1MeanZ

iTrader: (9)

As some of you may have known based on comments made around this part of the forum, Chazman has decided to go through with the T5 swap on his '83 Z28. Sean, known as 92RS(real slow) on here, and I went to Charlies and picked up the car. As we usually do at Thirdgenfest, we had a blast hanging out with Charlie and inspecting his awesome thirdgens. He throws down one hell of a breakfast too! With our bellies full and the car loaded, we headed back Indiana way to begin the transformation.

Once we got back to my place and got the car unloaded we decided to take it for a spin to see what we had to work with, and to get familiar with the car so we know what "normal" is for this car, sounds, handling etc. We also wanted to see if the LU5 was all it's cracked up to be. After driving it I can verify GM's claim of 165hp . From a dead stop the car really does try, especially with 2.93 gears. It tries to spin the tires, it spun a little for us, but it certainly wasn't like I needed to pedal it to keep from over-revving the little engine that could. Getting on the throttle hard from a roll, like coming off a corner, elicited laughter from both Sean and myself. I'm certain I could comfortably re-set the clock on the radio while going WOT down our narrow country roads over here. I think the Mayflower passed us during our brief WOT 2nd gear pull. After that brutal display, we decided that there was no point in any more WOT shennanigans, so we comfortably cruised back home in what is really a very tight and comfortable car. It handles very well and is still amazingly tight for it's age and mileage. It truly is a nice example of an early thirdgen. If I end up buying one after this is all said and done I'm blaming Charlie...

1MeanZ

iTrader: (9)

I had every intention of getting pix of this car in the garage with my GTA and my IROC, but I haven't gotten any yet. I will post some this week as the work continues. Charlie's car sits nose to nose with my GTA in my work shop, they seem to be getting along quite well. My IROC sits over on the other side of the garage with the wife's Escalade separating the friendly white F-cars from the angry Flame Red Metallic one like a burly referee making sure everyone plays nice.

At any rate, here is what we had to start with. Many of you have seen Charlie's car on here before, so these pix just focus on the swap and not of the rest of his car.

1MeanZ

iTrader: (9)

The first thing I do is swap the pedals. Removing the automatic trans pedal assembly is really easy because there are no clutch pedal support rods in the way of getting the lock nuts off the back of the brake booster.

Once all the stock pedals were out of the way I found this surprise. These early '83 cars must still have the provisions for the '82 only mechanical clutch linkage? I'd never seen this before, but this is the oldest thirdgen I've worked with. Luckily the plug is about 80% in line with the hole I needed to cut for the slave anyway, and once the slave is bolted in it covers the hole completely so it all worked out.

Step one is to make a gasket for the slave cylinder, this also doubles as a template for where to drill and cut the firewall.

Step 2 is to put the pedals in and just bolt them in snugly. Then I push the clutch pedal support rods down and mark where they rest on the floor. Then I remove the pedals and align the holes in my template with the marks for the clutch rods, and cut my holes.

1MeanZ

iTrader: (9)

In the case of Charlie's car having this body plug in the way, I ground the body seam sealer off and popped it out. Then marked the holes with my template and cut the new holes. I then masked off the surrounding area and primed and painted where I had ground the body sealer off. To finish up I used black silicone to seal the gasket and slave to the firewall and hold it all in place with my custom made slave U-bolt. (Charlie didnt have a regular U-bolt with his pedals so I made one).

I'll finish wiring and plumbing the pedals tomorrow night and get the console out of the car. More pix to come as we move through this swap. Stay tuned!

chazman

iTrader: (4)

It was fun hanging out with you guys. Too bad we don't live alittle closer. I'm sure we'd get into trouble.

subroc

iTrader: (2)

Awesome. Subscribed. I saw talk of this earlier and was interested to see what would happen if you went through with it. Im curious what a LU5 with a t5 is going to drive like.

eseibel67

While you guys are working on fixing GM's mistakes, any plans on changing the gears to 3.73? Or at least 3.42? Would be a nice compliment for that setup.

subroc

iTrader: (2)

Agreed. Didnt i read somewhere that that car had very steep (2.73 or worse)gears? If that is the case it will still be somewhat of a slug out of the hole. 700r4s got a 3.07 (if memory serves)first gear while the t5 only got a 2.95 or 2.97 (in that range). Might want to seriously consider a swap to 3.23/3.42s or there abouts for more enjoyment.

1MeanZ

iTrader: (9)

You guys must think we haven't thought about this very much!

Charlie's car has a 2.93 rear gear, so your concern about running a normal V8 WC T5 is valid. However we are running a trans out of a V6 car with a 3.74(if memory serves me) first gear.

