THE complete lowering spring thread -

[SVTPaul]

I just re-installed my H&R Race Springs on my 2004 Cobra and I decided to go with MM Urethane Upper Iso's and Stock Lower Iso's. It came out really nice. Measures 27" from floor to Front Fender Lip and 27.50" from Floor to Rear Fender Lip.

You have any good pics of your car with this setup? I just ordered a set of Race springs last night, now trying to decide whether to run stock or urethane iso's. Why did you decide on urethane uppers? I thought if you ran the urethane's it would put you close to the stock ride height with these springs? Although I realize running them on the uppers only would be a little lower than uppers and lowers. I guess I'll just try using stock iso's and see where I end up.

 

[GrimlokTT]

Why don't you keep the Sports in the back and add urethane isolators to the back only?

I decided I'm going w/ coilovers but until then: http://www.svtperformance.com/forums/showthread.php?p=3989527&posted=1#post3989527

 

[kirks5oh]

update--i just had my car aligned after about a month (i don't drive the car much) of having the H&R race springs in place and was surprised that the alignment was fairly off in the front and the back of the car. before i took it in yesterday, the car pulled ever so slightly to the right, and had a bit of a shake at 85mph. now the car doesn't pull at all, and is smooth as butter at 85+mph. and the best part was that i did not need caster camber plates.

you can see pics of my car a few pages back, but i have H&R race springs with all the stock iso's in place

 

[BLK03SVT10TH]

You have any good pics of your car with this setup? I just ordered a set of Race springs last night, now trying to decide whether to run stock or urethane iso's. Why did you decide on urethane uppers? I thought if you ran the urethane's it would put you close to the stock ride height with these springs? Although I realize running them on the uppers only would be a little lower than uppers and lowers. I guess I'll just try using stock iso's and see where I end up.

I'm out of town right now, but I'll post some pics when I get back. I chose the Urethane Uppers because they were the Thinner of the 2, the Stock Upper were considerably thicker and I wanted a little more drop, and it worked perfect. I got about 1/2 more drop out of the front and rear than I had on my 03 with the MM Urethane Isolators on both the top and bottom.

 

[hawaiiancobra]

kenny brown

i was able to get kenny brown springs b4 he closed shop. he will open again soon. i have 04vert, kenny brown springs 750lb. front and back,first went stock iso's, front w/x2 ball joints and bump steer kit. the drop was insane, the ride like a rail. i must also say i have all his suspension set-up including xstreme subframe system, the ems driveshaft safety loop xbrace and every other available suspension mod. the vert flexed heavily when stock, no flex any more. the drop was to much for speed bumps, couldnt go to mall to shop, and when i put michelin 335zr.35/17's they hit the fenderwells when taking off or going around corners, a very unsettling feeling. put mm iso on and no more problems. with stock tires on big dips car would bottom out. stock iso's front 25 1/4'' fenderwell to ground, rear 26 1/2'' w/mm iso's rear is now 27 1/4'', this is also with the spacers provided by kenny brown for the rear on a vert. i did not use spacers at first to see full drop,it looked awesome but i like these wide tires and cannot have them rub. no more rubbing. i may try taking the spacers out to lose 1/2'' and see if i will rub with just the mm iso's in. these cars dropped to the ground looks way to awesome, i think i would like airbag suspension for these cars, dont seem to be able to find them for irs. bumpsteer in front is off also, did not put in spacers provided by steeda w/x2 ball joints, eventually will probably add them in, the spacers are suppose to be good for 1/2''. this is just about trial and error and takes alot of time and down time with the car, since its only for hobby and not daily driving, occasional racing is what i am setting up for and getting the looks from the hot chicks lol

 

[GrimlokTT]

Questions:
2. When is a bumpsteer kit and offset rack bushing REALLY needed. (I know, I know...to correct the geometry. When? Why? Do you really know? MM says you don't need them...)

Here's MM's reasoning: BUMPSTEER
Bumpsteer is the toe setting of a wheel changing as the suspension moves up and down over bumps, or with body roll while cornering.

There is a myth that the tie rod should be kept parallel to the ground to avoid bumpsteer. THIS IS NOT TRUE! What IS required, is that the tie rod be kept parallel to the lower control arm so that as the suspension moves, the arc of the ball joint and the arc of the tie rod end do not cause any steering input to the spindle. As you lower your car, the tie rod end and the lower control arm move together, staying parallel. If you install offset rack bushings on a stock geometry K-member, you are making the tie rod end
and the lower control arm NOT parallel. You will actually CREATE bumpsteer by installing offset rack bushings on a stock K-member.

