halz93

I recently purchased a 1993 LT1, 6 speed, stock, 100,000 miles to autocross with: As recommended here, I just had the differential and tranny fluids changed. My mechanic went though all suspension and checked bearings, struts, shocks (Bilstein's btw), drive shafts, U-joints, rotors, pads, brake lines, steering, radiator, plugs, wires and said all components are in great shape (from previous owner). So cool as this has saved me a bunch of budget money!!!! I am now moving to next step: changing some rubber bushings in rear (current ones are dried out and look original).

Question one is this....I plan on changing bushings myself at home over winter. Is the spring the only item under pressure or tension I need be concerned about (safety wise)? I've read here that swapping bushings out can be done by an average shade tree mechanic like me who has a good assortment of tools and jacks. Next would be bushings on front.

Second question: My plan is to start autocross in 2018. I need new tires. Street driving of this car I limit to dry pavement days only, no rain, no snow, casual driving over weekends no back and forth to work. I live in the Midwest. My plan is to start in novice or stock class first year as I learn and develop my skills. What would you recommend for tires that gives me good performance on the course (that will hopefully last a couple years?), and can be used on the street? I'd like to stay under $1200 for the actual tires. I use the original wheels. Having 2 sets of tires (racing and street) and would be down the road....2019??? Should I keep using tire pressure monitors going forward? My Service LPTM light is on, but I check my own pressure every couple weeks.

Hope there is enough detail here for some good responses....? Thanks Hal

ddahlgren

Personally I would use heim joints every place possible and those evil to me poly bushings but make sure they are free and offer no preload at all. Obviously fresh ball joints and tie rod ends.

Kubs

Take a look at Banski Motorsports for the heim jointed components in the rear. Definitely a must if you are tracking/autocrossing, and it makes adjusting alignments a snap.

For tires, I would try the Bridgestone RE-71R. Depending how much you autocross in a year they may only last 1 or two years, but they have great grip.

c4cruiser

I used the Banski rear suspension components on my old '87 autocross coupe and I really liked how easy it was to make very small adjustments. I installed them myself wit no real effort. The car also saw street use so I added the rubber heim joint covers to protect the metal faces. They had a coating on them (teflon?) so they could be used in dry conditions, but the covers do help for driving a lot in the wet.

One thing you should do even while entering as a Novice, is to think about what class you want to run in. Most associations will have online rules about what mods you can do in stock classes and what you can do for Prepared or Modified classes. So make sure you set up a plan for the car so you don't get surprised at an inspection.

Also, buy a good helmet! Get one that has a "SA2015" rating. Most autocrossers use an open-face style, but consider a "full-face" version if you may try doing track days. Look at Bell, Simpson, G-Force, or Pyrotech for brand names.

hcbph

Add another vote for the Banski setup. I put the whole setup on my 86 last winter (trailing arms, camber rods and toe rods) and my car never handled those windy country roads better, and I'm pretty sure it would do the same with auto-cross. I did run into 1 issue that was easy to correct once identified: the bottom end of the camber rods are set up for an opening of 1.7" while the knuckle opening on mine was 1.64". A little modifying the spacers took care of that.

Put them on, get a 4 wheel alignment and you'll be impressed with the changes.

93Rubie

I think you should put a good set of tires on it and an alignment and drive it for a year on the stock stuff. Decide what class you want to run and build accordingly. Changing bushings by itself moves you to STU at minimum for SCCA. Those Banski parts would bump you right past BSP into SSM.

If your going to drive it some on the weekends. I don't recommend the RE71R's they where quickly with daily driving. I've done it with my NC Miata when I had it but i don't recommend it. Dunlap ZII* is a great tire. Wears excellent, offers almost as good performance as RE71R's or RIval S but much better wear just not stupid fast like those.

What wheel size(s) are on your 93.

FYI, those stock Bilstiens are crap IMHO. Koni's, you'll never look back.

Today's event. I set PAX and FTD. Second event in a row I did this. Car is still very competitive even in bigger regions. http://stcsolo.com/wp-content/upload...ax-Results.pdf



Don't get sucked into the "modifying" stuff because its better than stock game. Properly setup C4 with some driver mod will often beat modified machinery.

