Fender rolling the X

[Rodger]

Oh, and I forgot a key element. On the X, if you have wider wheels/tires, its far more likely to snag a front fender when turning. That is; when cornering hard. This is because the wider wheel/tire has limited clearance further forward in the wheel well. So when turning the outside wheel/tire moves forward as you turn the steering wheel and in response the chassis rolls, compressing the outside suspension and using up the available clearance. So I would suggest redoing your clearance test. Remove the spring and turn the wheel until the tire is closest to the leading edge of the fender opening and then compress the suspension, with the steering in that position, to see how much clearance you actually have.

When I was building my X1/9 racecar, I had to allow for 13x8.5 wheels and 225/50 tires, with the car cornering at very high lateral g _and_ accommodate full suspension travel at high steering angles. I ended up having to cut the leading edge of the fender all the way to bulkead for the headlight bays. Even then the tires would rub slightly in extreme situations. I also completely cut away the OE flares and used a Bayless front flare with the forward portion cut away as it didn't blend with the 1500 bumper cladding.

Reference the photo below, you might have seen it before. But take a closer look. Compare the top of the left front tire, which is a 20.5 inch tall tire, to the body line that passes through the fender opening. Now compare that position to that of your car. You have a much taller tire, probably nearly 23". So this car sits very low. Now consider how much the right front suspension has compressed. Yet the tire didn't rub and the suspension didn't bottom. This car does have considerably more suspension travel than most any street driven X.

View attachment 36800

I really appreciate your advice and input, especially about the outside tire on hard cornering. I was looking more at the inside, but I can see from your photo that the outside corner is what really gets compressed. I will play with it some more and will also see if I can find some bump stops to substitute for the washers.

 

[lookforjoe]

I really appreciate your advice and input, especially about the outside tire on hard cornering. I was looking more at the inside, but I can see from your photo that the outside corner is what really gets compressed. I will play with it some more and will also see if I can find some bump stops to substitute for the washers.

I have bump stops I bought to go with the Bilsteins in my coil over setup - didn't need them as the Bilsteins have internal stops. You are welcome to them. I can measure the ID & overall dimensions for you, to see if they meet the spec of your cartridges?

 

[Steve Hoelscher]

I have bump stops I bought to go with the Bilsteins in my coil over setup - didn't need them as the Bilsteins have internal stops. You are welcome to them. I can measure the ID & overall dimensions for you, to see if they meet the spec of your cartridges?

Just a quick FYI: Internal bump stops are intended as a 'fail safe' to prevent damage to the foot valve should the rod hit the bottom of the tube. They are not intended as the primary suspension bump stop. Assuming the internal stop is adequate, its possible, depending on the specific installation, that the strut housing will bottom against the upper mount/perch before the internal stop is engaged. The resulting hard bottoming will surely damage something.

I have a considerable amount of experience with Bilsteins. They are an excellent shock/strut that is easily rebuilt/revalved thus I often use them in applications where budget doesn't provide for high dollar adjustable shocks.

 

[rx1900]

Oh, and I forgot a key element. On the X, if you have wider wheels/tires, its far more likely to snag a front fender when turning. That is; when cornering hard. This is because the wider wheel/tire has limited clearance further forward in the wheel well. So when turning the outside wheel/tire moves forward as you turn the steering wheel and in response the chassis rolls, compressing the outside suspension and using up the available clearance. So I would suggest redoing your clearance test. Remove the spring and turn the wheel until the tire is closest to the leading edge of the fender opening and then compress the suspension, with the steering in that position, to see how much clearance you actually have.

Oh yes.....Rodger has already been to that rodeo......yes indeed when his tire the fender and damaged it...it WAS when cornering hard...and the damage was at the 10 o'clock or so position. He has since removed the spring and jacked the suspension up-and-down, and lock-to-lock...to check for clearance under ANY possible combination. And then rolled the most ALL of the fender lip accordingly to eliminate any possible interference. Whilst doing so he also checked for proper sway bar clearance at all points.

And yes...as Jeff suggested...it IS certainly better to roll the fenders BEFORE painting the car. No worries then about possible paint damage. Yes...as Rodger proved.....it IS possible...with a proper machine...to roll painted fenders without paint damage..but it is indeed a sphincter tightening exercise.

And of course.....whenever you are playing around with new wider tires or different offset wheels or new coilovers....YES you must remove the spring and check for clearance through all possible wheel positions...up/down and lock-to-lock. Fender clearance on an X1/9 is quite limited..less than you would think ! After all...the X was designed for 145/80-13 tires on a 4.5" wheel !!!!

