My subaru 1302 build thread

[Eatoniashoprat]

Originally Posted by Humble

Understeer and lifting the inside front tire could be caused by the same thing, rear springs/TBs that are too soft. I'd look into stiffer rear bars or coilovers before you touch anything up front.

Other than that it looks fantastic and seems to take a flogging well. I'm sure it pins you to the seat pretty good too

Thats good to hear, thanks. The very next thing on my list is install the 944 TBs and rear sway bar that I have. These pictures are all with the stock rear TB's and no rear sway bar. It understeers bad even with no throttle on, when you get on the gas it just wants to go in a straight line. Frustrating but I'll update this again once I make some changes and try it.

Mike

[Bug@5speed(US)]

Eatoniashoprat,

From some of the pics that our work firewall permits it looks like you are running the topline struts (page1) with the Bilsteins and 150 lb springs upfront, as well as topline swaybar and a strut bar, correct?

In the back it looks like, no sway bar, a kafer bar, and those white struts which I can't read or remember who makes, is that correct?

Definitely sounds like the front is sprung a little too stiff when compared to the rear.. hence your comment about thicker TB in the rear?

Couple of questions, were the bilsteins valved or designed for the weight of those springs? While this won't address your turn in issue, I am curious as to the setup, and how the car handled (transition of weight, front to back, side to side).

Having tracked an AWD, a frt Engine-rear wheel drive and a front engine-front wheel drive, puts me at a knowledge disadvantage with how the rear engine-rear wheel drive aught to be set up or handle.. but me thinks lifting 3-4" is a little much.. but not uncommon, as seen in some BMW such as the e30.. guess my point, and I am assuming since you make a comment about new to this.. is that be careful, not to make the car to difficult to drive on the track. Find something that eventually has a little understear and somewhat forgiving.. Coming in hot into a corner about 80 mph in a turbo AWD, and going sideways is not fun, but punch it and the front grabs and pulls you through it, did the same driving my old 330, and it was a little different in experience.. both cars were pretty balanced and could induce a little overstear to help get the rear round quickly if I needed, but under most conditions they were neutral with a little understear.. I use to run (hopefully, next year we get a car out to the track) in the north east, and places like Watkins Glen can be dangerous (125+ straights) if you have a tail happy car.. as can be see by the many Porsches that end up in the wall while lifting to quickly.. There is an art to getting those things to rotate, but I will be right behind you relearning in a few years.. for now I am just a by-stander..

Don't forget tires, brake pads will be part of you upgrade path to more speed..

Depending on the type of track and how these cars handle (SBs) you may want to play around with Springs Lbs vs torsion bar size, vs swaybar size..
Some cars like not having a rear sway bar and running heavy springs and TB, with appropriately matched strut cartriges..

Food for thought, but I am interested in your set up, as I may be ditch my Topline struts for some 944 housings with some koni's (beetle, 944 or custom valving) for the front (unsure of spring weight yet) and TPLINE SB, and for the rear probably sticking with the koni's for the beetle or 944 with 944S SB..
Car will run slicks (avons or khumos), 944 turbo calipers and race pads to complete the package.
VR
Alex

[Eatoniashoprat]

Alex,

You have it right, and the rear shocks are kyb gas-adjusts.

Keep in mind that so far I've only had it doing auto-cross and a few high speed on/off ramps, I won't get to a road-course for awhile.

I knew that going to 150lb springs in the front was going to make it handle worse, but it was the first change I had to make because the topline springs (~70lbs/in) were so soft that I could grab the bumper and push it down to bottom, and I'm not a very big guy.

The Bilstien's are just the non adjustable sport versions (albiet very expensive) and I'm unsure of the valving on them but they are a good bit stiffer than the sachs GTI inserts that came with the toplines.

In my non-expert opinion it feels really good and very tight. With no throttle or engine braking it won't steer, under throttle its even worse (pushes straight), in autocross I can't get it to trail brake. On 60mph off ramps I can steer by trail braking but that's the only way to get it to turn, and you have to be going pretty fast for it to work.

Tires will come once I get the suspension more balanced. On an autocross track I can't imagine needing more brake, maybe once I get tires I'll notice. The 150lb springs helped the brakes out quite a bit, I think its because the topline springs were bottom out and then the tires would skid. I think that's still happening but under much harder braking, which I why I either need to get the front end another 1/2" higher or go with a progressive spring.

Like I mentioned earlier, next step will be 944 TB's and sway bar, adjust sway, and see how it works. Keep in mind I drive this car to work everyday and take frequent road trips so there will be SOME sacrifice in all-out race setup versus being street friendly.

Thanks for the comments

[Eatoniashoprat]

Also, this is an embarrasing question to ask, but in a super beetle in the front k-frame, near the sway bar mounts there are two holes. I don't have any bolts in there, there is a little tab above them on the body but it didn't look like something you would bolt to.

I bought this car completely stripped down and part of the front end had been replaced, is the body supposed to be tied in to the pan there? It would seem to make sense?

Its my first beetle, don't judge me, lol

Mike

[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]

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

[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

[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

[ricola]

Glad you sorted it in the end!

[owdlvr]

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





-Dave