kev

I've got kyb agx's and Ground Controls with 350front and 300 rear spring rates on my 1997 200sx se-r. Everything I read recommended a 300/200 spring rate setup, but I decided to go a little higher. I autoX this car, and generally set my agx's to 3 in the front and 6 in the rear.

I'm not entirely satisfied with my setup, and I'll tell you why. Yesterday, I had the chance to autoX a friend's 2002 Spec V with Ground Controls (325 front and 375 rears). The car handled like a dream. The biggest difference between my B14 and the Spec V is that the Spec V had a lot of "lift throttle oversteer", which I like and want on my B14.

My question is...what can I do to induce throttle oversteer with my current setup? What would be the possible pros/cons of going with a higher rear spring rate? I'm willing to spend $50 on another set of rear springs to experiment if there is a chance it will help.

My other suspension mods include:
-front STB
-rear STB
-stillen rear sway bar
-stock wheels with dunlop s

 

motivational1

You could just try swaping your front and rear springs and see how that feels.

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Motivational Engineering
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spdracerUT

I think a stillen(as much as we don't care for them) adjustable rear sway bar will help a lot. It'll let you run a softer rear spring which will keep the rear from bouncing all over the place ( I think) and just crank the bar full stiff for when you auto-x. I think the bar will give you enough oversteer for an auto-x.

Khiem

spdracerUT

opps, just noticed you already had the rear bar. Hmm... and you still don't get oversteer? You could try playing around with your tire pressures.

98sr20ve

You need at least even rates front and back on a B14. I just put some 300's on the back of my car today (300 fronts). Other then that I have about the same setup as you. Stillen rear bar, etc. I am planing on bending the beam on my car to get zero toe. If I wasn't I would probably go with the 325 rear springs instead. I would try and swap the springs. Let me know how you like it. I am very curious. Also, do you have your rear bar set full stiff. Slide that bar all the way back.

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92 240SX Project Car.

 

kev

I'm happy to say I just found out that I didn't have my stillen bar set as stiff as possible.

98sr20ve,

If possible, could you tell me what part #'s you have on your springs? I just want to compare them to my springs.

Also, could somebody tell me how the part numbers for the ERS springs work. I thought the part numbers were supposed to be self-describing: 0800.250.0300
0800 = 8" spring
250 = diameter of the coil
300 = spring rate

is that correct?

Thanks

kev

I dug through all my invoices. Ground Control originally sent me the following springs:

Front Spring#: 150.64.53
Rear Spring#: 180.64.44

The front springs were too short, which didn't allow me to adjust my perches fully in the front. Ground Control then sent me springs that were 2" longer, and I shipped back the shorter springs (part # 150.64.53). I now have the 0800.250.0300 springs on my front.

So I think I might be running 300/300 and not 350/300 like I thought. From what I've been hearing...there is nothing wrong with 300/300. I'll have to call GC and bounce these part #'s off of them to satisfy my curiosity.

kev

Argh, I'm an idiot

I thought I had ordered 350 front / 300 rear spring rates. I talked to the folks at Ground Control today and it turns out that I have 300 lb 8" springs in the front and 250 lb 7" springs in the rear. Looking back at my paperwork, I did order 300/250.

98sr20ve,

Do you have the part # for your rear springs? Do you remember what length they were? I don't forsee any beam-bending in my future, so I think I'm going to order some 325 rear springs. Is your car fairly quiet...mine is

98sr20ve

My rear springs were used but they are 7 inch's. I would go up to the 350 or 375 rear spring. With my rear #300 my car still basically understeers. The B15 and the B14 are not that different. I would be super tempted to just copy their 375 rear spring rate. Remember B15’s have a bigger built in rear sway bar then the b14. In other words a b15 with 300/375 would have more roll stiffness in back then a b14 with 300/375 would if they both have no added rear sway bar. I know the b15 weighs more but % wise the roll stiffness is still proportionally the same. You may want to get a 6 inch rear spring over the 7 inch. I would call GC and get their recommendation.

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92 240SX Project Car.

johnnykomac

That beam has got to be our F*ckin probleum....

 

kev

The beam hurts those of us who are trying to introduce some oversteer in our cars.

I've driven a spec V with GCs 300 fronts and 375 rears with stock dampers. The car rotated quite well (throttle lift - understeer).

With that and what 98sr20ve has stated, I think I will be getting 375lb springs for my rear...then I too will have 300/375 setup.

I haven't heard of many comparisons of the b14 and b15 beams...but i'm sure they're quite similair

98sr20ve

Actually, its the front suspension that is our problem. The beam has too much traction compared to the front. Understeer is the act of the front wheels lossing traction, Oversteer is the rear wheels loosing traction. THe beam has soo much traction that it is very difficult to get the rear to rotate at low speeds due to the excessive rear traction. If we had the G20 front suspension we would not complain about the beam nearly as much. Kev, can you pm me with your impressions of the 375 rears on the car. I would really like to know. I think you will like them a lot.

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92 240SX Project Car.