car.

Paseb

offtopic,

would it be good to flush my brake fluid to upgrade to motul on a a street car??
would it improve the braking a little?



power mods:

catbypass
muffler bypass
kn intake

i did those mods and i noticed an hp gain

knfeparty

better brake fluid like motul only really matters for high temps seen from track use. Just regularly flushing your brake fluid makes a big difference in getting the water out of the fluid though! ATE super blue or gold is a good fluid that isn't as expensive as motul by a long shot but is better than off-the-shelf stuff you would get at autozone.

Paseb

thanks for the reply,

i will make a flush and put some new ate super blue,

jr2

For $400 (from Suncoast) + installation, the RS engine mounts are worth considering.