What rims and tyres to use at drags

[gts071]

Hey Peoples,

I went to the drag strip on Saturday and managed to get a 13.517

Car: VX HSV GTS
Engine: C4B (LS1) 300kW
Transmission: 6spd Manual

Reaction: 0.785
Sixty: 2.170
E.T: 13.517
M.P.H: 108.30
K.P.H: 174.28
(With my stereo gear & spare tyre, running on my standard street tyres)

Motors ACDelco Dragway Tasmania
Commodore Car Club Private Day
Saturday 25th November, 2006

http://i49.photobucket.com/albums/f285/gts071/GTS%20Photos/DragDay13.jpg

As I have the 315mm rear brakes what rims & tyres should I be using as I put the pressure down to 30PSI but I feel this was way to high still.

I don't really want to remove the stereo gear, also I have koni adjustable shocks which are set to the firmest setting.

I suspect I need slicks or semi slick, but I also need 17" rims. As my car is also lowered I don't know how much wider than 245 I can go without rubbing the guard.

What do other people use?

I only take my car to the drags about twice a gear and don't want to spend $1000's well not just yet anyway :)

Oh, and it has around 240rwkw.

Cheers

[Monaro CV8-R]

I let my rear tyres down to 15psi when i run it at the track, helps launch with less wheel spin. My tyres are 235x18x45.

And with your suspension, i pretty sure a softer setting will give you a better launch.. Try it next time!

[Souljah]

Set your rears as soft as possible and firm the front up as much as you can.

[gts071]

I knew I would be doing something wrong :)

I assume I want it set to soft so it squats more and gets better grip? or shall I say wheel spin less...

[HRT 8]

I knew I would be doing something wrong :)

I assume I want it set to soft so it squats more and gets better grip? or shall I say wheel spin less...
Actually quite the opposite will happen.
Too soft will cause the arse to bite down and the rear squat hard. We all know what happens to the rear camber angles of the tyres when that happens. Youll be using somewhat less than the full contact patch of your rear tyres, and it turn blazing them more easily.

You tend to find guys persisting with IRS rear ends at the drags run taller or at least factory height rear springs to try to keep the rear geometry witin an acceptable range.

The soft rear end hard front idea is to maximise the weight distribution to help eliminate the shock to the tyre when you launch. With IRS cars, is a harder proposition.

[juzzy]

Actually quite the opposite will happen.
Too soft will cause the arse to bite down and the rear squat hard. We all know what happens to the rear camber angles of the tyres when that happens. Youll be using somewhat less than the full contact patch of your rear tyres, and it turn blazing them more easily.

You tend to find guys persisting with IRS rear ends at the drags run taller or at least factory height rear springs to try to keep the rear geometry witin an acceptable range.

The soft rear end hard front idea is to maximise the weight distribution to help eliminate the shock to the tyre when you launch. With IRS cars, is a harder proposition.

or try 2-3 degrees or positive camber on a soft set up in the rear, that works 2, and take the rest of the crap out of you car.
regards Justin.

P.s Should run 110 mph.

[qldcharger]

Wish I could get into the 13's. Had my first outing last Wednesday night and after stuffing the first two runs up (traction control on - DOH!!!!) all I could manage was a 14.5 at about 103m/h. I have had it dynoed with 335rwhp so was looking to crack a 13. The starts were hard. I tried to keep an eye on the tree and at the same time check revs as I could not get grip until it was under 2400 rpm. Mine is a 6 speed manual - should I warm the tyres up starting in 2nd gear for the burnout as there is no way I can step off the clutch and lightly hold the front brakes and then try a gear change to boot. I simply did a 1st gear burnout for about 4 seconds - by this stage I had gone well past the start beams. Tyres are the original Bridgestone but almost illegal tread depth.
I am a teacher and when I described to some of my boys the traction control button oops they could not stop laughing!

[VooDoo]

I used my old 16" caprice wheels and some 255/50/16 Mickey Thompson ET Streets ($250ea) and was getting some 1.6sec 60 footers. On the older 17" NS2 nangkang's @ 20psi i did a best of 1.73sec 60 footer.

