Final decisions before suspension rebuild - Eibach springs or not?

[jjbuzzman]

Hello Q45 Gurus,

I will be re-building the suspension in Robert's old Q (the former ECU guy) and request input on several decisions. Here's the present set-up: 1993 Q45, Stillen front strut tower bar (similar to Jeff Williams), Q45a sway bar in the rear with stock bushings (bushings about 2 years old). Car has 18 inch 350z touring wheels with BF Goodrich G Force tires size 245/45/ZR18. With a good dip in the road, these tires rub in the front.

A guy I know put after market wheels on his 350Z so I bought his 17 inch stock wheels with Bridestone Potenza RE 040 225/50R 17 (front) and 235/50R 17 (rear). These tires are all new. I hope to put these wheels on the car and sell the 18 inch wheels.

I studied all the posts about suspension parts and have in hand from I.O.Scottsdale all bushings and Konico blue struts/shocks. The car had new upper links 18 months ago.

I also have a new set of Eibach springs for the car - Prokit model 6325-18. These springs will lower the car about 1 inch.

I now read the ideal set-up would be a Q45a front sway bar to match the rear.

So here's my questions:

Should I install the Eibach springs? What's the difference as compared to stock? The 245/45/18 tires have tire rub. If I lower the car with the springs, might I still get tire rub with the 225 & 235/50/17 tires? I still have some 15 inch stock wheels I could also use, although they wouldn't look as snazzy.

Should I not be able to find a Q45a front bar, and keep the stock front bar, should I install alternative bushings or make other mods to optimize the outcome?

There's a guy here at the old Chevy dealership with nice machinery and all he does is alignment and suspensions and I've negotiated a $500 price (not including the springs) for all the work (they used to be a Nissan shop too). He did my 1990 a while back and the result was wonderful. I live 3 hours away from T3 in Atlanta - would it be worth the trip and two days stay to get this work done at T3?

Thanks for the advice.

[qship96]

3 hours from T3? No Brainer...leave your house at 5am-drop car at t3 by 8am,shocks/springs shouldnt take more than 4 hours max,be home in time for an early dinner.

[Denver90Q]

I guess if you really want the car to handle at the expense of tire clearance, wear, ride harness, ground clearance and additional susupension wear you should install the Eibachs. I have some on my 1990 in addition to the rear "a" bar. You could probably just tighten up the front sway bar bushings instead of replacing it to get the desired effect.

[maxnix]

Hello Q45 Gurus,

I will be re-building the suspension in Robert's old Q (the former ECU guy) and request input on several decisions. Here's the present set-up: 1993 Q45, Stillen front strut tower bar (similar to Jeff Williams), Q45a sway bar in the rear with stock bushings (bushings about 2 years old). Car has 18 inch 350z touring wheels with BF Goodrich G Force tires size 245/45/ZR18. With a good dip in the road, these tires rub in the front.

A guy I know put after market wheels on his 350Z so I bought his 17 inch stock wheels with Bridestone Potenza RE 040 225/50R 17 (front) and 235/50R 17 (rear). These tires are all new. I hope to put these wheels on the car and sell the 18 inch wheels.

I studied all the posts about suspension parts and have in hand from I.O.Scottsdale all bushings and Konico blue struts/shocks. The car had new upper links 18 months ago.

I also have a new set of Eibach springs for the car - Prokit model 6325-18. These springs will lower the car about 1 inch.

I now read the ideal set-up would be a Q45a front sway bar to match the rear.

So here's my questions:

1.) Should I install the Eibach springs? What's the difference as compared to stock? The 245/45/18 tires have tire rub. If I lower the car with the springs, might I still get tire rub with the 225 & 235/50/17 tires? I still have some 15 inch stock wheels I could also use, although they wouldn't look as snazzy.

2.) Should I not be able to find a Q45a front bar, and keep the stock front bar, should I install alternative bushings or make other mods to optimize the outcome?

3,) There's a guy here at the old Chevy dealership with nice machinery and all he does is alignment and suspensions and I've negotiated a $500 price (not including the springs) for all the work (they used to be a Nissan shop too). He did my 1990 a while back and the result was wonderful. I live 3 hours away from T3 in Atlanta - would it be worth the trip and two days stay to get this work done at T3?

I'd keep the wheels as they are forged and light and 18" are where performance tires live. The offset is a little funky, but with care they can be made to service. My vote is to sell the 17" cast wheels as they are not as strong nor probably as light.

The dampers are by Tokico.

Read all of Q45tech's posts about Eibach's so you understand the additional expenses involved and the minimal performance gained. Tires (and by implication) wheels are so much more important once the suspension is up to as new OEM standards.

One thing that occurs to me to inquire with Joe about is if the later G50 being heavier had a higher spring rate? Front may not have changed as llittle of the extra weight went there.

