My 73 Suby drivetrain conversion upgrade!, New rebuild going in January 2025 Options

[JRust]

Change of plans. Shop has another 02 tranny. They can swap it for mine & have it back on the dyno this week. So I am buying that so I can get my car back quicker. The other tranny with a limited slip I will work on over time & swap it when I am done. Didn't want to wait another 3 weeks with shipping on the lsd & tranny.

I'll update when I have more info. Which wont be until later in the week. I should get my car back friday. Untll something else flippin breaks anyway

[Chris H.]

Good plan.

[Andyrew]

(IMG:style_emoticons/default/piratenanner.gif)

[Chris914n6]

post pics of the tranny carnage... inquiring minds want to know what failed (IMG:style_emoticons/default/confused24.gif)

[Amenson]

Keep your head up and wallet open Jamie...you are so close!

I am curious about your inclination to go to a 4.11/4.44 final drive. Porsti only had 305whp last time it was running and with the 3.9 final drive, first gear was pretty much useless for anything but creating noise in school zones. Second wasn't much better. Even with your wider tires and a bit more lag from the larger turbo, first and second will not do much for you with a 4.11/4.44. I am working on a plan to steal Stephen's 3.7 or 3.8 transmission in preparation for Porsti having higher compression forged pistons, forged rods and Flex fuel.

[JRust]

Keep your head up and wallet open Jamie...you are so close!

I am curious about your inclination to go to a 4.11/4.44 final drive. Porsti only had 305whp last time it was running and with the 3.9 final drive, first gear was pretty much useless for anything but creating noise in school zones. Second wasn't much better. Even with your wider tires and a bit more lag from the larger turbo, first and second will not do much for you with a 4.11/4.44. I am working on a plan to steal Stephen's 3.7 or 3.8 transmission in preparation for Porsti having higher compression forged pistons, forged rods and Flex fuel.

Shop was telling me I would stay in the power band better with the turbo. When I would go to shift I would be where the turbo is spooling. I will have some lag with the 3.90. As it is I am staying with the 3.90 for now. I will see how it feels before I end up buying another tranny. I did find a 4.11 5 speed out of an 04 RS imprezza. I am hoping to snag it but the guy hasn't gotten back to me. No big deal at this point.

[Amenson]

Keep your head up and wallet open Jamie...you are so close!

I am curious about your inclination to go to a 4.11/4.44 final drive. Porsti only had 305whp last time it was running and with the 3.9 final drive, first gear was pretty much useless for anything but creating noise in school zones. Second wasn't much better. Even with your wider tires and a bit more lag from the larger turbo, first and second will not do much for you with a 4.11/4.44. I am working on a plan to steal Stephen's 3.7 or 3.8 transmission in preparation for Porsti having higher compression forged pistons, forged rods and Flex fuel.

Shop was telling me I would stay in the power band better with the turbo. When I would go to shift I would be where the turbo is spooling. I will have some lag with the 3.90. As it is I am staying with the 3.90 for now. I will see how it feels before I end up buying another tranny. I did find a 4.11 5 speed out of an 04 RS imprezza. I am hoping to snag it but the guy hasn't gotten back to me. No big deal at this point.

Your car is probably much lighter than what the shop is used to working with...plus less losses from being only 2WD. There is barely enough load on the engine in first, and to some extent 2, to build much boost. I'll see if I can dig up any data logs.

[Andyrew]

I have bigger turbo than you with less displacement and more lag and while I found that my shorter geared trani and shorter tires on stickies make for quicker response, but on the street it made the car feel slower due to how often I needed to shift. I didnt percieve more power to the ground as I would have expected with shorter gears, in fact it felt slower... The longer geared trani felt more like a rocket with the short lag then a LONG pull.



Just saying I am really debating putting another long geard trani or a custom box with a short 2nd gear for autox.

Compare these two videos. The first video is short box with small tires. Second gear goes to just over 60. There is a almost an unnoticeable difference in time. Power is about 260-270whp.

https://www.youtube.com/watch?v=cVZpVREkpFw




Second video. Longer gearing, old tune, taller/heavier tires. Power is probably 280whp or so in second. Speed displayed is probably accurate, as it should be about 75mph at the top of 2nd. Thats 15mph difference with roughly the same time and a hair more lag.

https://www.youtube.com/watch?v=hliU58TRbFE




If all I did was autox and hill climb then the short box for sure. But on the street, that long box makes the car feel so much bigger than it is.

