Autocrossing a Spider

[jon8christine]

This summer I decided I wanted more performance from my convertible sports car. Almost pulled the trigger on a 2013 Boxster, but in the end decided to just put some money into performance upgrades for my 76 Spider so it would be fun to autocross if not competitive.

Here's the list of what I've done so far and my thoughts:

Wilwood big brake kit and HD master brake cylinder - If you're going to drive fast you need to be able to stop. This was a good upgrade and it now stops shorter, but it didn't wow me into amazement and I can't lock up the tires or anything. The old front brakes and rotors are for sale in the classifieds.

Monza 15" wheels and Falken Azenis RT615+205/50R15 tires - Speaking of tires the 15 year old 13" tires had to go. This tire upgrade was one of the best as far as handling upgrades along with the rear sway bar. The tires grip like crazy, flying around corners faster than you should definitely puts a smile on your face, and since I don't put a ton of miles on the car or drive it during the cold seasons I wasn't worried about the 200 tread wear summer rating. The old wheels, tires, hub caps and lug bolts are for sale.

Progresive Lowering Springs and Koni Yellow Shocks - Lowering the car a little and flattening it out, removing the bumpers, and putting the bigger wheels and lower profile tires on really gave me the mild restomod look I wanted. As everyone else has stated the Konis are firm on the softest setting, but great for autocross. Honestly they feel very similar to the Monroe Spectrum shocks I took off that were much cheaper. The old springs and Monroe shocks are for sale.

Rear Sway Bar - As I stated above the rear sway bar and the tires were the best upgrades I made for handling. I made my upgrades one at a time for the most part so I could evaluate them and the rear sway bar reduced understeer and body roll, making the car corner much better. Add in the springs and shocks and it's not quite a boxster, but it really corners well, stays flat and is fun to autocross.

Engine - Torque and horsepower are hard to evaluate unless you are on a dyno. So far the engine mods consist of removing the AC and Emissions systems and upgrading the 32ADFA carb to a 3236DFEV (all for sale). The new carb is still being tuned as it doesn't idle as well as the old one until the engine is warm (Mark gave me a couple jets when i bought the carb, and I may need to rejet up here at 6,200'), but the bigger carb is more responsive and the car does feel like it pulls better. More engine and exhaust mods to come...Allison's has been very helpful in this journey, thanks Mark!

My first autocross race was this past weekend and it was a blast learning to drive the car fast. As I said handling was great and I was surprised how fast I could push the car around cones in the slalom and tight hair pins. I've got to start playing with the steering wheel angle and or a smaller wheel to make managing the turns easier. I think the clutch is about gone (no idea if it's original to the 106k miles) as after the races driving home it felt like it was slipping and grabbing, making the car surge until I put the clutch in and then it was fine...weird. Several cars had their hoods up trying to cool off their bigger engines, but the Fiat stayed right at 90 and hummed along all the way to redline each 36 second race (small course as half the parking lot was pretty tore up).

I beat the only other old convertible there that was on race tires and upgrades, a Triumph Spitfire, by a tenth and a stock VW GTI that was driven by a 17yo kid I know by 2.5 seconds. Had to leave early to watch the kids play tennis, so didn't see any of the other results. So much fun.

https://drive.google.com/file/d/150ETut ... sp=sharing

[RRoller123]

Now that sounds like a lot of fun!

Try a lightened flywheel?

[jon8christine]

I actually bought an aluminum flywheel from Allison, but am waiting to install it until this winter...didn't want to miss any more races. May end up putting a performance clutch on and if I'm feeling really ambitious while I'm at it, pulling the engine and putting high compression pistons, header and exhaust in...we'll see. I was definitely getting beat in the straights, probably always will.

[SteinOnkel]

A performance clutch will chew threw that aluminum flywheel real quick. I would get the OEM one resurfaced and lightened.

I've seen aluminum flywheels explode on track. Not fun.

[RRoller123]

I put in the 4mm domed pistons from AR, raised the CR from ~8.1 to ~ 9.8. What a difference! Really good upgrade.

[TheBender]

Good looking car. Hope you can post some race pictures.

[ORFORD2004]

Put EBC Yellowstuff in your Wildwood.
Also what is HD master brake cylinder?

[SteinOnkel]

Put EBC Yellowstuff in your Wildwood.
Also what is HD master brake cylinder?

Please don't. EBC sucks.

Stop-Tech or Hawk.

[jon8christine]

Mark recommended this to keep the brake pedal up where it should be with the Wilwoods.

https://allisonsautomotive.com/collecti ... brake-kits

I'm running the Wilwood DL20 pads that Mark recommended for autocross. Are you saying Stoptech or other pads will make that much of a difference in stopping power? The brakes have great feel, just not the stopping power I was expecting with the upgrade on such a light car. My Lexus IS350 stops like it hit a brick wall in comparison.

[ORFORD2004]

My best upgrade was volumex booster and regular mc for pressure.

[joelittel]

Orford where did you get the Volumex booster?

[ORFORD2004]

Orford where did you get the Volumex booster?

Autoricambi and i delete the mc after couples years because i was not impress. You will have to enlarge the mc hole and use silicone to seal the mc and the booster.
Volumex booster is bigger. So more vaccum pressure but your mc is also bigger so you change 4 quarters for a dollar. But if you keep your orginal mc and add a larger booster, now you got gain on pressure.

[jon8christine]

Ok, finally got a video of the first autocross uploaded to YouTube. Definitely not posting this to show off my driving skills. It's just for fun.

https://www.youtube.com/watch?v=cVsEUarpCbQ

It looks slow, and definitely is compared to the Porsches, vettes and Camaros that were there, but it was a blast. I beat the only other classic there, a Triumph Spitfire, by a tenth.

Here's a couple screen shots

https://drive.google.com/file/d/1PbL2RN ... sp=sharing

https://drive.google.com/file/d/1FB09_G ... sp=sharing

[Nut124]

Cool video. I like it.

I would not bother with a clutch and a flywheel unless you do a total rebuild and have easy access to the FW. Neither will do you any good unless your current clutch is slipping.

The AASCO/Allisons aluminum flywheel has a steel friction surface. I am running one and like it but cannot really tell a difference in power. I run it because my 1800 spins to 8000rpm with some regularity and I do not trust the old cast iron flywheels to hold up and not come thru the trans bell housing when they break.

The fellow who suggested that a clutch will eat thru the alu wheel - I would like to hear if he has used one and knows about the steel surface. I was skeptical as well until I talked to AASCO myself. They are almost like "OEM" for Porsches and HiPo european aftermarket. This is not some unproven backyard job.