My subaru 1302 build thread

[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

[Bug@5speed(US)]

Clive, please don't leave us..

Will be missed as your insight is well appreciated..
Alex

[Eatoniashoprat]

Clive have a nice time away

I just checked QA1's site and they have a 140lbs 9" spring for the rear and that would go just right with the 944 TB's (which I already have).

I looked at 9" coil over spring length because that's what Sandeep used (going by his pics). But I'll have to do some measuring to see what spring length to use, might be different than Sandeep as he is using 400lb springs so a 10" spring might be in order for 140-150lbs.

have a good weekend

Mike

[Eatoniashoprat]

So I might win the dumbest thing of year award on this site, I don't want to admit this but I did not have the front body mount bolts installed.

Single best modification to my beetle: connecting the body to the frame.

When I bought my car it was just bare steel that a guy had done a bunch of body work to, so I'd never taken a beetle apart before to see where everything goes. He also replaced front body mounts with some new steel but there were no holes or anything to bolt to.

I had to drill a 5/8" hole in the inner fender to gain access to the inside of the body mount to fit a nut inside there,drill a hole up from the bottom and hold the nut tight with a screw driver.

All I can say is WOW does it drive better now . The k-frame and body before were flexed apart by about an inch, and the bolts sucked them together.

Mike

[evilC]

Thanks to all for the good wishes.

Originally Posted by Eatoniashoprat

Clive have a nice time away

I just checked QA1's site and they have a 140lbs 9" spring for the rear and that would go just right with the 944 TB's (which I already have).

I looked at 9" coil over spring length because that's what Sandeep used (going by his pics). But I'll have to do some measuring to see what spring length to use, might be different than Sandeep as he is using 400lb springs so a 10" spring might be in order for 140-150lbs.

have a good weekend

Mike

Mike, the length of spring will be dictated by the ride height (and any variation you might want to dial in later) and the maximum compression allowed that'll be defined by the bumpstops. With that criteria maximise the spring length for two reasons:
1) It'll give you maximum range of spring selection and strain the spring less.
2) It will load the damper lower down the tube where its stiffer and lateral bending won't be an issue.

Originally Posted by Eatoniashoprat

So I might win the dumbest thing of year award on this site, I don't want to admit this but I did not have the front body mount bolts installed.

Single best modification to my beetle: connecting the body to the frame.

When I bought my car it was just bare steel that a guy had done a bunch of body work to, so I'd never taken a beetle apart before to see where everything goes. He also replaced front body mounts with some new steel but there were no holes or anything to bolt to.

I had to drill a 5/8" hole in the inner fender to gain access to the inside of the body mount to fit a nut inside there,drill a hole up from the bottom and hold the nut tight with a screw driver.

All I can say is WOW does it drive better now . The k-frame and body before were flexed apart by about an inch, and the bolts sucked them together.

Mike

I feel for you, we have all forgotten to fit/tighten fixings so don't be embarassed and if it reinforces the checking procedure then highlighting it is well worthwhile.
By far the most interesting aspect of this tale is the effect of the body to the overall chassis stiffness. There is a presumption that because the floor pan is a separate element labelled 'chassis' it is as stiff as it needs to be. That is not true as shown by your experience. Extending the philoshopy that the body stiffens the chassis, then providing additional strut stiffeners by way of roll cage and struts in the luggage and engine bay can be of demonstrable benefit for car control. I have a suspension strut brace but I will also be looking at additional bracing in the luggage compartment as well as a cup brace in the engine compartment and your experience has dispelled any lingering doubts about doing so.

Clive

[Eatoniashoprat]

More adventures in suspension tuning!

I installed the 944 rear TB's (still with 150lbs front springs, 19mm front AR bar and no rear AR bar). And the car actually feels somewhat balanced now, what a difference! The front is still quite a bit stiffer than the rear but with no throttle I can make it oversteer! This felt like a major accomplishment consider how bad it used to push.

Even just during the daily drive to work the turn in is much more responsive.

I want to try the 944 rear anti-sway bar as the next change. Right now if you force it into an oversteer situation the rear comes out very sudden and my hopes are that a rear anti-sway bar will make it more predictable at the limits. Does this make sense?

Further, after putting a few thousand miles on the 150lb front springs they feel a little stiff, like they barely move driving on the street. I'm thinking, since I want to go to a taller spring (or threaded sleeves) for more adjustment, 130lbs might be the right balance (and go figure it matches exactly front and rear what judgie is running on his race car).

Mike

[ricola]

Glad you sorted it in the end!

[owdlvr]

Mike, taking it down the quarter last night...





-Dave

[Eatoniashoprat]

Sweet photo thanks for posting that Dave,

To be honest I was a little dissappointed with the quarter mile results but now to troubleshoot. I was running 11-12 psi on the second run and trapped 92 mph. At 2300lbs that translates to like 150hp at the flywheel . I ran 102 mph last year at the same boost (different track elevation, about 1000ft higher), timing map was slightly different. But even 100 mph seems slow for the power to weight.

Maybe the intake tract is too restrictive? Maybe I didn't have the throttle right to the mat? I'm looking into it

[Bugged]

Can I ask what size and brand fenders you are running? Both front and back, as well as wheel and tire sizes. Thanks! Looking sweeet!

[Eatoniashoprat]

Originally Posted by Bugged

Can I ask what size and brand fenders you are running? Both front and back, as well as wheel and tire sizes. Thanks! Looking sweeet!

Creative Car Craft, 3" wider rear, 2" wider front

Size: Front 16x7" / Rear 16x8"
Offset: Front 23.3mm / Rear 10.6mm

For the record the fenders were amazing quality. They came with a gel coat, fit perfectly and needed virtually no smoothing, just paint. Can't say that about all fibreglass fenders.

[B-rock]

What brake setup are you running?

[owdlvr]

So the latest rumor is someone's GL is in the newest issue of UltraVW.

I haven't seen it yet, but it will be part of the Great Canadian Volkswagen Show coverage...

-Dave