re4r03a vs. re4r01a valve body

Post by **3Q Jay** » Sat Jun 11, 2005 10:41 am

ok, so i know in general that the -01a is the lighter duty version used in J30's mazda mpv's etc. i'm searching around for a 'shift improver' kit for the -03a, and found one for the -01a, and it was actually listed on the website under the -03a. there's no one there to talk with today to see what's up.

so, anyone here know if the vlave bodies are the same?

http://www.bulkpart.com/Mercha...bkits

Post by **3Q Jay** » Sat Jun 11, 2005 10:58 am

here's another.scroll down to the -01a kit. definitely mentions the V8 -03a in the description.helps the 2-3 cut-loose [i assume that's overspeed]?Improved flow?

this sounds like the gods have answered....

http://www.txchange.com/sk.htm#Import

Post by **elwesso** » Sat Jun 11, 2005 2:30 pm

Regardless of if those will work, this is something the tranny guy will replace when you get it rebuilt... Better to stick with an IPT valve body (500) than to do that... This is more/less a "kit" with all the pieces.. not a replacement valve body

The IPT valve body will make your tranny shift like the upgraded ones from IPT or level ten, and make them signifcantly stronger

Post by **RobertsnewQ** » Fri Jun 17, 2005 12:43 pm

Jay, Have you seen this?

http://www.importperformancetr...#main

Check out the solenoid kit...

One more interesting tidbit taken from a Subaru SVX specialist (4EAT transmission, also used by Nissan in the Pathfinder and some others)

5. The solenoid pack, located on the valve body of the transmission, includes a line pressure control solenoid. If the transmission has more than 50,000 miles on it at the time of repair, the solenoid pack should be replaced. The line pressure control solenoid is pulsed on and off many times during the life of the transmission and has been known to fail early, mechanically. The resulting symptoms are long, sliding shifts which quickly leads to burnt friction elements (band and clutch fiber plates).

AND ......

Check out this pic of the SVX's valve body. Looks like the one you posted the other day...

http://www.drwtransmission.com...8.jpg

Modified by RobertsnewQ at 4:27 PM 6/17/2005
Modified by RobertsnewQ at 4:31 PM 6/17/2005

Post by **elwesso** » Fri Jun 17, 2005 4:24 pm

Maybe the shift solenoids are the culprit for our lagging 2-3 shifts?

Post by **3Q Jay** » Fri Jun 17, 2005 8:23 pm

good find Robert!

The IPT guy was posting here briefly 'transdude'. Before I saw your post, I was looking thru the fsm, and came upon the print that shows the plumbing to the 'high clutch'. this is the one that engages for 3rd and 4th. I started thinking...if there was a way to increase the pressure at that port.... anyway, that got me to thinking of the solenoids and some other stuff... so, maybe....I've seen other (cheaper) solenoid pax on the inet, just have to remember where. Maybe transdude does something special with his--don't know.Thanks for the link to the vb...deja vu! i'm digging deeper....

Post by **elwesso** » Sun Jun 19, 2005 4:33 pm

I think that you replaced that O ring proves that its not the accumulator pistons..... and it made no difference...

Depending on what the solenoid kit costs, i may try it...

Post by **RobertsnewQ** » Sun Jun 19, 2005 7:18 pm

elwesso wrote:I think that you replaced that O ring proves that its not the accumulator pistons..... and it made no difference...

Well...

I wouldn't expect the accumulator pistons to make much difference, if at all. Accumulators in an autobox are simply "shock absorbers" that move to absorb pressure spikes in the hydraulic system between shifts. This reduces the severity of the clutches engaging and makes for smoother shifts.

A common modification on full-race transmissions is to block the accumulators off - that makes the clutches engage harshly, but quickly. You could even do it yourself with a carefully measured section of copper pipe under the piston.

Post by **RobertsnewQ** » Sun Jun 19, 2005 7:30 pm

I performed a little experiment this evening with the line pressure solenoid.

- After looking at the wiring diagram for the TCU, I noticed that there is a resistor between one leg of the line pressure solenoid and ground. This resistor (I assume, not 100% sure) reduces the power draw of the solenoid. I do know that the way the resistor is wired in the circuit holds the solenoid slightly open even when the TCU wants the valve closed, reducing line pressure slightly.

