Littlehorn

I will be giving lightweight a go. Interesting 7-10 track days, i have only done 4 on the shockproof heavy and it seems to be starting to crunch a little. I had the same thing with my last gearbox running Castrol Syntrax the synchro clips came off then it stopped holding in gear so off throttle it would just pop out. The fork was fine but i had done damage to 3rd gear and a few other parts, some of which are no longer available so the only way to fix would be to get the parts machined. Cheers for the advice.

Spent the day in the garage sorting this out today, started with the car increasing toe out from static by about 6mm at full bump and ended with the car increasing toe out from static by about 0.5mm. What i found was even disconnecting the sway bar the car still moved slightly when jacking up, i guess it must be the shock not compressing easily. So that meant i didnt have an original group of measurements to look back at and means i dont actually know what my standard ride height toe is currently set at, but what it does mean is that the car is now only slightly toeing out at full bump. So if the car is set to 1.25mm toe in at static ride height under full bump it will now go to approximately 0.75mm toe in. I will pop into an alignment shop next week and get them to check what my static toe is set to and get them to adjust only from the lower toe arm, which means that the ratio of the camber to traction arm will remain the same and they will continue to swing on a similar arc. I think camber i wont be fussy with as long as it is somewhere between 0 and -1. So my actual adjustment on the arms ended up being to decrease the traction arm length by 4mm and increase the camber arm by 2mm. Traction arm is now 1/2mm of the shortest it can be set to.

No prob i am going to have another crack hopefully this weekend. Considering using a mates garage with a proper hoist and strapping it down to make sure there is no chance of movement.

I had a slight issue with the alignment the car was actually moving on the axle stands, i think it might be the sway bar that was causing this. So after a number of hours working on it i couldnt trust the settings, and im now considering one of these to make life easier. http://www-en.ikeya-f.co.jp/category/1983343.html

I took my baseline measurements this afternoon. Results show that the car is toeing out under compression and staying fairly static under droop. Not quite sure how to calculate what it is changing to in mm but it is toeing out approximately 1.64 degrees under compression from the base of 1.25mm toe in at the static position. Also the wheel is touching the guard so there is only 23mm of travel under compression. So i have some fixing to do!

Great Thanks for that. Should i be making changes on the tie rod as well as the camber and traction arms?

Awesome info cheers!

Had been thinking about trying the lightweight might give that a try next.

Cheers guys time to have a look around for a motorsport tuning shop with alignment gear then. Did i miss something, i dont think any posts have been deleted?

So i broke my last gearbox (running Castrol Syntrax 75w90) and replacement parts seem to no longer be produced for what i needed. So i ended up buying a second hand reconditioned box for an arm and a leg. After doing a bit of reading I decided to go with Redline shock proof heavy. I have run this for the last few track days it would be hopeless for road driving as it seems to take quite a while to warm up so shifting is very careful for the first 15 mins or so. It seems to run alright but i still get a bit of grating going into 4th and 5th when driving hard on race track (not silly quick shifting just careful shifting but at 6500-7000 rpm) So what do other people use in dedicated race cars? My second question is how often do you replace the fluid in your gearbox? It seems most other fluids are every 2-3 track days.

Cheers guys my terminology understanding is also pretty lacking, but i understand now. However it looks like something that would be fairly difficult to eliminate short of building custom pickups and having both arms the same length and mounted parallel.

Ok so here is a pic of my rear suspension. Lower arm is standard but the 2 upper arms are adjustable. So as the rear suspension compresses does the wheel toe in or out more? There is probably an element of this! The car has only recently been sorted after a few issues with gearbox etc. so i havent had a lot of consistent seat time recently.

Here is the footage, https://www.youtube.com/watch?v=C1uOcw1aLUc a little hard to tell how handling has been affected from this footage. The main corner where you want lateral grip is the last corner coming onto the front straight (with the big green brdge over top) this is where i can often feel the rear starting to drift and that wall is awfully close. I will deffinitely play with removing the rear bar, and will have a look into the rear traction arms as a next step. Yes i actually realised only in the last session that my pressure gauge was out by about 2 psi when compared to a mates good quality one so will deffinitely go down 2-3 psi and try. So this could be an issue. Tyres should last longer though. will have a look at the sidewall see if there is any markings about the compound.

It was at 350mm, now at 340mm. That pic was also taken coming out of a left hander so a little bit of compression on the right side. Another interesting thing to note, is that i alwasy seem to lap faster after about 7 or 8 laps, maybe these tyres are just towards the harder end of the spectrum, anyone used the FZ-201s before do they come in different rubber hardness?

