Rendez-vous June 1997 – Turbo or not Turbo

RSR Rendez-vous May 1997

I got to track my car last night for the first time this season. I am pumped about this summer’s DEWs. Continuing in the long standing tradition (actually, I began last it last year, but hopefully it will be a tradition sometime in the future) here are a few hints and tips for new and not-so-new “trackies”. Also I may be able to save you a few bucks along the way.

Engine Under Pans on 964 and 993:

Should be removed for the summer. Noted Porsche Authority Bruce Anderson has observed that the pan directly below the engine is responsible for excess heat build up and can result in premature valve guide wear on the lower side of the motor. The factory disagrees but I noticed that factory race cars also have them removed. Mine are off already. You can do it yourself in 3 minutes if you jack up the car, else ask your technician to do it when you’re getting a Track Inspection.

Go fast goodies for 993’s:

Since I didn’t buy a Turbo, I am particularly interested in improving the power of my 993. By now a few of you know that electronic gremlins nuked my column titled “The Top Ten Reasons I want a Turbo”, so I’ll summarize them here (the original was funnier):

#1 – George Grivakis

#2 – Wayne Martin (although I doubt a Turbo would be enough)

#3 – Gary Griffiths

#5 – 7 George Grivakis (again)

#8 – 10 I love the car.

The bad news is that most of the go fast goodies don’t do anything but suck money from your wallet. The 993 engine is almost perfect as it comes from the factory and short of going all out (spend 10 grand) there is not a lot you can do to make it more powerful. This bums me out since last night Gary Griffiths showed me how much faster his car was down the straight at Ste-Eustache.

Gary and Paddi are contesting the One Lap in the Porsche and I can testify to the fact that he has it very well sorted out! By the time you read this, we should know the results. I hope they do well. They deserve it. I’ve watched Paddi sitting in the passenger’s seat TYPING on lap-top computer testing various engine management tweaks while Gary is lapping the track. Talk about dedication! Not only do the Griffiths’ have a trick engine, the car has been stripped of all superfluous weight. Sort of like ” I don’t need no stinkin radio, I don’t need no stinkin heater, etc.” That, by the way, is the best way to improve the all around dynamics of any car. Trust me, it works. Still, I console myself by turning up the heat when it’s cold.

Basically there are a few things you can do to a 993 that will improve it on the track without spending a fortune. Some other things are neat to have but don’t count on passing Grivakis anytime soon. I’m going to list the go-fast goodies as Useful, Useless But Neat and Just Plain Useless. Note that these are just my opinions based on personal experience. Your mileage may vary but don’t count on it.


Exhaust Systems:

For the 993 can improve the sound (make it louder) but don’t count on a lot of extra power. I’ve experimented (at considerable expense, thank-you) with a B and B and Supercup as well as a cheap mod to the factory mufflers. The Supercups have the best sound by far. Awesome and they do knock about 25-30 lb. off the back of a 993 which is always a good thing. I cannot measure a power increase though and on long drives, such as Montreal to Mosport, the drone can be a nuisance. The rest of the time the noise will make you roll down both windows while driving through tunnels. Music!

The B and B sound nicer than stock but don’t have the “This here is a race car” sound of the Supercups. No power gain is observed over stock but the noise level is acceptable even on long boring drives. I’d suggest these as a replacement for the factory system as they are really well built and a lot cheaper than the factory parts. Borla also has a 993 system which looks interesting.

Modified Factory Mufflers. Oddly enough this was the cheapest alternative and there is maybe a slight gain in performance. I took the factory mufflers to a friend of mine who cut open the canisters and removed a huge amount of sound deadening material. How huge? He made a pile about 3 feet in diameter and two feet high with the stuff! He observed that the muffler itself was not restrictive and had only one baffle. He welded in a couple of braces to prevent the canisters from “oil canning” without the packing. The result is an exhaust which has a slight snarl to it much like the factory Engine Sound option.

The noise level when cruising is almost identical to stock but throttle response feels crisper. This brings up a really interesting (to me at least) factoid about 993 exhaust systems. In order to meet really stringent Swiss noise regs, Porsche has organized the 993 exhaust such that the noise from one back of cylinders cancels out the noise from the opposing set! Very tricky indeed. This explains while relatively unrestricted mufflers are so quiet!


Turbo-Super-Bullcookies-charged air filters:

We’ve all seen the ads right? “Super Charge your car, gain up to 25 horsepower with our super-zowie air filter”. Well, I should have been smarter but I suckered and bought one. Guess what? No difference. My brain said ” Bob if Porsche could increase the horsepower of the 993 engine by 25 horsepower for the price of an air filter, they would have done it themselves.” Still, I bought it thinking that “my trick exhaust system (yeah, sure) will flow better so I need more air”. No additional power over the stock air filter sadly.

