Need advice for racing
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nic_83
Junior Member
Thanks guys. U hv been very helpful indeed. U knw whats the best part? My bf was shocked or impressed when i told him about this. He asked how i know. u should have heard his voice then. kekeke. anyone can confirm on the tyre air how much to pump? i wanna surprise him more. keke
Never use air pressure below recommended. Tyre heats up more.
I think exhaust shop guy maybe wants more traction. More air pressure means over inflate will have less traction, but car will be lighter. 40psi all round is for track, but we have tried standing start before and find more air pressure is faster. You can also trial and error with different settings. Maybe bro. pomen mention of only more for rear works, as we tried all four same. This is where the fun is, trial and find the best......Car lighter with more air pressure, but less traction, therefore once you can control your initial take off with the least wheel spin, the pick up should be faster...
I think exhaust shop guy maybe wants more traction. More air pressure means over inflate will have less traction, but car will be lighter. 40psi all round is for track, but we have tried standing start before and find more air pressure is faster. You can also trial and error with different settings. Maybe bro. pomen mention of only more for rear works, as we tried all four same. This is where the fun is, trial and find the best......Car lighter with more air pressure, but less traction, therefore once you can control your initial take off with the least wheel spin, the pick up should be faster...
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nic_83
Junior Member
i dont understand. so can i tell him 40psi for all tyres? what is psi btw? is it a unit to show the how much air to pump in to the tyre?
Yup, psi - pound per sq. inch
If into kpa, 40psi is around 280kpa
Okay, I try to explain again what I mean.
You can use all around 40psi or less for the front two tyres, means maybe 36psi for the front, but maintain 40psi for the rears.....
I think what he's trying to say is that we should do trial and error to find out which one suits best. Well, now there are three theories.
1. Increase the front and rear tyre pressure to 40psi. This will cause you to have lesser traction which is crucial in drag races. However, this is compensated by having a lighter car.
2. Use the suggested tyre pressure for the front tyre for your car and increase the rear tyre pressure to 40psi. Here, you will have slightly more traction without increasing the weight by too much.
3. Use the suggested tyre pressure for the rear tyre for your car. Decrease the front tyre pressure to 25psi to gain more traction. But this causes the car to be heavier.
So, you should try out each theories and see which gives you the best result. I hope I have explained it right here. If its wrong, please correct me. I'm also learning.
For 1) can counter with clutch/engine rpm control. Once the tyre initial traction is on, then no need to worry about traction already or get a better grip tyres....
2) is okay, but still can play around from 32, 34, 36, 38psi
3) I still do not recommend any air pressure below manufacturer's recommended pressure. The only one using below recommended are the dirt bikes running in the mud tracks...
2) is okay, but still can play around from 32, 34, 36, 38psi
3) I still do not recommend any air pressure below manufacturer's recommended pressure. The only one using below recommended are the dirt bikes running in the mud tracks...
I just came back from a quick test drive. I'm not happy with my launching. I think I can improve on it. I tried as what ad_eg suggested.
Rev to 1.5k rpm then launch. I find that the car is struggling to move. I mean of course as I release thee clutch, I rev more but still quite slow.
So, I tried to rev to 2k rpm then launch. Quite similar result but slightly better.
Since 1.5k and 2k rpm didn't work for me. I revved till the rev limit which is 5k rpm. Not much of tyre spinning as I controlled the clutch. Felt more power but not moving. I think this must be because I was controlling the clutch.
Finally I tried revving to 3k rpm. This was much better. Just a little spin but the response was quite satisfying. Then, I came back as I didn't want to stay too long at the same place as I might invite unwanted visitors (police).
Maybe tomorrow, I'll try 2.5k rpm to see if that eliminates the tyre spinning.
Those experienced ones out there, care to share how to play with the clutch and throttle?
About the tyre pressure, I'll try with lower psi for front first. Then, if can, I'll try 40psi for both front and rear.
Rev to 1.5k rpm then launch. I find that the car is struggling to move. I mean of course as I release thee clutch, I rev more but still quite slow.
So, I tried to rev to 2k rpm then launch. Quite similar result but slightly better.
Since 1.5k and 2k rpm didn't work for me. I revved till the rev limit which is 5k rpm. Not much of tyre spinning as I controlled the clutch. Felt more power but not moving. I think this must be because I was controlling the clutch.
Finally I tried revving to 3k rpm. This was much better. Just a little spin but the response was quite satisfying. Then, I came back as I didn't want to stay too long at the same place as I might invite unwanted visitors (police).
Maybe tomorrow, I'll try 2.5k rpm to see if that eliminates the tyre spinning.
Those experienced ones out there, care to share how to play with the clutch and throttle?
About the tyre pressure, I'll try with lower psi for front first. Then, if can, I'll try 40psi for both front and rear.
Different cars have different torque, so you have to find yours. You are correct to play around the different range and see how it response. The main idea is not to wheel spin as this loses time and traction. Using the clutch to control so you can get into the higher power revs also good, but once you control the wheel spin and car is launching, you have to fully release clutch for best contact and at the same time keep the engine revs up. Once the revs fall it takes time for it to come up. All have to work hand in hand....