Interesting might give this a try next time i get a test day down at Hampton Downs. I must admit the logic of how a sway bar never quite made sense to me. I would think that increasing the weight of the rear sway bar means that the tyre on the inside or the unloaded tyre is being compressed by the sway bar so therefore getting better road contact. Doesnt this mean better rear end grip, Im obviously missing something here. Tyre wear after alignment changes deffinitely looks more even i will post temps below. Other car i was talking about is an S14 Silvia, running about 220kws but not as heavily stripped as mine, so it is probably a little lighter and a little less power. And yes it is alot of fun and tiring particularly since the power steering stopped working properly when i removed the hicas computer. So a reasonably successful track day at Pukekohe this weekend. The car deffinitely felt more stuck, the front end was very solid the rear is still a decent bit more lose it just seems to get very light in higher speed corners. Unfortunately not the best comparison because a different track but i am hoping to leave the settings as is and get down to another Hampton Downs track day for better comparison. I had a play with the pressures and to me it seemed more sticky as i reduced the pressures, so hear are the results: Front 34psi hot Temp from inner on the left side 63, 54, 48 Rear 34psi hot Temp from inner on the left side 61, 53, 45 So as you can see it looks like less camber would be desirable for this track, I am picking that at Hampton Downs these temps will look more even as the track is less bumpy and has a more grippy surface. I am just in the process of loading up video will post up this afternoon, but in conclusion it would seem that there has been a reasonable improvement (about 2 seconds part of that is driver confidence) but on this track the camber is to high. Oh and did i mention the car doesnt like bumps which im pretty sure this is down to the lower ride height, it seemed a little more unsettled than last track day through turn 1 which is very bumpy. Here is a pic of how it looks through turn 1 and a decent pic of the car

That is 2.8 toe out on front, and 2.5 toe in on the rear. Up to now i haven't really been considering where the weight comes from just any weight loss is good. Just considering whether keeping a more even Front Rear weight balance might have a positive effect on handling. But having a read around, as with anything it seems there are pros and cons.

Interesting regarding dropping the rear sway bar, I will see how i go this weekend maybe drop of if the rear camber hasn't made a big difference. Car is set to 340mm front and rear. Alignment set as follows: Camber front -3.1 deg Toe front -2.8 total Camber rear -1 deg Toe rear 2.5mm total Running a test day this Sunday at Pukekohe, will post up the results next week. What are your thoughts on removing vs adding weight into the rear. Is this going to increase or decrease oversteer. Ie if i leave my spare tyre in.

Ride height is currently set at 350mm guess i will go down to 340 and see how that goes.

Mine is set to second softest of the 4 on the front i can move it one more adjustment forward. I cant access the front most or rear most. Cheers for that i will measure it up tonight so you can all have a laugh! Should i cut down the standard bump stops? Hopefully lowering will fix this when i originally set the ride height i did notice the arms were on a slight upwards angle from the wheel to chasis. I assume that level is optimal. Unfortunately the car came with a fiberglass bumper. Nice and light but it protrudes quite far out the front and actually slants forward so the lowest point is right at the front edge not towards the wheels as with the standard bumper.

Interesting please do let me know. I believe there was also a beefed up end links kit i did wonder if you had to get that to get all the adjustment.

Yeah there is definitely some corner entry understeer and mid corner to exit oversteer. To me personally it feels like the oversteer is more the limiting factor because i cant step on the gas more to increase corner speed and exit speed. However the entry understeer will be next on my list if i can dial out the oversteer by improving contact patch in the rear then i will work on sway bars and maybe some toe out in the front as suggested. Have also been doing some reading on this site, very informative.http://turnfast.com/tech_handling/handling_tuningtable

You are correct on rim size im running 8" on the front and 9" on the rear. Interesting I need to get some lighter rims current are about 9ks a piece, will take this into account when i upgrade. What do you reckon 9" front and rear running 255s?

Yeah hard to recommend changing swaybars when the car is exhibiting both under and over steer. I found this interesting camber vs tyre pressure info that I will have a go at next track day http://www.turnfast.com/tech_handling/handling_pressure3 I will also lower it a couple of centimetres just a pain for road driving. I am going to peg rear camber back to about 1 degree if this fixes the rear end grip then maybe i can adjust sway bars to reduce understeer (softer in the front or harder in the back although the links on the whiteline kit seem to only fit in some positions)

Can i alter rear bump steer? Just checked my last alignment settings Front: Camber -3.1 Toe 0 Caster 6.5 Rear: Camber -2.15 Toe +0.6 thrust angle 0 Wonder if there might be a bit too much rear camber.

Oh and springs are actually around the other way 350lbs rear and 550lbs front. I upgraded the diff because the viscous one slipped hopelessly exiting low speed corners.