One brand (K and N) permits cleaning and re-oiling the filter. Over a couple of years, you save a few bucks by not replacing the factory one so often. Now if they only made re-usable pollen filters. What’s a pollen filter you ask? Heh-heh, wait ’til your 24,000 KM inspection when your dealer replaces the pair of them for $133 bucks! Before I leave the subject of alleged horsepower gains from air filters, be wary of filters which replace the factory airbox and ducting. They may look very racy with the filter sitting exposed but in many cases the engine is being fed with hot air instead of cool. Result, less power! Cool air is denser than hot air, which is why the factory engineers put in all that ducting and air box in the first place.


Wheels and R Compound Tires:

A spare set of wheels with R compound tires make sense if you plan on doing a lot of track events. You can buy a decent set of wheels and tires for about $2,500 Canadian. You can buy a great set for $4,000-$5,000. The difference is the weight. Really good wheels are not only very strong but light too. A lighter wheel means less unsprung weight which makes your suspension work a lot better. Sadly, strong, light wheels cost more than heavy ones. How light are they? Next time you’re at Talon Tire, pick up that race wheel and slick he’s got hanging on the wall. Trust me you won’t need help.

When buying replacement tires and/or wheels, resist the temptation to go too far with really oversize tires. Putting extra wide tires on a Porsche may reduce performance. Too wide increases drag and weight. The suspension works less efficiently (additional unsprung weight) and other than looking cool, your performance may actually decrease. Also, be wary of the overall tire diameter. The diameter varies from one brand to another. Try and pick the one with the smallest diameter. Incidentally, taller rims (i.e. 18 or 20 inches) are better than shorter ones, but right now, there are not a lot of tire choices for wheels above 17 inch diameter. The lower profile tires associated with the taller rims ride hard and pot holes are not absorbed gracefully. Howard Dexter blames a certain brand of tire (a good brand by the way) for lopping off 10 KPH from his top speed on the straight at Mosport. One other thing to consider is that wider tires are more prone to aquaplaning on standing water. That’s a pretty scary experience best avoided by all.

Harness Bars:

With a 4, 5 or 6 point harness. A really good idea. The harness will hold you securely while your car shows you just how much cornering force is available with a Porsche. This year there’s a change. The shoulder harness must be secured to anchors in the rear of the car as opposed to on the bar itself. I DO NOT AGREE WITH THIS POLICY ON 911’s and 944’s EQUIPPED WITH AUTOMOTION OR SIMILAR HARNESS BARS. I’ll take this up with Rennsport Tech Chairs as soon as possible. Still the rules are the rules.

I’d suggest that you consult your dealer or one of the Tech Inspection Approved garages for help with ordering the harness straps. If you order the right stuff, no holes need to be drilled in your car. I could explain, but this column is too long already and I am in the slash and burn process minding Dr. Weld’s deadline.

Track Tires:

“R” compound tires have three main advantages: greater traction than street tires; better durability on the track because they are designed to resist high temperatures and, best of all; they’re cheaper! This year we have a good assortment to choose from. Talon is carrying R compounds from B.F. Goodrich, Hoosier, Pirelli, Toyo, and Yokohama This fall, we might even get good news from Bridgestone. Peter Korsos is twisting arms to get us some of their R compound tires. If they’re as good as the stuff in F1, they are going to be hot!

Suspension Upgrades:

A sure fire way to improve the handling of your car. After-market springs and a track alignment will make a very noticeable change for the better. Be prepared for a firmer ride and in the case of a track alignment, faster tire wear on the street. I found a set of 993 M030 (Sport Chassis) Euro springs for my car at Windward in Vermont. I tested them last night and they work really well. On the other hand, I have one of the few M030 equipped cars in the region. The Euro springs drop the car one inch (like the cars sold everywhere else in the world) and allowed me to get a two degree negative camber on my wheels. Gary says my car stuck like superglue, ( it did, but that didn’t stop him from sucking my door off down the straight – sigh). The Eibach springs on the Silver 993 work very well and improve handling a lot. The car is lowered about 1.25 inches though and curbs and speed bumps require extra caution.

In closing, let me add that no modifications are required to really enjoy a track weekend. Somebody has a T-shirt I like, saying “Every Porsche ever built is a race car”. If you haven’t tried a DEW sign up now. If you don’t enjoy it, complain to me personally. I’ll be at every one.

If you still need a reason to sign up, I’ll let you in on a secret. TPICORBWFTE have done an OUTSTANDING job this year.


My favorite wine (I still want a Turbo!)

(OK, so you want to know what a TPICORBWFTE is don’t you? That’s “People In Charge Of Recruiting Beautiful Women For Track Events”)

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