I recently ordered and and received moog part # 5664 for the fronts and cc-635 for the rear. The front springs look to be incredibly stiff. I am looking for a somewhat stiff ride, with more of an emphasis on handling. I am upgrading from a stock RS suspension with KYB shocks/struts as well. Does anyone have any input on the 5664's? This is not my daily driver, but is mostly driven on the street. I am concerned that they will be way too stiff for the street...

 

I just recently had my springs replaced but the part # for the Moog front springs for my 92 Rs is 5610. Where did you get that part #?

 

I am not looking for the Moog factory replacement springs. I am looking for a stiffer spring that will improve my handling, however these look extreme. They are the Moog performance replacement, and rated at (i think) 767 lb/in?

 

After the new springs were installed, the suspension felt stiffer than stock, the front was slightly higher than when the stock springs were on but after a couple of weeks the springs settled but they still feel stiffer than stock.

 

Those springs are stock springs on a 89 iroc. Which are rated at 600 pound/per inch. I have these springs on my monte with one coil cut off and they ride about the same as my friends 89 iroc. They say your shocks have more to do with the ride than the springs. As far as I know these are the stiffest springs used on a f-body.

 

Those springs are the exact combo I have on my 83. They are excellent, you will love them. My car is a little light on the nose and it sits almost level, the nose is only about ½" lower than the rear. It sits a bit lower than stock overall.

 

Excellent... thanks for the replies, guys.. Looks like I'll be busy this weekend!

 

i just put stock Z28 springs in the front of my car in august, 5610 sounds more like the correct # (cant remember tho...) but anyway, they are stiff as hell! i can barely get the front to dip down if i slam my body weight onto the fender (164 lbs)...these babies handle well (but rough) with KYB GR2's in the front. as for the back...those are cargo-coil springs, which means they are extra stiff. i also have those installed, but i heard that for optimal street handling, you want slightly softer springs in the rear (someone please correct me if i'm wrong...) but i'd say thats true from my experience, as even w/ a tubular panhard bar, the rear end still feels a bit squirrely through bumpy or high speed turns. as a tip...you may or may not know, just make sure you have the correct spring compressor (and a ****load of washers) to put the new springs in. you need a compressor thats inside the spring, not outside (big duh to me...one of the many factors that held up my front suspension rebild) you will have no prob getting the old springs out w/o compressing them (if you want to take the risk, it was a little scary) but there's no way in hell you're getting them back in w/o compressing them.

 

hmmm...after looking through the moog on-line applications, i found that the 5664 says it's for convertible only, but they are the HD springs. actually, it doesnt even come up as moog...it lists as a TRW # CC5664, 89 Iroc 5.7 convertible. the only diff is probably the spring rate, but i'd also be concerned that they might make the front end sit a little higher. if i were you, i would play around a bit...http://www.federalmogul.com/moog/index.html

 

I did install the springs / struts / shocks in the car this weekend, and the front end does sit considerably higher than before. I have heard that this is somewhat normal, and that the front springs will soon break in a bit and settle down. It is enough now for me to want to pull the springs and cut 1/2 a coil or so off, but I will be patient if I have to...

RB83L69, you mentioned you had this combo, so was it necessary to cut the front coils at all to get the front to an acceptable ride height, or did they settle quickly? I dont have as many weight saving componets as you seem to have, so I can only imagine your front end was as least as high if not higher than mine.

Thanks for the input.. should I get the cutoff wheel out

 

ive had the problem since i installed my coils in august. i went with the 5610's though. im pretty sure of my problem(s). first off, i didnt have the weight of the car on the front wheels when i torqued the LCA bolts in the front. to fix this, i loosened the bolts a bit, drove around the block then pulled into my driveway straight (turned the wheel minimally) and drove onto ramps, then torqued the bolts. that helped a little bit. the reason i pulled in straight is because if i make a tight turn (such as pulling into driveway/parking spot) the front would jack up an additional 2-3 inches...it disturbs me cause it looks like a monster truck. i figured i'd let it settle a while, but it hasnt dropped much since. anohter problem: i didnt have the spring turned the correct way. the end of the last coil is supposed to sit in between the 2 drain holes in the lower spring seat, im waiting for some good weather / a free day to fix this. the reason i cut corners doing all this (tightening the bolts and not positioning the seat) was because i ran into endless problems w/ the whole install, and i was finishing up about 10 pm sunday night in the pouring rain because i needed a way to get to work the next day. anyway lol 2 lessons dont rush your **** and make sure you know all the steps you need to do. im not making any assumptions about your work or what you did, just merely suggesting problems i ran into. a third thing that i am unsure about was told to me by a mechanic who did my alignment. he said the springs looked liek they were in there upside down. well i put the white coil up top like the instructions said, so after re-positioning the springs, if i still have a problem im just gonna put a new set on there, cause maybe moog marked the top incorrectly. anyway, i hope my mistakes can inform you somehow, because it's *** damn ugly when you can fit your head in the wheel well, and guys at work ( i work at an auto parts store) still bust my ***** about it, it gets annoying. anyway, good luck w/ it.

 

Mine did settle somewhat over the next couple of weeks, maybe ½" or so. I don't have much space above my tires, maybe 1½", no more than that. I put the Moog replacement rear springs in too.

Having the springs turned wrong in the pockets will definitely cause this: in essence you're "unscrewing" the spring out of its seat.

My car weighs about 1900 lbs on the front wheels, and about 1500-1550 on the rears. It might be worthwhile to see what yours weighs.

 

I tested both the Moog 5664 (767 lb/in) and 5662 (706 lb/in) springs. On my lighter-nosed Z28 (aluminum heads, fiberglass hood, aluminum bumper support) both put the nose noticeably high. I ended up going with the 5662 springs, minus 1/2 coil.

The 5664 springs later ended up in SPD's twin-turbo IROC and even with all his extra weight up front (steel hood, 2 Garrett turbos, intercooler, etc.) it was nose-up. I think 2/3 coil removal was the sweet spot, can't recall offhand but there was definitely cutting involved.

I used a Dremel with heavy-duty cutoff wheel for mine, went slowly so as not to overheat the spring and lose it's temper.

 

I think im going to cut them. My 350 is hopefully going in this week, so I will wait until that is finished to see where that puts the nose. I can easily see taking at least 2/3 of a coil off.. the nose is that high now. That and having it settle a little should put it right where it should be.