Typical timing for street cars at Sepang SIC

[cqloh]

thats a good one adian... something i completely neglected..

soulV: if you've purchased a 2nd hand LSD the first thing i want you to do is to jack the car up on one side so the other front wheel is on the ground. if possible remove the wheel thats in the air and use a torque wrench to turn the 32mm drive shaft locking nut. you should have something within the vicinity of 50-65 Newtons..

if you don't have access to a torque wrench then try turning the wheel with your hands.. if it turns easily then its time to rebuild the LSD...

what you are describing are also symptoms of a worn or broken LSD...

if its not then breathe a sigh of relief and continue driving like a pro =)

 

[adian]

What about basic alignment and geometry setup fellas? Do you fiddle with that before a track day? It makes a huge difference, you'll be surprised! What do you guys set up?

I know it's "the in thing" to have lots of front static camber, but in reality it's not ideal. The more camber you run, the less traction you have under-braking, and also reduced steering response into the corner. There's a balance la. For road-cum-track day cars I wouldnt go more than -2deg. If you hardcore can try la -3deg.

Rear toe I personally like it to be zero. Some ppl use toe-out but I dont like that the car takes a little bit more wasted time and opposite-lock to straighten out compared to zero toe.

If you have adjustable height suspension, dont take for granted whatever height the foreman put for you. It's always best to start with a flat car ie front and rear rideheight the same. Raising the rear slightly (up 10mm) increases understeer, and lowering is vice-versa. OR you can raise the front or lower it, it's opposite of the rear (Raise front slightly to reduce understeer). There is a point tho where altering the ride height too drastically will create problems. Remember to get this set right for good cornering balance!

And of course you can also play with tyre pressures.

Tyre pressures can alter the balance a lot if you get it right. Plus, what works on the 1st lap out will not be the same by your 5th lap. So when you 'tuned' your tyre pressures, have a target at which lap you'd prefer them to be at their best response. Usually on track days most ppl only go out for 5-7 laps max and then come in for a rest (as you drive road cars and dont want to break em!), so tuned for optimum handling balance from Lap 3 till about Lap 5, and when it starts crapping up on Lap 6, you can come in to the pits :)

FWD cars can get away with high rear tyre pressures eg 2-3psi higher than normal, and you'd want to be 1-2psi lower than normal at the front. Of course this depends on the brand and type of tyre. Ideally you want a bit of 'looseness' at the rear for an FWD car, and not want to 'lean' on the front tyres so much that they overheat and you start understeering.

FR cars could do with 1-2 psi extra in the front tyres, and MR cars start with more or less equal pressures front and rear. This is just a guideline, you can "tune" as you go along. Just be sure you are driving consistently!

For all the hundreds and thousands of $$$ you spend on modding, just a few tens of ringgit getting the setup right can make or break 1-2seconds per lap!

/adian

 

[cqloh]

well said again adian...

just a few quick pointers.. always check your alignment before and after a track day.. alignment especially on street cars tend to run away from your initial settings, we check alignment on our track cars every time it sees the track to ensure that all our changes reflect the true results.

i'd personally prefer running 0 toe front and rear as this will reflect the true character of the car and tires, then progressively make changes. i never run toe out in the rears unless the car has compliance bushes built in (DC5s and FC RX7s take note) but as with all cars.. theres give and take.. if you run toe out.. you car will be unstable in the straights and tend to oversteer into a corner.. on rwd cars when the power is applied its gonna be a hand full..

buy a good tire pressure gauge and make sure you take the pressure when its hot. ensuring that all 4 have the same pressures.

but i have to argue the point regarding raising and lowering of the front and rears... maybe we'll save that for another day.

what is also important is that you log all your changes so you know what you're doing and where you're heading in terms of set up.

 

[minivan]

I usually set 0 toe all round and as i'm a road car i set just -1 to -1.5 camber all round. As for tyre pressure, i just set higher than normal by 2-3psi all round. But this one huh, some people say set lower then normal as the tyre temp will spike when the tyres are hot. I've tried it before, but the car understeers even worst and it feels loose and it scrubs the tyres' wall quite badly... so, i'm comfortable with setting higher pressure for trackdays...

