Posts like a Northstar
Join Date: Apr 2006
Location: Dimondale, MI
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Well guys, I did go ahead and decide to use your board as my primary for this project. This is a copy of my initial post on the Reatta board with some background and what I'm planning on doing...
There is what Reatta should have been,
what Reatta is,
what Reatta can be,
and lastly, what Reatta will be...
No more thinking, dreaming, wishing...oh no This time, It'* Real.
The original 6 speed thread, "Six speed manual thoughts"
And the original It'* Real thread, "Supercharging (this time, it'* real)
Mission brief: I am proceeding to replace the stock 4T60/440T4 automatic transaxle with the 6 speed manual known from here on as the F70. In the process will be the installation of a Series II supercharged 3800, known as the Series II L67. Without converting to RWD, I think this is the best engine and transmission choice you could pick for a practical swap into a Reatta. And this way, there won't be any reason to say "I should have used a...".
I'll begin with the transmission...my 440T4, to my knowledge, is original to my car and has not had major work and gave out at 172k miles. What it'* doing is that it feels like the car is always having to tow an extra 2k pound trailer. In reverse and any gear. Even at idle in park, I can tell the motor'* under a load. Lots of tests have been done, which I'll ellaborate on later, but it'* definitely the tranny. I'm going to pull the pan and see what I can find, but at this point I don't much care what'* wrong with it. It served well and lasted longer than I would have expected to. When we bought it at around 138k miles we had our local mechanic change the fluid and use a synthetic blend of sorts. He pulled the pan and changed the filter but I believe he only changed the fluid in the pan (not including the torque converter). In between I replaced the shift modulator to correct hard shifting. I supercharged the stock 3800 LN3 at 153k miles, which is when Ryan of GMtuners/Sinister Performance showed me how to adjust the modulator to firm up shifting, which helps for longevity as long as you don't overdo it. A few hundred miles later, I did a complete flush of the fluid, replacing the filter and refilling with Mobil 1 ATF, and added a large transmission cooler in line with the stock unit. Since I've owned the car the 440T4 endured many full throttle takeoffs, performance oriented downshifts, towing various things ranging from my jet ski, to my 6x6 AATV, to a pair of quads. The LN3, supercharged for almost the last 20k miles, did not contribute to making it last longer. Towing is one thing, but towing with more power available makes it worse.
My engine is the original 3800 LN3, also with 172 miles. It still runs well and uses very little oil between changes (and got better after I replaced the oil pan gasket, timing cover gasket, and crankshaft seal in the timing cover). Compression is still past 150 lbs. I've worked on it a lot but never because of major damage, just sensors, coil packs, thermostats...that kind of stuff. Recall that I did go in and replace the timing chain and related stuff a couple thousand miles ago, which restored a tiny bit of performance due to the old chain and sprockets causing the valvetrain timing to be slightly retarded. In reality though, since they very rarely break (and don't cause damage if they do) I'm going to say that it'* not worth it to replace it. At around 153 miles (last winter) I purchased a '95 Series I supercharged 3800, and proved that the related hardware could be swapped over to an LN3 successfully. I didn't have to swap the heads (and didn't) and everything bolted up fine. You may wish to review that thread for the details. The ECM needed to be reprogrammed which is where I employed Ryan. He was able to mail me a few different programs to try and I was able to get the car driveable. With that I took a day to visit him in Fort Wayne, IN where he used his scanner to find out what the engine computer was doing and program it to run like you'd expect it to. He did a great job. Many were worried about the LN3 being able to hold up to the obvious extra starin of being supercharged (increasing its stock 165 hp to over 200). I never got a chance to dyno the setup, but the '95 L67 was rated for 225 and Ryan believed it to be about the same. It'* a unique engine, having higher compression than the L67. I had the oil lab tested by Blackstone Labs (I'll link it soon) and they found that even supercharged, there was no abnormal wear and was within normal ranges. Oil consumption did not increase in this 19-20k mile period. It made a great difference, obviously in acceleration but in the overall enjoyment of driving a Reatta...it'* more like the way it was supposed to be.
This is my short list of stuff I'll have to deal:
-mounts (I'll fabricate myself)
-CV shafts: the 6 speed is used with the Pontiac G6 GT coupe with the Sport Package, and I think the convertible
'89 Reattas came with a 2.97 ratio. This is a link to a discussion on Pennock'* Fiero forum (those dudes are all into motor and tranny swaps) with good 6 speed info and pix. I will have to investigate what'* on my end. The transaxle side of the CV shaft on the F70 is different from the hub end of the Fiero CV shaft. I'm going to guess that Reatta shafts are also different, but will have to investigate this first. Their solution is to custom axles made from Moser Engineering (about $300 for both axles) which will allow the G6 inner part to be used with the Fiero, err Reatta, outer part. But as you guys know, I prefer parts-bin-diving, and I'll investigate any off the shelf options first. The shafts will also be of different lengths than what stock Reattas have.
