Suddenly tail happy
06-01-2009, 08:05 AM
#1
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Thread Starter
Suddenly tail happy
I'm looking for a little advice on where to look and what to do to tame a SUDDENLY tail happy car. By suddenly I mean other than when I accidentally ran too small a tire on the rear I've never had a tail happy problem until this last weekend. I prefer a car that's a little loose to one that plows, but this was ridiculous. My concern is the sudden ness of the change in handling characteristics. I haven't gone under the car yet to see if anything is torn or loose, but that will happen Wednesday evening.
I've hardly been able to autocross or do any HPDEs for almost 2 years. I got one autocross in last year and so far only one this year.
Historically I used to spend a lot of time on the track so I have some experience and am usually in the top 10% in just about any club type autocross situation. I've hardly ever been TTOD, but it has happened. I'm not a hot shoe, I'm above average, but in any case I'm quite rusty.
I am running an '02 with JIC FLT A2 15 way adjustables. The car is lowered, but not slammed I was running 235/265 Dunlop Direzzas version 1 tires. I bought the Direzzas last October just before my last autocross and had the car aligned to British specs. The car handled nicely.
The autocross this last weekend it was an absolute beast! I was 5-6 seconds behind people I'm usually running right with.
No changes at all have been made to the car since the last autocross. Everytime VTEC kicked in the back end kicked out.
Here's what I did. I played with the settings on the shocks and ended up with full hard on the front and full soft on the rear. I realized afterwards I was letting the tire pressures build a little too high, but still it was only a little too high. We get 4 runs basically back to back so tire pressures can vary a lot if you don't watch them. The Direzzas would climb to 40 and then start letting loose even more. Most of the time I had them in the 38 psi range which is what I ran the last time I used them and they seemed to be quite happy at that psi last time.
I'm going to go look at the alignment but over the winter I basically parked the car I have very few miles on the car since the last alignment so I'm guessing I won't find anything drastic there. Rear toe is my main concern. Translating from degrees (British) to inches over here hasn't seemed to be an exact science. IIRC I had them do 1/16" toe in. Should I go to 1/8"? The car was aligned with me sitting in the car.
When I autocrossed more I used to run a little toe out in the front, but wear got to me. Now I don't drive the car so much so I can begin to do that again. That will help turn in, but it shouldn't have an effect on the tail happy ness would it?
The JICs I bought used and took them straight off another car and put them onto mine without corner weighting. I wanted to run it once to see what it was doing before I corner weighted it. It was so much better than stock that I never bothered.
I've been working on designing a suspension for a Locost and with what I've learned it seems that maybe lowering the S too much puts you in a strange part of the suspension so I'm thinking of raising the car about 3/8".
How much improvement have you guys seen on the rear toe correctors? I've thought it wouldn't be worth it for a mostly street car, but is that what I need? If so now's the time for me to do it.
I'm thinking to make whatever wholesale changes I'm going to do and then go get the car corner weighted so I'm wanting to visit every aspect. I'm hoping you guys can give me a few pointers or some directions to look.
I've hardly been able to autocross or do any HPDEs for almost 2 years. I got one autocross in last year and so far only one this year.
Historically I used to spend a lot of time on the track so I have some experience and am usually in the top 10% in just about any club type autocross situation. I've hardly ever been TTOD, but it has happened. I'm not a hot shoe, I'm above average, but in any case I'm quite rusty.
I am running an '02 with JIC FLT A2 15 way adjustables. The car is lowered, but not slammed I was running 235/265 Dunlop Direzzas version 1 tires. I bought the Direzzas last October just before my last autocross and had the car aligned to British specs. The car handled nicely.
The autocross this last weekend it was an absolute beast! I was 5-6 seconds behind people I'm usually running right with.
No changes at all have been made to the car since the last autocross. Everytime VTEC kicked in the back end kicked out.
Here's what I did. I played with the settings on the shocks and ended up with full hard on the front and full soft on the rear. I realized afterwards I was letting the tire pressures build a little too high, but still it was only a little too high. We get 4 runs basically back to back so tire pressures can vary a lot if you don't watch them. The Direzzas would climb to 40 and then start letting loose even more. Most of the time I had them in the 38 psi range which is what I ran the last time I used them and they seemed to be quite happy at that psi last time.
I'm going to go look at the alignment but over the winter I basically parked the car I have very few miles on the car since the last alignment so I'm guessing I won't find anything drastic there. Rear toe is my main concern. Translating from degrees (British) to inches over here hasn't seemed to be an exact science. IIRC I had them do 1/16" toe in. Should I go to 1/8"? The car was aligned with me sitting in the car.
