Q TCU swap... Wooohoooo

[Desmoquattro]

If you haven't changed the TCU on your 90-93 Q yet, I highly recommend you do. It transforms the car, aside from the first gear start the shift points are much better. Feels less inclined to jump into third gear all the time, it sticks in first and second around town. I'm very pleased, for the price of a used TCU and a few minutes to install you get a whole new beast.

JC

[lino]

I just put mine back in last week since we won't be seeing anymore snow this year.

Where did you get yours?

[Desmoquattro]

Bought it used from DrewQ45. It's the 64U20 model, the stocker was 64U10.

[lino]

Drew's a great guy. I have the same 2 units too.

[Haitian_King]

If you haven't changed the TCU on your 90-93 Q yet, I highly recommend you do. It transforms the car, aside from the first gear start the shift points are much better. Feels less inclined to jump into third gear all the time, it sticks in first and second around town. I'm very pleased, for the price of a used TCU and a few minutes to install you get a whole new beast.

JC

Bien sur.

I love my 93 TCU. The first time touching the accelerator in Drive after installing it was exhilarating. I love it.

I don't even count red light kills anymore. They're almost too easy now.

I love being underestimated. And the look on peoples faces when they have their windows down and they hear my VH at 5500 RPMs. What's crazy is that I'll still be under 50 MPH.

[Desmoquattro]

I was getting tired of stepping on the pedal and rocketing up to... 3000 rpm in second and going way over the city limit. Mine wouldn't go into first unless you mashed the throttle at a dead stop, even rolling slowly it wouldn't go into first without manually shifting. Pissed me off because the manual 1-2 shift on my car was a bit harsh, there was an irritating delay before it popped into 2nd. You go flying from 1st, pause and slight decel, then it would pop into 2nd and accelerate so quick you'd feel like the axle was going to rip out. No more of that nonsense, shifts beautifully in drive now, even smoother than before.

[Haitian_King]

I was getting tired of stepping on the pedal and rocketing up to... 3000 rpm in second and going way over the city limit. Mine wouldn't go into first unless you mashed the throttle at a dead stop, even rolling slowly it wouldn't go into first without manually shifting. Pissed me off because the manual 1-2 shift on my car was a bit harsh, there was an irritating delay before it popped into 2nd. You go flying from 1st, pause and slight decel, then it would pop into 2nd and accelerate so quick you'd feel like the axle was going to rip out. No more of that nonsense, shifts beautifully in drive now, even smoother than before.

I know how you feel. I'll never go back to 2nd gear start.

Question about manually shifting. I was on the highway doing 80 yesterday, but cruising at about 2500 RPM. I pushed down on the accelerator to pass someone and it went, but after a slight delay. Really short, but you know me, I'm quite sensitive to the actions of my Q. I tossed the idea of pulling down to 1st from Drive at that speed, seeing as how my RPM's were low, but I wasn't too sure of the consequences. Would that have been a bad idea?

[jimbyjimb]

I doubt the TCU would have actually put the transmission in first. There's usually a safeguard that won't allow radical downshifts after a certian VSS input or RPM to keep the transmission and/or motor from blowing. If you had, and the Q did not have such a feature then you could have blown your motor or transmission and probably both. I think tops in first would be around 60-65mph. I could calculate it, but I'm lazy. Definitly not 80 though. That would have been over-rev city.

[Q451990]

1st gear at 80? I wouldn't try it... jimbyjim is right though, the TCU should lock you out of doing that. There is no direct mechanical link between the shifter and the transmission for 1st gear, so it's absolutely controled electronically by a switch in the shifter assembly.

Heath

[Haitian_King]

Thanks for the info guys. I'm glad I didn't shift.

But say i wanted a downshift at 80. Would I put it in third or second?

[goody90q45]

......I'm very pleased, for the price of a used TCU and a few minutes to install you get a whole new beast. JC

I just put a 93 TCU into my 90Q. I like it. A lot.

.....But say i wanted a downshift at 80. Would I put it in third or second?

Take note of the mph at which your transmission shifts from 1-2, 2-3 and 3-4. If you are going 80 mph and downshift into 2nd gear you'll probably rev up to 7000 rpm and leave your transmission and driveshaft laying on the highway. I would think that at any speed an alternative to manually downshifting would be to push the pedal to the metal and let the transmission decide to downshift on its own.

[elwesso]

id have to look at the manual but im pretty sure you can downshift into 2nd at about 75, i do it occasionally. however you're almost better off using 3rd because you just end up at about 6500 RPM. for those with ECUs its not bad because you get 1000 RPMs to play with, but for those who still have stock computers you only have about 400.

[Q45tech]

Depends on which transmission you have obviously the 94-96 can stand 5% higher down shift speed vs 90-93 [86-87 mph 3>2 manually]

Either transmission has 97-98 mph as the 2nd gear limit ASSUMMING the 90-93 has a Nico 7300 rpm limit and the 94-96 has a stock 6900 rpm.

