Drag Bags

[anonymous-user]

I'm looking to fit 9" rims with 275/285 tyres on the rear. With helpful advice from Roger I know they will squeeze under there with either a difficult to find offset or by cutting the rear arch lips but I came across this: www.highperformancepontiac.com/tech/hppp_0709_pontiac_gto_wheel_and_drag_bag_install/index.html

Might be an option and not too expensive?

Edited by anonymous-user on Saturday 25th October 11:02

[the muppet]

Summit do a kit also, www.summitracing.com

[anonymous-user]

So nobody on here has any experience of these. Are they crap?

[ringram]

Take a look on ls1gto.com and search there to see what the guys who have them think

[MyM8V8]

What they appear to be, is a quick and dirty anti squat device. Squat is what you experience when you hit the loud pedal for a launch. All the suspension components wind up like a spring and the rear end sits down violently.

This is where you would have problems with a wider tyre, which would move up and catch the bodywork.

The drag bag just increases the spring rate (hardens it up) and reduces the amount of movement depending on how much air pressure you use.

It would make for a very interesting driving experience if you left them pressurised for road use afterwards.

[-Z-]

Isn't the weight shift courtesy of the massive squat effect a benefit for increased grip under acceleration?

So you gain tyre width but lose out on weight shift?

[anonymous-user]

Hmmmm, after reading about them it looks like a bit of a bodge. You can achieve the same affect by fitting stiffer springs. If I could roll the arches I would but I really don't want to cut the bodywork.

Standard wheels are 8" wide with a 48mm offset. Assuming the widest tyres I can fit without bodywork mods is 275/40 on a 9" rim I think I'm looking at:

9" Rim
Offset: 48 mm + 13mm (1/2 inch each way) = 61mm

PCD: 5 x 120mm
Bore: 69mm

This sort of fits with the fitting guide I picked up from the guys on LS1GTO.com:

WIDTH..........OFFSET............WIDTH OF TIRE
8.0................+36/+65.............245/255
8.5................+42/+65...............245/255
9.0.................+48/+65...............255/265/ 275
9.5................+55/+64...............265/275/2 85

OFFSETS GREATER THAN SHOWN ABOVE WILL RUB ON REAR
FENDER LIP. (25MM FENDER LIP)

[MyM8V8]

-Z- said:

Isn't the weight shift courtesy of the massive squat effect a benefit for increased grip under acceleration?

So you gain tyre width but lose out on weight shift?

Yes. Providing that the shocks and rest of the components are tuned to take care of possible tramp.

Like most things on a race car it's a cock up to cure a cock up.

Squat (or anti squat) can be expressed as a percentage, under 100% the car squats, 100% and it should be neutral, anything over 100% would actually lift the car. The set up on a drag car could be well in excess of 100%, depending on which class etc.

So drag bags??? Well....................

Edited by MyM8V8 on Sunday 26th October 12:36

Edited by MyM8V8 on Sunday 26th October 12:38

[S600VXR]

285/25 on 10" rims fit easy...!

[Boosted LS1]

Like Gareth says squat and anti squat are two different things. Anti squat will give the bodywork lift whilst stuffing the tyres into the tarmac. You need geometry to raise the body mass. Squat is, just less. If going for anti squat you need to be able to disconnect it otherwise you may suffer from tramp and a load of other crap. A snubber would work ok or maybe a pair of slappers depends on the under floor of your chassis.

[anonymous-user]

S600VXR said:

285/25 on 10" rims fit easy...!

we both know that isn't true! any chance of a side-on view of your wheels Roger? I'm thinking of getting the silver version.

Edited by anonymous-user on Friday 31st October 19:21

[S600VXR]

Bit of a crap photo but its the only close up I have...

[anonymous-user]

Nice. Do they make them made to measure?

This looks interesting: www.performancealloys.com/custom_wheels.asp

They actually list the monaro if you search by model

Edited by anonymous-user on Friday 31st October 20:26

[S600VXR]

Not made to measure but they do adjust the offsets to suit I beleive. I tried these people when I was looking for mine but the site would not let me get past the Year stage so I gave up. TBH alot of people make wheels to fit, you just have to pay alot more for them. Mine were around £1200 I think, IForge or similair will be closer to £2500 just for the wheels so about double. Mind you I am looking to go with them next year...