dontnow

[QUOTE=Gages 944;7951434]What does reindexing the rear end mean? /QUOTE]

To re-index the torsion bars means you pull the spring plates, rotate up a number of splines and re-install. This is how you raise/lower torsion bar rear suspension.

Severian

xsboost90 thank you for your input...

It was exactly the kind of advice that I was looking for, that is, someone who knows WTF they are talking about!

I greatly appreciate it...

mikey_audiogeek

Hi Severian, sounds like you're on your way - please post your results!

Here's some background on my earlier comments: http://www.vwgolfmk1.org.uk/modules....topic&p=154420

Here's something else to whet your appetite:
Attachment 479131

Best regards,
Mike

Severian

Mike, didn't you recommend that I DO NOT remove the spacer?

There seems to be a lot of disinformation on this forum and I'm just trying to make sense of all of it.

thirdgenbird

He did. I would like him to explain as well. I understand you can go "too far" but I don't think that is in question here.

Sorry for trying to be sarcastic on page 1. There is a lot of great info in this site. Search, read, ask questions, and take notes. You wont regret it.

RDL

Severian, from my limited knowledge:
Assuming: Koni Yellow (adjustable struts on all 4 corners)
Assuming: Stock spring perches
Assuming: The rear ecentrics have not been previously adjusted
If the above is correct adjusting the rear ecentrics can lower the car approximately 3/4" to 7/8". Obviously this does not get you the full 1 1/4" of your spacers.
If you are looking to get a level condition you have 2 choices, 1. Re-index the rear torsion bars: described by others, 2. Paragon Products sells an adjustable spring perch that sets over your strut, provides new perches top and bottom and with a 10" spring can obtain a great deal of adjustment.
I installed this kit on the front of my car this past spring and adjusted the ecentrics in the rear. We were able to adjust the front to match the rear height.
As to ride height numbers it is a rather hard thing to find. If you are only dealing with the ecentrics in the rear once they are adjusted a measurement from the wheel well to the ground will tell you the amount lowered. You can then use this to determine the amount of drop in the front. I have seen ride height numbers before, try searching this site, Clarks Garage and Pelican Parts for information.
Assuming the spring rate and damper rebound are matched well, lowering a car will improve the handling. Anytime you can lower the center of gravity handling will improve. However this is a system that is dependent upon spring rate, rebound settings and many other items to function properly.
Good Luck

mhr

Excuse me if this is a dumb question but with all of the above assumptions and the 200lb welt springs he mentions do you need to change the stock torsion bars to balance the spring rate seeing as the 200lb springs are more than stock?

mikey_audiogeek

Yes, and I stand by that recommendation FOR BEST HANDLING.

Most people lower their car. This drastically lowers the front roll centre, which is detrimental to handling for a number of reasons:

1. It upsets the relationship between the front and the rear suspension by inclining the roll axis too much.

2. It increases the roll couple which requires drastic changes to spring rates and sway bar rates to compensate

3. Due to the obtuse angle between the strut and the lower arm, it results in more positive camber in roll than the factory arrangement.

What you often see is people putting on lowering springs, finding they have too much wheel tuck in cornering (also described as "lack of turn-in") then trying to compensate by putting on a really stiff sway bar which ruins the ride and damages the (expensive) control arms. Not cool.

The big difference between load transfer via roll centre, and transferring weight via springs and bars, is that load transfer via roll centre is instantaneous whereas springs and bars can only transfer weight once they have compressed - which requires roll angle, which takes time. The instantaneous response of a good RC height gives a much more stable feel than relying on stiff springs and shocks.

i have played around with ride height on my H&R RSS coilover setup and even a 15mm rideheight change at the front has a drastic effect, even with 400lb/in springs and M030 sway bars. I actually find it easier to tune the handling with ride height than with sway bars, the effects are bigger.

