Mark 4 VW 1.8T GTi Build - RallyCross - MF Class

I'm going to put a little more effort at being serious in... you're still not listening. Bilsteins are fine as a manufacturer. 36mm Bilsteins can be perfectly fine as a family of products, but the family covers a lot of ground. 36mm Bilsteins sold as go-fasterer street suspension (which is what it looks like you posted pictures of) often are designed for people to stiffen and lower their cars, and so have shortened bodies, less potential travel in the insert, stiffer spring rates, and valving designed for those stiff spring rates. So, you have a member of a family of suspension that includes products suitable for rallying... but in all likelyhood, these specific ones, designed for another car and application, have unsuitable spring rates, unsuitable valving, and unsuitable travel. Because of this, odds are decent they would require more time and money than the purchase price of something more correct in order to make them work as well as an OEM replacement strut. Or it's barely possible that they may not - there is literally no way to know from a picture of them.

To quote John saying the same thing:

"You could not be troubled yourself to find what the travel, what the damping or range of damping is, what the spring rates and what the max travel before coil-bind in the photo is.. Nope just like a 11 year old you post "whaddya think a dis"

We think its too short, too stiff, too expensive and there will be coil bind but we also think that you are going to fire off more angry shit---then somebody else will post the same thing, you will NOT acknowledge that what you were told was right, you will not take responsibility for your offensive behaviour, you will not apologize for offending the general community and the person giving you the BEST advice consistently... "

Daniel;
Here it seems that an assumption on my part, could partially lead to the issue at hand. I have already done the research on the spring rates, and have therefore purchased the HotBits springs which are for rallying, for my chassis, and match the HotBits rear suspension I have already purchased. So spring rates were researched, gone over, and decided upon before purchasing. I never asked anyone about the H&R springs in the photo. Only if the struts could be modified to fit the Mark 4 spindles.
For once, I was actually looking forward to John's insight, as he has much fabrication experience and skill, and works with Bilstein all of the time.
However, I assumed that since these 36mm coilovers were listed on this site, that they were for Rally. Therefore, valved appropriately. And since they are for a Mk.2/Mk.3 VW, that they would already be good for chassis dynamics and weight of my Mk.4. I did not contact the seller yet, to those assumptions; as I did not want to waste his time unless someone here actually said "Yes, they can be modified".
I was actually looking for discussion of my thoughts, on this "discussion board"; but as usual, instead of anyone discussing them, everything starts with B.S. attacks on my character and intelligence, and so on, from John, and just goes downhill. Most of you guys have tried to be helpful, and I've learned a lot; but a couple of you are just complete jackasses.

What works well for stage rally and what works well for rally cross is usually not the same. Generally rally racing suspension will have stiffer springs, and heavier dampening. Rally suspension is designed to take large inputs at very fast speeds. Rally cross average speed is about half of stage rally.

What courses are you running? What are the speeds of the fast 2wd cars, average speed, what is the surface like?

Just got back from the latest event this past Saturday. The leaders in 2wd are hitting 50-60 in the straight sections. Usually redlining 2nd, or just shifting into third, and back down; depending on their box ratios. The averages are in the high 30's to low 40's, throughout the course.

The FWD cars are keeping speeds up with the AWD guys, and just losing times in the tight corners; which I believe is what anyone would expect. The RWD competitors are behind those two groups; doesn't matter if Modified, Prepared, or Stock.

Our conditions in order of most often is sugar sand, sand, mud from sand, actual mud, then maybe grass once a season, if at all.

The springs I have are 50 Kg/Cm front, and 40 Kg/Cm rear; both with 20 Kg/Cm helper springs. This is where my lack of understanding into the rally world hurts me. Even when trying to convert them to normal lbs/in numbers, none of those numbers make any sense to me. Which really pisses me off, as my only ASE certification when I was a mechanic 20+ years ago was in suspension and steering. So I should be able to understand it, but just cannot get my head around the numbers.

Quote
Robert Culbertson
What works well for stage rally and what works well for rally cross is usually not the same. Generally rally racing suspension will have stiffer springs, and heavier dampening. Rally suspension is designed to take large inputs at very fast speeds. Rally cross average speed is about half of stage rally.

What courses are you running? What are the speeds of the fast 2wd cars, average speed, what is the surface like?

... what he said...

But then... these points have been made numerous times, so this is the reason people are getting fed up Daniel.

