Tyre Choice For Mt Cotton Hillclimb

[SLVR32GTR]

Hey Guys,

I am entering in the Tighe hillclimb series this year that predominantly runs at the Mount Cotton Circuit here in Brizzie. I did the test and tune that was held a few weeks ago and loved it!

I will be using my 32 GTR that has 270awkw and is equipped with HKS GTSS turbos and all the supporting mods. I have bought a second set of rims so I can look at some semi slicks or the like. I ran the test and tune on my standard street tyres and really felt the lack of grip in the hair pin and tight corners.

Im currently looking into what would be best suited considering the tyres would be cold for atleast the first run (as I would swap wheels once I got there and considering there is a gravel road into the hillclimb complex i couldnt drive there on them to warm them up, and there isn’t anywhere to drive around pre-run to warm them up). At the moment im tossing up whether or not to go something like the Federal 595RS or Kumho KU36 (which I have read warm up quick), or go all the way and get a set of true semi’s like the Kumho V70A (hard compounds).

I have rung around a fair few places and have found that I can get the federals or kumho ku36s for around the $330/tyre mark for 245 or 255/40R17’s, and for proper semis like the V70A’s or RE55’s, its around $470/tyre for 245’s.

I just wanted to know which way you guys think I should go and why re the pseudo semi slicks or the proper semi slicks. This will be the first decent tyre I will have raced and driven on, so obviously anything is going to be an improvement. Im not going out there to win it either, just have some fun enjoying my car, so squeezing every tenth out of the right selection or class of tyre isn’t imperative.

Thanks in advance for your advice guys!!

Edited February 17, 2009 by SLVR32GTR

[jenkies]

hey mate ive just bought my first set of semi slicks, bridgestone re55's the grip when cold but dont shine till warm so this may be a downfall for you.. all in all they are a great tire altho i have no idea how they would go on gravel

[SLVR32GTR]

hey mate ive just bought my first set of semi slicks, bridgestone re55's the grip when cold but dont shine till warm so this may be a downfall for you.. all in all they are a great tire altho i have no idea how they would go on gravel

Thanks for the reply.

Just to reiterate, the actual hillclimb track is a sealed bitumen track, but the road in off the main highway is gravel. I just pointed this out to explain why i couldnt go out and just drive on the road for say 10km to warm them up prior to doing the hillclimb track.

[Marlin]

Hi mate, since you have a spare set of wheels, I'd suggest you go with a proper R comp tyre.

Mid 400's will definately get you a Kuhmo V70A, and yes I'd go with a hard compound. They're a good tyre although not the cream of the crop, they seem to have moved on a little since this tyre was developed.

The top tyre right now in my mind is the Dunlop 03G, and I'd suggest an "SR". This compound is between a medium and a hard. They offer similar grip to a hard, but heat up a little quicker. Back to back, same car, same day, a HARD Dunlop was exactly one second a klm faster than the hard Kuhmo. The Dunlop is dearer than the Kuhmo, but I think you should still get for under 500.... I just ordered a set of 235/45/17 and found them for 420.

I'm not sure if you're allowed to run them, but it could be worth seeing if you can use the Silverstone S575. It's a quick tyre, but not elligable for tarmac rallies, except ARC. It's relatively cheap too so worth asking the powers that be.

Cheers, Ben

Edited February 17, 2009 by Marlin

[hrd-hr30]

I've done about a zillion hillclimbs at Mt Cotton over the years.

Get a proper semi slick. The Federal and Kumho KU36 will be giving away too much time to everyone else in the AWD Turbo class. You will get tired of that before the end of the season! For Hillclimbs on a heavy car like the GTR I'd go with Medium compounds in whatever tyre you get. Hards are for circuit racing and tarmac rallies that have to make tyres last an entire event. Mt Cotton is only 980m long! and you'll normally get 4 runs per event, so they will still last a long time.

My old R32 GTR ran 46.24 at Mt Cotton on 225/50*16 RE55S SR compound a few years ago. I know that's the hard compound and goes against what i just said, but there was only the choice of hards and soft (wet) compounds and I intended to do some Supersprints as well. They worked OK at the Hillclimb, but I didn't have as much power as you - mine was basically stock apart from exhaust and Mine's ECU, and Buddy Club coilvers.

If you do go with semi slicks look into getting them from down south. I just saved $90 per tyre compared to local prices on Toyo R888's from St George Tyres in Sydney, and WRXkilla buys his RE55S from Donellans in Melbourne I think.

[SLVR32GTR]

Thanks for the replies guys, they are very helpful.

Im leaning towards some proper semi's in a hard compound at the moment (as i will be doing some sprint days out at Morgan park, QR and hopefully Lakeside as well during the year)

I will give the tyre places down south a call as well and get some prices, thanks for the heads up. I am going to check into the Silverstone S585's and see if they are ok to use too.

FYI, the second set of rims im putting the semis on are 17x9in all round.

Edited February 18, 2009 by SLVR32GTR

[Marlin]

Good luck mate. Look forward to seeing you around......

[SLVR32GTR]

Good luck mate. Look forward to seeing you around......

Thanks Ben, im looking forward to getting out on the track. Will see how long the standard bottom end lasts though, as there arent any oil mods except for the 19row cooler and approx half a litre overfilling.

hopefully the GT-SS's ive got on there are the best option for the hillclimb circuit.

