93 TCU swap sanity check

[91QAZ]

I have spent a good deal of time searching for info on a TCU swap to give me 1st gear start in my 91Q. I've read several archives and found a bit of info that sounded contradictory (or maybe I'm just tired and should go to bed . If I distill all of this info down , this is what I am left with:

best choice is a 93 TCU (I know - check the part #'s to make SURE it's a 93) since shift points are the same.

It makes no difference whether the car or TCU is California or not - they're all interchangeable? (some confusion in the posts on this)

Wes and Jesda determined that a 94 TCU will work in a 92Q just fine even though the shift points are a little different.

So conclusion: Don't go through the headache of finding a 93 when the 94's are pretty plentiful in the junkyards, right? Are there any other factors that I am missing? My 91 is a CA model. Main question is will any 94 TCU give me the desired results without screwing up shift points?

Thanks for your patience with the newbee questions,Tom

[Jesda]

There's some variation among them too. After Wes got his green Q, we swapped again, and I now have smoother shifts while has has firmer/crisper shifts.

We think its possible that I now have a 93, but this also holds the gear to over 7000ish rpm, so maybe its a different 94.

Confusing!

The California thing doesnt matter. And with the 94 TCU, you get the results you want and it doesnt affect driveability in any way.

[pito11213]

It seems to be a throw of the dice. I would want a first gen considering they had different gearing so I would really say go with the 93 tcu.

[elwesso]

Believe me.. I have driven a few 90-93s and Jesdas with my 94 TCU.. IT doesnt make any difference

The *only* thing it does is when you go all the way to the redline , instead of it just barely tapping the redline, it stays there for just a fraction of a second longer, then shifts...

Get a 94 TCU, dont waste time trying to find a 93.....

California doesnt matter with the TCU.. hell it doesnt even matter with the ECU, as I tried a california, TCS, non hicas in my hicas, non TCS, federal Q, drove it for like 200 miles, and it was fine.....

The shift points arent really determined by the TCU, they are to a certain degree, but its more based on throttle position.. We drove Jesda's Q and the shift points felt perfect, right exactly how it should be..... Except for that redline thing, which is hardly an issue, i kinda like it holding there for that little extra instant, it makes the shift much sportier......

[91QAZ]

Cool. The redline issue is not a big deal for me. Like you said, Wes, it's even a bonus. My main motivation is the 1st gear start. Thanks guys, I appreciate the input...

Tom

[Q_SHIP]

Well, I have a 93 that starts out in first gear. IMO don't even waste the time, money on this. The car is still a slug out of the whole. The car will never be a good city driver. I don't think it's worth it to start in 1st gear. The only thing it might do is increase fuel mileage. I could be wrong on this but the only place my car has any impressive power is out on the highway doing about 70. You mash on it there and the car responds very nicely but in the city, it's a slug.

[Jesda]

Made a world of difference for me. In town it takes some care to keep the tires from spinning.

[Q_SHIP]

I wonder if there is somthing wrong with mine than. I can mash on it and all I get is a little squeek from the tires. The car seems to run fine but is a slug in the city. How is everybody elses?

[elwesso]

Q... I was able to do a nice roasting with Jesda's Q...

The 90-93 with the better gearing is very nice out of the hole... Sounds like something is wrong...

[redmanfx]

For the most part the Q was designed so your tires won't sqeal and don't normally loose traction enough to "burn" some rubber. However, on loose gravel expect to ping the guy behind you. Q45tech had a really good thread about the subject a while back. I've found my Q to be a little different in that if I'm not carefull I could spin a little burn from time to time.

I drive very aggresive and my car now knows how I drive, so it's used to me taking off like a rocket.

red

[Q_SHIP]

Well, I could do a roasty one if I starte in a break stand (but what rwd car couldnt) I don't really beat on the car at all except for out on the highway for passing. It seems like it runs just fine. I'm a little concerned now.

[Jesda]

Q_SHIP: Run a can of seafoam through the brake booster and see what happens. It made a huge difference for me.

[Q_SHIP]

I just ran 1/2 a can and it made it a little better I guess. Should I have used the whole can?

[Jesda]

I usually run 2/3 of a can, then put the remaining 1/3 in the gas tank, then the next day run another 2/3 of a can, and another 1/3 in the gas tank.

I also drive on the highway afterwards. Its not very effective long term if you pour it in then tool around town.

[elwesso]

If your using it through the intake.... Its not good to run that very often, because it can wash away oil from the rings... Eventually it will clean too good... It also can get into the oil.....

Id use it max every 90 days, and as close to an oil change as you can get...

[SFBayQ45]

Q_SHIP: Run a can of seafoam through the brake booster and see what happens. It made a huge difference for me.

Jesda - Where's the brake booster that you're referring to? Any pictures?