Evil_Fiz wrote: ↑Wed Jan 03, 2018 5:42 pm
I will be running an Subaru engine and seek the best handling possible.
Thanks,
Emil
Having built a subaru powered car, I can tell you your big challenge will be trying to balance the car front to rear.
Do EVERYTHING possible to move the engine/trans as far forward as possible. The best way to do this is a Subaru trans (with a subaru gears kit. The other big advantage with this kit is affordable LSD centres, 5 speeds and strength way above a VW trans). Same for anything else you can move forward/to the front of the car. Battery, driver seat, radiator, fuel system, ECU, exhaust, etc, etc. Everything in the back of the car should be super light, full of speed holes and or/made of fairy wings. If you don't get this right, you're going to be fighting understeer everywhere, followed by snap oversteer.
More about the subaru conversion. The subaru 5 speed once converted to VW use is a 14.5kg penalty. Sure you get 5 gears, but a VW 4 speed could be regeared.
Thank you, petew and Bruce2, for your advice. I am learning as I go along so the voices of experience will serve me well. Since you both have first hand knowledge of Subaru powered cars, what shocks would you recommend for a Ghia convertible lowered with drop spindles and hopefully drop spring plates (I will go adjustable plates if the Atomwerk plates are not to be had.) I have read about Koni and Bilstein shocks in this thread but all the talk of custom valving and some of the Koni shocks being NLA has me a bit sideways. This will be a street only car with a focus on handling over raw speed. I am looking for performance/stbility up to 100 MPH but will rarely, but most likely never, go over 80 MPH. Should I still be considering Koni or Bilstein, or should I look at a set of KYB shocks? Model or part number information would be most helpful.
Bilstein or Koni adjustables will help you. However with such a radically different car, you're better off going along to a shock specialist and getting them to build you something that does what you need. This is because the "off the shelf" options won't represent the weight specs of your car.
Just out of interest, which subaru engine are you planning to use?
petew wrote: ↑Thu Jan 11, 2018 1:03 pm
...Just out of interest, which subaru engine are you planning to use?
I have not decided yet but I will most like stay NA since I am not after 1/4 mile times. I am leaning towards the most recent EJ25 that still has a cable throttle or an EZ30R or which ever one has the individual exhaust ports. My reason for going Subaru is for the reliability and cost of an EFI engine. I know I can get a relatively reliable EFI ACVW engine built but the cost appears to exceed that of a comparable Subaru swap even when I factor in all the "conversion" costs. I may be completely wrong which is why I ask so many questions. I don't want to hijack this thread with Subaru conversion issues. Feel free to PM me. I welcome the opportunity to scavenge as much information from you as you are willing to part with
Thank you once again for providing me detailed information I can use.
Evil_Fiz wrote: ↑Thu Jan 11, 2018 12:17 pm .... and hopefully drop spring plates (I will go adjustable plates if the Atomwerk plates are not to be had.)
Please don't become the latest victim of Charles' theft. Read his feedback topic on the Samba for the list of people waiting sometimes for years.
On top of that, his IRS drop plates are a complete fraud. They offer no benefits whatsoever vs the stock spring plates. The spring plate is simply a rigid link connecting the TA to the torsion bar. The shape of this link has no effect in the handling of the car.
Since your car is going to be a lot heavier in the rear than stock, a stiffer valved shock should work. Maybe someone who's used KYB gas-a-just shocks in the rear will give their opinion on this. It's been about 25 years since I used those shocks at the rear, so I don't remember much about them, only that the same shock on the front was unbearable.
More recently, I found a pair of Koni yellow shocks designed for the rear of a 944. They are valved much stiffer than a regular Koni red. But I found them just fine on my car.
Bruce2 wrote: ↑Sat Jan 13, 2018 5:23 pmOn top of that, his IRS drop plates are a complete fraud. They offer no benefits whatsoever vs the stock spring plates. The spring plate is simply a rigid link connecting the TA to the torsion bar. The shape of this link has no effect in the handling of the car.
I have read the entire feedback thread on TS and ss far as the whole fraud thing goes, my plan is (if I go that rout) to get the spring plates on eBay or a swap meet from someone who actually has them in hand. On a side note Charles Adams is no longer manufacturing or selling the spring plates, they are being built and sold by NW Fluidpower & Machining.
I understand you point about the plates being a rigid link but if I understand it correctly they lower the rear by raising the mounting point of the diagonal arm without re-indexing the spring plate. Does that not keep the proper preload and spring rate on the spring plate as opposed to lowering by re-indexing? I am not trying to be argumentative so please correct me if I am wrong. I want to do things correctly and in the most effective manner possible.
Evil_Fiz wrote: ↑Wed Jan 17, 2018 5:17 pm
I understand you point about the plates being a rigid link but if I understand it correctly they lower the rear by raising the mounting point of the diagonal arm without re-indexing the spring plate. Does that not keep the proper preload and spring rate on the spring plate as opposed to lowering by re-indexing?
