morris

iTrader: (2)

If I recall correctly the GS300 tranny was different that the 1UZ 340 E tranny, does it also have the funny buisness where it doesnt have individual gears like the A340E. For anyone that may not know the 340 is technically a 5 speed transmission but in reality it only has "if I remember correctly" 3 individual gears and then two overdrives to yield a 5 speed. It is my understanding that this is one of the biggest problems with the A340 transmission when it comes to building it for Torque and HP.

Alexus_300

iTrader: (4)

Morris, you're getting the A340e and A650e transmission mixed up. I've torn both of these transmission apart and from my observation, the A650e transmission found in the 2GS does not have a dedicated first and fith gear. First gear is simply the overdrive of second gear and fith being the overdrive of fourth. I'm still in the testing stage for the A341e(derivative of A340e) transmission right now since I had some help making custom billet parts from a well reputable shop that builds all hewland transmission for Indy and Formula Atlantic open wheel car. I'll report my testing once it's finalized.

Alexus_300

iTrader: (4)

Jeff, I'm not sure if you ever inspect your friction plates and steels after your rebuilds. But from what I was taught by some of the best transmission builders in Concord NC which builds all the formula atlantic and indy cars was that you simply do not stuff more friction plates because you think that it'll last longer. That's not the way to go about it. Every gear hub has only certain amount of space and therefore needs the exact clearance. That's why the steels inside of the transmission for each gears come in certain thickness to compensate that. When you try to stuff more friction plate in and as the steels heat up, they expand which causes more friction on the clutch plates thereby wearing it out faster. As for the sprags, they do not need to be replaced. What damage them is when you have wheel spin and continue to lay into the throttle without lifting off. Make sure to inspect and replace the bearings that transfer the load onto the hub if they are worn out since a seized bearing will eat up the friction plate.

morris

iTrader: (2)

You are right thanks for correcting me, like I said it has been a minute.

JeffTsai

iTrader: (1)

Well, the performance rebuild kits usually relplace the extra steels in the transmission with clutch pakcs for more friction surface. The performance rebuild kit retains the same clearance spec as stock though.

As for the stock sprag, from my experience in this transmission it will generally self destruct at around the 400-450rwhp mark on a 2JZ, which is about 350-400ft/lb or so. The intermediate sprag is only rated to handle approx 350ft/lbs of torque. If you go higher than that, the sprag starts to slip at first and then the excessive stress and continuing wear will eventually destroy it. If you can explain to me why those don't need to be replaced, I really want to know the reasoning. This is the sprag that holds the 2-3 shift, so most guys don't have the power to spin through 3rd gear....there's no wheel spin yet the sprag still blows up.

Alexus_300

iTrader: (4)

Which performance rebuild kit are you using? Because the only two friction company that makes any performance friction for our cars is Alto and Raybestos. I personally have used both and have found that the Alto Red Devil friction plate to be of better quality. From the various builds that I've done, I've always source my own parts from different vendors. The friction plates that come as a kit from Alto retains the same number of plates and steels instead of squeezing in more clutch plates. What they do is make the clutch plate material thicker per my observation. Also note that I use all borg warner sprags and have yet to have one fail on me. I've seen a few cases where transmission shops will get lower quality sprags due to cost savings and installing it into the so called "built" transmission. Currently, the A341e transmission that I'm building uses what I called special order sprags from Borg Warner. All you would need to do is measure the size and thickness of the sprags you would need and contact Borg Warner and tell them that you need it for a certain HP/TQ. requirement and they can custom build you one. As far as the intermediate sprag replacement, how were you able to calculate the forced need to damage them? From what I was told, most sprags get damaged when the bearings that they ride on gets damage from excessive heat which doesn't allow the sprung hub to engage quickly. What I'm looking into is seeing if they make a ceramic bearing that will take the load and heat better in these transmission. I know that SKF makes great bearings and I've contacted them about this issue but still have not received any response back from them yet.

gs400 civi

iTrader: (4)

hey, i have some questions, i want to run a smaller pulley and apparently I can't just buy one from vortech and there are specific specs it needs to be machined to, not just the standard 6 rib pulley. Also w/ a smaller pulley what size belt to use? Gatorback? i've heard that name thrown around.

Alexus_300

iTrader: (4)

Have you ever consider giving the guys over at 928 motorsport a call. They service both powerdyne and Vortech units and have a vast majority of parts for us supercharger guys.

JeffTsai

iTrader: (1)

Keep in mind, it's hard to "type" a voice tone over the internet. I'm speaking purely from a curiosity/knowledge sharing standpoint and of my experience. Not arguing or any smartass-ing here(again hard to express your tone by typing). It's just that almost nobody builds up these transmissions, so our aftermarket trans upgrade options are very limited. I'm curious to find out what you did on your rebuilds. All the stuff I've done so far is mostly trial n error and testing on my behalf.