I ran this exact same combo in my 91 Trans Am when I converted it from auto to 'stick and that car had 2.73 gears. With stock unported L03 heads, LT1 cam, custom Y pipe with stock manifolds and stock unported TPI setup, that car could hang the tail out in 1st gear like a muscle car should. It did a great job, and is our basis for making this choice on Charlie's car.

Charlie will have the best of both worlds, it will have as much or more punch in 1st gear than it has now, and he'll have a great overdrive ratio when he's cruising at highway speed. For lower powered thirdgens <~300hp, it's the perfect situation. Even if Charlie caves in to my prodding and lets me build him a completely stock looking Crossfire 350 thats been tweaked to about 300+hp, I still think this combo will serve him well for what he wants to do with the car.

Good catch though, you're keeping us on our toes.

chazman

iTrader: (4)

When you calculate the ratios, the 3.76 1st/2.18 2nd/1.42 3rd gear, when combined with the stock 2.93 gear give the same torque multiplication as a 3.73 rear in 1st gear, 3.42 rear in 2nd gear and 3.08 rear in 3rd gear - when compared with a standard 2.95 1st gear T5.

In the end, I had a good operating 2.93 posi, and chose to keep it. The Iron Duke T5 ratios should give me the torque multiplication I need and still let me cruise at low RPM on the highway.

Van Nuys born

Subcribed.....

Jason E

This is awesome, guys. Congrats!! I say this as in a few minutes, I will be collecting a bank check for the sale of my 99 Wrangler. I will have about $6,000 to play with. And of course, last night, wouldn't you know it? I came across a bone-stock, ORANGE 88 IROC L98 t-top car with leather, Bose, the works...and guess what? Its only $6k. Coincidence???

I'll be calling on it later today, as the pics look good but he gives all the details except the mileage...betting its well over 100k Enough hi-jacking of Charlie's thread...I look forward to seeing the outcome.

I wish I lived near all of you, too...some day I will make it down to Thirdgen Fest, minimally with the IROC on a trailer...

chazman

iTrader: (4)

Wow, a medium orange metallic IROC would make a great bookend to your medium gray metallic IROC. It goes without saying but - post pics!

Jason E

My thoughts exactly

http://boston.craigslist.org/gbs/cto/3794470466.html

That's the car. Now, if any of you ******* calls him before I do? I don't know what I will do...but it won't be pretty....

Still debating if I want another IROC, or a GTA. I found an 89 convertible last night...different, dare I say?

http://providence.craigslist.org/cto/3749799457.html

chazman

iTrader: (4)

You know I love MOM IROCs, but boy oh boy, a 5.7 convertible.......

yaj15

iTrader: (3)

This is great. What really would have been cool is if GM gave the LU5 more power to start with. I like the L69 motor but I always thought if the LU5 had more power the single TBI L03 motor would have had more power and wouldn't have been given such a bad rap.

TBI is a good simple system and it wouldn't have taken GM much to make that motor have the same or more power than the L69 motor had.

An LU5/T-5/3.42 or 3.73 geared car would be a lot of fun to drive. Thirdgens handle very well from the factory. Still 30 years later I can beat most cars today that are considered good/great handling cars in my IROC.

People tend to forget that in 1984 the Z28 won Car & Drivers best handling American car award. They said that next to the Corvette the Z28 was the best handling car in America.

Jason E

Uh huh...and therein lies my issue. I was selling the Wrangler to downsize a little because sales, while coming back, were lousy over the fall and early spring. It kinda made me realize one person needs only so many vehicles

Now, I see these things...and it gets me thinking...

chazman

iTrader: (4)

Honestly, I think a 3.73 is too much gear for this engine. It's pretty much "all in" by about 4500 or so. Past 5000 rpm, you're only making noise. Had GM certified this engine with a T5, I'd doubt they would have gone much steeper than a 3.23 rear gear.

FormerL69

iTrader: (2)

Congrats Charlie. It'll be cool to see this come to life...

subroc

iTrader: (2)

Ok that makes a ton more sense! Awesome. That is along the same lines as what i did with my tko 500. It has a 3.27 first gear that pairs well with my 9 bolt 3.27 rear gear for getting me out of the hole very fast and still have the ability to cruise on the highway comfortably.

alan91z28

I would get the vert... When you get tired of it I will come buy it from you

Jason E

Well if that's the case....

How's my old girl doing? I sold my blue one the day after you picked yours up...and I've been scouring Craigslist for the last 6 months to find another one

alan91z28

real good, i enjoy the t-top / 5 speed combo of course...

about 1000 miles more on her since you last saw her and a couple of pa inspections, and i also physically removed all the alarm pieces but otherwise still the same great trans am...

