racer x 1

iTrader: (27)

the swag says that using the mrx3 arms does not affect the way the car handles.

Ron C.

iTrader: (2)

Performance would stay the same.
They were mainly for clearance purposes.

Ron C.

iTrader: (2)

Hi Fsturbo15,

On a related side note : The arms that come with the MRX4-R Kits are new Front Upper arms (not of the MRX3).

When comparing one from the other, the MRX3 arms are wider (assuming you're looking at the car from it's side).

With the MRX4 (arched) or MRX4-R (not arched) arms, it allows the car to have more available caster settings.

cdelong

iTrader: (12)

Ron,

I thought the MRX-4 and 4R upper a-arms were narrower because the 4 series has an adjustable wheelbase, although I see that you could possibly use the extra clearance to drastically alter caster angles.

Do you ever have occasion to place the top 3mm wheelbase shim different from the 3mm lower wheelbase shim (one forward and one backward)?

BTW- I like the new yellow shoe. How much clutch nut are you running in combination with 3 chamber pipes and the yellow shoe?

Thanks,
Corey

mrgsr

iTrader: (15)

how far do you guys have your clutch adjust nut screwed in ?
is the books setup any good/bad ?

i saw a guy at the track yesterday and on his evolva he had the nut screwed pretty much the whole way in .. weird ?

cdelong

iTrader: (12)

I think 1.0mm is a good starting point.

It all depends on the track, clutch, engine, pipe and your driving style.

kenshu

iTrader: (1)

I have my MRX4-R done and I'm ready for Cinn this weekend. It's been 16 years since I drove 1/8 on-road. Should be a blast.

mrgsr

iTrader: (15)

is thier a 1 piece engine mount for the mrx4 ??

Nitro-mech

iTrader: (102)

Yes, part # H0772 single piece motor mount.

Ron C.

iTrader: (2)

Hi Corey,

It's correct, the MRX-4 and 4R upper a-arms are narrower (than of the MRX3) because of both reasons you cited.

I just mentioned it on the last post because we had some guys asking if the Front Upper arms in the MRX-4R kits are of the MRX3. They are actually new Arms.

Ron C.

iTrader: (2)

Measuring it with a caliper from the tip of the crank to the flat part of the clutch nut, I start off at 9.2 and work my way in from there.

As Corey mentioned, "It all depends on the track, clutch, engine, pipe and your driving style."

Ron C.

iTrader: (2)

Hi mrgsr,

That is weird because he is not allowing the clutch spring to function properly.

cdelong

iTrader: (12)

Ron,

Your quick and informational replies are greatly appreciated from the "little guys" like myself.

How long before 4R spares (A-arms) are readily available? My retailer is not getting his orders regularly filled with 4R stuff and I can't get A-arms. I need 4R front and rear lowers (not old "4" lowers) and 4R front uppers.

Mike_Swauger

Hello cdelong,

The MRX-4R lower arms have been in stock for about 4 months. It is a running change so it is the same part number. We have the new MRX-4R upper arms in stock now. Like the lower arms they are a running change so they will be the same part number. What hobby shop do you deal with? We have had these arms in stock for a while so they should be easy to get.

cdelong

iTrader: (12)

Mike,

I deal with Robert from Ashford. He said he talked to you a few weeks ago on the new style arms. He got the front lowers and that's it. Nothing else (a-arm wise) was filled. He should be placing another order tomorrow.

Thanks for the update!!

Corey