 

[km_chew]

but i have to argue the point regarding raising and lowering of the front and rears... maybe we'll save that for another day.

I'm following up on this thread very closely, eager to know about this part. Free to explain more ? This kind of technical knowledge really helps to interpret a lot of When / How / What / Where for me ..

Thanks again to CQ / Adian. You guys are helpful.

 

[soulV]

hmm...

Bump: hmm...

Bump: hmm...

 

[adian]

Minivan: Well said. This is because different types and brands of tyres react differently. Some tyres work best at 35psi hot, some best at 32psi hot, etc.

CQ: Re raising and lowering the ride height, not correct meh? I have always started setting up with a flat car, measured from wheel centre hub. And for track and drifting I always try to dial in something lower at the rear by 5-10mm, as it helps a lot braking deep into the turns, and i'm able to achieve a better balance point.
I do know however that raising the front a by too much promotes 'push', and the opposite for the rear. You're explanation, when you have the time, is most welcome!

Basically, everyone talks about power and GT wings and AD08 tyres, but very very often I notice some ppl never bothered to work on the basic geometry setups! Basically, reducing lap times for almost free :)

Bump: Minivan: Well said. This is because different types and brands of tyres react differently. Some tyres work best at 35psi hot, some best at 32psi hot, etc.

CQ: Re raising and lowering the ride height, not correct meh? I have always started setting up with a flat car, measured from wheel centre hub. And for track and drifting I always try to dial in something lower at the rear by 5-10mm, as it helps a lot braking deep into the turns, and i'm able to achieve a better balance point.
I do know however that raising the front a by too much promotes 'push', and the opposite for the rear. You're explanation, when you have the time, is most welcome!

Basically, everyone talks about power and GT wings and AD08 tyres, but very very often I notice some ppl never bothered to work on the basic geometry setups! Basically, reducing lap times for almost free :)

 

[soulV]

hmm...another question to ponder..

 

[akuma]

1 more thg i'd like 2 add..BRAKES!very important component too 4 track days....might need 2 spend a lil more but w better brakes....u tend 2 brake later n also more consistent......+ on a lightweight car like my EF CRX..heheee.....i can brake @ almost d 50M mark on d main straight n continue doin so for 4-5 laps...no brake fade @ all......
oh,btw,i'm running EBC Red Stuffs front w Brembo slotted rotors n EBC Green Stuffs rear w stock rotors.....front camber -2.5deg,rear -1.5deg....195/55/15 AD07..my laptime?dun ask...d only time i my passenger "managed" 2 time me,i did a 2.56:xx...chis!hahahahahah

 

[soulV]

thanks akuma...very gud info...thinking of using kinda like ur set up as a base bef getting my own since we drive similar car.....:proud:

whats the price for those ebc stuff? where to get?

 

[cqloh]

CQ: Re raising and lowering the ride height, not correct meh? I have always started setting up with a flat car, measured from wheel centre hub. And for track and drifting I always try to dial in something lower at the rear by 5-10mm, as it helps a lot braking deep into the turns, and i'm able to achieve a better balance point.
I do know however that raising the front a by too much promotes 'push', and the opposite for the rear. You're explanation, when you have the time, is most welcome!

a few key factors we have to take into account is that:

1.under steer and over steer is a difference in the lateral grip front and rear of a vehicle.
2.geometry is a function of ride height and thus grip generated from correct geometry is a function of the vehicle operating at that ride height
3.lowering a vehicles ride height reduces the height of the vehicles center or mass

having stated the above a question pops into mind.. 'ive lowered my car.. why does it drive like a piece of shit?'
the simple explanation is that your vehicle was designed to run at the height that it came with out of the factory.. by lowering the ride height you have effectively changed the vehicles camber change, anti dive, toe change and caster change in ride(up down movement of suspension) and roll..

you are correct when you said raising the ride height at the front would reduce understeer, because you're going closer to the height the car came with.. however, it doesn;t improve the vehicles total lateral grip.

lowering a vehicle doesn;t just involve buying a set of shocks thats height adjustable.. it also involves putting back all the variables i have stated above..

i apologise for jumping the gun because you were refering to balance... not to increasing grip

 

[akuma]

soulV,
EBC stuffs u can generally get 'em frm Pentagon......price varies....try asking Chris...

n hey...1na ask abt corner weighing......will a street car like mine gain anythg frm it?shud i do it?n whn shud i do it coz i understand dat even minute stuffs like tyre/wheel changing can upset d balance....

