seat vs bushings vs diff vs sway bar: most fun for the $
 

Ok so I'm in a position where I can afford pretty much one modification before next autocross season. I've narrowed it down to getting one of the following options:
Sparco Sprint V seat
Energy Suspension Master bushing kit
FC rx7 clutch type diff
Racing Beat front sway bar

For those of you guys with some or all of those parts, which brought the most fun to the table? Which of those options will improve my driving experience the most? If it helps, my car is fairly stock aside from tein HA coilovers, wheels, a rollbar, intake, catback and steering wheel.

Any input is much appreciated!

Diff, cuz 1 wheel drive sucks

1. FC rx7 clutch type diff, as said above, one wheel drive sucks.
2. Sparco Sprint V seat, it´s easier to drive when you can sit without hanging on your steeringwheel.
3. Racing Beat front sway bar, better turn-in.
4. Energy Suspension Master bushing kit, not least but in this case last.


I would do it in that orded.

I can't comment on the rb unit since I bought FM's reasonably priced f&r package, but i will say that it transformed my stock suspension. I had literally uncontrollable oversteer, if and when the back stepped out. Changed to very easily controllable under steer with the FM sways.

Edit: ^^really good point about the seat.^^ I still might do sways first if this is a DD.

Thanks for the replies guys. I was leaning toward the seat or diff. The seat would be very nice to keep me in place as well as being somewhat of a cosmetic mod compared to my ripped driver's seat. The diff would also be super nice considering my interest in drifting. May have to flip a coin haha.

The reason I'm not thinking the sway is so important is because my car handles pretty neutral with its current setup (stock front sway, racing beat endlinks, no rear sway)

That's one thing I had never tried, disconnecting the rear sways. I just knew there was a specific angle of around 20*, that if I went over it there was no way I could correct it, I'd just spin.

I run without a rear sway because of tire lifting issues that we had in my stepdad's car running the front and rear FM sways. Around tight turns, the car would lift the inside rear wheel. That combined with an open diff resulted in some major lost time in our runs. My car never has this issue and feels nice and planted on corner exit. I may throw the factory rear sway back on when I finally get a diff, but at the moment, I like how it feels without it.

What condition are the the OEM bushings in?

I have all of these things (except that my front sway is an Eibach, w/e). My order was:

1. Bar, along with the rest of the suspension
2. Diff
3. Bushings
4. Seat

My diff is Savington's FC clutch type, tightened to 100 lb/ft IIRC. It has some drawbacks on the street, in that it shudders when hot and has a slightly abrupt engagement, but the peace of mind that it's less likely to break than the TorSen was is nice. YMMV

Buy the seat first, with a harness. That will improve your times and consistancy nearly at much as sitting in it more!

Seat if jot a daily, or a swaybar.

Will say the seat also, security for you and grip for your booty..... harness ONLY if you have a harness bar.

Afterward, buy a diff + bushings while you're there.

I'm not fond of any of the options.


Clutch diff is fun for drifting. It's not fun for predictable handling, smooth launches or parking.

seat is a seat. it's not about fun--your left knee will thank you.

bushings are bushing.

sway bar will probably add the most fun per say, but if it causes too move understeer then it's not as fun.

Get stuff used and maybe you can afford more stuff. I know there are after market sways if the FS section. Have you thought about frame rails? What year is your car?

I was trying to keep the car in STS Solo autocross class, but it appears via the rulebook that a clutch type lsd is not allowed and I'd have to make the move to CSP.

I don't know the condition of the oem bushings, but I assume pretty crappy. The car's a 99 with around 130k.

Harness only if I have a harness bar? I have a hard dog bar with harness tabs, thoughts?

The seat would be nice since I'm 6'1 and would like to sit lower. I can't even heel-toe right now because my right knee hits the steering wheel when I do. I buy most of my parts used. I'm in college. Modding on a budget is like my second job lol.

I have thought about frame rails but I'm not sure about how they'd affect my classing for autocrosses.

I may have found a trade for the diff, so getting that won't affect my budget. I think a seat will be next in line, if I can still afford tires too.

If it helps anyone, here's my build thread with more info about the car.
https://www.miataturbo.net/build-threads-57/pats-fruity-two-seater-beater-56205/

Just my 2 cents but a good bucket seat is worth its weight in gold. Transforms how much feedback you get from the car on track both through your butt and through your hands.