When i revved to 5k rpm, this is what i think happened. i didn't release the clutch fully. when its on high rpm and i release the clutch won't the tyres spin.
wow... din know pasir gudang night sprint getting famous... damn long din go d...
but to TS, ur bf is going for night sprint or other events??? i checked PG website, today n tml was booked from 9am to 5pm... so might be some private event???
but if he's goin tonight, then i'm quite sure he's goin for the night sprint the guys were talking abt here...
bro AD_EG... got ur suspension setup theory... wat i heard was different le... for FF cars, front should b softer n rear should b stiffer... reason is simple, coz when u launch, ur rear will squat, so making the rear stiffer will ensure less squat happens when launch... as for the front, putting it softer coz when launch, the squat will cause ur front to "lift off", softer suspension will let ur front drop faster thus getting the traction... tis is the explaination that i've got n accepted... hope my explanation is understandable.... heehee
for tyre pressure... i was pumping 40-45psi on my 15" R1R.... grip all is good... using on a wira evo.... lauch at around 3-4k rpm.... but cant full throt on first gear... only 2nd gear n above can hentam.... FF turbo... sigh....
bro ddv_nk12... i suggest u dun control ur clutch when u r launching at high rpm... u'll "goreng" ur clutch... althou it really feels much more powerful to launch like dat... rev up a bit... allow a little of wheel spin when u launch... then control ur throttle.... sure bro ad_eg can giv u tips la... he's vtec kaki...
anywya... all my dua sen... damn long din go... since i sold off my wira evo....
but to TS, ur bf is going for night sprint or other events??? i checked PG website, today n tml was booked from 9am to 5pm... so might be some private event???
but if he's goin tonight, then i'm quite sure he's goin for the night sprint the guys were talking abt here...
bro AD_EG... got ur suspension setup theory... wat i heard was different le... for FF cars, front should b softer n rear should b stiffer... reason is simple, coz when u launch, ur rear will squat, so making the rear stiffer will ensure less squat happens when launch... as for the front, putting it softer coz when launch, the squat will cause ur front to "lift off", softer suspension will let ur front drop faster thus getting the traction... tis is the explaination that i've got n accepted... hope my explanation is understandable.... heehee
for tyre pressure... i was pumping 40-45psi on my 15" R1R.... grip all is good... using on a wira evo.... lauch at around 3-4k rpm.... but cant full throt on first gear... only 2nd gear n above can hentam.... FF turbo... sigh....
bro ddv_nk12... i suggest u dun control ur clutch when u r launching at high rpm... u'll "goreng" ur clutch... althou it really feels much more powerful to launch like dat... rev up a bit... allow a little of wheel spin when u launch... then control ur throttle.... sure bro ad_eg can giv u tips la... he's vtec kaki...
anywya... all my dua sen... damn long din go... since i sold off my wira evo....
You must not have too high a rev until too much wheel spin. I am saying when the car is launching already, means already have traction, then clutch have to be fully release and step on the accelerator. Never let the clutch slip too much, or it will get cooked....
It is all in the matter of timing, control wheel spin, release clutch and accelerating...
---------- Post added at 01:25 PM ---------- 6 hour anti-bump limit - Previous post was at 01:14 PM ----------
Good explanation, that was what I was trying to say when mine was like a prancing horse before I mod the suspension....
Your tyre are R-1R so traction is good already.....
Never slip the clutch too much, sure goreng one....
Elemental
Active Member
I've not heard anybody using 40psi on slicks/ semi slicks. where u obtained the information? what tire is that?
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Just a general info for what to change to if really going for race in the tracks.
Anyway, most of it were trail and error we did last time.
You can check out here too.....
Tire Tech Information - Air Pressure for Competition Tires
Anyway, most of it were trail and error we did last time.
You can check out here too.....
Tire Tech Information - Air Pressure for Competition Tires
Elemental
Active Member
I see. However, most semi slick/ slick from the manufacturer will have their own recommended pressure. Not seen any with that requirement.
Is it? Because for normal road cars, air pressure is determine by car manufacturers, even though they may have the same tyres.
Most going for fun are not on slick or semi, but normal tyres, but there is a limit too...
Most going for fun are not on slick or semi, but normal tyres, but there is a limit too...
Elemental
Active Member
as far as i know, mostly the race team using full slicks in Malaysia run averagely bout 22 psi. check this out..hope u enjoy it.
www.scribd.com/doc/25197303/Michelin-Race-Tire-Catalog"]Michelin Race Tire Catalog
and this
PROXES R888 | High Performance Competition Tires | Toyo Tires
click on "set-up and care"
www.scribd.com/doc/25197303/Michelin-Race-Tire-Catalog"]Michelin Race Tire Catalog
and this
PROXES R888 | High Performance Competition Tires | Toyo Tires
click on "set-up and care"
alamak bro cal...i might be wrong also la bro...maybe the other way round ...
but my understanding pulak, when we launch, alot of energy is thrown on the front shock and causes it to lift, which means wasting energy... therefore we need to minimize the cars energy from being wasted on lifting the front abs...so front must be stiff...and the rear slightly softer from the front, helping in energy transfer from front to back and giving more traction. the back is not drastically softer, but slightly softer.. i might be wrong, this is from my "feel" when i use to play..
anyway bro cal, congrats on ur new ride :) was eyeing that too but you got it 1st..she is a beauty. and also send my regards to Ram bro. hope all is well n good.
Thanks for the links.
After some reading I think it is like this.
First the R888 which is more for our type of cars. Recommended is 32 to 38psi, so pressure is still from normal to high. R888 also made with stiffer sidewall.
Then the Michelin link. These tyres are more for real type race car competition tyres and I think the sidewall is super hard like runflats, therefore do not require too much air pressure. If you look at the tyre size they are 22/54-13, 27/68-18 and 28/71-18 and description is 22cm width, 54 cm diameter on 13 inch rims. These tyre are of totally different make.
Back to our fun race with road tyres, that is why we have to put more air pressure.....
Elemental
Active Member
dude..u were saying 40psi on slicks/ semi slicks previously. Besides, pump in 40psi as a cold inflation pressure on street tires in race track, pressure will climb up to 46 atleast in just 4 laps (eg. sepang circuit - for normal practice). While the R888 pressure stated on the website was referring to Hot inflation pressure, not cold.
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