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i have an 04 gto and as soon as i got it i noticed the amazing bounce i get when shifting the car. i also get some wheel hop sometimes. now i plan on upgrading the car to making 500HP. can someone recommend a spring for me so that i don't get wheel hop and it doesn't raise the car that much so it doesn't look retarded.

Thanks
Anthony
 

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For springs the main players are Lovells, Pedders and Kings. The stock rear shocks are slightly weaker than a screen door closer and yes drag bags are a good and cheap investment
 

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as far as stock shocks. some dont have the money for the super hi-pro ones, would a higher tier shock from goodyear or whatever be an improvement over stock ?
 

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There are multiple causes for wheel hop. For spring choices you should decide on what height you want. This will also depend on tire clearance concerns as well.

If you are putting down 500hp at the rear, there is not a bushing in the back that can properly control this movement. You need every bushing in the back:
a. sub frame or cross member bushings
2. Diff insert or Harrop cover
3, all 4 LCA bushings.

these are the majority causes of excess wheel hop. If you need help deciding a spring height, lets start off with giving us some info and desires

mike
dms
 

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I was just looking at at the Kollarracing site at all the Springs and pads. they all have a MM rating or measurement for them. What does that mean? for instance, if i got the 37MM springs and a pair of 12MM spring pads. would that bring the rear end of my car back to stock height. i do not want to lower the rear end in any way! Thanks
 

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I was just looking at at the Kollarracing site at all the Springs and pads. they all have a MM rating or measurement for them. What does that mean? for instance, if i got the 37MM springs and a pair of 12MM spring pads. would that bring the rear end of my car back to stock height. i do not want to lower the rear end in any way! Thanks
the challenge or knowledge base is what do you think is a normal height for the rear? I say this because nearly all GTOs had collapsed and damaged rear coils as they left the boat. The back end of the GTO measured 607mm from the lower wheel lip, thru center, to the fender opening when it was in Au. When it arrived, the back end averaged 590 to 594mm in the show rooms. Now they average 575mm to 585mm. So what height do you truely want the back end at?

mike
dms
 

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I was just looking at at the Kollarracing site at all the Springs and pads. they all have a MM rating or measurement for them. What does that mean? for instance, if i got the 37MM springs and a pair of 12MM spring pads. would that bring the rear end of my car back to stock height. i do not want to lower the rear end in any way! Thanks
Mike's right about the original height and how they sagged. The problem we have is that Pedders and Lovells measure the same thing two different ways. Pedders measures from the bottom of the wheel to the fender and it seems most other makers measure from the center of the wheel to the fender. The advantage of the center measurement is it doesn't matter what diameter wheel you have on. The bottom of the wheel measurement means you don't have to guess the center of the wheel but it really isn't hard and most of us could care less if it's a millimeter or two off. To complicate it further both are in millimeters. If you don't have a mm tape there are 25.4mm to an inch. If you like the look of it now it may be at the lowered height on new springs and "stock" height might look too jacked up. Measure and decide.
 

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Mike's right about the original height and how they sagged. The problem we have is that Pedders and Lovells measure the same thing two different ways. Pedders measures from the bottom of the wheel to the fender and it seems most other makers measure from the center of the wheel to the fender. The advantage of the center measurement is it doesn't matter what diameter wheel you have on. The bottom of the wheel measurement means you don't have to guess the center of the wheel but it really isn't hard and most of us could care less if it's a millimeter or two off. To complicate it further both are in millimeters. If you don't have a mm tape there are 25.4mm to an inch. If you like the look of it now it may be at the lowered height on new springs and "stock" height might look too jacked up. Measure and decide.


We measure in mm because in Au, they use metrics. Plus, after using mm, it is seriously easier than 27 13/32 for example.

It is true that we measure on purpose from the bottom wheel lip, thru center to the fender opening. Why? To eliminate variations in tires. We are quite accurate with our coil rates and heights. You can have 5-7mm variations just in tires alone.

thanks
mike
dms
 
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