Hey guys, Have asked this before in the past and have half fixed my problem. Basically my car was grippy as hell. Was good as I could throw it in at stupid speeds and not spin but it really bogged down. Changed my front 30+mm swaybar out for a standard one and not it slides like no tomorrow.....on 17s..... Recently I changed from a 215/45/17 tyre on a 9" rim to a 225/40/18 tyre on a 10" rim.... This is where my problem began again. It started to really bog down in 3rd. The overall diameter has changed maybe 5-8mm between the tyre sizes so I dont think that would change too much?? I tried to overcome this by increasing tyre pressure, increasing rear damper, decreasing front damper. It helped a little but im at the extremes of everything now. With 17s I run 33-35psi HOT. With the 18s I was at 55PSI. My thoughts were they should fry like no tomorrow with that much pressure?? I really didnt think a 225 over a 215 makes any difference as a 235/45/17 still spins fine. I also didnt think the little difference in diameter would make much difference? Im running 4.3 gears already. My car drove perfect on 17s however to keep up with the kardashians as to speak I wanted to change from my chinese 17s to some legit work wheels. Ive outlaid almost 5k in wheels (not just one set lol) so want to be able to use them haha. Or do I just need more power?
0 rear toe. traction arms set to 210mm. wears tyres almost perfect all the way across. -2.5 rear camber
Try toe out in the front and the rear Start with 0.5 - 1 degree. Be careful with this though as it'll change the steer-in and mid corner massively
55psi hot isn't a lot, you could up that more to reduce grip, but really, with standard power its going to start to bog with 18s unless you can keep your speed up.
Yeah, 55psi doesn't sound a big deal to me, I've gone 75psi on full slicks before to get the grip down. Tyre pressure doesn't affect wear much in my experience, tyre speed compared to road speed, and contact patch are the main two. If it helps, despite them always claiming they run low tyre pressures and are magical superheros, I watched with my own eyes Ken Nomuras pit crew but 65psi in the 265 wide semi slicks he was running on the back of his R34 D1 car. "Wow, they say the only run 2.2bar, how does he smoke up those mega wide semi slicks?" By lying about the pressure, that's how.
Serious? thats rediculous haha. Ive never heard of anyone around here running that much. I thought 55 was crazy high and ready for the tyre to explode? I dont really want to have a tyre pop and destroy a mint VSSD either haha. More power would def help. It was tuned to 170RWKW which is not a lot however ive since changed the exhaust to 3" straight through, wound boost up to 19psi from 16psi and got it to breath a lot better. Checked with a wideband obviously. I wouldnt say im DK but im no beginner. On an average day Im lucky to spin out more than once and can lay rubber within around 3" of my last run consecutively. Been doing it now for 6 years haha. I usually enter around 140kmh at a day sesh but night sesh they shorten the run up due to more amatuers and more people on track so i can only enter at around 110kmh otherwise im too close to the corner when i scando. My car isnt low. with a uras kit the rear sits around 100mm lol. Does this play much on s chassis? My front with 9J-7 wheels sits with the guard around 6mm above tyre height. The rear with 17s sits around the same. With 18s it looks too high and I plan to lower the rear another inch or so now im running stagger fitment just dont want to lower it and destroy my allignment just yet so ill let it look high until i have time to do it properly. And in regards to toe out. I was running 15mm toe out on the front. Wound it back to 5mm. Was too snappy. Went 3 turns back out at the track so id say around 10mm. Going to dial that back again this sesh so make it a bit snappier. I dont want rear toe. My other car has it and it pushes wide in corners. I can drive it fine but its slower and crapper. I would rather more rear camber haha. Worst part is im starting with my 18x10s....still havnt tried my 18x11s with 235s haha.
You might want to google tyre force load vs camber curves as well as pressure Slip ratio Slip angle Blablabla that lot... I used to run 1 degree toe out in the front and rear with a stage II CA18DET worked like a dream with entry speed up to 140 kph
Just for your information, 55psi is not crazy high, and the tyre will not explode. We run our rear tyres anything from 70-90psi (if the machine will go that high sometimes it wont) and there drifted on, usually all day long with very little tyre changing. Thats on an MX5.
Is PSI different in the northern hemisphere? lol. I spoke to my local drift shop guy yesterday who runs a 400hp sr and he said he has never run more than 35-38psi without getting major delam. Hadnt looked at slip angle yet. Might do some research. For tonight im just sticking with 17s. Ill do some research and try again in a fortnight on 18s. 1mm toe out on the front for me is too little. I dont like the way it drives. When i get home from work ill change my front toe to a little less than it is but it certainly will still be around the 6-8mm mark lol. When you talk camber curve are you talking about what my tyre does under acceleration in regards to the rear of an s chassis setup? I have it dialed in about perfect with my ride height. My problem is it drives PERFECT on 17s. I want it to drive exactly the same on 18s lol
I'm talking about the lateral load capacity of your tyre depending on the camber (static and dynamic) For toe... I use degrees, not mm... I guess you align with string around the car?
