rear end difference question.

[return to dirt]

a local track is having a kind of open mod race and one of the rules is that if you run a quick change you have to add 50lbs. is this a common thing? what is the weight difference between a quick change and a ford 9in? i always thought a 9in would be lighter if you used the same weight parts in both. thanks.

olin

[rubbinsracin]

the quick change offers the same resistance and much easier tuning ability. winters website says they weigh about 10-15lbs less than a 9", especially if its an aluminum tube, aluminum birdcages, lightweight gears, and one of the newer pumpkins that is much smaller, therefore lighter, than the older quick changes. have a ton my gear choices with small increments to really dial in your power. also, if you get into a wreck its a lot better to just slip a new tube on it as opposed to having to weld on a tube straight and true on a 9"

the quick change is just superior in all ways in my opinion.

[chapa9]

dont see why they would have you add weight tho. makes no sense. Most of the tracks I race at is a mix of 9 inch and the QC, out of 20 races won its prolly 50/50.

I agree a QC is alot better, wish I had one but i have no problem running up front. What sucks is when a track rains out its alot harder to hurry and catch another race at another track! lol

[rubbinsracin]

all the A-Mod tracks around here are NOT alowed to run any type of quick change, only a 9". We did recently have the USMTS Mods here and 90% or more had a QC under there.

i know our mods have to weigh 2450 and when the usmts cars were here they only had to weigh 2400. so im guessing they are just saying, if any traveling cars show up, they need to add the weight to be on the same playing field as the rest of the local cars. i bet they have to add the 50lbs in front of the midplate too.

[return to dirt]

here's a copy of the format. i just thought the main advantage for the q/c was if you run on different tracks, didn't know there was that much of a performance advantage.


"I have collaborated with Mark and Ed. Both would like to express that for this weekends races, IMCA or UMP style rules apply.
1) Quick Change rear ends are allowed. If you have a quick change you will be required to add 50 pounds of weight
2) Aluminum heads are allowed. Must add 50 pounds of weight if you have this type of motor.
3) 2450 lbs with driver minimum weight. If your car has either of the above two items, then you need to weigh 2500lbs.
4) Basically we are trying not to exclude cars that want to race with us."

olin

[TeamGRT12x]

I'd give up 100 pounds to have a quick change in IMCA. The quick change isn't a performance enhancing deal. I just bought 15 sets of quick change gears for $300. You can't touch one of my 9" Hogs for $300.

The weight won't be an issue. Neither is the "tuning ability" of a quick change. Run what's convenient for you. You won't get beat because a guy has a QC in the back, just saying.

[FLYNBRYAN]

The 9" is heavier( can't give you exact numbers ) but about 10 years ago we did some chassis dyno testing, and the brand new QC soaked up about 3.5 hp and 4lb/ft of torque.
I run under WISSOTA rules and the last race was in it was about 50/50

But the gear splits are so much nicer