My subaru 1302 build thread

[Steve C]

Hi

Yep should be a fairly large bolt fitted in there.

Steve

[evilC]

Mike,
do you know what the cornerweights are? My guess is like the others that the rear is way too soft for the front. Modify the rear of the car in stages so you can get a detailed assessment of the effect of each mod. Which TBs are you going to use? If they are the standard 944 - 23.5mm ones, even these might be too soft for the weight of that scooby in the rear. Why don't you get some coilover dampers or a kit for the KYBs and add your 10" 150lb/in springs onto it. At a guess, the combination with std 944 TBs will give the correct springing for the heavyweight rear although the KYBs might be a little soft on the damping side. A good rebuildable damper is the best way to go to allow further options.
I'm a firm believer in leaving the antiroll bar off until all the springs and dampers have been selected and then using them to fine tune the handling. I would interested to see what happens with the 150lb/in springs/billys up front and 944 23.5TBs with 150lb/in coilover in the rear with no antiroll bar front or rear. I think you will find that the current set up overloads the front outer tyre and the anti-roll bar has no chance of coping with the roll. Once the rearis stiff enough the load will be taken off the front outer and then steering will return.

Clive

Oops! just realised that you can't leave the front anti-roll bar off so just use the standard one for now.

[Eatoniashoprat]

Hi Clive, The car is about 2350lbs, 42% front. So:
front: 987lbs
rear: 1363 lbs

I've run the numbers in my spreadsheet and with 150lbs in the front, stock rear TB's, and 150lbs rear coilovers gives (approximately) an 11.2%CPM difference, 104 front, 117 rear. So 150 lbs coilovers would be perfect as far as the numbers are concerned.

With the extra weight I think I will need the stiffer front AR bar as well as the rear AR bar. I mean, everybodies doing it ! It seems that all the cars I see are running rear sway bars, is it because its needed? because its the thing to do? Compensating for too low rear spring rates? My car understeers even with the weight fully transfered to the front. The only way to get the rear to turn is by serious trail braking at high speeds, massive amounts of throttle input turns the rear into a steamroller and the car straightens even more.

Mike

Originally Posted by evilC

Mike,
do you know what the cornerweights are? My guess is like the others that the rear is way too soft for the front. Modify the rear of the car in stages so you can get a detailed assessment of the effect of each mod. Which TBs are you going to use? If they are the standard 944 - 23.5mm ones, even these might be too soft for the weight of that scooby in the rear. Why don't you get some coilover dampers or a kit for the KYBs and add your 10" 150lb/in springs onto it. At a guess, the combination with std 944 TBs will give the correct springing for the heavyweight rear although the KYBs might be a little soft on the damping side. A good rebuildable damper is the best way to go to allow further options.
I'm a firm believer in leaving the antiroll bar off until all the springs and dampers have been selected and then using them to fine tune the handling. I would interested to see what happens with the 150lb/in springs/billys up front and 944 23.5TBs with 150lb/in coilover in the rear with no antiroll bar front or rear. I think you will find that the current set up overloads the front outer tyre and the anti-roll bar has no chance of coping with the roll. Once the rearis stiff enough the load will be taken off the front outer and then steering will return.

Clive

Oops! just realised that you can't leave the front anti-roll bar off so just use the standard one for now.

[Humble]

The rear is way too soft right now, I know because I'm dealing with the same problem on my street bug It's got the same behaviour and it drives me crazy. I think Clive is on the right track with the addition of 150#/in rear coil overs on top of what you already have. If you want to stick with torsion bars I'd suggest a stiffer 25mm bar instead of the 23.5mm which I think might be too soft still for the weight of the subie.

Normally, with a well setup beetle, turn in should be instant and direct without hesitation. As the suspension loads up it'll feel like it's turning sharper on it's own (a feature of the suspension design) and should be neutral with a tendency to understeer when pushed to it's limits.

Right now when your bug enters into a corner the weight transfers to the outside rear because its the softest corner. With the weight away from the front wheels they can't do their job so it pushes. To make matters worse, when you finally pour on the power coming out of the corner what little weight you had on the outside front corner now transfers to the rear as the rear end squats. Basically, the beetle is a point and squirt car at this stage, since there's too much weight transfer to do more than one thing at a time.

[evilC]

Mike,

If you haven't already got the 944 TBs then as you have the coilsprings a decent upgraded pair of dampers sounds like the way to go with the stock TBs - maybe some QA1s on the rear?

Be cautious of just adding a rear anti-roll bar as understeer is predominently safe, oversteer can catch you out and as I said I prefer to use anti-roll bars as fine tuners rather than expecting them to deal with fundamentals.

I'm signing off now for a couple of weeks so I will have to check out this thread when I get back - enjoy yourself!

Clive

[Eatoniashoprat]

Originally Posted by Steve C

Hi

Yep should be a fairly large bolt fitted in there.

Steve

okay thanks, I'll have to find another super and check it out because on mine there is a little tab on the body above that point, but there are no holes in it.

What made me think of this is because in this picture it looks like the body is flexing wrt the pan, if you look at the front apron and the roll bar. Could be just the angle/sun playing tricks though.



Mike