[Haitian_King]

Thank you everyone for the info. Very good to know.

[Desmoquattro]

If I really want to pass in a hurry I usually shift down to second, that's around 60 mph (100-110 kmh). Above that, no way, going from 2000 rpm to 4500-5000 in a split second is bad enough, I don't want to be anywhere near redline.

[NightRiderQ45]

I never really understood why people take off at red lights like jackrabbits? Man usually if I'm at a red light, especially if some accord or civic or highschool student is besides me, they take off like I want to race with them. I bet the idiot think that, "man, I smoked him" because I gradually take off at the light. My 20's are made for crusing...

[DrewQ45]

I'm very pleased, for the price of a used TCU and a few minutes to install you get a whole new beast.

JC

Glad it worked out well for you. I felt the same way when I put mine in. Unfortunately at the time, there was an explosion of Nico members buying them up from all over the US. The sellers got wise and and I ended up shelling out $150 for one.... guess that shows how bad I wanted one.

Now... to feel the full potential of the TCU and get even crisper shifts with the transmission, replace your ATF and filter. You can also wash the filter as I've described here.... It's a long winded post.

zerothread?id=234307

[Desmoquattro]

What, don't you like acceleration? It's the reason why I pay to feed this big fuel sucking pig of a thing.

Plus with first gear start it doesn't struggle as much, try driving a manual car around without shifting into first and see how much fun it is.

[maxnix]

Now... to feel the full potential of the TCU and get even crisper shifts with the transmission, replace your ATF and filter. You can also wash the filter as I've described here.... It's a long winded post.

Replacing the filter, O ring, gasket and one time use bolts is the key, as washing the filter screen surface is probably at best only a cosmetic exercise. Well known to original board members.

I've posted this a few times- but the first for this new forum...It is clear that the filter IS NOT CLEANABLE. Even when it is REMOVED FROM THE TRANS AND CLEANED, so how does the writer expect it to be done by a machine. He is either lazy or ignorant (or conditioned by prior customers looking for the cheap way out?)

Check out:

http://www.atcdg.com/TechBulletins/bull_153.htm

This is a tech bulletin from a manufacturer of trans rebuild kits.... they ought to know.

Adam

zerothread?id=503

[DrewQ45]

Replacing the filter, O ring, gasket and one time use bolts is the key, as washing the filter screen surface is probably at best only a cosmetic exercise. Well known to original board members.

zerothread?id=503

How many times do we have to go through this? Love it when you challenge me on this because I know it works. I know you know the link to this post well. I'm posting it again for those who might not. Guess you question pictures and results? Here, dispute this!

zerothread?id=238955

[Kiven422]

I would like to try the 2nd gear TCU see if its comfortable to drive around town.

[DrewQ45]

I would like to try the 2nd gear TCU see if its comfortable to drive around town.

I've a got a few if you need... cheap. $30 shipped. Now you're sure you mean 2nd gear and not 1st gear start right?

[Drake57]

I searched but did not find which bolts in trans are one time use. Can someone enlighten me?

Thanks, Drake.

[goody90q45]

Transmission pan bolts are one-time use.

[DrewQ45]

Transmission pan bolts are one-time use.

I've "used" mine about 15 times now. No leaks.

[Desmoquattro]

If you buy the kit from Scottsdale you get everything you need, including a new filter / oil pickup, bolts, o-rings, gaskets. 48$ for the whole thing, good deal.

[Haitian_King]

I've "used" mine about 15 times now. No leaks.

Really?

I was under the impression that I was leaking ATF because of the failure to use the one-time bolts when I had my pan dropped.

Damnit. If that's not the cause of the leaking, I don't know what else it could be.

What are some other causes for ATF leaks? I couldn't find my symptoms in the FSM.

[DrewQ45]

Really?

I was under the impression that I was leaking ATF because of the failure to use the one-time bolts when I had my pan dropped.

Damnit. If that's not the cause of the leaking, I don't know what else it could be.

What are some other causes for ATF leaks? I couldn't find my symptoms in the FSM.

Usually a gasket issue.

[Haitian_King]

Usually a gasket issue.

Like RTV? Or another rubber type of gasket. Hopefully not something internal.

[Q45tech]

Turbine sensors and other electical connectors have gaskets which fail from acidic ATF and failure to change at reasonable intervals.

The most common failure is turbine sensor and pan leaks, then rear shaft and front seal ndripping into bell housing, then out the bottom.

One normally uses the time on the lift while oil is dripping out during a change to use a flash light to examine everything and spray brake cleaner on leak areas so that the next time [90 days later] you have a cleaner surface to pinpoint leaks.

I use a full can of brake cleaner every oil change to remove dirt and road grime and clean up after filter change.