Anybody Have Experience with Quickchange Rears?
 

ok, so I found out today that I live within 15 miles of the head quaters of Winter's Performance, which is one of the biggest manufacturers of Quick-change rear ends, and as it turns out one of my co-workers has a relative that works there, So I may be able to get a discount on parts. My question is, does any body have experience with quick changes? has anyone put one in an FB? and are they high maintenance?

thanks in advance

They are actually quite impressive but for the most part, expensive and completely useless for weekend type of racing. If you plan on visiting various tracks, a quick change is an excellent choice because you can change the ratio to suit the track.

They are actually quite large and fitting one in the FB without hacking up the rear floor will be a challenge. If you get the cast version, you can expect to add a lot of weight to the car as well.

If you are in to hardcore racing and there is no chance of the car being used on the street, then go ahead. But for a weekend warrior, it may be overkill.

I have a friend that uses one. He got it because a TV show said it was cool and he was going to change gears all the time. He spent a pretty penny on it and he hasn't even needed to change the gears yet!

I'd be interested to know what pricing you get. I know what a center-section costs around here and they are well out of my pocket book.

well the car will be a track only car, and i figure the cost will pretty much even out when you compare rebuilding a gsl-se diff with all new parts for 500 in parts, another 500 for a r&p, plus 500 for 5lug axles and turbo brake adapter kit like i plan on doing, and thats not even including the cost of a shop to set up the pinion preload and gear lash

Extra set of gears, extra heat, extra power to run, extra weight. I had looked into one for a tube frame project, decided it wasn't worth it. There is more to gain on individual tracks with a good transmission and an assortment of gears for that.

Yes but the weight savings alone is worth it. I don't really know what you need to replace but the R&P is about the only thing that would be needed. I would replace the seals but other that, if the bearings don't make any noise, then don't bother. The nice thing about the rears is that you don't need to do any major surgery if you need to change an outer bearing. The inners will (or at least should) be replaced when you change the R&P. Local shops charge about $100 to change a R&P if the customer supplies it.

In my car, I drilled the axle flanges for 5bolt and cut my own brackets for turbo brakes. It's really not that hard and definitely didn't cost me anywhere close to the $$$ you are talking. I still run the 4.10's and with my engine, there is more than enough juice to turn 'em.

QC's are common in SCCA GT cars. Small ones are available for small displacement cars and they don't tale up allot more space than a stock rear end. They do require more space behind the housing than a stock rearend would, to accomodate the QC gears I think the main attraction is light wieght, strength (they have floating axles) and the ability to make a car with a narrow power band work on allot of tracks. It must be worthwhile because a QC takes more HP than a typical rearend does.

As far as expense I would say that a QC with spare gear sets along with all of the mods to put it in the car would cost allot more than a big bearing housing and 2-3 posi-center sections with different ratios. As far as maintenance....pure racing parts always seem to require more maintenance than modified OE parts.

The RX7 racers that I know get by with a selection of different center sections with the following ratios- 4.88 and 5.13. But it really depends on the tracks raced on, engine power band, tire diameter and the transmission being used. It is possible that only one rear end gear would be needed depending on where you race. For example in the midwest if you spend all of your time at Mid America Motorplex and Heartland Park you only need one rearend ratio.

If you know where you are going to race and how your car is going to be setup then you should be able to figture out what you need to run for a rearend gear. You might want to talk to some of the guys running RX7's.

That's still a lot cheaper than a quickchange. Quickchanges need axles and brakes and gears and stuff too.

I'm not sure that a decent diff is even available for a QC, I think the only option is a spool.

I was looking into it, because it'd be nice to, say, run a 4.56 ring and pinion, drive to events on a gearset that gives, say, around a 3.8:1 final drive, then pop the cover, flip the gears, and then have 5.47 final drive for competition.

It's not worth it though, bare QC rears go for nearly $2k at the cheapest you can reasonably get, and the off the shelf units are all too wide so a custom unit would need to be done. And again, you still need brakes and stuff, and if you are taling about paying a shop to set up your gears and make a brake adapter, then you'd really be in for sticker shock when it comes to mounting the thing in your car and getting a driveshaft made for it.

Your estimates for making the stock rearend work seem high, but they are not unreasonable. It's a shame that the car is not more common/popular, we had a GM A-body that needed a stronger rear and were able to get a Ford 9", with new gears and limited slip and NEW pumpkin and a NEW housing that was a bolt-in to the GM chassis, and new brakes, basically a 100% new drum to drum drop in replacement for the GM rearend, for less than you're expecting to spend. Economies of scale.

Agreed! A fully built 8.8, 9" or even bowtie 10bolt for road racing application can be had less than $1k for bolt in status!

However, depending on your track, a spool isn't a bad idea. There are drivers that set records on mini and full spools. I personally don't want 'em but hey it works for some.

Not suggesting that a QC is a great option here but there are allot of differential options for a QC. Stuff like Gold Trac's, Torsens, Locker's etc. Allot more options than a spool. Like I said they use these in hight end roadrace cars and they ain't running a spool in those cars.

Back to the cost of setting up an Mazda rearend. These are some of the easiest rear ends to setup. Backlash is adjusted easily and pinion depth is not hard either. Because the mazda rearend has a drop out center section it is something anyone can do on a bench. I am also a big fan of the Mazda Posi. These things have proven to be very reliable and have a very positive action.