MatthewMiller

Everything 93Rubie just said, write on your bathroom mirror and read it every evening when you go to bed and every morning when you wake up. Stay in Street (stock) class for now, start learning the skills, get seat time, and then start deciding what class(es) you want to race in for the long term. Once you determine a class to race in, build for that. For now, find all the SCCA, NCCC, and other solo events in your area (there must be quite a few around Chicago) and go to them. Also consider a training course such as Evolution. Invest in your skills now, and the car later.

I mostly agree with the Dunlop ZII recommendation, but it depends on your budget. If you can blow more money on tires more frequently, the RE71Rs are one of the two best tires to use, the Rival S being the other. You can probably get 120 runs or more plus a little street driving out of either one. But the Dunlops will still last a lot longer, are still pretty fast, and have good and benign handling characteristics. Based on what you've written (especially about a second set of wheels being a future upgrade rather than right now), I agree with going for the Dunlops.

Also, you may find you want a brake pad with a little higher heat range than what you have now. Unless you know what kind of pads are already in it, you'll have to see how they do for autocrossing. Honestly, autocross runs aren't usually that taxing on brakes. I am just using PowerStop Z26 pads on my car that has way more power and grip than a stock C4, and they are plenty.

The other thing to spend some time and money on is alignment. In general, you want as much negative camber as your class rules will allow, and around zero toe front and a smidgeon of toe-in on the rear. If you don't maximize negative camber, you are giving away both grip and tire life.

kimmer

Kumho XS if they still make them. They were the tires I learned on before I went to slicks.

gerardvg

Banski suspension components are great, ease of "precise" adjustment, especially for replacing the offset camber washer/ bolt.
I track my car as often as I can, being able to adjust my rear camber precisely and easily is a must. The damn standard offset washer always moves a little putting rear camber and wheel alignment off.
Ever since going to the Banski setup it is precise and will not move after a few laps, so easy to setup various ride heights and quick easy alignments.

All bushes must be replaced as a minimum, dual adjustable coilovers make ride height and tuning to tracks a breeze..

j.martynuska

I never ran TPMS.

Rear spring is pretty easy to deal with (compress). Floor jack with a block of wood near the bolt makes a quick compressor. Don't scratch the spring.

Those bushings have 100,000 miles and 23 years. May be worn enough that trying to learn on them will be an exercise in frustration due to inconsistent handling. An alignment shop may not want to do the job with slop in the bushings either.

If you end up in STU, don't feel you need every mod right away. Build over time as ability increases and you can take advantage of the mods. (Kinda wish I'd stayed with my C4 and moved to STU.)

In novice classes, you should be competing with other novices (novi?).

Your Bilsteins will be fine or starters, one less rope (rebound adjustment) with which to hang yourself You can upgrade later.

I liked a big front sway bar.

Take Evolution schools, take local novice classes, take instructors. Often over looked, find an experienced driver to take you on a course walk.

Do the LT1 cars have the lap belt lock feature the L98 cars have? Helps hold you in the seat.

Great advice here and still a wealth of information.

Good luck, perhaps most important, have FUN!

MatthewMiller

Yes, they do.

64Scout

Another vote for reading the rules first. Changing suspension bushings to anything other that rubber moves you out of stock.

Tom400CFI

X4 on keep it stock, improve the driver/get familiar.

Purple92

Excellent Advice !!!!

If you go to poly bushings - you will not be running in a stock class !!!

So - IMHO - the first thing you need to decide is if you are autocrossing to win trophies, or if you are autocrossing to have fun and improve your driving / car control skills.

If you are there to win trophies - you aren't likely to be doing that running in a non-stock class on a street compound tire. You are going to get your posterior waxed !!!

On the other hand - if you are there to have fun, and you really don't care that your best time is six seconds off the winners time in the class that you are running in, then by all means, go with the poly bushings to replace the old rubber ones, put on the bigger sway bars, and learn to drive the car !!!!

One last thought - after you've done a few autocrosses - if there is a road race track within a few hours of you - try a track day. It's quite different than autocrossing, but I think it's more fun (of course I've been doing them for more than 20 years - so I may be a bit biased). In autocrossing - you can't afford to be real smooth - on a road race track - being smooth is paramount. One caution - track driving should probably have a surgeon general's warning about being addictive... If you try it - you may find yourself grinning from ear to ear days after the event. Just sayin......