briannutter1

I'm taking weight off the front of my mostly autocross C5z and the left front in particular. The Brake booster, ABS module, and factory steering column are three things that contribute most to the problem.

I don't know about going full manual brakes on an autox car at 3200lb race weight, but has anyone ever tried Hydraboost or some other method reduce/move the weight of the canister?

Typical drag steering columns are kind scary and unsupported. Any better options there? I can move the switchgear elsewhere.

Some have moved their ABS module to the passenger footwell. Is running/flanging the lines a nightmare, or is there an easier way to do it?

RX-Ben

If you move the ABS, you can measure the lines you need and the order pre-flared lines. Which I think is a good idea considering how important proper sealing is and the cost of a proper flare tool. I got mine from here: http://www.hoseandfittingsetc.com/pr...tive-plumbing/
You could go to a manual brake setup but a bit of your potential weight savings could get eaten up by the weight of the new pedal box and proper mounts (i.e., not to the balsa floor).

briannutter1

Ok, that makes quite a bit of sense. So they were stainless flex lines? Do you still have the measurements and an approximate cost for your project?

froggy47

Curious because, isn't that the corner you shift weight onto when you corner balance an otherwise stock c5?

Did you already move the battery & do other lightening on other corners?

Driver weight?

RX-Ben

Get the EZ Bend lines, which are NiCopp and you can bend them by hand and they don't rust/corrode.
$173 for all 6 lines.
Measurements are highly dependent on line routing and module location. This is only a ballpark. I looped the lines at the M/C to better allow the hard lines to flex due to M/C movement.

(2) 1/4" lines:
126" and 132" lengths
The front brake line uses a 12x1.5mm ISO bubble flare on a 1/4" line (applies to each end of the line). The rear uses a 12x1mm ISO bubble flare on a 1/4" line (applies to each end of the line). You do NOT want an inverted or double flare.

(4) 3/16" lines:
~67", 80", 109", 117"
M10 x 1.0 ISO bubble flare on both ends

briannutter1

Thanks for your help guys. Yes I believe getting the static weight better will require less corner balancing with the ultimate goal of getting static the same side to side and more more rearward bias. So far I've dropped the a/c, headers, miata battery in standard location, light steering wheel. McLeod RXt 45lb clutch/flywheel, but heavier 22lb Quicktime bellhousing. Containment seats and 6 point have added weight so I'm 3316 race weight as it sits. LF 887 RF 805 LR 806 RR 818 static before cornerweighting with my 191lbs in it and 3/4 tank of gas (I'm down from 203 earlier this year )

briannutter1

I've got the ECS Alternator Relocation bracket/kit on order as well to move the weight to the passenger side.

drivinhard

The alt is about the same weight as the ABS, both together are pushing 30 lbs which is significant.

The RR of these cars is always the light spot, so my thought process was if you're going to move it, then get it all the way to the RR. The 97 and early 98 cars had the ABS in the rear (behind the diff) so I just got some 97 lines from vettenuts in TN and used those from the MC through the center tunnel back to the diff, and did unions from there up into the tub. Had a fab guy friend help with a lot of that, but the wiring I did ended up being the biggest time sucker and is still in progress (but functional).

Ton of work, but the biggest advantage (besides the weight being in the right place) is more room to work under the hood, I can swap my ABS pump in 5 mins if needed, it stays much cooler, and all the brake lines run through the center of the car and in the rear tub, so nothing is on the front or rear cradle. Makes cradle drops/clutch jobs/general work much much faster and easier.

froggy47

I had no idea on the abs location on the early cars, seems they went backwards when they moved it to LF?

RX-Ben

Putting sensitive electronics between the exhaust pipes does not seem to be the best idea.

briannutter1

Great ideas, thanks for your input. I was looking at lightweight steering columns today. I don't know if the C5 column is as heavy as my c4 was, but that's gotta go if it is. I don't drive in Comp mode or anything, but is there a steering angle sensor that that will cause problems with ABS if I can't adapt it over?

RX-Ben

If you don't need AH/TC, then the steering angle sensor only controls the variable assist PS. And it is useful for datalogging.

LateBreak

AIR Pump is in the LF under the bumper, you can definitely get rid of that junk but I'm not sure how much weight it will save.

Scooter70

The AIR pump is below the driver's side headlight. You can remove it and the associated hoses if you haven't already.

briannutter1

Yep, pulled the pump too. I looked into lightweight alternators. A 95 amp Denso is a lot of money per lb saved.

briannutter1

Is it possible to put a rheostat or something to dial in boost instead?

drivinhard

the 97-00 pumps are boat anchors to. The 01-04 are probably 1/3 smaller, and the C6 ones about 1/3 smaller than those

the rear diff mounted ones are in the way for rear work/clutch jobs, etc. so kind of a pain most of the time. But the weight is in the right place, and they are mounted lower than in the later cars to

RX-Ben

You can run it with nothing hooked up, which I believe is the easiest setting. You can also hook up 12v to it, which I have heard is what the EBCM feeds the rack at high speed (i.e, the highest effort, but note that you are still getting a significant reduction in effort vs going full manual).
Or, you can feed it something in between.

LateBreak

In my experience, the hydraboost weighs as much or more than a vacuum booster.

Other options:
Windshield wipers? The motor is heavy, you could just use Rain-X and delete that whole assembly, especially if you're really only Auto-Xing.
Carpet? Even the floormats can have some weight to them.
HUD delete, not sure what this weighs though
Remove the airbag from the steering wheel or switch to a Momo/Sparco/etc
Window glass and regulator on both sides
Pop-up headlights deleted or swapped for Fixed

mountainbiker2

Take off the door panels so you can remove the glass when you get to the track. Very easy to do.

Steve