The white camaro has been running w/o a functional speedometer ever since we finished building it at the end of last summer. Obviously this is a problem, but i've been kinda lazy about getting it fixed because of unsuccessful previous attempts. Here's the deal... The 700-R4 is originally from my old 89 IROC and now resides in my 92 Z28. sooo.... it originally had a cable driven speedo, but the 92 uses an electric signal instead. To make matters even more complicated, the Z28 originally had a WC T5. Naturally, the T5 VSS doesn't fit into the 4L60, and I tried an electric VSS for a 4L60, but it doesn't work quite right. The speedometer would go through it's full 0-180 MPH within the first 0-5 actual MPH. obviously the ratio's were all horribly wrong. But the gears used were supposed to be right for a 3.42 final w/26" tires. The ecm is supposed to translate every 4000 pules into one mile, but i'm wondering if it's different for the 700R4 as opposed to the originally installed T5. Anyway, w/o the converter locking up, the car uses up over a quarter tank of gas to get to the tracks, and it's too expensive for me to drive that car everyday... which sux cuz i gotta drive the bone stock V6 RS.
So if anyone has a known working VSS laying around that i could test out, or if you know someone who does then i'd really appreciate it.
On a side note... i'm looking for lowering springs to drop my RS, and some rear chassis components to get rid of wheel hop. When i stomp the gas in the RS, it shakes so violently that i gotta be breaking something. And if anyone is selling SFC's locally i'd be intersted... runnin on the cheap with this RS. I'm tryin ta save up for a nice 68, and another small block maybe an LS1?
ooohhh, and i almost forgot, A working V6 speedometer too... mine stays pegged at 7K+!
Thanks guys - Danny

 

Can you rig a manual lockup switch for the trans, to engage it on the freeway?

For the speedo, a check of aftermarket gauge companies might turn up the needed part, VSS or otherwise.

The white car has that carbed 11-sec 383, right? I'd guess the gas mileage is around 12-14 anyway, huh?

 

There are conversion parts out there to modify the cable driven speedo output on the tranny to electronic VSS output. You're only gonna find them for people into the Hybrid Conversions involving GM drivetrains, so SBC Jaguar swaps, SBC into older 300ZX, etc etc. Off the top of my head I think KDS Performance makes the conversion you need, but you'll probably need to do some searching on the internet or make a few phone calls. Good chance Painless or B&M also make a conversion. Then once you got that converted you might come to the issue of the VSS pulse. Hopefully that first conversion box will allow you to specify pulse, but if not you can use a second conversion box made by Dakota Digital called the SGI-5. It'll convert the pulse to whatever you specify and send the right pulse to the ECM.

For the lockup you can either do a manual switch (this is what I did), or you can get a TCC lockup kit from B&M. Spiffy looking conversion box with a dial that lets you select the RPM you want TCC to occur and it'll do it automatically.

If you had hit me up about V6 parts a few months ago you coulda had whatever you wanted. Unfortunately that car is now soda cans and frying pans.

 

thanks guys, i'll look into the cable/electric speedo converters. I actually already have the B&M box installed, but it doen't work until you reach a certain MPH, 35 i think... so right now it just sits there.
The white Z28 is fuel injected w/a stealth ram, and that sucker still gets like 8-10 MPG.

 

Ah, the price to pay & run 11s But it looks awesome & runs great!

 

Ouch! I'll remember that when I build another stroker SBC, and make sure to stay with a dual-plane intake and demon instead of hassling with FI...

 

actually Ed, I think the crappy mileage is due not to EFI, but rather to the sheer amount of airflow at lower RPM. combine that with the lack of lock-up AND the 3000 RPM stall converter. basically, the motor is moving major air/fuel just to get the car moving.... even worse when traffic is stop n' go. I could tune the motor to run a little leaner at the lower revs, but i wanna keep temps as low as possible, and not have to worry about detonation with sudden off-idle bursts.
I'm seriously considering another small block to put into the RS tho b4 i get my dream '68. I'll be in the market for a TPI motor once i figure out how i wanna build it. I've got a 305 block sitting in the driveway right now... but i figure i can get more power for the same amount of cash if i just get a 350 block.

 

Absolutely right on all points Danny -- improved speed and acceleration isn't free and shaping engine and drivetrain characteristics to go faster and quicker reduces fuel economy.

Your mileage is about what it should be for a race car.

Heck, if I had an 11-second car I'd be happy to get 10 mpg, but it would be a weekend warrior, with a 13-14-second car for my daily-driver-traffic-fighter.

My comment about EFI vs carb was only that EFI makes a lot of sense for fuel economy and high-end race engines like Indy, etc, but for budget race cars a carb setup is cheaper, easier to tune and gets fuel mileage in the 8-12 mpg range.

BTW, next time you take that fine Camaro to the track for a "test and tune" let me know and I'll pop 20 gas bucks in your tank to give my son Martin a ride -- I'd like him to feel what it's like to blast off in a 3rd Gen with real *****!

 

Hey Danny, Eventually I'll need to figure out this whole mess when the T56 goes in but I sorta don't follow what's going on here. The T5 that you sold me, did have a electrical connector for the VSS but you do realize that it was driven by a gear and it was not like the newer reluctor style ones.

I'd almost bet that getting the right sending unit would've (plug and play) solve all your problems but as you stated the 4L60 one didn't do it for you.

Well little history on my project...'86 SS uses the optical 2 pulse VSS that your '89 prolly would share. Since the plan was to usea '730, IIRC $8 mask uses the 4000 pulse VSS. In the PROM, I had to change the VSS to 2 pulse so I could use it with the OEM G-body speedometer. It's possible your PROM is set up for the 2 pulse but YOU would have to have done it. Unless you borrowed the bin from someone with a pre'89 car (like Mike Ds '85) that's currently running a '730.

stew

 

well i took a look at the .bin and it is correctly set a 4000 PPM, but the speedo gauge would go through it's entire range of sweep within the first 5mph of actual car speed. The VSS did work, sorta... since it was sending a signal, but the ratio was obviously out of whack. I'm not sure which gears were used as far as GM part numbers, but the guy who built our trans says they were the right ones. Probably just a problem with trying to use an electric VSS in a tranny meant for a mechanical one. I'm currently looking at the mechanical/electric converter units.

 

Unless you have the book, download this and see if there's anything useful here:

http://www.jagsthatrun.com/V8-chapte...ed-Sensors.pdf

Also, Look at the pictures of the output shaft where the VSS sender would mesh with, looks like a machined integral part and kinda tells me that there's one part for all applications. Why isn't yours working!!! stew