race_line

Question
Do you guys tried the Desoto Racing Aero Front Bumper - Cobra GT ? Its Better than stock? Thanks

Cilal

iTrader: (7)

I was also wondering the exact same thing

Cilal

iTrader: (7)

What does everybody use for setup wheels on their cobra gt?

dan_vector

iTrader: (27)

A used set of regular Sweep Tires which I kept for setup purposes.

dan_vector

iTrader: (27)

I have one of the Desoto bumpers I bought with an order sometime ago but never fitted it as it seems quite fragile to me and where I race sometimes there can be some *cough* significant contact!! I use the stock bumper and have never broken it or had any issues.

Cilal

iTrader: (7)

And obviously you race with sweeps.. So I assume a set of whatever brand of tire I run is what I should use..

dan_vector

iTrader: (27)

Yes, exactly.

Cilal

iTrader: (7)

I've just built a new diff and casing. Car was second hand when I got it. The manual says use 2 shims on the pinion to gear mesh. Seemed tight. Should I drop it to one or stick with two? Bearing also seemed slightly stiff when I screwed the pinion into the casing. Again will it loosen up after a run or two? I haven't messed up the process- followed manual and also copied the original to ensure it all was correct.

Cilal

iTrader: (7)

When I say screw the pinion in, I mean the 3 screws that hold the bearing down with the pinion the on it.

dan_vector

iTrader: (27)

Make sure the 3 screws are only just touching the bearing. They need to be almost loose to stop binding the bearing.

The new diff gear may not be meshing very well if the pinion is old. It's best to replace the pinion with a new one so that the diff gear and pinion break in together to create a good mesh. I would recommend changing the pinion if the car has run quite a bit. If the car is relatively new then you'll get away running the existing pinion.

You can run the mesh slightly tight and feel some tight spots around the rotation. Run it for an hour and it should free up. If it doesn't you can drop down a shim. If it is super tight from the outset then drop down a shim straight away.

wkloppen

Yup....good asnwer...Had exactly the same thing. The 3 bearing screws only just touching the bearing and the gears with no play in the beginning. I have to open it up now after 4 races and some training to see how they hold up. The feel while yanking the wheels a bit seems to be fine and loose.

w.

dan_vector

iTrader: (27)

When you take it apart just check the backlash in the gears you may need one more shim now it has fully broken in. On all 811’s I’ve built which includes the GT (4 of them) buggy and truggy all needed adjustment after the first 1-2 hours. Then it stays perfect for a really really long time.

howardns

does anybody have starting set-up for 3.1 parts at the track that is holding on-road nats ?

Cilal

iTrader: (7)

Great answers thanks.
Wow I found even with the screws barely touching it was still slightly binded. I'll back them out another tiny bit of a turn at a time until it is no longer binded at all.
What do you mean by check the backlash?

Cilal

iTrader: (7)

And after running it in, have you found the 2 shims works best or does it vary?
And yes I had new pinion and diff hears so all good there.