My subaru 1302 build thread

[Humble]

Very cool and it looks fantastic, nice to see some updated pics

[Eatoniashoprat]

Thanks! Here is another pic I found

I've got a decent tune on it right now that will run and drive the car quite well, and runs up to about 11psi. The timing isn't optimum (conservative and not very smooth) but I'm waiting for dyno time to really dial it in. The motor should be fairly reliable up to about 18 psi, but for mainly street driving (some auto-cross and some drag strip) I think 15-16psi with careful tuning it should be plenty fast enough .

[bow]

that things sexxy

[Humble]

Yeah, Jeff helped to build that k20 bug and I think stupid fast is a good description of it. As far as I know he's using a rancho pro-drag swing axle tranny, also without weddle gears. I'm trying to convince the same guy to give me a hand with my swap and possibly "the next big project" down the road.

[NO_H2O]

Nice ride.

[Eatoniashoprat]

Update

After a bunch of tuning I've found that my intercooler solution (I should have known) is not the greatest. Although it fits nice and looks impressive it can only handle about 11 psi with the current setup before temperatures go through the roof. I'm using a GM intake air temperature sensor and datalogging it. I've bought an air to water Spearco unit good for upto 500hp, but I don't want to stop driving the car right now so it will have to wait until next winter to get installed. I plan to put it in the luggage tray behind the rear seat so it will get no heat soak at all, then put a cooler spaced a couple inches in front of my rad up front. hopefully it will handle 300hp, which is all I'm after .

In other news:

I installed 150lb/in 10" QA1 springs in the front as well as bilstein dampers. My first regret is buying 10" springs instead of 12", I'm at the highest adjustment slot in these pics.

On the street I find the 150lb/in to be on the edge of being too harsh, keeping in mind that the streets around here are not smooth and there are giant potholes to dodge everywhere. If the roads were nice and smooth with the occassional bump I wouldn't hesitate going even stiffer. I just saw that QA1 has a 12" 100-200lbs variable rate spring which might be the perfect balance. Anyone wanna buy some 10" springs lol?

On the track it handled as expected, even more understeer than before. I found a set of 944s torsion bars and anti-roll bar that will be getting installed when I have time but for now I'm stuck with it pushing reaally bad in the corners. The only way I could steer is by doing all braking in a straight line and trying to use the brakes to compress the front right before the corner. I'm new to all this in cars so its been a learning experience.

After seeing the picture below I'm going to have to go and check that the front k-frame bolts are still there because it looks like the body is lifting off the frame. A couple guys mentioned that the front tire was getting 3-4" off the ground.

Comments welcome

[volkdent]

Cool action shots!!!

Jason

[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

[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]

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.