Tyre pressure and delam are unrelated. Grip/heat and delam are, but pressure itself? No, not at all. And considering I said in the first post about seeing Ken Nomura run 65psi on the back of his D1 car, well.
nope. on a proper allignment machine. hmm might try next session with my 18s and ill bump them up to around 70psi. Worst case if it delams it shouldnt explode? Just dont want to ruin my new wheels hahaha. The moved the start line again which sucks even more. Down to around 120m run up into the corner which isnt enough to get enough speed then scando in. Can only arse drag in which sucks haha. New tune is on the cards very shortly. Also, to save me opening a new thread. got a question on hydros..... I have one in my fc thats inline and i HATE it with a passion. Cant handbrake and footbrake at the same time to wash off speed. If i install a shut off tap into the 'in' line from the master and shut it off once bled will my brakes still work fine? aka front brakes only work off foot brake, hydro work seperate, and if I need to pull up really quick you use both footbrake and handbrake? Or should I bite the bullet and go twin caliper? Trying to sort out what setup I run in my e30 project as the stock handbrake position sucks! So its either weld on an extra bar which makes the handle long and feel wierd, inline hydro with shutoff valve for when drifting, or twin caliper which is even more fab work lol
As for reducing rear grip, throw a GTR / GTS4 swaybar on the rear, and if you can put heavier springs in the rear. As for the hydro, I'm guessing when you're on the HB then touch the footbrake the rears stay locked on when you come off the footbrake? That's the mark of a cheap/faulty master cylinder.
Already have a GTR rear swaybar. And driftworks CS2 coils so running 7kg rears?? Havnt had a problem so much with it getting stuck on its moreso you cant do both at once. Which annoys me as my driving style has a lot of handbrake while footbraking washing off speed. Im thinking about just welding a bar onto the fc handbrake to bring it over to the drivers side. Was going to try and relocate the whole assembly to the otherside of the tunnel but that seems like way more work than a simple 'U' shaped bar to trial it haha. hopefully that would work. As for the e30. Still trying to decide. Just been busy getting these cars going right first
I'm running 8kgs in the back so close to the same and have next to no grip. Strange. Only thing left is use more speed. The hydro thing sounds very weird, but having never fettled with one on an RX7 i can't comment from experience. But are you using footbrake, then handbrake? Or other way around? Handbrake first then footbrake is more common, to "tuck" the front towards the apex
I have to confess I'm a bit confused here. A 170rwkw s13 is roughly a stage 1a sr tune over here, 230whp-ish. Even when set for maximum grip with a soft rear end and toe in to maximise traction I've never had issues spinning up standard road tyres of that size with that power at the pressures you're describing. It sounds like all the things you've done will have compromised the overall handling of the car quite badly when all it really needed was an increase in pressure to the tyres/more aggressive clutch kicks (delete as appropriate). Put it this way; a mechanically grippy car with a high tyre pressure to overcome traction handles more predictably and less likely to spin than a mechanically grip-less car at normal road pressures and is much more versatile. There's nothing wrong with going to high psi to break traction if you're really struggling but I certainly wouldn't start compromising the overall grip level of my setup to make a 300bhp s-body spin up a 225/40r18 in what sounds like a 3rd gear corner. I MIGHT be tempted to look for a shorter ratio diff to help it a little but that's it. Higher pressures are your friend here for sure, not compromising the car Also, you say a 120m run up isn't enough to do anything other than an arse drag. Is there something wrong with your clutch? Doesn't need to be a Scandinavian flick of massive proportions to clutch kick, just a tiny bit of weight shift and timing.
Your local drift car shop guy, clearly doesnt know all there is to drift cars then at all lmfao! He runs a car with a shit ton of power of course he isnt going to need high pressures.. You put your driver in a 90hp MX5 and see how he gets on with daisies sitting at 35 psi ! There was a BDC car at Driftland who I went up to, and said .. "Mate, Think you got a flat." - "Ah no, its just I dont run any air in the back, its like 8 psi or something." wtf guys..
That sounds all well and good in a practical sense, but this is drifting. I've found too much body roll is dangerous, the weight shift is more prodigous and feedback is laboured. Stiffened up, the car is more responsive to throttle and steering, with the added benefit of allowing me to run it low.