Clutching: for the most part, this entails having the 3800s flywheel have the same depth within the bellhousing as the 3900, which is what the F70 is used with. From there I will investigate exactly what flywheel, clutch plate, and pressure plate to use.
Bellhousing: the F70 and the 440T4 use the same bellhousing pattern, so no issues there.
Clutch pedal etc: As Scott of The Auto Shop did (Series II L67 and the Getrag 5 speed manual) and what our Greg Ross did, I can use the clutch pedal from a Beretta. As Scott and I believe Greg did, I'll trim down the Reatta brake pedal (big honkin thing) to give some room. I don't anticipate any issues mounting it, nor any with the master cylinder and resevoir. The fittings between the master cylinder and the slave cylinder/throwout bearing are different, so I'll have to figure out something, but I don't think this will be an issue.
Electronics: I don't anticipate any real issues here. The stock Reatta ECM will be reprogrammed again to operate the Series II. The sensors pick up the same data and all. No issues with the touch screen ECC. I'm thinking the speedometer will need a Dakota Digital speedo-signal "translator" like Greg used, but they're not that expensive nor complicated. The transmission related codes will have to be de-programmed by Ryan but this is not an issue. A clutch-in safety switch will be wired in place of the park/neutral switch. Supercharged 3800s don't really have electronic boost control or anything, which makes things simpler.
Shifting: I believe the G6 cables will reach. There'* some room to work inside the Reatta center console. I don't think that mounting the shifter will prove to be difficult.
Ryan installed a Series II L67 in a Reatta before but used the donor'* engine computer and a 4T60-E transaxle. I'll have to check it out again and link you guys.
This is going to be a lot of work, and a lot of money, yes. But, it will be worth it..
-The supercharged LN3 doesn't make the power of the Series II L67, which is an underrated 240 hp. Plus, there'* lots of aftermarket support that the Series II has but the "Series I"/LN3 doesn't. Besides, since the motor'* coming out, why not? This would also solve any longevity issues which the LN3 might have (but hasn't shown, yet)
-I already have a bad transaxle, and having it professional rebuilt and "beefed up" will be around $1400. Why, when it will still be a rather weak transaxle? The 440T4 is not electronically controlled, for otherwise a better 4T60-E could be used. I know the Bonneville guys are experiemnting with using 4T80s (Cadillac Northstar transaxle) in place of their 4T65-HDs. Don't know if it could be done in place of a 4T60-E, which '91 Reattas had. The best choice if I wanted to stay with an automatic would be the F-7 (not to be confused with the F70) which was used with the 4.1L and 4.5L V8 in Cadillacs of around the same era. I haven't looked into it much but it'* based on the 440T4 but with some modifications to take more power. Another thing is that 4 speeds are sometimes not enough and you can't get a nice match for the motor'* RPM. But lastly, I prefer driving a manual.
A yard near Flint has a NEW 6 speed manual for $500 . I don't know if they have the other stuff I need (CV shafts, clutch stuff) but will ask. Another yard has a pull with 2k miles on it, but they want $700. However, I'm assuming they have the rest of the stuff I need, so I may be buying the new transmission and going to the other yard for the rest. The L67 is much easier to find and I plan on buying one with around 100k miles, maybe less if I can afford it. I'll get one with all the acessories on it for I don't think I can reuse much of the LN3'* acessories, if any at all.
I'm estimating total costs to be around $2k. I can't really predict how long it'll take me, but plan for this to be spaced over a couple months. As I've done before, my Reatta'* parked indoors for the winter (damn Michigan road salt) so I'm not exactly suffering, though I kinda am . I've currently raised about half of the funds required, so I've got some startup capital to work with.
There'* probably a lot of stuff I've forgot to say yet but I will be updating this often, with multiple posts a day at times. Don't worry, they'll be LOTS of pix and details.
'89 Buick Reatta. Formerly propelled by a supercharged LN3, soon to have Series II L67/ 6 speed manual http://<a href="http://www.bonnevill...sc&start=0</a>
'93 LeSabre Limited...$450 fixer upper my friend bought and is having me fix up though currently my driver for the time being