Guest Posted August 18, 2006 Share Posted August 18, 2006 Guys, I am puzzled. The understeer strikes back after I put on the JDM GT/Bilsteins/springs! I also run JDM GT rsb and RE070 tires. I waited to have alignment done (yesterday) to confirm that, but unfortunatelly that's the case - when pushed hard the car understeers badly, noway I would be able to rotate it. Btw, alignment has been set to 0 deg toe all-around, and -0.7 deg camber in front, front caster being between 5.6-6. In stock form, my LGT wagon had strange feeling of initial oversteer quickly transforming into severe understeer (and massive body roll). After puting the RSB it became neutral with a hint of oversteer (nice). What's up? It's not my imagination, I think I need to play with tire pressures a bit more (I think I have 36psi front, 35 rear at the moment), but still. Anyway similar impressions I had with GY F1 DS-G3 pumped to 39/37 front/rear. Looks like I am back in the market for a new bar(s). I will probably wait and install Pinks first, see what happens, and if I like them, I only will think about new bars then. I am not suspension expert (yet :-), so any opinions/suggestions are very welcome! Link to comment Share on other sites More sharing options...
PGT Posted August 18, 2006 Share Posted August 18, 2006 roll center has changed with the new suspension. I found the JDM RSB to be a good upgrade for stock USDM, but not enough for the Bilsteins as well. Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 roll center has changed with the new suspension. I found the JDM RSB to be a good upgrade for stock USDM, but not enough for the Bilsteins as well. And did you find better match? I recall you went for some KYB suspension, so perhaps that's a different story. Now my options are Cusco bars, rear AVO bar, or perhaps Cobb.... Link to comment Share on other sites More sharing options...
PGT Posted August 18, 2006 Share Posted August 18, 2006 I sold my Bilsteins and picked up Cusco coilovers, and sold those and picked up the current set. I had Perrin bars on with the Bilsteins too....handling was much improved, if only the rear had been designed not to hit the rear control arms. I'm currently running a Cusco RSB only, but will do the Cobb set once they've worked out their issues too. Link to comment Share on other sites More sharing options...
Saul_Good Posted August 18, 2006 Share Posted August 18, 2006 Get a Cusco RSB, you WILL rotate. Prolly a little more than you'd like. Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 Get a Cusco RSB, you WILL rotate. Prolly a little more than you'd like. Just RSB? Are you running it with Bilsteins or stock KYBs? Link to comment Share on other sites More sharing options...
wcbjr Posted August 18, 2006 Share Posted August 18, 2006 I have a Cusco RSB and STech springs, stock struts. I don't get a whole lot of oversteer. I forgot what I was supposed to remember. Link to comment Share on other sites More sharing options...
Xenonk Posted August 18, 2006 Share Posted August 18, 2006 change the tire pressures to match the new suspension, that's the cheapest and easiest way to deal with understeer. Keefe Link to comment Share on other sites More sharing options...
Xenonk Posted August 18, 2006 Share Posted August 18, 2006 Get a Cusco RSB, you WILL rotate. Prolly a little more than you'd like. heck, if people look at my setup, most people will think I have the most tighest and most understeer-proned car there is, but I beg to differ: http://teamwtf.org/gallery/albums/album513/wdcr_06_5_stu_106.sized.jpg http://teamwtf.org/gallery/albums/album513/wdcr_06_5_stu_105.sized.jpg you can watch the video here: http://f6.putfile.com/videos/d1-13621355480.wmv Keefe Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 change the tire pressures to match the new suspension, that's the cheapest and easiest way to deal with understeer. More specific hints for a noob? Lowering pressure in front? EDIT: actually increasing front is suggested. Some info here: Tire Tech - Air Pressure for Competition Tires Link to comment Share on other sites More sharing options...
Xenonk Posted August 18, 2006 Share Posted August 18, 2006 I would check the tires to see which tire has the rollover.. usually your fronts are rolling over.. sidewalls dont have grip up the fronts, that should help.. if the car is still not rotating enough, but your front tires are not rolling over, go ahead and up the rears some at 2psi increments. Keefe Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 heck, if people look at my setup, most people will think I have the most tighest and most understeer-proned car there is, but I beg to differ:you can watch the video here: http://f6.putfile.com/videos/d1-13621355480.wmv Nice!!!! Why most understeer-proned? What suspension/tires do you run? Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 I would check the tires to see which tire has the rollover.. usually your fronts are rolling over.. sidewalls dont have grip up the fronts, that should help.. if the car is still not rotating enough, but your front tires are not rolling over, go ahead and up the rears some at 2psi increments. I have RE070s, these things have concrete sidewalls (literally), I don't think they roll over. I'll play with tire pressures, thanks for advice. But something tells me I'll need a new rsb though. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted August 18, 2006 Share Posted August 18, 2006 With my Bilsteins I found a stiffer RSB (COBB's set on stiff) and higher front pressures were the ticket. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 With my Bilsteins I found a stiffer RSB (COBB's set on stiff) and higher front pressures were the ticket. Cobb setting on stiff? Interesting. Isn't the car too tail happy in this setup? And do you run rear Cobb/front stock? Btw, did Cobb resolve the clunking issues on lowered cars? Link to comment Share on other sites More sharing options...
Saul_Good Posted August 18, 2006 Share Posted August 18, 2006 Just RSB? Are you running it with Bilsteins or stock KYBs? I had it with just the bilstein Spec B's and it rotated alot. Then had it with the bilsteins and STI Pinks, it rotated alot. I now have added the Cusco FSB and it balanced it out for me. Still rotates, but i dont get that powerslide feel when you accelerate out of a corner too fast. It's smoother. Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 I had it with just the bilstein Spec B's and it rotated alot. Then had it with the bilsteins and STI Pinks, it rotated alot. I now have added the Cusco FSB and it balanced it out for me. Still rotates, but i dont get that powerslide feel when you accelerate out of a corner too fast. It's smoother. Ha, so it looks Cusco front and rear FTW. I read about front suspension bushings being killed by Cusco fsb (or other stiff fsbs, for that matter). Any signs of excessive wear on yours? How many miles have you been running your setup? Link to comment Share on other sites More sharing options...