 

[cqloh]

akuma... corner weighing is probably the best thing you could do for a street/track car when you've run out of options..
but there aren;t many people that can do it right here.. my general experience is that most street car owners will think i'm mad for charging them what i do.

what most street car owners don;t understand is the amount of time taken to make the correct adjustments and the experience required to balance the car... any monkey can get the weights correct.. but they haven;t taken into account the other variables when you overload the preload in the springs...

to answer your question, i'd suggest trying everything you can with set up (leaving your engine and gear ratios as is) until you are about to give up.. then give corner weighing a try..
and yes, small changes do upset the balance.. wheel and tire size are a given.. tire compound, tire pressure, even what you pump into the tires makes a minute difference..
at the end of the day.. the guy that does your set up should tie all that together and give you something to start off with.. in my opinion.. if he;s taken your money.. he's obligated to solve all your problems and make sure you're happy with what you get.

to clear things up.. corner weighing isn;t about putting your car on a set of scales and then moving stuff about.. there alot more to it.. you've got to take into account ride frequencies, spring slag, alignment changes, weight transfers etc... not to be putting down other workshops.. but they're charging you 200 bucks to get your car on the scales... you're getting ripped off..
it takes about 4 hours to do a good corner weight (unless my guys and me are that slow?!?)
so its something thats rarely done on a street car...

anyway.. thats my 2 cents..

hope it makes sense

 

[minivan]

1 more thg i'd like 2 add..BRAKES!very important component too 4 track days....might need 2 spend a lil more but w better brakes....u tend 2 brake later n also more consistent......+ on a lightweight car like my EF CRX..heheee.....i can brake @ almost d 50M mark on d main straight n continue doin so for 4-5 laps...no brake fade @ all......
oh,btw,i'm running EBC Red Stuffs front w Brembo slotted rotors n EBC Green Stuffs rear w stock rotors.....front camber -2.5deg,rear -1.5deg....195/55/15 AD07..my laptime?dun ask...d only time i my passenger "managed" 2 time me,i did a 2.56:xx...chis!hahahahahah

Wah bro... i would say for a light car like the EF/CRX, u've got a really good set of brakes... I use to run metal kings all round on stock rotors on my EF, but it never skipped a beat... but then again, i may not have been pushing as hard as u.... on the camber setting, i ran almost the exact opposite of what u've done, front -1.5 rear -2, as my EF's rear end was tail happy in corners, so i needed a bit more grip in the rear...

But there is a huge difference with a light and heavy car on how they feel/react in corners/under braking. I once had the opportunity to drive a friend's E7 (1400kg) at sepang compared to my EF's +-980kg. Brakes eventho were brembo, i thot can late brake kaw-kaw, but ended almost overshoting corners as i forgot how heavy the car was, and in corners, well... i prefered my EFs feel, much more fun and enjoyable. I'm used to the feel of lighter machines, so i'm sticking to hondas...

 

[soulV]

minivan,
can u pls help me by explain why does ur car o/steer more than u/steer since normally ef will u/steer...is it the set up?

 

[K-Kid]

CQ, :top: Great write up. I always thought lowering the vehicles center or mass is the way to go. Anyway, so how do we improve lateral grip? Mind to give a few pointer?

 

[minivan]

minivan,
can u pls help me by explain why does ur car o/steer more than u/steer since normally ef will u/steer...is it the set up?

EF's are a tiny bit weird. Yes, they do tend to understeer like any other FF car, but its the rear end that tends to be a bit loose and 'tail happy'. I'm not making up this term, i read it in an article about the handling characteristics of EFs on the net somewhere (can't remember where i got it from). And its not so much of oversteer like what happens in an FR car, where the back wheels want to overtake the front, but its more of the rear end coming loose under a cornering situation, so its more like slowly slipping into a spin.

