Major changes to Astra chassis

Post by **PrecisionBoost** » Thu Jan 22, 2009 5:04 am

In my opinion the biggest issue will be at the top of the fender... not at the lip.... because I want to lower the car significantly.... so flaring the fender won't help much.

I already made one fender out of fiberglass that looks like your drawing... it's not even remotely close to being able to handle a huge 325mm width tire

I thought about cutting the fender at the top edge and adding a 6" strip of metal to push the fender out but then I wouldn't be able to shape it or blend it easily.

If I make a whole new fender out of fiberglass I can modify the crap out of it and blend it.... then when I'm happy with the shape I can make a mold and produce a light weight composite fender.

Odds are I will make a mold and send it away for another company to use the mold to make the composite parts in order to ensure that I get the lightest strongest components.

On another note found a really nice OMP group N + A certified roll cage... 12 pt... but I am in the midst of talking with Castrol Raceway here in Edmonton to find out what is acceptable at the drag race track ( looking for a technician to discuss the cage details )

The NHRA rules give a very specific 6pt full cage design.... but I really would prefer something that not only meets FIA requirements but passes it.

OMP also makes a 6pt FIA cage similar to the NHRA one but with more supports ( X brace versus horizontal bar design ) but I really want to tie into as many chassis points as possible to add rigidity to the car.

Post by **PrecisionBoost** » Sat Jan 24, 2009 11:49 pm

well.... I risk these pictures showing up as "hillbilly duct tape performance car of the year" but I wanted to mock up a fender that would fit a 325/30/19 tire up front.

As it turns out with the spacing requiements I had to add 6" to the fender to ensure clearance ( if I were to use the stock fender )

So... with some styrofoam and duct tape I managed to get it placed to see just how crazy it would look.

Hopefully this gives some perspective of how drastic the change needs to be to move from 185mm wide tires to 325mm tires

Post by **PrecisionBoost** » Sat Jan 24, 2009 11:54 pm

On a secondary note this is my very first Passport Optima with a C20GET ( I have three of these cars , plus a lanos and an Optra )... I've had it apart for quite a while.... today I fabricated a few things to get it running again.

I injected some oil into each of the cylinders prior to turning it over ( took out spark plugs) and wow did I manage to make a giant cloud of smoke inside my shop in a matter of 2-3 seconds of run time.

It was incredible.... it filled up 5000 sq ft in a matter of less than a minute... it was like a thick fog you can't see through.

It took nearly 3 hours to dissipate... that's with opening up the main 10ft X 14ft bay door twice for 10 minutes at a time in -25 deg Celcius weather!

I probably just ate through $50 worth of natural gas trying to get the heat back up

So.... I guess I will remember next time that no matter how cold it is outside (very cold right now) never start up an engine indoors if you've injected oil into the cylinders !!!!!

Post by **PrecisionBoost** » Sat Jan 24, 2009 11:58 pm

I'd say that based upon my estimates this fender is probably 2" to 3" wider than the "widebody rieger kit" which I hate so much.

At this point I don't think this type of setup will work..... If I mold a completely new fender I can increase the width around the tire but pull it back towards the body more.

So... that would mean a 4" gap instead of 6" at the front and back.

I still think it's easiest to simply continue the fender into the door with the same width.... that way there isn't this quick drop off from the fender to the door.

wolfhound · Post by **wolfhound** » Mon Jan 26, 2009 7:01 am

Isn't that the Mattig kit on the Mk2 Astra ? I remember Fast Car did this conversion in the 90's. It used a 300 odd wide tyre at the rear as well. the only rims they could get to fit were specially made steel wheels by Wheeler in the UK - musta been heavey as hell.

Good luck with the project dude, nice to be different.

Sean

Post by **PrecisionBoost** » Tue Jan 27, 2009 7:45 pm

Yes... Mattig... not Rieger... I got confused.

I have a supplier in the UK for the Mattig kit... but I really don't like the way that they flare out and then go back in.... I prefer the other way where the fender line continues on accross the door from front to back ( like most of the supercars out there )

For some reason I thought I remember the Mattig having largeer rear tires but the fronts were something like 285mm .... which is funny since the bigger tires should be on the front not the back.

It's been ages since I read anything about them.

As far as wheels, that doesn't concern me too much as I can figure something out by machining new suspension components/spacers with a different bolt pattern.

Post by **PrecisionBoost** » Tue Jan 27, 2009 7:50 pm

http://www.designercars.net/membercars/4250

Here is another widebody.... just flared fenders... but nice looking.... might fit a Lanos since they are the same chassis.

Post by **PrecisionBoost** » Tue Jan 27, 2009 8:49 pm

Here is a post on a guy with the Mattig kit

Post by **PrecisionBoost** » Tue Jan 27, 2009 8:50 pm

Post by **PrecisionBoost** » Tue Jan 27, 2009 8:51 pm

Not sure who makes this "testarossa" kit

Post by **PrecisionBoost** » Tue Jan 27, 2009 8:53 pm

here is the Reiger kit....

Post by **PrecisionBoost** » Tue Jan 27, 2009 8:56 pm

So with the Reiger kit it quotes:

225/35/18 or 215/40/17 Front
265/30/18 245/35/17 Rear

The Mattig kit managed

245/45 Front
345/45 Rear

benzino · Post by **benzino** » Tue Jan 27, 2009 9:58 pm

IMO the reiger kit looks a lot nicer than the mattig.
The Mattig kit just looks like someone with too much in their pockets, as in, it looks bulgy, but not in a good way.

Post by **PrecisionBoost** » Wed Jan 28, 2009 2:42 am

I agree that the reiger kit is better than the mattig kit but neither come close to my goal of 325mm wide tires

The Reiger kit gives 225mm max front... a full 100mm ( 4 inches ) thinner tire than I want.

The Mattig is better at 245mm but it's still nearly 3" shy.

The problem is that they were trying to make wheels work with the stock suspension/spindel where as I don't want to go with the stock setup.

benzino · Post by **benzino** » Wed Jan 28, 2009 4:01 am

So are you converting it to AWD as well?

How is it going to handle with such wide tyres? Do you have to change all the steering rack?