1995 z28 lt1 TunerCat RT question

**OldManz95** · 1 Week Ago

I have a 1995 Camaro Z28 LT1 6 speed that I am trying to Tune after a pretty much stock engine rebuild. I picked it up with 40,000 miles and two spun bearings, and metal everywhere. I pulled the engine and was going to just swap it when I ran into a race engine rebuilder who took pity on me and tore it completely down. Everything was replaced with better that stock parts, however the only major "change" was a .40 overbore.

This lack of major modifications, was mostly due to the lack of OBD1 tuners anywhere near me, and my initial fear of computers (I don't think these things will catch on.)

But now here I am. I recently had some time to research tuning it myself and bout a cable and this used laptop. I downloaded Cats winflash and TunerCat RT.
Pulled the stock code, changed cylinder volume, turned off VATS and CARS. But now have a minor issue.

Prior to my ownership the previous owner upgraded the wheels/tires. They are now 255 40 18. I'm trying to change the speedometer. I know it's minor but I am gradually trying to do more with the tuner capabilities. I found the spreadsheet that figures the speed scaler, fraction scaler and speed scan tool settings, but read that I need to change the "time between pulses for 'stop'". I have no idea what this is or how to figure it out.

Anyone out there able to lend a hand? And any other basic tuning advise would be appreciated as well.

**Terminal_Crazy** · 1 Week Ago

Welcome to the club. I'm in England with a High compression 383 6 speed 95 Z28.

Down load EEHack & Flash Hack & read all info on Steveo's website : https://ecmhack.com
There are also his xdf on there.

If you search for Kur4o he aslo has a very detailed xdf file with a lot of extra info

Search for Gary Doug. he also has some good free software

There is a value at 12006 : Stopped vehicle VSS pulse delay which might be what you're looking for.
It's not something I've altered from stock but a tune i have is slightly different and an LT4 tune is a lot longer delay.
Interested on feedback as my low trac light comes on when i come a stop as back tyres are 1 size bigger than the front.

Read Steveo's site on tuning ... lots of times.
Search for Solomon. He was/is an early tuner with a lot of detailed info on tuning on his website. again lots to reread naby times.

I'm always logging when i drive & messing with the tune, i really should just leave it alone and drive it:-)

We're here if you need more info.

Good luck
Mitch

**OldManz95** · 1 Week Ago

Thank you for the information. Looks like I have some reading to do! I didn't think I would ever dive into this but I'm going to do exactly that.

I will start with Steveo.

Thanks again.

**2xls1** · 1 Week Ago

Attach your bin file to a post here. Also what is the stock tire size on your Camaro?

**OldManz95** · 1 Week Ago

modification1 z28.bin

Hi. Not sure if I attached this correctly.

The tires are 255 40r 18 Nitto Invo.

**ULTM8Z** · 1 Week Ago

There's a parameter in there "Speed pulses per driveshaft revolution"

I'm wondering if this is what you want to change. Maybe it's as simple as scaling it by the ratio of your new tire diameter vs old diameter since the rotations of the driveshaft is a linear relationship to the rotations of the tire.

1995 is $EE code. I'm more knowledgeable about $8D (1990-91). In $8D, the parameter is in speed pulses per mile, which is what I changed to re-calibrate my speedometer. Which is why I"m thinking your speed pulses parameter might be the right one.