I figured that disconnecting the resistor would increase line pressure since the solenoid can close all the way. Conveniently, the resistor is mounted to the inner fender behind the battery where it's easy to get to. I unplugged it and went for a test drive.

The result?

The 1-2 shift was HARD, like neck-snappingly hard. The 2-3 shift was perfect - fast and no delay.

The TCU caught on to the disconnected resistor, and gave me a "Transmission Malfunction", so I plugged it back in.

Anyway, this points even more to the slow 2-3 shift being the result of a lazy line pressure solenoid and/or sloppy TCU programming that lets the 2-3 shift take way too long. The first could be cured with a new solenoid pack, the second by possibly modifying the value of the solenoid resistor.

After my little experiment, I did some web searching and came up with this link:

http://www.smallcar.com/svx/tsk.htm

(remember the Subaru SVX shares the same basic transmission). This replaces the resistor by a variable resistor that is sensitive to engine manifold pressure.......

Post by **elwesso** » Mon Jun 20, 2005 4:19 am

EDITED: I found it, im gonna disconnect it and try it!

edit 2: I tried it and 2-3 shift is PERFECT... 1-2 is a bit hard, the car just lurches forward, however its quite golden.....

Post by **RobertsnewQ** » Mon Jun 20, 2005 7:08 am

Good to hear it. I'm determined to cure mine - I might do something like the smallcar switch if I determine that the solenoid is good.

Post by **elwesso** » Mon Jun 20, 2005 11:25 am

Ive been driving around all today with it like this, and its a bit firm for me, but its nice... I think ill probably plug it back in for a while..

Id like to experiment with a different resistor.....

Post by **RobertsnewQ** » Mon Jun 20, 2005 12:36 pm

elwesso wrote:Id like to experiment with a different resistor.....

Me too, but first I have to measure the stock one.

Here's a cheaper performance valve body:

http://www.phoenixhardparts.co...D=507

More cool stuff (pricey, though)

http://www.powertraincontrolso....html

Seems like by the time you went down that road you'd be better off doing a 300zxTT manual swap but who knows.

Modified by RobertsnewQ at 4:20 PM 6/20/2005
Modified by RobertsnewQ at 4:22 PM 6/20/2005

Post by **elwesso** » Mon Jun 20, 2005 5:04 pm

Hmmm.. Not bad... good prices..

i think im gonna get some IPT shift solenoids and see if that helps it...

Post by **elwesso** » Mon Jun 20, 2005 5:05 pm

$200 for IPT shift solenoids, compared to 279 for the level ten!

http://www.importperformancetr...#main

Post by **3Q Jay** » Mon Jun 20, 2005 8:05 pm

more good finds, guys!

I haven't gone looking for the resistor--now, where is it? by the coolant tank? behind the relay box? i don't think you guys are running tcs, but Wes would remember relative to his crimson Q.

also, Robert and Wes--you guys need to tell me [with resistor engaged] how your 2-3 upshift is following a 3-2 or 4-2 downshift. mine is VERY different. there is still some delay, but no overspeed. whereas if the 2-3 follows a 1-2 leaving a lite, there is overspeed on the 2-3 [worse when hot].

tried 2oz lubegard red today. going up slowly, but no change after first increment.

Post by **elwesso** » Tue Jun 21, 2005 4:27 am

alright I did some work this morning...

Attached is a picture of the location of the resistor. It would be a little tough to get to with the TCS actuator there, but they did not relocated it for car with TCS.

I also measured the resistance, and mine came out to 12.7 ohms... Im not sure if we'd want one with more or less resistance?

Post by **3Q Jay** » Tue Jun 21, 2005 4:44 am

thanksfor the picture

Post by **RobertsnewQ** » Tue Jun 21, 2005 7:43 am

More resistance, since the higher the resistance, the less the solenoid opens with the same pulse. I just don't know how high we can go before the TCU gets upset.

Same principle as low v. high impedance injectors, BTW. You will likely want a rather high wattage resistor. You could probably use a variable resistor to get close to the right value.

A vac. operated switch like the smallcar one would be a good idea, then you could have a very, very high-ohm resistor that comes on in place of stock when you mash the throttle. When you drive your girl to the movies the stock one would stay in circuit.

My next step is to test the fluid temp sensor. I may just jumper it with a resistor to simulate a warm signal and see if that helps the shifting.

Post by **3Q Jay** » Tue Jun 21, 2005 5:45 pm

elwesso wrote: It would be a little tough to get to with the TCS actuator there, but they did not relocated it for car with TCS.

understatement. i can't even see the connector.....