If preload is defined as the torsional stress on the bar while the spring plate is resting on the lower stop, why do you think that has anything to do with the handling or ride when you are driving down the road with the spring plate not resting on the lower stop? It's a condition that doesn't exist while you're driving.
Compare a lowered car with stock spring plates re-indexed to the same car at the same height with drop plates. The corner weights will be exactly the same. Given the weight on one rear tire and the length of the spring plate (from axle centerline to torsion bar centerline), the amount of torque being applied to the torsion bar can be calculated, and they will be exactly the same. The torque on the bar is force (weight) times distance. The shape of the spring plate changes neither of these two values.
Then when you start driving it, a 1" bump will cause exactly the same change in angular twist of the torsion bar. Same for a dip in the road. There is no difference!
When he first offered IRS drop plates, Charles was quick to proclaim that his plates prevent the spring plate from hitting the shock tower. This cemented his ignorance since the stock spring plate NEVER hits the shock tower. The bump stop prevents it. Even if you took the rubber bump stop right off, the stock spring plate is still miles away from hitting the shock tower. In that case, the trailing arm hits the top of the shock tower.
Thank you petew and Bruce2 for the excellent explanations and advice. I was on the fence about whether what you explained about the spring plates was the case. As i stated before I am learning as I go along. It looks like I will be going with adjustable spring plates rather than the Atomwerks items. my plan now is as follows:
Desired ride height is 4" at the rocker panels with a flat stance or no more than a 3" drop.
Rear
- Delrin inner diagonal arm bushings
- Prothane graphite/Moly loaded black urethane spring plate bushings
- Adjustable spring plates (brand not determined yet, need advice)
- Stock or narrowed diagonal arms (not sure if i need to narrow for tire fitment)
- Rear disk brake conversion with street Porterfield pads (brand advice welcome here as well)
- 17 x 7 - 7.5" wheels and 205 - 225 40 17 tires
- koni or Bilstein shocks valved accordingly based on weight
- high density OE progressive foam bump stops (as suggested by piledriver earlier in the thread)
- 924/944 14mm sway bar (recommendations needed)
- Wheel BS and ET to maintain factory wheel center line
- Reshaped Wheel arches to fit and follow wheel
Front
- stock with adjustable beam with inner Delrin, Micarta, or bronze bushings and outer bearings
- Drop spindles (brand recommendations needed)
- Stock calipers with porterfield street pads
- Drilled and slotted rotors
- 17 x 7 - 7.5" wheels and 205 - 225 40 17 tires
- Rebuilt OE stering box
- koni or Bilstein shocks valved accordingly based on weight
- 19mm sway bar
- Wheel BS and ET to maintain factory wheel center line
- Reshaped Wheel arches to fit and follow wheel
Please advise on the sanity of my choices and add any corrections or improvements that need to be made.
Make sure you get an adjustable front axle that allows you to adjust from a normal ride height downward. We bought one once that started with a two-inch drop!
FJCamper wrote: ↑Fri Jan 19, 2018 2:52 pm
Hi Emil,
Make sure you get an adjustable front axle that allows you to adjust from a normal ride height downward. We bought one once that started with a two-inch drop!
FJC
That's the problem I have with my current front end. The pork chop that installed the adjusters wanted it scrapping itself to death.
I know this thread is more Ghia related than Beetle, but there's a lot of great stuff in here. I saw an earlier post with someone asking about drop spindles and 155/80r15 tires, on an otherwise stock '66 Beetle would that combo cause tire rub? I'm planning my build for a "vintage race" setup, and I know most governing bodies want OE style equipment/upgrades. Heck, I'm not even sure drop spindles would be legal for this type of racing/autocross. Thanks for the comprehensive post!
Drop spindles (quality welded, forged) get you a trouble-free two-inch lowering.
You can decamber the rear (tricky to get right) or install adjustable spring plates ... if you think tech isn't looking for such modifications.
There is a third, almost never used lowering trick for the rear. And it is visible if someone looks.
You unbolt the swing axle from the spring plate, and link the two together at the bolt holes with a small but strong steel adapter plate. The axle is moved up slightly so the lower bolt holes on the axle tube are just in line with the upper bolt holes on the spring plate.
FJCamper wrote: ↑Thu Mar 15, 2018 8:46 pm
There is a third, almost never used lowering trick for the rear. And it is visible if someone looks.
You unbolt the swing axle from the spring plate, and link the two together at the bolt holes with a small but strong steel adapter plate. The axle is moved up slightly so the lower bolt holes on the axle tube are just in line with the upper bolt holes on the spring plate.
I can't see why anyone would do that. You can achieve exactly the same thing by re-indexing the spring plate on the torsion bar.
