some jerk rearended my wifes 95 roadmaster wagon, 27,000 original miles! it was totaled. I got it back from insurance and I'm putting the motor in a 89 iroc.

I already sorted out the wiring harness for the iroc, it took like 2 nights till 3am to seperate and identify all the wires.

I just finished modifying the right hand motor mount cup to help support the AC compressor, I took the compressor with the modded bracket and placed it on the mount in the car to see where the frame had to be "adjusted" for clearance, it actually cleared pretty good. The clutch and pulley seem a little close to the idler arm mount though. I have pictures I can link to if anyone wants to see them.

Here's some questions-

1.Will the iroc vehicle speed sensor work with the LT1 pcm? Where is it located? Is it inside the speedo?

2. will the iroc VATS module work with the LT1 pcm?

3. Can I use the LT1 a/c compressor with the iroc evaporator, condenser and reciever/dryer?

I don't have a lot of money but I have time and a good workshop so I want to adapt as much as possible. Thanks.

 

1. No, the VSS is on the transmission tailhousing. You will have to get a buffer that converts the signal.

2. No, getting VATS programmed out is the easiest thing to do.

3. Yes. Not that big of a deal, just purge and clean the system before you charge it to clear it of any of the old oil unless it has already been converted to R-134a. I'm assuming since you are modifying the passenger motor mount that the a/c compressor mounts low on the right. If so, you will have to notch the crossmember to clear it and get a custom a/c line made.

 

thanks for the reply. I was looking at the tailhousing for the old transmission from the iroc and it doesn't seem to have any kind of VSS, just regular speedo gears. The 4l60e that's with the lt1 has a coil and a reluctor but no provision to drive a speedometer cable.

I have an AKM cable, I can pull the program out of the pcm and email it to someone to get the vats removed. I liked the idea of the vats for thieft prevention but without it I'll just get a huge dog or something and teach it not to s#!t in the car or eat the upholstery.

I just got done porting the exhaust manifolds, there's metal dust everywhere.

 

Hey, I would really like to see your pics. Working on LT1 swap for an 87 Firebird and am trying to explore all my options.

Thanks!

 

OK, here's some pics of the compressor mount. I sawed the ear off the old mount, notched the motor mount cup for clearance and welded it all together.

mount 1
mount 2
mount 3

I also started tracing the wires in the car out tonight. It seems the car had some bose powered speakers which were butchered for a crappy install of another system. between the remnants of the 2 different sound systems and the alarm install I'm having trouble figuring out what all the F'n WIRES! are for. I ended up pulling the whole dash apart and I'm going to loose about 20 pounds of copper. this car must have had every option. I'm seriously thinking of ditching the power seat, power windows and the tilt colum for the stock equivalents from this 6 cyl coupe I have. I found the VSS, it's a little yellow module on the back of the speedometer. I'm going to see if there's a way to get the stock speedo to work without a cable, I have the guts from the speedo that was in the car the LT1 came from, maybe I can graft the innards into the iroc speedo.

 

Nice job on the AC, my LT1 and Tranny will be here tomorrow, did you have to notch the motor crossmember after altering the mount like that? If not, I could use some tips from you .

 

While the huge dog thing might work too, since you want to keep VATS the other option is to get a new VATS module from GM, one for a 4th gen, repin the connector, and use it that way. It allows you to keep VATS operational as the new module will program itself to your key the first time you try to crank it.

Also, for the speed sensor I was thinking you had an electronic speedo. Having a cable speedo makes things a little different because you either have to switch to an electronic one, in which case an aftermarket one such as an Autometer would be best because you wouldn't need any kind of buffer box. Or, there is a buffer box somewhere that I have seen that has a cable output. I think. I just woke up so I could be making that up......