For those of you wishing to lower the static ride height.....things get tricky pretty quickly. And you will run out of suspension compression travel or the tire will hit the fender- not a good thing. There was not a whole lot to start with !! Add in bigger tires and things get worse. Basically...you will have to limit travel...or roll the fender lips. It is a complicated intertwining of many factors.....

Yes...if rolling your fenders is in your future....this roller will do the job easily and cleanly and neatly. Sadly.....as I have found out....most - if not all - of the Eastwood or Ebay fender rollers will NOT work on an X1/9 !!! Our fender openings are just so small and those machines will NOT adjust short enough to fit. And they are pretty expensive for a tool you will likely only use once.......Yes...you can modify them to work....but trust me there is a LOT of mods needed. And most of them will not even bolt onto the X1/9 hub. They seem to be designed for a minimum 100mm bolt circle. And do not have provision for the X's wheel pegs and rotor bolts. And then you have to re-engineer/shorten/re-drill/re-weld all the telescoping bits. That was a major pain......

 

[Rodger]

I have bump stops I bought to go with the Bilsteins in my coil over setup - didn't need them as the Bilsteins have internal stops. You are welcome to them. I can measure the ID & overall dimensions for you, to see if they meet the spec of your cartridges?

That is a nice offer, Hussein, thanks. My Koni shafts measure just a bit smaller than 7/8", that's why I went with the washers I did. If the internal dimension is about that, they may work. I can always cut them down to equal my washer spacing. Right now, I have the soft bump stop that MWB included with the coilovers, then the spring perch, then the washer stack. In my mind, bump stop is not really the proper term for what is in there as it really does compress a lot before it won't go any more. Spring aid or spring assist is a better term for sure. I am going to take out the springs one more time to check the outside turn compression as Steve recommended. I was focusing more on the inside tire on a left turn. I will try and get some more accurate measurements of the dimensions of the soft stop before and after compression as that will give me a better idea of actual suspension travel.

 

[Dr.Jeff]

Rodger, if possible I'd like to see a pic of the bump stops you have. I'm curious how they compare in design/style to the ones I use. The older VW Bilstein struts have very similar dimensions as our X struts and even many coilovers. The bump stops for those VW applications come in a couple of varieties and are cheap and easy to get. So that's what I've always used. They are a foam material and have an accordion shape, so they compress as the strut contacts it. Some are extra long and can easily be cut down to the needed length. They also have different firmnesses available. Might be the same as you have. Here is one example of what some of the VW items look like:

 

[lookforjoe]

Just a quick FYI: Internal bump stops are intended as a 'fail safe' to prevent damage to the foot valve should the rod hit the bottom of the tube. They are not intended as the primary suspension bump stop. Assuming the internal stop is adequate, its possible, depending on the specific installation, that the strut housing will bottom against the upper mount/perch before the internal stop is engaged. The resulting hard bottoming will surely damage something.

I have a considerable amount of experience with Bilsteins. They are an excellent shock/strut that is easily rebuilt/revalved thus I often use them in applications where budget doesn't provide for high dollar adjustable shocks.

I was basing that on the directions that came with the B8's (34-184530) I used.

I was somewhat amazed that all four corners didn't blow out from my off roading - they all seem to be damping just fine & no signs of leakage

 

[lookforjoe]

Rodger, if possible I'd like to see a pic of the bump stops you have. I'm curious how they compare in design/style to the ones I use. The older VW Bilstein struts have very similar dimensions as our X struts and even

From his pics above: Looks like a foam-style (like VW/Volvo, etc.) w/o the accordion feature - don't look like poly for sure.

 

[Dr.Jeff]

I would assume by "preload" you mean the spring is partly compressed with the strut at full extension. This is rare with coilovers unless you are using a very soft spring or spring tenders (which are very low rate springs used to keep the primary spring located on the perches). The spring will certainly compress under the car's weight but if you jack the car up, thus removing the weight from the suspension, the strut's extended length is longer than the free length of the coilover spring.

Steve, I've been thinking about this and realized I might have stated things poorly. I agree what what you said, but I've found it is very different depending on some variables, namely the length and rate of the springs and the ride height. Let me describe a typical example.

On a street application with relatively soft springs (say around 20% above stock), the coilovers I've used tend to have rather long springs (plus tender springs) to allow ampel travel. When the car is up on stands with the suspension in full droop, and the lower perch is threaded ALL the way down, then yes - there is free play in the spring and no preload. However for a street set up with these soft springs you could not leave the lower perches at this low of setting; the struts would completely bottom out with just the weight of the car. By the time you raise the lower perch enough to get a decent ride height, then the spring is in preload - even when sitting on stands in full droop....the coilover is at full extension but the lower spring perch is not at its lowest position.