Ford engineers have actually done a very good job at designing a low level of bumpsteer for daily driven cars. Specifically, Ford has designed the bumpsteer to toe out the front wheels under bump. This is a roll understeer
condition; the outside loaded tire will turn to the outside of a corner as the body rolls. This condition is designed by Ford by positioning the tie rod end slightly low relative to the steering rack.

Increasing caster raises the tie rod end relative to the steering rack. Increasing caster up to half of the adjustment range with our Caster/Camber Plates will actually HELP bumpsteer and help performance by reducing roll understeer. If you increase caster beyond half of the adjustment range, the bumpsteer curve will shift toward toe IN under bump, or a roll-oversteer condition. In this case, it is beneficial to raise the rack, but only by about 1/10 of an inch. Offset rack bushings raise the rack far too much. The best solution is to lower the tie rod end using a bumpsteer kit (MMTR-3,-4). See our test results in the July 1993 issue of Super Ford for details. Competition cars using stock K-member geometry will also benefit from an adjustable tie rod end kit (MMTR-3,-4). These kits provide an assortment of spacers in .015"increments to best position a rod end at exactly the correct height; thus taking into account suspension geometry tolerances.

Offset rack bushings DO have a purpose and may be beneficial if you have raised your inner control arm pivots using an aftermarket K-member. In this case, raising the rack will help match the geometry of the raised inner control arm pivots. If you do use offset rack bushings, be sure to only use aluminum bushings - polyurethane offset bushings do not work. The urethane has too much “give”, and therefore it is impossible to get the rack mounting
bolts tight enough to prevent the bushings from rotating during hard cornering.

What are your thoughts?

 

[badsube]

guys, what about just removing the stock isolators? i can't drop it too much, only looking to get maybe 1/2 to 3/4 drop? thanks.

 

[GrimlokTT]

I got .5 an inch when I cut off .5 a coil...

 

[badsube]

I got .5 an inch when I cut off .5 a coil...

isn't it easier to just remove the isolators? thanks.

 

[GrimlokTT]

isn't it easier to just remove the isolators? thanks.

If you don't have a tool to cut them, then a lot easier. If you have the tool, then not really a big deal either way. A lot of people say you don't need the isolators, but I personally just prefer to keep them in there...

 

[badsube]

If you don't have a tool to cut them, then a lot easier. If you have the tool, then not really a big deal either way. A lot of people say you don't need the isolators, but I personally just prefer to keep them in there...

alright. thanks alot.:beer:

 

[GrimlokTT]

Oh, and when I say tool...I just mean something to cut them with--nothing special.

 

[ubnsmkd03]

Got some pics. H&R race front isos removed rear stock isos. AFS 18's.

Sorry for the quality..

looks awsome hope mine looks that good when i get back

 

[pianoman90]

When you guys are lowering with H&R Race/SS, do you have to roll the fender at all?

 

[jzepp]

I was told by maximummotorsports that the poly spring isolators do not raise the ride height at all and are comparable to brand new rubber spring isolators in height...........some of you guys say it raises 1/2"........is that correct?

For you guys that are using the H & R race springs and leaving out the isolators in the front are you getting a 1.5" drop compared to the 1.25" drop they advertise? Arent the race springs gonna be kinda harsh for the street with that very high rate spring rate?

 

[JPIStang]

No, more like .25 total (upper/lower combined).

Yes.

Yes. (read my other posts to see what I think of the ride with a 'vert and race springs)

 

[huben94]

Eibach 3594-140

Installed Eibach pro-kit, MM caster/camber, stock insulators, bear bump steer kit and urathane sway bar end links. Rides better that stock, there will be no scraping after the exhaust is adjusted.

 

[huben94]

Installed Eibach pro-kit, MM caster/camber, stock insulators, bear bump steer kit and urathane sway bar end links. Rides better that stock, there will be no scraping after the exhaust is adjusted

 

[04MC]

Those with H&R race springs ... with all factory isolators installed will the front be lower than the rear? I don't mind that, but I'v seen some removing the fronts instead of the rear iso and other cars the rear looks so high that they removed the rear to match the fronts?

 

[JPIStang]

Those with H&R race springs ... with all factory isolators installed will the front be lower than the rear? I don't mind that, but I'v seen some removing the fronts instead of the rear iso and other cars the rear looks so high that they removed the rear to match the fronts?

Yeah they'll be a little lower up front.