Bang for buck track mods?

Well, Ive tracked my 4S 5 times in the last 10 months and I have been contemplating some modifications to stabilize the car during these spirited drives. So far, Ive noticed a lot of dive while braking, a bit too much body roll during hard cornering, moderate understeer when accelerating out of slower turns and a lack of traction typically in hairpins style turns. My car is bone stock. I only lower my tire pressure only while on track. (street tires) I have a good idea of which mods will improve these issues however coilover suspension, lightwheels and race tires, drop links sways etc etc can get a bit pricey if purchased all at once. I know a lot of you guys have been tracking your cars for years and have experience with mods that find a nice balance between a daily driver and track weapon... What mods should I start with to be more effective on the track? PSS10s or drop links, adjustable control arms and sway bars? Do I need to add all of these to feel a noticeable difference? Should I add them one by one to gradually sharpen the handling? And yes, Im aware most drivers prefer to do safety mods before any performance/handling modification. Ive already taken some precaution to keep this addiction safe. Helmet, harness, half cage, fire extinguisher are first on my list. So far Ive only driven with instructors and have found thier guidance extremely valuable. So? If you have read this far I thank you. If you could list some bang for buck handling/performance mods Id be gratefull.... Im not too concerned with increasing power at the moment only road handling for now....

How's your alignment? Are you running street tires or "R" comps? The big issue on 996's is you typically can't get enough negative camber with the stock components. I would start there first.. camber and a good alignment. I'd also ask, how long do you plan to track this particular car? Sometimes, once people have truly slid down the slippery slope, it becomes apparent the desire for 1) a dedicated track and 2) a civil street car. Many years ago I instructed in a 996TT with the X74 (?) factory sport suspension package and was quite impressed. If it works for the Turbo, maybe it also works on the 4S. One nice thing about factory stuff it that it does work well, the compromise between "street" and "track".

I just posted a thread on how to deal with understeer in the rain, and a couple people suggested changing my driving style. So I've been practicing on the street 12am on ramps mostly. Brake later/trailbrake to deal with understeer. I'm not upgrading until I'm at the limit of the car, and driving it 10/10. I think I've got a lot more track days/years left to master driving a stock 911.

Seat time. Seat time. Seat time. Professional coaching. 100% gaurantee those will be your best bang for the buck.

Well, safety and instruction first, but you've stated you already know that. However, I'll add that if you're going to do harnesses, you can't do it without seats fixed back seats designed for harnesses. And DO NOT go with harnesses without a HANS. Your car is a 4S, so it will probably eventually present limitations on the track that are just unavoidable. Getting rid of understeer is going to be difficult. Depending upon how far you take things, eventually you may prefer a 2wd car. That said, if you are going to do the suspension, do it all at once. I'd do the PSS9's, GT3 control arms, rear toe links, adjustable sways, and drop links. It will take the control arms, to able to get rid of most of the push you are experiencing. Trying to get rid of the push without the control arms will just leave you chewing up the outside edges of your front tires. Just be aware that putting in sufficient negative camber will cause you to wear the inside edges of your tires on the street. Suspension is where I'd start for performance upgrades. Brakes: SS brake lines are a very good idea. Along with that, all you really should put in some SRF of Motul for fluid. You should consider this much of the brake mods as a safety issue and probably do it sooner than later. Later you will want to go to track pads. Once you put in the track pads, you will start to overpower your tires on braking, which leads you to... Tires: I would not go to r-comp tires until you have more experience. They don't communicate loss of grip as well as street tires, and when they lose grip, you will be going much faster than you would be on street tires. Hold off for a while on that. These comments are all aimed towards someone who wants to upgrade a car that will be primarily street, but wants a car that is ok on the track. If that's not what you ultimately want, just track it the way it is for a while, and then get a dedicated C2 based track car. Be careful, this is a very slippery slope!

BTW, I agree with the seat time comments. I'm just assuming that you know that already.

Quotes source post: 8011798

I had an alignment done at at tuner shop here in south fla. I told the guys i was tracking the car and let them adjust camber but not too aggresively that id destroy my tires too quickley. Again she is a dual purpose machine at the moment.. i think X73 is made for turbo and 4S models.. im considering them or the pss10s.

Quotes source post: 8011805

Yeah man more time in saddle is going to happen for sure. Im still learning a lot each time session I drive...

http://www.skipbarber.com/driving_sc...p/default.aspx Best performance money you can spend. And the car stays nice for daily driving. Start with 2-Day HPD, then Advanced HPD, then 3-day Racing school. Follow with 1-day fun courses, then lapping days. Then go to the PCA DE's with confidence, skill, and faster times than the boy-racer prepped (sans professional training) cars. Over 70 PCA DE's at 8 different tracks in 20 years, and I never owned a track tire. PCA Instructor Certification. I run in the fastest run groups, in an essentially street stock C2 coupe. I drive to and from on the same tires as on track. No hassles. Just fun. Any time, any place.