Robert, I like your jumper idea for the fluid temp sensor. in my case the loooong 2-3 is for the first couple of miles. then, when 'warm' it shifts satisfactory [still not crisp, but ok]. this is until about 15 minutes of driving, then it's hot enough to overspeed. i'll bet it is something that could be cured with the vacuum controlled solenoid.

Post by **RobertsnewQ** » Wed Jun 22, 2005 12:38 pm

Jay - I paid attention to the upshifts after downshifts and found what you did. The second upshift is much faster. Must have something to do with the way the fluid circuits change for a downshift.

Post by **3Q Jay** » Wed Jun 22, 2005 4:37 pm

thanks, Robert for the confirmation--may I conclude that you also have 2-3 overspeed when hot (following 1-2)?

Post by **RobertsnewQ** » Wed Jun 22, 2005 9:39 pm

Never overspeed/cut loose/false neutral. Only slow 2-3 shift when warm. I hate to sound negative but I think you're further along the path to a dead trans than I am...

Post by **elwesso** » Thu Jun 23, 2005 6:14 am

RobertsnewQ wrote:Never overspeed/cut loose/false neutral. Only slow 2-3 shift when warm. I hate to sound negative but I think you're further along the path to a dead trans than I am...

Same here... My 3-2 downshift is lightning fast..... but no overspeed (slippage)

Post by **3Q Jay** » Thu Jun 23, 2005 9:08 pm

elwesso wrote:
Same here... My 3-2 downshift is lightning fast..... but no overspeed (slippage)

nay. my 3-2 is also fine. its only the 2-3 following a 1-2 that is sloppy. every other upshift or downshift is ok, including the 2-3 when following a 4-2 or a 3-2.

yeah, I'm sure it's not factory fresh, but the better 2-3 under certain conditions encourages me that a tweak could make it satisfactory without full teardown.

Post by **RobertsnewQ** » Fri Jun 24, 2005 6:49 am

Pull the resistor and see if that helps. If it does, then maybe higher line pressure will work.

Post by **3Q Jay** » Thu Jul 14, 2005 6:51 pm

well, finally got to this today. let me say that it is a **tch to get that connector on a tcs car. you will have to remove the battery, bend the bracket with the connector until you can access the release, etc.

anyway, after i wasted a bunch of time getting it, i then went for a drive.the N-->D engagement was harsh (but not P-->R or N-->R).shifting is like Robert described. way firm on 1-2 and 3-4. but the 2-3 was absolutely perfect. crisp, not harsh.I had more fun driving it around like that than i've had so far with this car. nice firm 1-2 mashed at 6900. Not enough room to keep it mashed to redline in 2nd, but i did have about a 7/8 throttle shift at 6000, and it was awesome.

now, i started to experiment. went to radio smack and got a 5-pk of 100ohm 1/2 watt and a 5 pack of 330 ohm 1/2 watts.

put in the 100 ohm [single]. almost as firm as open circuit, but not quite. still uncomfortable on a 3/8 throttle 1-2, everso slightly delayed 2-3, but no overspeed.put in two 100's in parallel (50ohm net). now very similar (but still firmer) to the factory 15ish ohm. at full operating temp, the 2-3 has a small overspeed. 1-2 is harsh but passable, and the 3-4 is just solid firm.I should note that in this configuration the resistors are getting quite hot, can't be permantent as i'm pushing about 4 watts thru a 1 watt rated network.i'm off to solder 4 330's in parallel, that will be tomorrow's driving configuration. If I get it right, at least I'll only be pushing 2.5 watts thru a 2 watt network.....

Robert--did you ever experiment with the thermistor (ATF temp sensor)trickery?

btw, Wes--thanks for the picture. I never would have found it without that. still never even saw the factory resistor..just felt around...

Post by **Q45tech** » Fri Jul 15, 2005 1:28 am

"low v. high impedance injectors" Again impedance is an AC term that is not applicable to a DC powered solenoid [injector].

LOW HIGH RESISTANCE INJECTORS.

Consider that you can tune [attack/release] an inductor/solenoid via a capacitor in parallel also.