-----

also a couple comments on this thread... i really like what you guys are doing with the cross fire / t-5... i have been looking for a really nice '82 pace car with the 4-spd... i have thought about swapping a t-5 into a cross fire version since they are easier to find, but i would only do that on a higher mileage pace car...

good job on thinking through the transmission and gear ratios

chazman

iTrader: (4)

At first we had considered a 9 bolt 3.45 and a WC 2.95 1st gear T5. The donor car was a junked '89 G92 IROC-Z - a twin of my black one. The plan was to strip this car of whatever goodies it had. The 9 bolt turned out to be a 3.27 with a completely blown posi, needing a complete rebuild, (not in the budget). The T5 ended up being a stray V6 unit of dubious history.

On to plan B. I located an '84 T5 which started it's life in an Iron Duke Firebird, locally. The price was right so I brought it home. I checked it's forward ratios and started to feel that it would work well with my stock 2.93 (with working posi). Jeremy's experience with his Trans Am made me feel better about my math.

yaj15

iTrader: (3)

Yeah thats probably true. Either way its still nice to see an early Z28 that still has the Crossfire Injection system on it and wants to make it faster!

chazman

iTrader: (4)

Hopefully we'll get a good result. As Jeremy mentioned in his first post, the engine is really trying. But the combo of a 2.93 gear and automatic trans, really conspire against it.


I know this combo will never be blindingly fast, but I'm hoping it'll be alot more fun to drive. Beyond the improved torque multiplications this T5 version offers, the T5 also has far less parasitic power loss and is lighter than a 700R4 and of course, greater driver control that a clutch pedal offers.


Anyways, if I were going to predict, I'd say that the old girl will potentially be good for low 15 second 1/4 miles when we're done. In the 3rd gen world, not shabby.

chazman

iTrader: (4)

Oh BTW, I'm thinking it's making more than 165 hp now, with the L69 exhaust manifolds and 3" exhaust. Let's call it 180-ish.

scottmoyer

I'm not sure why you guys stated that the LU5 was such a slug. Are you sure the thing is running right? I had an 82 CFI car that ran great. When I bought my '88 SC years later, and not knowing the difference in the engines at that time, I felt the L03 was a dog in comparison. I ended up selling the '88 because I thought something was wrong with it due to it being so slow in comparison to the LU5. My '82 would leave long patches of black stuff whenever I wanted it to. It was also very easy to put that car sideways.

chazman

iTrader: (4)

Keep in mind Scott, that Jeremy's two 3rd gens put out over 500 horsepower. In comparison, EVERYTHING is slow

It certainly feels healthier than an LG4/L03 to me.

1MeanZ

iTrader: (9)

I'm pretty persnickety about tuning (ive tuned both of my cars and they run like stock despite being heavily modified). I'd like to think I can tell when something isn't right. That is one of the reasons I drove the car before I even touched it, to see how it acts and get a feel for how it runs. The car starts right up for me, it idles a bit high when cold but clears up when it's warm. It has good sharp throttle response and drives very well without any issues. What gears did your car have? I'm certain if this car had a 3.23 rear it could light the tires pretty easily. I've only gotten on it 2 times from a dead stop, and all I did was let off the brake and let the car creep, then briskly roll on the pedal. I didnt stomp the pedal from a dead stop, nor did I stall the converter up and leave off the brake. Both times I rolled on it I was on good level pavement and it squeals the tires for for a few feet, but it's not anything that would leave marks or smoke. I'm sure with a better gear and more aggressive driving it would act as you describe yours did. It is substantially more lively than an L03 automatic car. I've been around and driven a couple L03/A4 cars and they embarassing. It's amazing how much better my dad's L03/M5 RS ran than the A4 equivalents. I'm hoping to have the same difference with this car.

Where Charlie's car really lacks is in power coming off a corner. This is where the gear spacing of the 700R4 and the inability to make power at high rpm really hurt. Peanut cammed LB9/A4 cars are about the same way. They are lively from a dead stop, but try roll racing your buddies 5spd mustang on the express way and be prepared to get slaughtered...

chazman

iTrader: (4)

Hey bro, less talking, more wrenching.

chazman

iTrader: (4)

I know exactly what you are referring to. There is a spot in 2nd gear where you are going a teeny bit too fast to downshift into 1st, but don't have enough torque/RPM to accelerate with authority in 2nd. It's kind of a flat spot. Hopefully, a manual trans can help that.

1MeanZ

iTrader: (9)

There has been wrenching. I tried to upload pictures last night and for some reason I couldn't.