Garandman Posted August 18, 2006 Share Posted August 18, 2006 I would check the tires to see which tire has the rollover.. usually your fronts are rolling over.. sidewalls dont have grip up the fronts, that should help.. if the car is still not rotating enough, but your front tires are not rolling over, go ahead and up the rears some at 2psi increments. We used to run a line of white liquid shoe polish from the sidewall up into the tread in 3-4 places on each tire. After a run you would see if you were in the ballpark. I also had a pyrometer to check the tire temp outside, middle, and inside. Equal temp meant the tire was working hard and the suspension had good control. We would tune the fronts to stick as well as possible, then tune the back to get the handling attitude desired - a 1-2 lb adjustment was often all it took. Who Dares Wins スバル Link to comment Share on other sites More sharing options...
Xenonk Posted August 18, 2006 Share Posted August 18, 2006 Nice!!!! Why most understeer-proned? What suspension/tires do you run? Endless-Zeal Function V6 coilovers (8kg springs front/6kg rear) 23mm Cusco Vancanza Front Sway 21mm Cusco Vancanza Rear Sway (adjustable) The stock suspension is different to where the front springs are not as stiff vs the rears.. the relationship is different on a stock car vs what I have.. I have some very frong biased springs.. but I have intentions to get them to have less suspension travel up front and a more direct feel to the car.. while others may seem to think that my setup is very understeerish, they are correct ASSUMING that the driver overdrives the car's limits.. most of the time for autocross and track use, I have the front shocks turned up to near full stiff while the rears are only near soft or middle.. I rarely turn the shocks in the rear to full stiff. Keefe Link to comment Share on other sites More sharing options...
Xenonk Posted August 18, 2006 Share Posted August 18, 2006 We used to run a line of white liquid shoe polish from the sidewall up into the tread in 3-4 places on each tire. After a run you would see if you were in the ballpark. I also had a pyrometer to check the tire temp outside, middle, and inside. Equal temp meant the tire was working hard and the suspension had good control. We would tune the fronts to stick as well as possible, then tune the back to get the handling attitude desired - a 1-2 lb adjustment was often all it took. that's how everyone should tune suspension. of course, there's even more of an advantage when using a pyrometer because that will help a lot for those who can do alignment changes like camber, caster, toe, etc.. but on a car that doesnt have that, the only left to change would be the tire pressures. +1 on explaining the process of how to dial in the correct amount of tire pressures. Keefe Link to comment Share on other sites More sharing options...
LittleBlueGT Posted August 18, 2006 Share Posted August 18, 2006 Cobb setting on stiff? Interesting. Isn't the car too tail happy in this setup? And do you run rear Cobb/front stock? Btw, did Cobb resolve the clunking issues on lowered cars? After market bar alone (Like Whiteline) was a little stiff, and prone to oversteer. Now I have both COBB bars and with the rear set at stiff, it understeers a bit. I would actually like a slightly stiffer rear bar. Increased front tire pressure helped a bit too. Clunking problem supposedly solved, new bars being shipped out in 2 - 4 weeks. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 After market bar alone (Like Whiteline) was a little stiff, and prone to oversteer. Now I have both COBB bars and with the rear set at stiff, it understeers a bit. I would actually like a slightly stiffer rear bar. Increased front tire pressure helped a bit too. Clunking problem supposedly solved, new bars being shipped out in 2 - 4 weeks. Still understeer? Me not likey understeer. I suffered enough of it in Altima, missing my 300ZX. I guess Cobb designed their bars around USDM stock suspension. Cusco is Japanese, right? So their stuff might be good match for Bilsteins. I also would be interested in the new Avo's bar. I didn't see any reviews of it here. Link to comment Share on other sites More sharing options...
LittleBlueGT Posted August 18, 2006 Share Posted August 18, 2006 Still understeer? Me not likey understeer. I suffered enough of it in Altima, missing my 300ZX. I guess Cobb designed their bars around USDM stock suspension. Cusco is Japanese, right? So their stuff might be good match for Bilsteins. I also would be interested in the new Avo's bar. I didn't see any reviews of it here. COBB bars are actually just slightly stiffer then CUSCOs, and the rear is adj. Only reason not to COBB is the RSB clearance issue, which is suposedly solved, but you might want to wait for proof. Full tune of 68HTA, KSTech 73 MAF, Racer X FMIC and ID1000s................by the DataLog Mafia!!! Link to comment Share on other sites More sharing options...
Guest Posted August 18, 2006 Share Posted August 18, 2006 I had it with just the bilstein Spec B's and it rotated alot. Then had it with the bilsteins and STI Pinks, it rotated alot. I now have added the Cusco FSB and it balanced it out for me. Still rotates, but i dont get that powerslide feel when you accelerate out of a corner too fast. It's smoother. So neutral with some dose of oversteer, so you can rotate it when you want? That would be cool. Looks like I am in the market for a set of Cuscos. Link to comment Share on other sites More sharing options...
KartRacerBoy Posted August 19, 2006 Share Posted August 19, 2006 Unclemat, How much understeer are we talking? Gobs and gobs? If gobs, are they new Bilsteins or takeoffs? If takeoffs, might you have a duff front damper? Just an idea... Link to comment Share on other sites More sharing options...
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