This would be very different on a race car with the typical short stiff (e.g. 400-600 lb) springs they usually use. In a case like that there will be no preload - even at its ride height setting - when in full droop because the stiff springs only move an inch or so. Therefore you don't need to lower the bottom perch fully to see a lack of preload like you do on a street set up.

In Rodgers case I'm assuming he has springs more like the ones I typically use and therefore there will be some preload - with the lower perch at ride height setting - when the car is raised. If his upper mounts were moved on top of the towers, the whole strut would be moved up (lowering the ride height) and the lower spring perch would need to be raised accordingly to achieve the previous ride height. Thus more preload.

I'm basing this on what is usually the opposite situation in my case. I typically want to lower the car more than the strut will allow without bottoming out. So I need to move the strut as far upward (e.g. "body drop" by modifying the top mounts, etc) to get as much travel as possible while still sitting at a low ride height. That allows me to move the lower spring perch up, adding a little more preload, and gaining some travel. A stiffer spring rate would achieve the same result but I find them to be too harsh of a ride on the street. So it is a compromise.

My point is I find there IS preload with coilovers on my lowered street (long soft springs) cars, when sitting at the ride height setting (i.e. not with the lower perch cranked ALL the way down). Hope that clears up what I was trying to say previously. Perhaps it's a different scenario than what you might typically see on your race cars?

 

[Rodger]

Yes, it is a foam type. That photo showed how much spacer I was using before I rolled the fenders. I was right on the stop at that point.

 

[fastx19]

So, take this for what it is. The sway bar mounts in the front trunk. The section they are bolted to is actually hollow, and if you plan to really push the car hard, I would think about reinforcing that area. I have ripped off the front control arm mounts of my race car before as well. However, if you are planning on mostly driving and occasional spirited fun, then on worries.

You have a gorgeous looking car and the bottom of it is amazing! Love what you have done. Also, thank you for moving the strut mounts to where they should be. Drives me crazy when they are on top of the strut tower.

 

[rx1900]

So, take this for what it is. The sway bar mounts in the front trunk. The section they are bolted to is actually hollow, and if you plan to really push the car hard, I would think about reinforcing that area. I have ripped off the front control arm mounts of my race car before as well. However, if you are planning on mostly driving and occasional spirited fun, then on worries.

Ummm...no !!! Look again...that IS the main frame rail on the front of the car. THE strongest section on the whole front end. And also very close to the strong vertical strut tower and the firewall structure. Yes...that section is hollow...all frame rails are !! That is what gives them their strength.

Furthermore.....look closely at the pic again....those bolts ( with washers to spread the load ) are just to bolt on a substantial re-enforcing steel channel about 10" long That is what the sway bar brackets bolt to.

I would happily tow or lift the entire car from that channel. It IS that strong !!! Trust me......that mount would NEVER fail.....ever...

Would you prefer I mount the sway bar with little mounts on to the middle of the trunk floor sheetmetal like everyone else does ?

 

[lookforjoe]

That is a nice offer, Hussein, thanks. My Koni shafts measure just a bit smaller than 7/8", that's why I went with the washers I did. If the internal dimension is about that, they may work. I can always cut them down to equal my washer spacing. Right now, I have the soft bump stop that MWB included with the coilovers, then the spring perch, then the washer stack. In my mind, bump stop is not really the proper term for what is in there as it really does compress a lot before it won't go any more. Spring aid or spring assist is a better term for sure. I am going to take out the springs one more time to check the outside turn compression as Steve recommended. I was focusing more on the inside tire on a left turn. I will try and get some more accurate measurements of the dimensions of the soft stop before and after compression as that will give me a better idea of actual suspension travel.

 

[Steve Hoelscher]

I was basing that on the directions that came with the B8's (34-184530) I used.
View attachment 36817I was somewhat amazed that all four corners didn't blow out from my off roading - they all seem to be damping just fine & no signs of leakage

That's interesting. Bilstein specifically states to retain the OE bumpstop on other fitments. I suppose it might be specific to the application.

Oh, and I'm not surprised yours survived the offroading. If you saw how endurance racers beat on curbs and the occasional 'off', you might rest more easily. One of the things I like about Bilsteins on racecars is they seldom fail from such offs. And as long as they don't get bent, they can be fixed.

 

[Steve Hoelscher]

Ummm...no !!! Look again...that IS the main frame rail on the front of the car. THE strongest section on the whole front end. And also very close to the strong vertical strut tower and the firewall structure. Yes...that section is hollow...all frame rails are !! That is what gives them their strength.

Furthermore.....look closely at the pic again....those bolts ( with washers to spread the load ) are just to bolt on a substantial re-enforcing steel channel about 10" long That is what the sway bar brackets bolt to.