Quotes source post: 8011843

Good advice Mike, thanks for your response. I am running motul fluid presently which i forgot to mention. Brakes are strong and im still learing thier limits. Im actually ok with the understeer for now but it does hinder my exit speed a bit. In particular leaving a hairpin i can get hard on the gas but car runs wide and leaves me in a bad angle for the straitwaways... this makes me have to drift across the track to line up the next turn. Yes, I daily drive the car and the roads in my city arent the best but ill still sacrifice comfort for handling on track days. When I was shopping for the Porsche i only wanted a rear wheel drive car but love the widebody look. Do you know anyone that converted a 996 4S to 2 wheel drive? how complicated is it?

Quotes source post: 8011900

I actually plan on attending the January HPD school. My cousin is a trans am driver and made the same recommendation. Cheers Thundertub and thanks for your response ........

Im in a very similar situation. Torn between adapting the 4S for track (DE) use, and just sucking it up and getting a much more radical track car. There are guys on here that know much more about the suspension mods so I have nothing valuable to add there - but I've spent some time researching the conversion of our car to 2WD... Since our 4S's are based on the Turbo chassis, check out Tom Kerr's posts in the 996 Turbo section (also on 6Speedonline)... he did an amazing conversion to a full race care. great work. In short you have to disconnect the front drive shaft - then start dismantling the front diff in order to get the half shafts out... then you wrestle with the wheel hub nut (holding the half shaft in). The question becomes - what to do with the front suspension... probably GT3 lower control arms, GT2 wheel carriers, and most of the suspension mods mentioned above. There are some issues though... the PSM and ABS are setup for AWD, so Im not sure if its wise / safe to assume the 4S's system will work. A switch to a standard C2 ECU might be a good move. --- In the end - for my car - I think keeping the AWD will be the way to go for the foreseeable future. I still remember some crazy slides I recovered from by just staying in the throttle and letting the front end claw its way back on line. Several times when I used to run with an instructor he'd look over and say "well you paid for AWD, glad to see you're putting it to use."

Rear sway bar only will help the understeer quite a bit.

While I'm fond of harping on seat time, you might find this article I wrote interesting: http://hcp.pca.org/aircooled/AirCooledSpring2010.pdf

As you get more aggressive with suspension setup-Rcomp tires etc. Think about protecting your engine with an Accusump setup.

Quotes source post: 8011906

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).

Well put Van, thanks for reposting.

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..

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

+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.

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

Quotes source post: 8014119

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!

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

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

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.

Quotes source post: 8015212

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.

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

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.

Quotes source post: 8015674

thanks for the reply, i will make a flush and put some new ate super blue,

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

Quotes source post: 8015914

I just put these in, and yes they are an improvement, but in terms of performance, you're talking about tenths of a second at best. I race my 996, and flog the crap out of it. I went for quite a while with stock mounts and they really didn't pose much of an issue except in the most highly loaded moments, and even then it wasn't nearly as big an issue as things like setup, tire pressures, aero, and the loose nut behind the wheel. If I were building a race car, I MIGHT put these in right away, but honestly, I also might just wait until I need to replace the stock mounts. If you are racing, or driving at the highest level in DE's, then I'd consider these. Otherwise not unless your stock mounts fail. Instead, I'd spend the $400 on a DE weekend. JMHO Mike

Quotes source post: 8016562

Fair point on the improvement equation of seconds per $. I just use my car on the street and the $400 factory part price + installation was not a lot of $$ to me and greatly improved the feel and driving experience (have PSS9/GT-3 links/sways, etc.) -- at least in my own head! My stock mounts had normal minor wear, but I had the car in for a new clutch and while the transmission was dropped, also did the IMS upgrade/renewed the [non-leaking] RMS -- similarly, while it was in the shop, had them put in the RS mounts as well.

Don't let the naysayers let you believe that the 4S's 4wd is crippling for the track. I've been tracking mine for years now, and it is an absolute blast. It is the perfect car on which to learn skills. As well, it is a great car once you've learned those skills. If the tail end comes out on you, application of throttle will stabilize the car, every time. Even with the 4wd, you can have fun with the back end if you want to. If the car is understeering, then you are probably not using the best line for this car. Here is what I've done, in the order I've done them, to make the car more track-oriented: Spare tire removal(weight savings) Interior strip(for weight savings, not Really necessary) Roll bar Racing brake pads & fluid(stock brakes /fluid never once faded on me, but I'm hoping to get more life out of these) Lightweight wheels(more weight saving) Muffler bypass(again for weight savings) x51 oil pan Racing seats + harness(safety + weight savings, coming soon) x73 suspension(coming soon, this is more track oriented than street. Suspension seems to really help drop times on these cars though) I'll most likely be doing an accusump next year to go with the new suspension and r comps. As others have mentioned, oil starvation is definitely a problem on our cars with upgraded suspension and racing tires. I've tracked this car many times, and am just now going to R compounds. My advice would be to stick with street tires for awhile. Get to know the car fully before going to the R compounds. They are a blast, but give much less warning when approaching the limit than street tires. Breakaway characteristics are also much more abrupt. Edit: As for alignment, my local tech told me that with the stock suspension, the max they could do was very minimal neg. camber(a few tenths of a degree). The rear tires do rollover past the limit, depending on the track so the car could certainly use more camber.