[BigJim]

I use 16 x 7.5 camaro rims on my GTO with MT ET street radials 255x50x16 and these with dead stock HSV suspension have netted 1.58 60ft times and after 4 runs with the GTO i have consistent 60ft from 1.58 to 1.61. Tyres PSI 18. Even on my old VZ clubbie turboed with 400rwkw in a M6 they netted 1.7s consistently. Great drag tyre

[VU_SS_UTE]

If they're not already sold, Ben with LS1UTE had a perfect set of pursuits with sticky dunlop tires on them....going pretty cheap from memory and they handled his 270= at the treads ok

[markone2]

You tend to find guys persisting with IRS rear ends at the drags run taller or at least factory height rear springs to try to keep the rear geometry witin an acceptable range.

.

...................:teach:.................. :yup:

[RedVYIISS]

Set your rears as soft as possible and firm the front up as much as you can.

My setup I do exactly the opposite (I have fairly stiff lowered springs).

My setup is more geared toward roundy stuff than quarter mile, but for the quarter I set the front to full soft and the rears stay pretty firm. This way the nose can lift to transfer weight to the rear, and the rear doesn't squat excessively, so doesn't go into bad neg camber.

I too run 16" wheels on the rear with Micky Thompson 255 radials. Its only had 6 runs down the quarter in its current configuration, and I'm still to find the best launch technique, but last run netted a 1.650 60ft.

[Leppy]

I just trial fitted a set of genuine SV5000 rims (16" x 8") onto my VYIIR8, and they clear the 315mm HSV premium's... Not much room, but they do fit. The offset is off a little though (as in the rims stick out a little further) but I'm hoping this won't hurt me.

Has anyone else fitted the SV5000 rims to their car with rear premiums? I'm about to buy some better rubber for them, and was guessing something like 16" 255's might do the job.... TNT is on the 19th Jan for us folk here in Mackay.

[RedVYIISS]

I run 16 x 8 VT Calais rims though with the 255 MT's I've had to roll the guards.

[SS_Brute]

I run 16 x 8 VT Calais rims though with the 255 MT's I've had to roll the guards.


Can you confirm that these are genuine Holden Rims as a friend in the spare parts section at my Holden Dealer checked for me earlier today and couldn't find an 8 inch Holden rim in the VT series.

Also if anyone could give me a contact number for where i can get a pair of 16 x 8 rims i would be grateful.

[Animal]

snip .. but last run netted a 1.650 60ft.

Ya gotta be happy with that mate

[choppo]

Can you confirm that these are genuine Holden Rims as a friend in the spare parts section at my Holden Dealer checked for me earlier today and couldn't find an 8 inch Holden rim in the VT series.

Also if anyone could give me a contact number for where i can get a pair of 16 x 8 rims i would be grateful.

Hi guys, i tried a 16" chaser rim with 255 ET streets on my VZ R8 last weekend and the rims didn't fit over calipers! - was told they would fit (when i bought them:cussing: ).
Anyone have a definitive answer on a 16" rim that will definetly fit OR a 17"/18"set up (what wheel and tyre)?

[lowr8]

I run 265 18's on mine and with rolling the guards it doesn't scrap!! Anything under I can't get traction

[RedVYIISS]

Can you confirm that these are genuine Holden Rims as a friend in the spare parts section at my Holden Dealer checked for me earlier today and couldn't find an 8 inch Holden rim in the VT series.

Also if anyone could give me a contact number for where i can get a pair of 16 x 8 rims i would be grateful.

They're genuine, but are marked HSV, so I might be wrong about VT Calais. Someone told me they're off a Statsman Interrnational? but I don't know for sure. I'll take a photo, someone may know their origin. I bought them from Nick at NVU some time ago.

[Leppy]

They're genuine, but are marked HSV, so I might be wrong about VT Calais. Someone told me they're off a Statsman Interrnational? but I don't know for sure. I'll take a photo, someone may know their origin. I bought them from Nick at NVU some time ago.

Offset and clearance is the secret here people. I can fit the SV5000 rims over my premium brakes on the VYIIR8 (315mm rears), but the offset is wrong. Here's what I found on my car:

Stock (factory wheels) are VY GTS 19" x 8", 48P offset.