1.) Don't confuse wheel size with overall loaded diameter.

2.) No, you really don't want to firm it up. If you want more oversteer, go for polyurethane rear bar mounts. Lubricate them or suffer the squeaks and groans.

3.) A competent shop with knowledge of Z32/G50 suspension set-up should be able to handle this. The more important thing is to get an immediate alignment at a great shop with a Hunter system. Wait until you have mechanical malfunctions or major work for the Atlanta expedition.

[elwesso]

Oh boy, some serious confusion to be cleared up.

Not to toot my own horn, but outside of people who have coilovers on the Q, I have done the most suspension work/tuning on G50. Ive had about every combination. Chances are, when it comes to G50 and suspension, Ive been there, about all I havent done is my own alignments because I dont have 25,000 to spend on my own hunter alignment machine. Maybe someday...

First, with regards to the wheels. The 17s and 18s have the same offset, and your OD's on those tires are going to be close.. The 17s may not have adequate load rating, I'd have to check...

The 245-45-18 is BY FAR (let me emphasize, BEST) the BEST tire size you can run on your G50. Ive had 245-45-17, 245-40-18, 255-40-18, and my current 245-45/275-40-18 setup... My current setup is the favorite, I like it a lot.. When I switched from my 15s on 235-60-15 i couldnt tell much difference in ride harshness.. A little, but nothing like those noisy and harsh 245-40-18 (not to mention they were below load).

Let me guess, the tires rub in the front drivers side? I have a trick you can do that may fix it. If tis both sides, you may need to roll your front fenders.. Nothing a low temp torch and a baseball bat cant fix (im being serious as brutal as that sounds)

The stillen FSTB is amazing, consider yourself lucky.

IMO its not really worth the effort to get the front bar from the active/touring. Just put in new bushings, maybe poly in the rear. Im running poly end links (1 inch from energy suspension, search posts for that part number)... I'd start with that, in the spring I may go to poly frame bushings as well as mine are starting to get iffy (had a small PS leak that is starting to rot them)

The springs are more of a cosmetic thing. The wheels and tires will not rub any more than they do now with lowering, as little sense at that may make.. Camber gained as you drop, all that fun stuff you should know about.. While they realyl dont help your handling so much, they make the car feel more poised. You'll like em, even with new tokicos the OEM springs are made for confort... The springs IMO dont really take away much comfort.. If you dont want them someone here will. I still my eibachs in my attic since they're so hard to find.

I had eibachs on a new stock suspension... Ride just wasnt as compliant but i liked it a lot.. It was a lot more stable on high speed maneuvers... With my SUPER HICAS car, I hit those 90* turn sweeping on ramps at about 3/4 throttle going about 65 coming out.

IMO for suspension its not worth it to drive to T3. Anyone can work on the suspension on these cars, especially when your just R/Ring parts... its very simple.

Remember tires and tire pressure is going to contribute to most of your handling and ride.

[Q45tech]

T3 doesn't do alignments but we send you to shops near by who are competent ------------------unless precision is desired.After aligning mine a few dozen times It is tough to get it to stay in rear without everything brand new.

[jjbuzzman]

I appreciate the advice on my suspension set-up.

One additional question - are there any performance tires out there that are more quiet than others? The BF Goodrich G Force 245/45/18's on this car are really noisy. I put some Michelin Hydroedge 15's on my wife's Q45 and they are absolutely silent, smooth as silk, and not all that bad handling (obviously, they also are not speed rated, etc.). By comparison, when I get in my car, it sounds like a jet aircraft off.

I suspect the Bridgestone Potenza RE 040's I have on hand may not be all that quiet either. Is there such thing as a quiet 245/45/18?

[elwesso]

Quiet, grippy, cheap. Pick 2, forget about the other.

Just out of curiosity what G Forces are they. im guessing they are the T/A KDW.

The RE040's arent going to be much better I dont think...

I like my dunlop's, theyre way quieter than the michelins especially over bridges.

Read the reviews on tirerack.

[jjbuzzman]

Yes, you are right - they are the G Force KDW's.

And you are also right about the tire rub occurring only on the driver's front. So, I would be interested to hear about your clever remedy to this situation. And that would be nice - to swoop through a dip in the road without that annoying squeal from the tire contact.

Thanks for the help.

[maxnix]

Michelin PS 2 are light, strong, incredible performance in wet and dry, quiet, but not cheap.

Also read the sticky in Infiniti General.

[elwesso]

Check and see if the plastic shield in the front of the wheel well is removed. It will have little slits toward the bottom... its really only there for active cars to protect the active cooler.. Chances are its scraping against it.. Turn the wheel all the way one direction and see if you can see a wear spot on it.

Mine was removed ages ago and its been fine...