Has anyone seen the build specs for the BMW rally cars from back in the late 80's early 90's. Ford did a great job with the Escorts and I'm hoping BMW kept track and published that stuff too. JVL maybe you could chime in? im interested in spring rates and alignment specs.
Miller

What type of BMW? E30 or E36 you can probably just check out Sierra Cosworth build specs. Pretty similar wheelbase, weight, suspension design, etc.

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Grant Hughes

NoCoast Wrote:
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> What type of BMW? E30 or E36 you can probably
> just check out Sierra Cosworth build specs.
> Pretty similar wheelbase, weight, suspension
> design, etc.

See!!!???

There's a man that's thinking!

>
> Grant Hughes
> www.nocoastmotorsports.net
> Denver, CO

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John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.

sorry my bad, more details... its a 1991 318IS (E30) since I had so much fun with the VW and Rally cross. I sold it and decided to go RWD and see how I can do. since I grew up sliding my Firebird and RX7 getting used to RWD again should be like hooking up with an ex-girlfrind except without the messy cleanup! i'm interested in alignment specs and I will not be using adjustable camber plates at this time. i just got a set of Bilstien HD's and some H&R M3 springs to start. I'm trying to get the rates from H&R. i just had a 4.10 LSD installed. luckily my wheels from my GTI work!! including my rally tires and wheels. i have a E36 rack being shipped to me for install this week. PS delete (keep your opinion about this to yourself). lightened flywheel and exhaust to go along with my perfect power eng managment module.

From E30 tech:

Spring---------------------Front(lb/in.)-------------Rear(lb/in.)

Stock 325i*-----------------------106------------------------245
Stock 325is*----------------------118------------------------265
Stock 325ix*----------------------106------------------------308
Stock M3*-------------------------114------------------------314
Stock M3--------------------------140------------------------250
Dinan Sport-----------------------172------------------------300
H&R OE Sport---------------------180------------------------380
H&R Sport-------------------------180------------------------380
H&R Sport (29664)---------------200------------------------285
H&R Race-------------------------315------------------------ 570
H&R Coilovers***----------------340------------------------380
Eibach Pro-Kit--------------------102-------------------------277
Eibach Race----------------------160-------------------------445
IE SIII----------------------------315-------------------------570 [Group Buy - $285]
Koni Coilovers-------------------342-------------------------407
Cosmo Coilovers----------------450-------------------------560
Tokico----------------------------165-------------------------265
TMS J-Stock**-------------------680------------------------1026
Alpina(est.)---------------------~200-----------------------~350
FK 60/60 cup kit-----------------379--------------------------379
Vogtland Standard***--------115/197-----------------------360
Vogtland CS***---------------137/200-----------------------400
Vogtland--------------------------225--------------------------360
Intrax-----------------------------126--------------------------250
Apex: --- ---
KW: --- ---
Spax: --- ---


We've got Bilstein HDs plus the H&R OE Sports on our 325i and it handles great on rough roads.

Changing the rack to an E36 Z3 rack makes the car a lot of fun - I think it ends up about 2.7 turn to turn. Keep it power - you will need it.

Here's a thread with some cage pics: http://www.rallyanarchy.com/phorum/read.php?5,25794,25794#msg-25794

We triangulated the cage to the diff mounts, shock mounts, and other areas per pictures of the Group A E30s.

Wilson

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"Talk about drugs. Driving a car like that, going that fast, it’s like all the drugs at once." - Tommy Byrne

"Now, Pinky, if by any chance you are captured during this mission, remember you are Gunther Heindriksen from Appenzell. You moved to Grindelwald to drive the cog train to Murren. Can you repeat that?" - The Brain

It's kind of funny, I was just thinking to myself this morning, "I wonder what the best steering ratio you can get for a BMW is."
After this statement, "P/S delete is one of the stupidest things to do in a rally car ever!" I will no longer say anything else and will keep my opinion on it to myself.

