Originally Posted by dryseals

A solid diff mount woud help, but make for a rougher ride.

Originally Posted by Motormouth

What are you talking about? Firstly, you absolutely want squat in a suspension. The squat is rearward transfer of the weight of the car and results in increased traction. why do you think ultra stiff race cars have such terrible 60ft times? it's a compromise between purposes but EVERY car for any purpose is made to have squat. from the race car that needs it to launch out of a corner to the drag car that needs it for launch.

Secondly, harder rubber can exacerbate the problem as the grip profile leads to loss of traction. You want grip not slip and I don't think the OP was wanting to spin at all.

Thirdly, solid differential bushings in NO WAY lead to a harsher ride. The only negative aspect is increased gear whine transmitted through the chassis. You get more consistent handling better lateral traction and force the suspension to act more positively. the car has soft bushings between the subframe and the frame that absorbs the harshness.

so your whole post was wrong, and leads members to the wrong conclusions. don't do that.

In a related note to a post someone made: a VLSD will not help your car on launch. They simply do not function that way, if anything they make it worse because of the slip difference they allow before affecting any sort of positive influence. A mechanical LSD helps, but I can tell you it cannot and does not cure it. Addressing this issue with anything other than bushings or spring changes are simply a bandaid and do not address the root cause of he behavior.

Another note from my direct experience (something it seems a bunch of you lack and thus the ridiculous assertions in this thread) is that the stock carrier bushing (the liquid filled one) is prone to failure. I would even venture to say a large amount of Z owners have a failing bushing and don't know it. Every modified Z that is increasing grip levels (wider tires, better rubber, stiffr suspensions, aftermarket aggressive LSDs) is abusing this bushing and experiences negative performance they don't realize if they don't address it. As little as two launches at the strip has been shown to destroy the integrity. You can check yours by looking under the car the next time you arer so inclined: if the bushing has torn, you will see black streaks running down the subframe that holds the rear bushing and possibly on your exhaust pipe if you can see yours (spl's pics on their site show how theirs broke as well if you need a visual aid) or if the front-side of the rear bushing tore you can tell because the actual center metal portion of the bushing will not be centered and will be 'sagging'.

So why pay to have the same piece of **** bushing installed again? get a solid bushing. These bushings are integral to isolating suspension loads to be handled where they should be: the suspension.

/end

PS: support SPL as they are the one of the only companies (in the US no less) putting out the suspension parts we crave and that benefit the whole community. Their service is beyond amazing, their products are wonderful and their pricing is very reasonable for the amount of RnD they perform.

Originally Posted by Motormouth

Secondly, harder rubber can exacerbate the problem as the grip profile leads to loss of traction. You want grip not slip and I don't think the OP was wanting to spin at all.

Originally Posted by speedracer05

Will the solid rear diff mounts also take car of the issue some of use have with the rear end ripping out, that would be from the stock bushings that alow movement so the soilds would restrain it more?

Originally Posted by dryseals

Not to get in an internet fight, but I've built cars for many many years, I'm 50, I'll be 51 next month. Been building since I was 13. Squat is a rearward transfer of weight no doubt, but it's not good for traction and control. Thus we use ladder bars on a solid axel to gain the advantage of lifting the whole car and planting the lift weight on the rear. It also keeps the twisting action of the rear end to a minimum and allows for the front tires to still maintain traction and control. You squat, I'll lift.

The hard tires are for burning up and smoking, so many posters tend to want to tear up tires doing donuts and such. If he really wants good traction, get some drag slicks. And if he doesn't want trouble from the law, he could find some tires rated for winter driving, ie snow tires. Their soft, heat them up once and they'll be sticky and still pass the boys in blues eyes.

As for the rougher ride, yeah not too much, but road noise is terrible. I've had two other car with independent rear ends, a Corvette and a Jaguar XKE. Although both mounted differently, replacing the bushings with solid mounts helped but made for a tad rougher ride.

Originally Posted by Redline_Burner

Actually I do enjoy some wheel spin, reminds me of why I got rid of my AWD WRX. Certainly couldn't spin the rear tires when I felt like being a douche every once in a while in that car. Don't get me wrong though, I absolutely love this car and am taking every precaution to keep it in the best shape possible the entire time I have it. Got my clear bra, always drive the speed limit (or a few over - one speeding ticket in my previous car because cops hate Subaru's) and always stay up on maintenance.

All that said, I still like having a 306 hp (yes I know I know, that's just the factory-stated number) sports car and drifting around the corner coming out of my neighborhood every once in a while.

Thanks for all the responses guys. I was pretty sure it was wheel hop, if there was a secondary traction system stepping in and causing that kind of interference it would be retarded.

Last time I drove an IS 350 (has VDC and TCS) I took it to a parking lot that is like driving on ice when it's wet (super smooth asphalt) and tried to do ONE spin out with the TCS OFF button pressed. The car let me spin the car 180 and then the dash flashed the "traction" light, beeped and turned the system back on. Instantly stopping my slide as if I'd hit a wall. I assume this is what the Grand Touring 2007 models have on them, safety wise it's great in the rain and dicey conditions, but otherwise these systems are a b!tch when you just want to have some fun.

Haven't decided if I'm going to mod my HR, suspension or power. I spent a bunch of money on my WRX to get it to the point where it could beat an HR easily but that was definitely not the car for me. But if I do, suspension and wheels will be the first mods

Thanks again for the replies

Originally Posted by Redline_Burner

I'm not taking any shortcuts with this car if I do mod it. Is it genuinely agreed that coil-overs of some sort are the best way to improve handling on Z's while lowering slightly as well?

I'm also thinking I'm going to end up buying the dual HR intakes, I love the sound of aftermarket intakes on these engines, and of course the few extra HP doesn't hurt either. :-D

Originally Posted by Motormouth

stiffer suspension can make it worse.

and yes: SPL solid diff bushings are the bomb. they were so nicely made and had a great price. the install (did it myself with a friend) was the biggest pain in the *** ever, but totally worth it.

Originally Posted by Redline_Burner

This hasn't gone away for me. It's incredibly annoying, I can't launch it in a straight line hard without either the wheels hopping uncontrollably or my clutch slipping going into second gear (guessing it's because I still haven't had the master cylinder recall taken care of). I really hope this problem changes when I have different tires once the stock RE050's are gone.