Legal weight reduction for SM2
 

I am preparing an FD3S per the SCCA SM2 autocross class rules and to also be used as a track day car a couple of times a year. This car will be licenced but will not be street driven.

What I have been able to glean from the web is not very definative and I'm not sure that the "official" SCCA rules are any clearer since SM2 appears to be an extension of the SM rules.

This is what I think you can remove -
The AC system (not the heater)
Power Steering pump
ABS pump
Power brake booster (not real clear on rules on the replacement master cylinder)
Radio and power antenna
Front & rear inner bumper supports (assume this since body panels can be replaced)

I understand that you cannot remove the Interior panels or sound deadening
(I'm not sure about the panels (bins) in the back of the car since SM cars can pull out the back seat.)

I understand that you can replace the seats with lighter ones.

No on the bumper supports. The rule says you can replace the body/fascia piece only. The foam, fiberglass, and metal bumper reinforcements are not attached to the front nose piece, so I don't see how you'd be allowed to remove them.

You can also save alot of weight in the powertrain which is open by the rules (like exhaust). Seats save alot plus seat rails.

For auto-x I don't think you'd want to dump either the ABS or the PS.

Look to the national champ type guys for examples.

Weight Reduction
 

Yes the ABS and PS are heavy and would save you a lot of weight.

Jeff I think he should do all of his planned mods. The car will be lighter than any of his competitors.

Shame on you for not wanting to help the poor guy.

Allan

So if powertrain is open, can you use lightened rotors, e shaft, trans gears, Al flywheel, gun drilled trans shafts and axles, Al or CF driveshaft, lightened ring gear, gun drilled pinion shaft? That would be alot of weight saved in probably the most effective area.

I think he meant that PS and ABS are both really nice to have on an autocross course, and that he would rather have them than the weight lost by removing them.

Weight loss
 

Steven, Steven, Steven Jeff is just worried that if we all get lighter we will kick his butt. So you can never ask Jeff for advice!

Steve I know Jeff personally, I keep posting here because I know he will read it and I will get a response from him!

If you autox I cannot believe you have not pulled out your PS and ABS. If you have not you are too slow!

Allan,

I still have ABS and PS in my car and plan to keep them. I think the tradeoff is not worth it considering the benefits ABS and PS provide. I guess I am too slow.;)

-Andy

So Allan, you think that removing the bumper supports is legal? That was one of his planned mods.

-Andy

ABS & PS
 

Andy I was talking trash. Some people actually remove the two to save weight. Yes they can, yes it will reduce the weight, and maybe you can notice the difference. Me, I will keep them thank you very much. However I am not above removing them if that is what I have to do to beat that other RX7 driver in our class. I think you know who he is! His wife co-drives with him.

Hey I ordered 800/600 for my car. Also an interesting item I found from another post. Tein RA coil over uses 895/895, tein N1 uses 1119/1119 for spring rates. Interesting how they are the same rates. Do you still plan on going 1000/800?

Allan

2nd fastest autoxer in a RX7, one day to be the fastest (I HOPE)

Glad your on here posting.

Man I'd really hate to beat you again in my car wearing stock wheels, again:). Of course I still have AC so that is probably what makes my car faster!

Lesson Learned
 

Yeah, I learned to stay off your home track! You use your car as a 4 wheeler beast going over the curbing. Some of us have cars that are sprung a little tighter and going over curbing is not a good thing.

Now, I will just stick to the courses that you and I have the same amount of time on. But no matter what, my car looks better, not to mention sounds like a beast.

Remember jealousy is a horrible thing big man!!!

P.S. I emailed someone about getting his CF fenders. If I get them then you know I will need a CF bumper. Man my car will look so good compared to either that red cream puff or yours or the soon to be yellow marshmellow!!!

Allan

Did you say somethin':)?

Fastest RX-7? Hmm....

Dan
(currently building a turbo FB for SM2)

Yes
 

Yes you heard me right.

hey spank!
you never return my calls man! whats goin on man?, long time no talk!

ill drop you a call today..

Jason
 

I would return your calls if you called!

208 484-7126 cell.