 

Great job on those photos. Thats one of the things I've needed a photo of for the swap guide I'm putting together. You don't mind if I use those for the guide do you? Also, like pasky asked, did you end up notching the crossmember? If so, I could definitely use a photo or two of that. Thanks

 

Sure, you can use the photos, I'll send more. I don't understand why the compressor cleared the crossmember, some photos of other peoples cars seemed to have the compressor a little further back. This was an original V8 car so I figure the motor was in the right place. After the photo was taken I beat the crossmember back a little just to be on the safe side, I probably could have ground the corner off the compressor too.

I guess using the existing cable driven speedo/VSS is out of the question? I think Painless Wiring makes a VSS that goes in the speedo cable but some of their prices are far from painless.

I used a rake and hedge trimmers on the wiring.

 

Here's some pics of the frame notch. One picture also shows how I put some plates inside the motor mount to limit the travel

mount 1

mount 2

mount 3

I'm getting ready to drop the motor in right now. You're all going to s#!t when you see how I lift it.

The trans will go in as soon as i figure out a cheap way to add a speedo drive and keep the VSS. Mr. LT1Texas, if you want any of these pictures you better take them because i'm using a free service and I don't know how long they'll be up.

Here's some other pics of the donor car and my turbine projects, but be carefuil if you're on dialup, i didn't get a chance to squash the last 2 down.

1 2 3 4 5 6 7 8

 

With an Electronic stock speedometer , a calibration box is not needed TexasLT1, please stop posting this, the LT1 pcm puts out the same 4000 pulse / mile signal the tpi /v6 ecms and tbi buffer box do.

Serpent, i believe you may be able to pull the VSS out of the trans and replace it with a cable drive piece from the original 700R4 then run a painless wiring VSS since it allows the cable to still be used.

 

they have 2 VSS in there catalog, one is for early LT1 I wonder if that will work?. The reluctor in the 4L60E I think is 40 pulses per revolution and I figure maybe 2500 rpm shaft speed at 60 mph, which is a mile a minute so it turns 2500 times per mile times 40 = uhhh a hell of a lot more than 4,000

OK, what am I missing here? There must be more to this, why would someone go through all this trouble if all they had to do was put a cheaper VSS in the speedo cable?

 

4000 is the signal from the pcm / ecm to the speedometer not the input on the computer, the vss insert was based on the possibility of the stock vss hole on them being the same, since i dont have a 60E here at the moment, this place has the housing conversion you'll need.

http://www.hotrodlane.cc/LT1LT4/LT1LT4ACC.html

 

that tail housing they show sure looks like some stock parts, i wonder what they come off of?

I was thinking of relocating the reluctor and maybe using one of the sensors off the antilock brake system from the donor car.

 

The engine is in-

picture 1
picture 2
picture 3

The Jeep does nice wheelies with that engine hanging off the back. The A/C compressor clears real nice. Next is sorting out the VSS problem and installing the transmission, then on to the hookup and wiring.

Any ideas on how to hook up the heater hoses and the vent pipe from the back of the cylinder heads? Should I use the pressurized tank from the LT1 donor car?

 

The only reason I've been posting it is because that was the information I thought was correct. Thank you for finally correcting me. I was under the impression they all needed it, I did not know the tpi/v6 car was different.

 

All of the speedometers use a 4000 pulse / mile signal, 4th gen LT1's and 3rd gens, tbi v6 and tpi, the only time a dakota digital box should be needed is with a non stock 4th gen trans is used with the lt1 or a T56 is used with a tpi / tbi computer, the tbi cars can use the LT1 signal by skipping the buffer box, as it outputs the 4000 pulse / mile signal the speedometer gets.

 

Heres what i did for the heater lines, www.thirdgenparts.com/LT1cooling the hardline set is from a V6 3rd gen, retained the heater control valve, the bleeder section is from the V8 4th gen car, get a 93 camaro LT1 upper radiator hose, it will have a small hose that you can connect the coolant pipe from the back of the heads to.

 

I found the sensor they used in the speedo conversion, it's not cheap. I'm not paying $100 for a stinkin coil of wire and a magnet. I have a lathe so I can move the reluctor to wherever I want.