What I can think of causing the sprag to blow up is usually due to excessive heat. When the shift engages, the sprag can't hold the torque being output from the engine. I spec'd the OEM intermediate sprag from Borg warner, and it's only rated to hold around 350NM of torque, which is a bit less than 350ft/lb. When you exceed that torque rating, I assume the sprag starts to slip and the teeth on the sprag wears down badly and gets damaged. If you keep slipping on the sprag, eventually the cage will fail and the whole assembly will blow into pieces.

Also, this is for the A650E, not the A340. The 340 has a ton of selection when it comes to this stuff, but the 650 is very limited. You said you got the BW sprag for the 340, but have you sourced one for the 650? I managed to get a few out of TH400 torque converters, but they are very hard to come by and not exactly cheap either.

As for the rebuild kit. The last one I used was the alto red devil. There was one extra clutch pack in certain sections in the transmission. It replaces the steels with clutches. The oem cltuch setup in the 3rd gear(I think it's called the 2nd brake) is like this CL: clutch ST: steel
END PLATE-CL-ST-ST-CL-ST-CL-ST-CL-ST-ST-CL-END PLATE
The rebuild kit changed it to this:
PLATE-CL-ST-CL-ST-CL-ST-CL-ST-CL-ST-CL-PLATE

I think that is how it is off the top of my head, but basically it replaced a few of the doule steels with clutches instead.

PS: I would be thankful if you can share with me how you sourced your sprags. Or who do I call to get a custom built one? All the places I have called only request a part number, and can't spec it out by diameter/dimensions.

Alexus_300

iTrader: (4)

Hi jeff, sorry if I came off as being "harsh" which I wasn't. I'm in the same boat as you when it comes to the A650e and A341e transmission. Alot of trial and error has been spent on my end with these transmission. I'm fortunate enought to have a great transmission builder and racing consultant who could help me out with these transmission. What we've found damage in two of my transmission is the premature wear of the bushings due to heat and friction which caused the oil galleys to clogged up therefore limiting fluid transfer to the clutch packs. As far as the sprag is concern, my friend who owns CTP has been studying the borg warner sprag and thinks that it is the design of them which limits its strength. Since these sprags were designed for OEM engagement, it can't be a harsh transfer of load. So right now, he's looking into making custom ones which I'll have to ask him the next time I see him from who. But I know from his contacts in the racing world its doable. Another option that we're going to try the next round in my A341e transmission is to change the springs on the hub in front of the direct clutch and the one behind the second brake clutch to a higher tension spring so that clutch engagement is quicker to prevent further slippage and heat buildup. Lastly, I've noticed that you said that you have to change out your friction material in the clutch pack on every rebuild, CTP has been working with Dupont and Dow chemical to create a treatment for the steels similar to the salt bath chemical that comes on the Koleen Steels to reduce friction and wear on steels and friction material. I had this treatment this last buildup and the wear is not as bad as the non treated ones.

RMMGS4

iTrader: (5)

Check your pm.

gs400 civi

iTrader: (4)

hey does anyone know the diameter of the power steering pump /main sc drive pulley? (the custom machined one that has 2 belts, power steering and sc? I'm trying to do some calculations but am missing this info. I have a 2.62" sc pulley on right now w/ the vortech v2-sq (I might be able to trade up+cash for a newer model w/ the same mounts etc.

RMMGS4

iTrader: (5)

5.25" . . . . .

gs400 civi

iTrader: (4)

yes, thanks rmmgs4.

I've been reading and researching, do you/ anyone have a BLV, or BOV on your gs? have you ever considered a restrictor plate/ pipe before the sc? the way i see it is this, BLV valve, limits the psi by bleading off air after the sc but makes the sc work just as hard as if it wasn't there (air is still compressed and then bled off). the restrictor seems like a good Idea but sizing/ type is an issue as well as vacuum etc etc.. the BOV option i'm not sure about, think that involves a boost controller etc. The goal being to make whatever your desired amount of boost at a low rpm, 3000 obo and hold that pressure to redline. I'm also really interested in a different setup to deal with the belt slipage I will/ have encountered, with the main drive pulley being 5.25", was that on purpose, woudn't a 6" pulley have been more suitable (especially considering that it had to be made?). A 6" cogged/ 8rib or whatever no slip method main drive pulley w/ a 3" SC pulley should offer what is desired/ offer more flexibility and more power.

GILLEXUS

iTrader: (14)

When you say BLV do you mean Boost Limiter Valve? That and a BOV, Blow off valve are totally differrent. I believe everone with a S/C or even turbo that I've seen here had a BOV but I have not seen the anyone using the BLV .