[sleeper393]

try stuckey's in preston victoria they have a great range of race type tyres

Trading Hours

Monday - Friday: 8:00am - 5:30pm.

Saturday: 8:00am - 12:00 noon.

Phone: (03) 9386-5331

Edited February 18, 2009 by sleeper393

[PHaT MR30]

Hi mate, since you have a spare set of wheels, I'd suggest you go with a proper R comp tyre.

Mid 400's will definately get you a Kuhmo V70A, and yes I'd go with a hard compound. They're a good tyre although not the cream of the crop, they seem to have moved on a little since this tyre was developed.

The top tyre right now in my mind is the Dunlop 03G, and I'd suggest an "SR". This compound is between a medium and a hard. They offer similar grip to a hard, but heat up a little quicker. Back to back, same car, same day, a HARD Dunlop was exactly one second a klm faster than the hard Kuhmo. The Dunlop is dearer than the Kuhmo, but I think you should still get for under 500.... I just ordered a set of 235/45/17 and found them for 420.

I'm not sure if you're allowed to run them, but it could be worth seeing if you can use the Silverstone S575. It's a quick tyre, but not elligable for tarmac rallies, except ARC. It's relatively cheap too so worth asking the powers that be.

Cheers, Ben

Far out thats a better price than I just got them for!!!!

[Marlin]

You told me we got em for 420 cock? Am I wrong again?

[Marlin]

Tony, that car of yours, it's a '94 model correct?

[SLVR32GTR]

My cars a 92 model, so the smaller oil pump drive. If it wasnt an engine out job i would do the oil mods, but i dont really see the point in spending all that time and money if im not going to forge the engine at the same time.

Is there any relatively easy mods to do that could help prolong engine life?

[SLVR32GTR]

try stuckey's in preston victoria they have a great range of race type tyres

Trading Hours

Monday - Friday: 8:00am - 5:30pm.

Saturday: 8:00am - 12:00 noon.

Phone: (03) 9386-5331

Thanks Alan, i will give them a call and see what sort of prices they can do.

[Marlin]

My cars a 92 model, so the smaller oil pump drive. If it wasnt an engine out job i would do the oil mods, but i dont really see the point in spending all that time and money if im not going to forge the engine at the same time.

Is there any relatively easy mods to do that could help prolong engine life?

Oh ok... I thought I knew the car is why I asked. You know all the issues the GTR's have obviously, but my suggestion is just don't rev it too hard. Stay under 7200 to 7300 and try to "gear up" wherever you can, it's often quick as well. (easier done on circuits than hillclimbs though )

[hrd-hr30]

My cars a 92 model, so the smaller oil pump drive. If it wasnt an engine out job i would do the oil mods, but i dont really see the point in spending all that time and money if im not going to forge the engine at the same time.

Is there any relatively easy mods to do that could help prolong engine life?

biggest thing is to stay off the rev limiter - the hard cut causes alot of vibration in the crank and can fatigue the oil pump drive. Its very easy to hit the limiter at Mt Cotton out of turn 1 and the hairpin in both directions.

then there's the usual running an extra bit of oil, that you probably already know about.

on tyres here are the local prices I got quoted for the 245/40*17 rears for my Sil80 which is probably similar size to what you want on the GTR:

03G $560

RE55S $457 (+$15 freight ea)

V70A $465

R888 don't make a 245/40. 255/40=$473

The 255/40 R888 out of Sydney were $350ea + $65 freight on the set

build dates were end of 07 and early 08, so they were current stock and GG compound.

[SLVR32GTR]

Hey guys, yeah I have the car tuned for the street with a meaty mid range and good average power, so there isn’t really an advantage to getting every last rev out of the engine. I have the redline set at 7800, but usually change around the 7000 mark.

On the first 2 runs I left the car in second for the first corner and hairpin but found there was just too much lag around mt cotton. The last 2 runs I changed to 1st, but yeah, it was very easy to hit redline. Although with semi’s, it should have more grip than the crappy road tyres I had on there and shouldn’t spin up (or atleast as much) making it a bit easier to stay off limiter. I always run atleast an extra 0.5L of extra oil to be safe also.

Thanks for the tyre prices too Harry. I can definitely live with $350 a tyre for R888’s! haha. Will call around when I get a chance and get some prices together. I will put them in this thread for reference too.

Cheers guys, you’ve been very helpful!

[phunky_monkey]

Those 888's are quite reasonable, and not too old either. Much better than what I'm paying for RE's this weekend

[SLVR32GTR]

Well I just did some ringing around and got the following info:

St George Tyres (Syd) – Sold out of both 245/40 and 255/40 in 17s and aren’t getting anymore in anytime soon due to the aussie dollar falling

Stuckey’s (Melb) – Dunlop DZ 03G’s in 255/40 are $567ea + deliv or $20/tyre.

Hornibrook Tyres (Bris) – 245/40 Kumho V70a’s $465, 255/40 - $480, Toyo R888’s 255/40 $473, RE55s 245/40 $457 and KU36 in 245/40 $327

Access Autoworks – Federal 595RS 255/40 $320ea + deliv

I will keep ringing around and getting prices, but any other contacts you guys could offer would be great thanks!

[hrd-hr30]

try Taleb Tyres Sydney

if you are considering the 03G, call QR. They have a very good post sales service offer.