When I autocrossed more I used to run a little toe out in the front, but wear got to me. Now I don't drive the car so much so I can begin to do that again. That will help turn in, but it shouldn't have an effect on the tail happy ness would it?
The JICs I bought used and took them straight off another car and put them onto mine without corner weighting. I wanted to run it once to see what it was doing before I corner weighted it. It was so much better than stock that I never bothered.
I've been working on designing a suspension for a Locost and with what I've learned it seems that maybe lowering the S too much puts you in a strange part of the suspension so I'm thinking of raising the car about 3/8".
How much improvement have you guys seen on the rear toe correctors? I've thought it wouldn't be worth it for a mostly street car, but is that what I need? If so now's the time for me to do it.
I'm thinking to make whatever wholesale changes I'm going to do and then go get the car corner weighted so I'm wanting to visit every aspect. I'm hoping you guys can give me a few pointers or some directions to look.
06-01-2009, 09:52 AM
#4
Originally Posted by Wildncrazy,Jun 1 2009, 08:05 AM
Here's what I did. I played with the settings on the shocks and ended up with full hard on the front and full soft on the rear.
Because if they're new suspension components to you... and you wound up going full soft on front (compression) and full hard on rear (rebound), then your car would act the way you're describing.
BTW, this exact scenario happened to a National Champion at a local event in the rain... he had new shocks and thought he was going "full soft" but went "full stiff." Everyone was wondering why he was doing so poorly....
06-01-2009, 10:04 AM
#5
Registered User
Thread Starter
I'll go check them again since I haven't touched the car since I left the track.
I'm back and Ahhhmmmm, I think I goofed. I went full counter clockwise which should be soft on both the front and the rear. While they aren't new to me, it has been a while since I had to adjust them. I was standing in front of the car so I turned it to the left and when I went to the rear I turned to the left as well thinking that I'm reversed so I need to turn the knob the opposite way from the front.
Now I feel so stoopid!
I think I'm going to find a way to mark these things.
The sad thing is that I thought this through several times during the day because I was worried I hadn't turned them the right direction.
Oh well I'm still going to go thru the car, get it realigned and finally get it corner weighted.
Now about those rear toe controllers. Necessary or not?
I'm back and Ahhhmmmm, I think I goofed. I went full counter clockwise which should be soft on both the front and the rear. While they aren't new to me, it has been a while since I had to adjust them. I was standing in front of the car so I turned it to the left and when I went to the rear I turned to the left as well thinking that I'm reversed so I need to turn the knob the opposite way from the front.
Now I feel so stoopid!
I think I'm going to find a way to mark these things.
The sad thing is that I thought this through several times during the day because I was worried I hadn't turned them the right direction.
Oh well I'm still going to go thru the car, get it realigned and finally get it corner weighted.
Now about those rear toe controllers. Necessary or not?
06-01-2009, 11:31 AM
#6
Originally Posted by Wildncrazy,Jun 1 2009, 10:04 AM
I'll go check them again since I haven't touched the car since I left the track.
I'm back and Ahhhmmmm, I think I goofed. I went full counter clockwise which should be soft on both the front and the rear. While they aren't new to me, it has been a while since I had to adjust them. I was standing in front of the car so I turned it to the left and when I went to the rear I turned to the left as well thinking that I'm reversed so I need to turn the knob the opposite way from the front.
Now I feel so stoopid!
I think I'm going to find a way to mark these things.
I'm back and Ahhhmmmm, I think I goofed. I went full counter clockwise which should be soft on both the front and the rear. While they aren't new to me, it has been a while since I had to adjust them. I was standing in front of the car so I turned it to the left and when I went to the rear I turned to the left as well thinking that I'm reversed so I need to turn the knob the opposite way from the front.
Now I feel so stoopid!
I think I'm going to find a way to mark these things.
Glad I could help. Our Motons have the nice little +/- sign on the knobs otherwise I'm sure I'd forget.
Was noodling at a test and tune and it's AMAZING (to me) how much difference shock settings can have. With just a few clicks of a knob, they really can make a car undrivable. Which makes me wonder how many ricer kids totally f'up their handling by having cobbled together setups....
06-01-2009, 11:38 AM
#7
Registered User
Thread Starter
I went with single adjustable because I knew there was no way I'd ever get enough testing and tuning time to truly understand a double adjustable shock.
AND I STILL SCREWED UP!
I still chant "righty tighty, lefty loosey" when I'm working on a car.
AND I STILL SCREWED UP!
I still chant "righty tighty, lefty loosey" when I'm working on a car.
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06-01-2009, 01:25 PM
#10
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Originally Posted by CKit,Jun 1 2009, 02:31 PM
Which makes me wonder how many ricer kids totally f'up their handling by having cobbled together setups....