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Grant Hughes

Wilson are those backwards, ie aren't rears softer then frounts?

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In the long run reality always wins.

thanks Grant!! I appriciate that. i just feel its pretty sloppy with PS. what I might do it try to run the PS with the quicker rack (4.7 Lto L turn stock compared to 3.2 LtoL turn for the E36) my only problem is that I think the PS lines are bigger for the E36 rack...
as for spring rates I have the 50406 HR springs

ohh, yeah this will not be a rally car. its application will be Rally cross and maybe some autoX. my wallets not fat enough for a rally car.

derek Wrote:
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> Wilson are those backwards, ie aren't rears softer
> then frounts?

Derek:

Interesting observation. Never really thought about it - just went with the old saw that you double the stock rates for a rally car (worked in the VW as well). The OE Sport springs were the closest based upon what I posted.

FYI It is an IRS car with a rear sway bar. Like the XR4ti.

Wilson

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"Talk about drugs. Driving a car like that, going that fast, it’s like all the drugs at once." - Tommy Byrne

"Now, Pinky, if by any chance you are captured during this mission, remember you are Gunther Heindriksen from Appenzell. You moved to Grindelwald to drive the cog train to Murren. Can you repeat that?" - The Brain

I noticed the higher rear rates too... Makes no sense.

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Michael LeCompte

I think that something to do with the placement of the spring so close to the pivot points equates to higher spring rates needed in the rear. If you go to coilovers you stick with a more normal spring rate. Or some such nonsense. I don't pay enough attention since I never intended to stick with stock stuff.

Rallycross you'll especially want power steering! It is not

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Grant Hughes

NoCoast Wrote:
-------------------------------------------------------
> I think that something to do with the placement of
> the spring so close to the pivot points equates to
> higher spring rates needed in the rear.

This. Wheel rate is lower than the raw spring rate on these cars, just like in a Datsun 510 or most Hondas, etc. It's all about leverage.

So keeping the ps isn't that big of a deal. I'm keeping it. Any alinment specs? Or we can bunny trail...

Doivi Clarkinen Wrote:
-------------------------------------------------------
> NoCoast Wrote:
> --------------------------------------------------
> -----
> > I think that something to do with the
> placement of
> > the spring so close to the pivot points
> equates to
> > higher spring rates needed in the rear.
>
> This. Wheel rate is lower than the raw spring rate
> on these cars, just like in a Datsun 510 or most
> Hondas, etc. It's all about leverage.

Yaeh
here's some Bavarian Maggot wagon:


Notice the spring is moved forward on the trailing arm?


Here's an Opel Omega:


Another Beeeeay Em Fay:


Ratsooon 510---looks like the Ford GpA square beam

>
>

And since we have 10 Xratties in the PNW alone, here's stock XR4x4


GpA Ford:


In every case but the last the spring is Levered on" by however much the trailing arm extends past the spring.
Consider the spring position the FULCRUM and the arm behind it the lever.

If we had a 200 in/lb spring and we pushed on the SPRING with 200 lbs it compresses an inch; if we push with 200 lbs at the spindle and its say 6" behind the spring, and the arm in front of the spring is say 18" then we have a 33% lever on it so 200 lbs x 1.33= 266 lbs is "felt" at the spring.

Looking the other way if we want 200 lb/in rate at the spindle, we better put a 266 lb in spring at the spring seat.

Claro?

(By the way, the problem with these up the arm things on all these shown cars and like Fucus/Maz-dog/Volvo stuff is that usually there is just so much space to accomodate the spring and going firmer means fatter coils, means less space for travel, hard to do pre-load etc. for any other than OEMs)

---

John Vanlandingham
Sleezattle, WA, USA

Vive le Prole-le-ralliat

www.rallyrace.net/jvab
CALL +1 206 431-9696
Remember! Pacific Standard Time
is 3 hours behind Eastern Standard Time.