Pedals are finished, wiring is finished, hush panel is modified and back in place. Old fog light wiring has been completely removed, console is out, and car is in position to be jacked up for trans removal. Shifter removal and TV cable removal, then jack it up and pull the trans. Trans will be out this weekend. Clutch, flywheel and all other parts are ready to bolt in the car. All I'm waiting for is ARP fasteners for the flywheel and clutch, clutch disc, and speedometer gears for the trans.

chazman

iTrader: (4)

I know bud, just bustin' your chops.

scottmoyer

You know, it's possible my car had the 3.23s. I don't know. I was 17 when I had it and RPO codes meant nothing at that time. I bought the car used in 1986. It did have every option under the sun except for fabric seats which kind of blows me away since it had the custom carpeted interior panels and the rear hatch cover (D27), TTops, Power Seats, PW, PL, Tilt, Cruise, etc. Maybe the original owner ordered the car with the top rear axle.

I do have to agree with the Mustang comment. A friend had an '84 GT 5 speed and that car seemed more responsive, but mine seemed to be faster than almost everything else at the time. He must have had good gearing also.

yo soy el warg

I used to own an '83 Z28 crossfire automatic with the optional 3.23s it had every option available except T-Tops. It was extremely fast and you had to be careful not to burn rubber when you gave it the gas. It must have been the rear gears in mine that helped its performance.

82tarecaro

iTrader: (4)

The worst thing about the Crossfire is the wall it hits at 4500 RPM. It sounds great and feels great up until that point.

Jason E

I will second the comments about the peanut cam LB9/A4 cars and the way they drive. My 86 TA was a beautiful car. I miss it more than I expected...more than even my 88 LB9/M5 car I bought, originally, to replace it (ended up owning both at the same time for a year). I think it was the fact that the powertrain was so smooooth....and the base suspension in the TA felt great for touring. Plus, the blue/silver combo with the screaming hood bird was the perfect combo.

At the same point, acceleration? Yeah...past about 3,800, it was kinda like "ok, please shift....sometime...please? Maybe now?" Flooring it and waiting for it to shift at 5k yielded slower progress than letting off at 4k, letting it shift and going WOT again.

When your wife looks at you and says, "this is it?" when you go WOT in your freshly painted TA, you know there's a problem

chazman

iTrader: (4)

Luckily, she was talking about your T/A.

1MeanZ

iTrader: (9)

..and on that note!

Back to swap progress.

Here is a pic of the installed clutch master cylinder. You can see that the hole is a bit too large, but the master covers it up nicely. I have the correct hexagonal clutch pedal pad on the way, and Sean is providing the bracket for the clutch master cylinder reservoir.

1MeanZ

iTrader: (9)

Charlie's original hush panel on the driver side was broken where it mounts to the gas pedal stud. I supplemented the broken one with one from an '84 Z28 that I had around here. I didnt know the hush panels were different year to year but the differences are pictured. Charlie is this thing an early 83 with all the old mechanical clutch linkage compatible parts? Was the T5 not available until mid 83?

1MeanZ

iTrader: (9)

here is a pic of the different clutch cutout profiles.

1MeanZ

iTrader: (9)

Next step was to remove the console and get the wiring taken care of.

Here is Sean removing the console, watch out for the headliner! Thankfully for all of us the console is covering most of Sean's face.

1MeanZ

iTrader: (9)

Next was the wiring. The large purple and yellow wires go to the clutch safety switch, so when you depress the clutch the car will start. (Charlie, the switch your pedals came with was broken so I put in a new one). The black and orange wires get wired together, because they are connected by the shift switch when its in park or neutral. I believe this is how the ECM knows if the car is in park or in gear and controls the IAC appropriately. We don't want stalling with the AC on or any other funny business like that. The green and blue wires are for the reverse lights which will be wired up once I get a new switch for the trans.

The strange brown box stumped Sean and I. We have no idea what it is or what it does, I've never seen one before. We dubbed it "the crossfire mystery".

chazman

iTrader: (4)

T5s were available from the beginning in '83. They were all mechanical clutch. First year for hydraulic clutch was '84. BTW, car was built 12/'82.

chazman

iTrader: (4)

In addition to the dealer installed Pace Car 140 MPG speedo and clear headlight covers, my paperwork shows dealer installed foglights - maybe it's related to that? It also appears that the car had an alarm installed sometime in it's life. It still has the alarm lock behind the rear license plate. Thank goodness they didn't drill it into the driver's fender as was the custom in the day.

1MeanZ

iTrader: (9)

I completely forgot the T5 had a mechanical clutch the first year. That explains what I've found then. Well you've got the correct hush panel to go with your hydraulic setup now LOL.

I've removed every remnant of the foglight wiring, there was no real funny business there. The brown box could be the alarm, we didnt chase the wires. We just had fun calling it the "cross fire mystery"

Jason E

Indeed, I am lucky...

And with that, back to our regularly scheduled programming

1MeanZ

iTrader: (9)

Another 700R4 relieved of duty

chazman

iTrader: (4)

Hoping the T5 which takes it place, turns out to be a good one!