BACK EMF a serious problem with no resistor [could blow TCU driver transistors or worse].

http://www.okaya.com/FAQ2.htmlhttp://ww ... gl....html

Post by **RobertsnewQ** » Fri Jul 15, 2005 7:01 am

- when speaking of solenoids, coils, etc that are driven by a PWM signal. people speak of impedance. I'm no electronics engineer but it has to do with the way the resistance changes as the solenoid plunger moves in and out of the coil - the inductance created by the coil opposes the reluctance of the magnetic circuit (iron plunger) until both are in equilibrium (the plunger is all the way in). That's what gives you the spike at the beginning of an injector pulse, as I'm sure you know, and it's why large injectors are usually low-Z - the low resistance allows current to build faster and thus pull the (heavier) plunger in faster.

You're right, resistance is the right term for a pure DC component like a resistor or a solenoid in a fixed state of extension. Injectors aren't that, though.

- I don't think the resistor in the line control solenoid circuit is for reverse voltage dissapation - normally they'd use a diode for that. I think it's to take the peaks off the solenoid duty cycle pulse but I'm not 100% sure. I do know that it has it's own driver in the TCU. If it was what you're suggesting, there's no reason it couldn't be just across the solenoid. Maybe Jay or someone with a better understanding of analog electronics could make a better theory.

Post by **RobertsnewQ** » Fri Jul 15, 2005 7:07 am

GQ Jay wrote:well, finally got to this today. let me say that it is a **tch to get that connector on a tcs car. you will have to remove the battery, bend the bracket with the connector until you can access the release, etc.

anyway, after i wasted a bunch of time getting it, i then went for a drive.the N-->D engagement was harsh (but not P-->R or N-->R).shifting is like Robert described. way firm on 1-2 and 3-4. but the 2-3 was absolutely perfect. crisp, not harsh.I had more fun driving it around like that than i've had so far with this car. nice firm 1-2 mashed at 6900. Not enough room to keep it mashed to redline in 2nd, but i did have about a 7/8 throttle shift at 6000, and it was awesome.

now, i started to experiment. went to radio smack and got a 5-pk of 100ohm 1/2 watt and a 5 pack of 330 ohm 1/2 watts.

put in the 100 ohm [single]. almost as firm as open circuit, but not quite. still uncomfortable on a 3/8 throttle 1-2, everso slightly delayed 2-3, but no overspeed.put in two 100's in parallel (50ohm net). now very similar (but still firmer) to the factory 15ish ohm. at full operating temp, the 2-3 has a small overspeed. 1-2 is harsh but passable, and the 3-4 is just solid firm.I should note that in this configuration the resistors are getting quite hot, can't be permantent as i'm pushing about 4 watts thru a 1 watt rated network.i'm off to solder 4 330's in parallel, that will be tomorrow's driving configuration. If I get it right, at least I'll only be pushing 2.5 watts thru a 2 watt network.....

Robert--did you ever experiment with the thermistor (ATF temp sensor)trickery?

btw, Wes--thanks for the picture. I never would have found it without that. still never even saw the factory resistor..just felt around...

Glad you were able to repeat my results. Are your part-throttle shifts sloppy, or just full-throttle?

- I haven't tried to fool the TCU temp sensor yet, I've been too busy with other stuff. Maybe I'll give it a shot today.

- Also, I was just at Fry's and they have a good selection of 2-10 watt resistors if you're looking for some. Good experimenting!

Oh, I found one more interesting thing the other day:

http://www.racerwheel.com/hks-4505sn002.html

Spendy, but interesting. I wonder how it works?

re4r03a vs. re4r01a valve body

re4r03a vs. re4r01a valve body

Re: re4r03a vs. re4r01a valve body (GQ Jay)

Re: re4r03a vs. re4r01a valve body (GQ Jay)

Re: re4r03a vs. re4r01a valve body (GQ Jay)

Re: re4r03a vs. re4r01a valve body (RobertsnewQ)

Re: re4r03a vs. re4r01a valve body (RobertsnewQ)

Re: re4r03a vs. re4r01a valve body (GQ Jay)

Re: (RobertsnewQ)

Re: (RobertsnewQ)

Re: (elwesso)

Re: (RobertsnewQ)

Re: (elwesso)

Re: (GQ Jay)

Re: (elwesso)

Re: (elwesso)

Re: (RobertsnewQ)

Re: (RobertsnewQ)

Re: (elwesso)

Re: (RobertsnewQ)

Re: (GQ Jay)

Re: (Q45tech)

Re: (GQ Jay)

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