1949 resto mod new project

[jimcol]

Originally Posted by joedoh

neat start! the truck will be so light with all those aluminum parts, you might have 8 gears and only use 3 haha.

I hear the GM 8 speed automatic is so smooth you don't feel it shift. I've never ridden in one. In this truck that might not be a good thing. This thing will be light and with at least 400 to 430 hp it could get away from someone pretty easy. I believe as far as the rear weight the Mark 8 subframe and differential are a lot heavier than the 10 bolt I pulled out.

[joedoh]

Originally Posted by jimcol

I hear the GM 8 speed automatic is so smooth you don't feel it shift. I've never ridden in one. In this truck that might not be a good thing. This thing will be light and with at least 400 to 430 hp it could get away from someone pretty easy. I believe as far as the rear weight the Mark 8 subframe and differential are a lot heavier than the 10 bolt I pulled out.

thats interesting, is that counting leafs too?

I was more referring to the all aluminum vette engine and trans compared to the cast iron six.

the irs will be a good way to keep the power down, a guy named coach did a tbird IRS on here a couple years ago.

edit for the link to the IRS install

http://67-72chevytrucks.com/vboard/s...=coach&page=35

[jimcol]

Originally Posted by joedoh

thats interesting, is that counting leafs too?

I was more referring to the all aluminum vette engine and trans compared to the cast iron six.

the irs will be a good way to keep the power down, a guy named coach did a tbird IRS on here a couple years ago.

edit for the link to the IRS install

http://67-72chevytrucks.com/vboard/s...=coach&page=35

Best I can find The LS2 is about 180 lbs lighter than the old cast iron inline 6. The fun part is going to be the 350 hp difference.
The Mark 8 used Ford's 8.8" diff. internals. They are an open diff. because the traction control would handle the wheel spin. Since I plan to use the Mark 8 anti lock brakes I am going to try the traction control. If it don't work then I'll put a locker diff. and a gear ratio close to the 06 vette.

[joedoh]

I thought of something else regarding the 8 speed, I drove an 8 speed camry to ohio and back in 30 hours, and when the cruise was working it was wonderful because the radar cruise would hold the higher gears and accelerate/decellerate smoothly enough not to downshift/upshift a lot. then the weather started sleeting, and the cruise kicked off, I had to use my right foot. and no matter how hard I tried I could not maintain a steady speed, if I started slowing down on an incline, a slight push on the gas pedal would downshift to 6th, sometimes 5th, and the acceleration was just so rapid in those gears that I would let off. I spent about 1200 miles floating between 68 and 80mph, shifting up and down. I could select 6th and lock it but the fuel economy went down, nothing above 6th was selectable.

I know a 4 cyl camry doesnt have a lot to do with a 400 hp v8, but that was my experience. make sure the cruise works and "talks" to the trans or you might have the same rubberband effect.


make sure the Mark VIII traction control isnt just applying the brakes to the spinning wheel. my pilot works like that, called vehicle stability assistance, and in snow it overheats the abs. its not a good thing for acceleration either. feels like its getting punched in the gut.

[jimcol]

Originally Posted by joedoh

I thought of something else regarding the 8 speed, I drove an 8 speed camry to ohio and back in 30 hours, and when the cruise was working it was wonderful because the radar cruise would hold the higher gears and accelerate/decellerate smoothly enough not to downshift/upshift a lot. then the weather started sleeting, and the cruise kicked off, I had to use my right foot. and no matter how hard I tried I could not maintain a steady speed, if I started slowing down on an incline, a slight push on the gas pedal would downshift to 6th, sometimes 5th, and the acceleration was just so rapid in those gears that I would let off. I spent about 1200 miles floating between 68 and 80mph, shifting up and down. I could select 6th and lock it but the fuel economy went down, nothing above 6th was selectable.

I know a 4 cyl camry doesnt have a lot to do with a 400 hp v8, but that was my experience. make sure the cruise works and "talks" to the trans or you might have the same rubberband effect.


make sure the Mark VIII traction control isnt just applying the brakes to the spinning wheel. my pilot works like that, called vehicle stability assistance, and in snow it overheats the abs. its not a good thing for acceleration either. feels like its getting punched in the gut.

Yes the 93 Mark viii's traction control operated by applying brake to the spinning wheel. Also the Mark viii's did not have limited slip diffs because the traction control handles that issue.
I'm still going forward with the anti lock brakes and shutting off the traction control feature.
The Mark viii's use the Ford 8.8 diff. So I think we'll just go with a locker or limited slip diff along with the best gearing for the LS2/6L80e.