You are in the fortunate position of having stiffer springs that AREN'T lowered. By all means, try lowering the car by removing the spacers, and report on your results. Reading about something on the web is nothing like trying it. Only then will you appreciate the situation.

Our suspension is based on VW 1303 Beetle, which has evolved in VW Golf and now Boxster/TT. Google VW +Golf +roll +center and see what you find.

Hope this helps!

Mike

mikey_audiogeek

You don't have to change. I ran 400lb front springs with stock S2 rear torsions for a while. you can trim with tyre pressures, camber and sway bars. Turbo rear sway bar (18mm)might be a good idea.

thirdgenbird

Can you expand on this? How do you get better track times from worse handling?

What is your front camber setup? I have -2° lowered without camber plates.

mikey_audiogeek

By having more GRIP. Handling is what happens once you've exceeded the available grip... race cars don't have to be pleasant to drive, just fast and quick in traffic. If fast cars were all nice to drive, then anyone could be Michael Schumacher or Jackie Stewart.

Front camber about -1.8, fine for 16" wheels but with the 18" Goodyear F1 Asymmetrics was a bit too much and need to drop back to about -1.5 or -1.3

dykaar

"worse handling" can mean a car that tends to slight oversteer. That will help with turn in. Production cars tend to be setup with mild understeer to protect the driver from their own mistakes. Wider front tires, suspension changes that increase rear grip (e.g. larger rear tires, smaller rear sway bar, softer rear springs, and conversely the opposite of those things at the front). All that is exclusive of aero changes. It can get complicated, which is why many people duplicated the cup setup which porsche ran for the race series, originally in Europe, but then also in north america.

Regards,

doug
Waterloo, Ontario Canada, eh


86 951 (http://www.pcaucr.org/index.php/visu...egory&catid=61)
01 E320 (W210) 4matic Wagon (http://www.benzworld.org/forums/w210...body-do-2.html)
00 540i-6 (http://forums.bimmerforums.com/forum...3&d=1283457963)
94 855 turbo Wagon (sold in 09)
85 535i-5 (sold in 07)
76 300D (sold in 92)
83 944 (sold in 86)
I apparently only buy cars designated by numbers

M758

Lower = better for these cars.
944 spec cars run 4" to the rocker. That is the practical limit for a 2450llbs race car with 3x stock spring rates.

I would not run full weight stock spring car at that height as it will bottom too much. Running lower than approx 4" does not seem to be benenfit.

Remember lowering the CG reduces weight transfer which will increase cornerng power. Of course you can't just lower the car. You need to realign the car as if you lower it the alignment settings change.

M758

Huhh?.

Good handling = good lap times. Bad handling = bad lap times .



Maybe things are different down under?

M758

I once ran 350lbs springs with 28 mm t-bars. The handled poorly untill I cranked the rear sway bar full stiff (Running weltmeister adjustable bars). That was fine except for the horrible wheelspin on corner exit.

So I put in 30 mm t-bars and finally got a good spring rate match front and rear. Then I could back off the rear sway bar to keep corner exit traction while having the proper mid corner balance.

So if run 400lbs front spring with stock rear t-bar (126lbs-in) the car will understeer like a pig unless you really screw around with the rest of the chassis to compensate. Then you might get it to turn and it might even be faster, but it still not good as if you just went with a proper rear spring.

You are also correct in that roll centers change when you lower the car. However that is counter acted by the benefit of a lower CG. My 944 race car is faster 4" than it would be a 5". Now I am not taking about ride comfort as that is irrelevant in track car, but I am talking about handling balance.

I noticed this picture in the MK1 golf thread.


944's don't see this severe an angle at 4 right height. My car is also low as I can go an has 1/2 the up angle. Remember the despite using the some of the smae parts the 944 starts lower begin with and the 4" ride height uses 225/50 R15 tires. These are 1" shorter diameter than stock 215/50 R15 tires. So that lowers the chassis down another 0.5" with no change in suspension geometry.