Whats the difference between a BRF tranny and a BQ tranny?

[2kSSLS1]

Im finally having my tranny built and Im upgrading to the '86-'87 servo. Im getting pretty much the full race built set up except without the deep pan and billet input shaft. What makes my '85 BQ tranny different than a BRF? Is it going to be any weaker if they were both having the same upgrades made to them? Should I reconsider, sell the '85 tranny, and have a BRF tranny built? Let me know, thanks.

 

[boostmaster]

BQ

Many make the same mistake that you are about to do, because you think the BR is a better trans than the BQ. Well suprise!! outside of the BR's larger servo you'd be hard pressed to tell any difference between the two. Almost identical calibartion. Do a search on BQ and see for your self.

 

[2kSSLS1]

What mistake am I about to make? Im paying lots of money to get my tranny built, so I dont want to have any worries about making a mistake! I was just wondering if I made a good choice going with a BQ rather than a BRF since I picked the BQ up for a awesome price. I was told that all I would need to do is upgrade to the bigger servo, plus the build. I was also wondering if the BRF is any better than the BQ. What sets them apart besides the letters in the code, and the one came in the '84-'85 models and one came in the '86-'87 models. Should I have waited and looked around some more and had a BRF built? Im just really worried now that I could have made one of the biggest mistakes of my life! I just gave up a whole lot of money!

 

[jakeshoe]

The only differences are the Servo (biggest difference) and you would usually replace it with a billet unit, 200 servo, or a BRF one anyway.

The BRF valve body and governor are slightly different than the BQ but very minimal and as long as you have them as a pair either VB will work fine.

As well as a CZ, and other performance VB's.

Even the low-performance VB's can be made to work so don't sweat it.

I've disassembled and measured all the differences in a BRF, BQ, and a generical lo-po VB.

No biggie,
just be sure your internals are up to the task and your VB calibration will be fine.

 

[2kSSLS1]

Well...thats really relieving to hear! I thought I was making the mistake of buidling a BQ because I so happen to pick it up for a great price. I originally was having the tranny built with a BRF servo, but I changed my mind and got the billet servo. How much and what kind of a difference is it going to make going with a billet one rather than the BRF one? Im also getting the billet drum, and extreme 4th planetary. (I dont know if its billet, I just know its an upgrade) Its getting several other parts, but its too much to list. What kind of power or times do you think this will hold up to? Its going behind my 2000 Camaro SS that is currently pushing 420rwhp/390rwtq with cam and most bolt ons with 6 speed, stock 10 bolt with 3.42s. I plan to do heads shortly down the road which will definately put me well above the 450 rwhp range. I picked up 52 rwhp with the cam only. Do you think that I should upgrade to the billet input shaft and do you think that the build that I chose is going to be enough for my set up?

 

[KEhrhardt]

Originally posted by jakeshoe

I've disassembled and measured all the differences in a BRF, BQ, and a generical lo-po VB.

Jake,
Care to share this info? I bought a lo-po VB to learn about these VB's and for measurement/experimentation purposes. I have disassembled, inspected and cleaned the unit. I also have a CZ VB that I have yet to do the same. I've been reading the posts here regarding the differences in the performance VB's. My lo-po VB has the following stamped into the VB bushings:

'15' 2->3 TV Bushing
'14' 1->2 TV Bushing
'T' 3->4 TV Bushing

I have yet to measure the valves and springs, but I will get there.

It would be nice to compare notes. Thanks.

 

[jakeshoe]

Here's a quick copy of notes between an generic and a BQ...

I have more specific notes and all the valves drawn out and measured but no way to put up here.

I also have the BRF measurements now that aren't listed here.

ll Item numbers are as listed in the ATSG Tech Manual Valve body exploded view.

#302 TV same

#304 was different but was from TransGo SK, longer by .060

#305 TV plunger was .040 larger diameter small lands in BQ code GN valve body.

#308 TV Limit valve spring is shorter and stiffer on BQ

#309 TV Limit valve is same on both vb's

#312 TV Mod downshift smaller lands are .100 larger diameter on BQ.

#313 TV Mod DS spring is similar

#314 TV Mod Upshift valve is the same

#315 spring is different but part of TransGo kit I beleive.

#316 spring is similar

#317 valve is same

#318 Line bias valve small land is smaller on BQ
.317 on BQ vs. .345 on BY

#319 Line bias spring is different shorter stiffer on BQ but likely changed by SK

#321 Accum spring lighter, shorter on BQ, likely changed by SK.

#322 Accum valve is larger on 2 pairs of lands and smaller on rt end as pictured on the BQ coded VB.
.330 vs. .315 on pairs (4 lands) and .370 vs. .470 on large end.

#323 valve is different, smaller lands on both ends of BQ VB.

#324 3-4 Throttle valve is different, larger lands all around on BQ.

#325 spring is similar

#329 spring is essentially the same

#330 valve is the same

#331 1-2 shift valve is the same

#333 Lo detent shift valve is different, all lands are smaller on the BQ VB.

#334 1-2 Throttle valve, smaller left land (as pictured) .065 smaller than BY.

#335 1-2 Throttle valve spring is same

#341 2-3 shift valve is smaller by .030 on all lands

#342 2-3 throttle valve is different.

#343 spring is different

 

[KEhrhardt]

Thanks Jake. I finally took the measurements on both valve bodies and came up with similar results as you have posted. I have an MS Excel spreadsheet with the results. Unfortunately, there is no way to attach a file to posts on the board. If you are interested, I could email you the file.

Thanks,

Kurt

 

[jakeshoe]

Yeah shoot me an email.

I have more specific data but it is sketched and there is now easy way to display it here..