Drag rims I've actually tried on the car...
HSV SV5000 rim - 16" x 8", 30P offset, 360mm internal measurement (brake to rim clearance 5mm), 255/50/16 MT's fitted (hits on outer guards by a mile)


HSV International rim - 16" x 8", 38P offset, 360mm internal measurement (brake to rim clearance 5mm), 255/50/16 MT's fitted (hits on outer guards by a couple of mm). Rolling the guards will help.


VE steelies - 16" x 7", 45P offset, 355mm internal measurement (brake to rim clearance less than 1mm but still fits!) 255/50/16 MT's fitted (clears inner guards and outer guards by plenty). Rolling the guards will help.


Speedy "Tarmac" Mags - 17" x 8", 45P offset, can't remember the internal dimensions BUT these fit over my mates VZ R8 Maloo Premiums, and have a mile of clearance on my VY) 275/40/17 MT's fitted (clears inner guards by plenty and outer guards by a flydick!). Rolling the guards will help.


Keep in mind that my car is stock, with stock suspension and does NOT have the guards rolled....yet. I can fit the 17" 275 MT's on the car, but it will be in my best interest to roll the guards for safety...


Some other info...
This information is for those of you with a VYIIR8 Clubsport with Premium brakes on the rear.
Wheels - 19" x 8"
Offset - 48P

Drag rims choice
16" range
7" wide - can have any offset from 35P to 60P
8" wide - can have any offset from 45P to 50P

17" range
8" wide - can have any offset from 45P to 50P


I don't want to turn this into a technical thread, but to measure offset you need to know 2 things. The backspace of the rim, and the actual width of the rim, from inner flange to outer flange.

Backspace
Backspace is the distance from the back edge of the wheel to the hub mounting surface. To determine the wheel backspace:
1. Position the wheel face down.
2. Lay a straight-edge across the back of the wheel.
3. Measure the distance from the straight-edge to the wheel's hub mounting surface.

Wheel offset
The wheel's offset is the distance from its hub mounting surface to the centerline of the wheel. To determine wheel offset:
Position the wheel on a flat surface and measure its overall width.
Divide the overall width by two, then subtract this result from the backspace value.

Offset = Backspace - (Rim Width ÷ 2)

The offset of a wheel can be one of the following three settings:

Zero offset:
The hub mounting surface is even with the centerline of the wheel.

Positive offset:
The hub mounting surface is toward the front or wheel side of the wheel. Positive offset wheels are generally found on front-wheel drive cars.

Negative offset:
The hub mounting surface is toward the back or brake side of the wheel's centerline. "Deep dish" wheels are typically negative offset.


I also found this website to be handy to assist with rough calculations. It will assist you in deciding what rims will fit with different offsets.
http://www.driftworks.com/index.php?action=resources&resourceId=17 :deal:


I hope this helps someone??? I have had all sorts of problems with rims, and it seems most people out there just "change the rear premiums to stockers" which to me, simply isn't an option. Please check your car and dimensions for yourself though - the last thing I want to do is give people a bump steer!

Cheers
Leppy

[VooDoo]

HSV International rims are 16x7 not 16x8. Ive checked into this a few times and there doesnt seem to be an 16x8 rim from Holden.

I used the WHII Caprice rims i had (16x7)and they fit over the 315mm rears no problems (with the 255/50/16 ET's)

[Leppy]

Sorry - I stand corrected. The HSV Internationals I have are indeed 16" x 7" with a 37P offset. Its a shame I can't machine any material out of the hub on the SV5000's.... They are a genuine 8" rim and fit perfectly except the offset!

[RedVYIISS]

Markings on mine are:

HOLDEN SPECIAL VEHICLES
8JJ x 16
N2025
40P
disk cap
PN.10B 741901
made in australia

They come with a big chrome plated centre plastic disk with a fancy emblem in the middle (Holden Insignia of some sort from memory). I've taken the plastic disks off them.

You do need to roll the guards to fit these though.

[SS_Brute]

Thanks guys, lots of great info there and so if you're all happy running a 255 tyre on a 7 inch rim then i may give it a go then.