I would happily tow or lift the entire car from that channel. It IS that strong !!! Trust me......that mount would NEVER fail.....ever...

Would you prefer I mount the sway bar with little mounts on to the middle of the trunk floor sheetmetal like everyone else does ?

I like your swaybar design. Its very similar to the mk1 MR2.

When I was still using swaybars on my race X, I welded a similar mount in a similar location. Through bolting should be fine there. Just don't overtighten and crush the box section. I had an enormous swaybar on my '74 X and the mounts were always fine.

 

[JimD]

I like your swaybar design. Its very similar to the mk1 MR2.

When I was still using swaybars on my race X, I welded a similar mount in a similar location. Through bolting should be fine there. Just don't overtighten and crush the box section. I had an enormous swaybar on my '74 X and the mounts were always fine.

Steve,

I just picked up a raceX with Granada springs at all 4 corners. It's a SteveH approved suspension!!

 

[Steve Hoelscher]

Steve,

I just picked up a raceX with Granada springs at all 4 corners. It's a SteveH approved suspension!!

That's hilarious! Who's car was it? Any pictures?

For those late to the party.... Back when I was racing an X and in my early days of learning the engineering principles of suspension and chassis dynamics, I came up with the silly idea of testing a setup that had no swaybar and compensated with very stiff springs. At the time, the class I competed in didn't allow for a full coil over setup. The springs needed to sit on the original spring perches, although any spring could be used.

I didn't want to invest a lot of money in springs to test of a hair-brained idea my poorly educated brain had devised. So I set off to a local junk yard, with a set of calipers in hand, in search of a set of springs that would fit on the stock X perches yet had a wire diameter of approximately .500 inches. I had determined that a .5" wire spring, with the stock X spring diameter, and the length I needed would produce the rate I would need to give the total roll rate and roll ratio I needed to duplicate that which I had with the big front swaybar.

After digging through the junk yard for a few hours I found that the front springs on a (late 70s) Ford Granada were the right coil and wire diameter to do what I wanted. So for $25 I headed home with a pair of Granada springs. I cut them to the desired length and tested them the following weekend.

The results of that test were a revelation. I went back to the junk yard and bought the springs off every Granada in the yard. I then tested a few variations until I had it dialed in. I ran the following season on one of those sets of springs with excellent results. I finished 3rd at that year's National Championships, running on a $25 set of salvage yard Granada springs.

With my success that season (1995) lots of people started looking at the car more closely and the lack of a swaybars and the funky springs had a lot of people scratching their heads. It didn't take long before the Granada spring setup to get out and soon other X1/9s started turning up with them. A year or two later the rules were revised to permit coil overs and I ordered a set of coil over springs with the rates I can calculated for the Granada springs.

If you look closely, you can just see the end of the big tubular (1.5" OD) front swaybar behind the front spoiler.

 

[Dr.Jeff]

That's interesting. Bilstein specifically states to retain the OE bumpstop on other fitments. I suppose it might be specific to the application.

I'm not familiar with the specific stock bump stops on that Volvo, but on many German cars they are similar to the X1/9's rear dust boots. In other words they are not on the center shaft, but part of the upper mount and more of a large sleeve than a small cylinder. That might make some stock applications not fit the Bilstein design well, which might be why Bilstein doesn't recommend using the stock ones in those cases?

Oh, and I'm not surprised yours survived the offroading.

Bilsteins were the gold standard for off road race trucks and buggies for ages. This is back before the development of the huge multistage, remote reservoir, bypass type units of today, so they were the same design and type as the street Bilstein units. We used them on our rally cars in the 70's. They were built to be that tough, which is why they had a million mile guarantee. I actually got a free set of replacements for some 20+ year old Bilsteins under that warranty.

 

[Dr.Jeff]

Also, thank you for moving the strut mounts to where they should be. Drives me crazy when they are on top of the strut tower.

I get where you are coming from in terms of the tower (particularly the strength of the top area) and the load coming from the strut below. However I feel there is another serious consideration with the X and its struts. These cars sit so high and the struts are so long that any added spacing between the tops of the struts and the tower make it almost impossible to get a decent ride height while retaining a decent amount of travel. Much like Rodger's situation in my opinion. I'd be inclined to reinforce the top of the tower with added plating (e.g. along the lines of the "big foot doublers" but welded in) to offer enough support, and mount those big thick camber adjusters on the top. This will prevent all that added height being between the strut and tower. However I'm also not a big fan of using solid top mounts like these camber adjusters typically are, so it really doesn't apply to me anyway.

 

[JimD]

That's hilarious! Who's car was it? Any pictures?

I will send some pics when I get home Steve.