You get tons of excellent advice, but none of them imply buying new shiny stuff - deal with it!

It really is like you don't listen to these gentlemen, but you just go on, and on, and on, and on in direct contradiction to the advice you get.

How would you have people react to the above situation?

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Brgrds
Brian

http://bfy.tw/7RiO

Let me google that for you

280 in/lbs

I already googled it, LOL.

I have 280 fronts, and approximately 225 rears. But that doesn't take into account the helper springs, or how they add into the equation, or how they are added in for end results.

My IT cars were simple, compared to this. I had multiple sets for different tracks. Some linear, and some progressive. Depending on how the car was set up, I could completely change how it felt with just spring changes. I didn't even need to adjust the sway-bars.

The rally world is all about suspension. RallyCross, Rally Sprints, or Stage rally. The suspension is the biggest, most important, single thing. I got that. I understand that. I don't understand the numbers, or how to interpret them for different results.

The golf III Kit cars run by VWMS ran 300-60-40 springs front and rear. With the only variation being their helper springs. Even those were damn close at 60-60-60 front, and 50-60-30 rear.

So I am assuming this is 300 mm of free length, and 40 Kg/Cm of spring rate? Is the middle number spring length fully compressed? I have looked at both Eibach and H&R charts, and cannot seem to figure that part out.

spring length - inner diameter in mm - rate

Thanks. That makes a lot of sense, since most European springs for coil overs all seem to be 60mm. Sadly that limits my coilover choices however, as most stuff sold is for either 2 1/4" or 2 1/2" I.D. springs.

On the other hand, since everyone says good condition stock stuff works for RallyCross; I could use the adjustable camber plates set for 60mm I.D. race springs, with the coilover conversion kit sold by ground control or similar, and install everything on a set of new Bilstein HD struts.

or just go to a 2.5" spring and don't worry about it, the diameter of your spring makes zero odds to anything but whether it fits with your sleeves and shocks.

You can't compare the rears of the Mk 3 platform to your Mk 4. The Mk 4 has a vastly different rear suspension system.
With the Mk 1/2/3 design there is virtually zero leverage, since the shock/strut attaches right next to the wheel.
On the Mk 4 the spring is wedged in between the chassis and the swing arm somewhere at the middle of the swing arm, meaning you'll have a ratio.
It might be as much as 1:2, meaning that 100 lbs of force at the wheel, equates to 200 lbs at the spring.

Finally - just once more: stop fretting about spring rates as long as you are "only" going rally crossing - stick with stock stuff as has been stated mucho times.

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Brgrds
Brian

Quote
DanielSL
I already googled it, LOL.

I have 280 fronts, and approximately 225 rears. But that doesn't take into account the helper springs, or how they add into the equation, or how they are added in for end results.

That's just about double what you should be using for sand-o-cross. as a point of reference, the Volvo 242 stage rally car uses 225lb/in in the front (approx @ wheel) and 150lb/in (NOT at wheel) in the rear. When I grass-o-crossed my mk2 gti I was using 150lb/in (approx @ wheel) fronts and 125lbs/in (at wheel) rear, 2.5in 12 or 14in long springs on stock Bilstein HD struts and rear shocks. It was a bit too stiff.
I took a stock volvo 240 wagon with blown out suspension and did decently well.

Just go out there and drive with stock suspension. Grass-o-cross (well most motorsports) is about grip and driving. There's a few ways to get grip, but there's only one person driving. Work on the biggest variable first... You.



Edited 1 time(s). Last edit at 08/29/2016 11:15AM by Robert Culbertson.

Pay no mind to Danster, he's from Scotland so probably hopped up on a mixture of Diamond White, Irn Bru and deep fried Mars bars.....

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Yes, it's a Ranger.
Xr4Ti, it is rwd and was made in Germany.

My $.01

order a set of these, http://www.kermatdi.com/mk4-shine-racing-real-street-spring-kit/ slap on your bilsteins and be done. The fast guys up here all ran Shine springs on bilsteins.

The fastest FWD guys I see who will let me in on what they are running have all said they run stock springs and better dampers.

One of the fastest AND most controlled-looking Civics I've seen on course apparently is using Integra Type R takeoff shocks/springs because that is what was lying around. By "controlled" I mean body motions were well-controlled, not too stiff and not floppy, and large bumps were controlled in a single massive compression and rebound and the chassis was unfazed, tires stay on the ground gripping.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.