Offsets and 17 inch wheels

[daveparry]

Hi, I am getting a little confused about what size 17 inch wheels will fit my Chimaera, according to the stamp on my 15 inch wheel the ET is 25 and on the 16 inch it is ET 32. I have seen advertised wheels for a Chimaera/Griff with offsets up to 45, do they just go straight on or are spacers required on the front or back?

I really fancy a set of OZ Superleggras or Turismos, anyone?

[rigga]

Offsets and wheel widths go hand in hand,the front wheels which are et25 are 7" wide,the rears which are et32 are 7.5" wide,you can run rear wheels on the front with little or no issues depending if the body is square on the chassis,and the steering rack is central (not all cars are so rack stops/spacers may be req) also tyre size fitted to the rims can cause issues if too wide,esp the front,rears tend to have a lot more room,i run 17" wheels with et35 all round with no problems,spacers i would avoid if at all possible,just my preference.....two sites that may help you here

Wheel offset calculator
http://marksink.com/tire_wheel_offset/offset.html

And a tyre and wheel size calculator
http://www.rims-n-tires.com/rt_specs.jsp

Punch in your current wheel and tyre size,and then you can see what options run close to your current spec regarding where the wheel will sit in the arch

[dnb]

I found that the offset on the rear of my Griff was in fact ET35 on the old wheels. It's now ET42 because I have 8" wide rims on the back. The front I left as ET25 because I stuck with 7" wide rims. All diameters are 17".

If you buy from somewhere like Compomotive, they will make the wheels to your specified offset for very little cost.

[dbv8]

I contacted Silverstone performance with a view to squeezing a pair of Mickey Thompson steet ET 275/40/17's under the rear of my Chimaera purely for the drag strip.
I have it on good authority these tyres are excellent for drag racing but only come in a limited range of sizes. I currently use a pair of 225/50/16 Toyo R888s which are very good but i now need more grip to cope with over 100 bhp of nitrous.
They reckon a 9x17 could fit with a 40mm offset but werent sure about the tyre as the rolling radius is increased. The wheels would be bespoke in the Sp12 pattern to match my fronts and would be £247 each to have made up.
The diameter would be nearly an inch more and closer to the bodywork.
My concern is wether the tyre would scrub the inner arch on launch.
My car really squats low at the back already as it is.

Question is do i gamble over £800 so the car looks good with matching wheels and should knoch a couple of tenths of my 60 foot times?
Decisions decisions.

[Chimjunkie]

dbv8 said:

Question is do i gamble over £800 so the car looks good with matching wheels and should knoch a couple of tenths of my 60 foot times?
Decisions decisions.

This sport is obviously your passion, and if you can offord to then do it! My other half spends every last penny on her rally car and lotus

Edited by Chimjunkie on Thursday 14th May 09:46

[dbv8]

Thanks for the encouragement.
Credit crunch my @rse. You only live once and all that!
Im waiting for a price on a pair of team dynamics pro race 1.2's as they can come in the size i need and will save me maybe £150. Only difference with the SP12 is they have 'Team Dynamics' written on the rim otherwise i think they are identical.

[steve-V8s]

Not familiar with how you do things on the drag strip but would have thought to get a good launch you need a fairly soft and compliant setup which if anything would mean fitting a higher profile tyre on a smaller rim rather than the other way round. lower profile rubber in my experience tends to have stiffer sidewalls and therefore less grip off the line but has the benefit of staying in shape under cornering, presumably you don’t plan to do a lot of cornering on the strip.
I got some 17inch ProRace 1.2s ( 7.5 front 8 rear) from Halfords as they were the cheapest supplier. Was a bit of a struggle ordering them because unless you have your hat on backwards and drive a Saxo with a bucket on the back the computerised order system becomes confused.

[dbv8]

I got a pair of 255/50/16 Mickey Thompson Street ET radials from LA racing.
They have a very soft compound and a 5" soft sidewall ideal for drag racing.
They are road legal (just) and i have run 1.8's to 60 foot upto now.
Looking forward to giving them some more stick at York on the 1st/2nd