So the article simply suggested for the rear chamber to be set more negative then the front. Thats what i tried and it worked. The rear end gripped more and that funny feeling of possibly loosing it in the corners was eliminated. Before that, i spun my EF a couple of times in Sepang...

But, this characteristic has also been put to good use, its one of the reasons why EFs are popular as FF drift cars, like the falken EF drift car...

 

[soulV]

thanks minivan,
i've also read something similar like this in the web(also cant remember where,probably the u.s guys)
where they liike to use stiffer spring rate at rear than front on their ef to prevent o/steer...hmm...for the time being i think need to stick to the conservative set up n spun a few times then only change...heheh..

Bump: thanks minivan,
i've also read something similar like this in the web(also cant remember where,probably the u.s guys)
where they liike to use stiffer spring rate at rear than front on their ef to prevent o/steer...hmm...for the time being i think need to stick to the conservative set up n spun a few times then only change...heheh..

 

[adian]

CQ: Ahh, you're referring to the change of geometry from lowering the car. This no doubt changes. For a good explanation with diagram references, do check my webpage http://www.the-yeins.com/pages/cars/projectv-1.htm

My reference to lowering and raising the ride heights is, of course, with the basis that this is conducted within a maximum lowering of about 50mm from standard, and if you have adjustable tie-rods this would be better. And also, adjust the alignment, camber etc all over again everytime you change the ride height.

It all sounds quite hardcore, but this is what we go through when we "dial-in" our race cars. People think it's such a fun job to go whacking around the track all day 'testing' a race car, but actually it can be very tiring and boring. It's like, you go out for 5 laps, get a reading, am not happy, try 5 more laps to confirm that you dont like it, then the boys jack up the car and make all the adjustments including alignment and geometry checks (total time is about 60mins) and then you go out again for 5 more laps, and find out it's even worse, and you're back to square one and keep on testing and adjusting and testing and adjusting :)

For your street car tho, honestly, before heading to the track, set the ride height to flat, do the alignment properly, and go have a whack! It'll make a big big diff!

Akuma: Regarding brakes, this is a good point too! It all comes down to $$$ tho. At minimum, you'd want to get yourself some proper hardcore brake pads. When I was developing R3 cars and parts, we tested over 10 different types and brands of brake pads. And when we test, it's very exhaustive and follows strict processes and procedures with the proper OEM-level (expensive!) equipment to ensure proper results. Brand new discs with each new pad test, same driver, same car, same environment, etc. We tested EBC Greens and Reds, Mintex Redbox and M1144 and M1155 and M1166, all of Project Mu's and Endless different grades (abt 4 grades each brand!), Hawk (from US), Ferodo DS 2000 DS 3000 DS 4000, TRW, and Tarox.. and some local stuff like StopTech and AXT (I think that's abt it if I recall!!).

As you may know, in the end we chose Mintex M1144s as the official R3 brake pads. Expensive tho, and may squeek sometimes, but great all-rounder... imagine EBC Redstuff but even better! However they're a bit expensive.

Some other great stuff (these are not my personal recommendations, merely observations and my personal point of view. Do not blame me if you buy them and dont like them):
- For track days, EBC Reds are great. Greens are pointless.
- Ferodo DS2000 didn't do well at all. DS3000 high wear, expensive
- Project Mu and Endless stuff can't go wrong, but you get what you pay for. I recall the middle-level compounds were great all-rounders.
- TRW & Mintex Redbox are simply OEM + 10% levels. That's why they're affordable. But they don't squeek, have less dust, and last ages.
- The local pads were dangerous! At SIC, there was a particular brand (I forgot their name, not StopTech) ate up a brand new set of discs in 7 laps! And I think AXT has very high pedal travel and pressure required, it's like your brake pedal goes to the floor before any braking was felt!

And lastly, for your rear brakes, just use standard discs and standard pads. They will never overheat or wear out, as they only do about 30% of the braking at most :)

/adian

 

[cqloh]

adian: LOL... heaps of people think that driving, building and setting up a race car is so fun and so cool.. there are times when you wonder what the heck you're doing all this for.. hahah...

for the guys out there.. racing is about practicing and testing.. the more testing you do.. the more data you collect.. the more experience you have.. the more likely you're going to be competitive.