[rhodyguy]

109 in 17 sec not trying too hard? WOW. In town no less. (IMG:style_emoticons/default/dry.gif)

[JRust]

Tranny is in & it is back on the Dyno! Heading down in a bit to get it. I'll should finally have some numbers today

[Andyrew]

109 in 17 sec not trying too hard? WOW. In town no less. (IMG:style_emoticons/default/dry.gif)

Well call it a private separated 4 lane road with canal median... In Mexico...







But I want to see some numbers!!! Glad to see some on schedule progress Jamie!!!

[JRust]

Okay well I did get to drive my car & brought it home. The boost controller wasn't working. They didn't have anymore in stock. So at the moment I am at just 11lbs of boost. I'll go back down next week for the new boost controller & will get my turbo cranked up then. I'll get a much better dyno sheet as well. This one hardly shows the graphs. Sorry the lines are so faint. I'm at 230 hp to the wheels at 6150 rpms & 214lbs of torque at 4750 rpms. Nowhere close to what I expected but my boost is so low.

Having said all that. It has been raining all day & I have done nothing but drive it a few miles. It pulls amazing but I really didn't go all out. To wet outside I just spin the wheels with much pedal. I also ran out of gas about 5 miles from the shop. Forgot with my fuel issues we had to drain the tank. They put in gas to run the dyno but not a lot. I did see the gauge on empty but just thought it wasn't working. LOL! So got to sit on the side of the road for a half hour while I waited for more fuel. Put in close to 5 gallons & fired right up. Drove right to the gas station where it took 12 gallons. Then hooked up to my truck & flat towed it home. MY passenger rear wheel is either bent or out of balance. I saw it on the dyno & didn't feel it so much when I drove it. My day is pretty shot tomorrow unfortunately. So I won't get to do anything with it. Hopefully Sunday afternoon I'll have a little time to play around

[dan10101]

Okay well I did get to drive my car & brought it home.

Awesome! I can imagine what went thru your head when it ran out of gas.

You're getting close!

[Andyrew]

Awesome!!!! That looks near identical to my setup up to about 6k when I'm on ~11psi!

Seriously promising stuff there!

Next time if your there on the Dyno and the controller doesn't work just add small "t" valves to the boost line to the wastegate. They'll bump up the pressure so you can at least tune for the bigger boost.

That or a $30 bleed valve.. surprised your tuner didn't just throw one on so you wouldn't have to revisit them...


Congrats on great progress!!

[914forme]

Your getting really close Jamie - enjoy the car.

[76-914]

Congrats Jamie. It's been a long road and unfortunately, one you couldn't drive on. (IMG:style_emoticons/default/av-943.gif) Your torque is the same as my 6. By the way, stay off wet roads unless you want a repeat! (IMG:style_emoticons/default/shades.gif)

[JRust]

Well I took a quick 20 minute drive tonight. Heard a little clickety clack one the road. Turned around as it is a sound I am familiar with. One rear wheel was a bit loose. Torqued that wheel & check all the others. Good thing as there was at least one loose nut on each wheel. Took it back out. Pulls through all the gears great. I always get gearing back words but these seem pretty long. Other than 1st gear the rest seem fairly long before needing to shift. Also my Speedhut speedometer isn't working. It lights up but the needle isn't moving. The calibrate doesn't seem to be working. I've got to look into that some more. My shifts are really short & quick. I have to say the Zero decibals bell crank setup is smooth & precise. Really impressed with it & he is just finishing his own shifter. I can see that on my wish list

[Maltese Falcon]

Awesome!!!! That looks near identical to my setup up to about 6k when I'm on ~11psi!

Seriously promising stuff there!

Next time if your there on the Dyno and the controller doesn't work just add small "t" valves to the boost line to the wastegate. They'll bump up the pressure so you can at least tune for the bigger boost.

That or a $30 bleed valve.. surprised your tuner didn't just throw one on so you wouldn't have to revisit them...


Congrats on great progress!!

As they always mentioned during Moon landings (that little air bleed knob ) " Cycle the Parker valve " (IMG:style_emoticons/default/smile.gif)

[Robarabian]

Congratulations Jaime!! Sounds like it is finally a GO Go GO!!!!! I cant wait to see the car in person one day.

[Chris H.]

Well I took a quick 20 minute drive tonight. Heard a little clickety clack one the road. Turned around as it is a sound I am familiar with. One rear wheel was a bit loose. Torqued that wheel & check all the others. Good thing as there was at least one loose nut on each wheel. Took it back out. Pulls through all the gears great. I always get gearing back words but these seem pretty long. Other than 1st gear the rest seem fairly long before needing to shift. Also my Speedhut speedometer isn't working. It lights up but the needle isn't moving. The calibrate doesn't seem to be working. I've got to look into that some more. My shifts are really short & quick. I have to say the Zero decibals bell crank setup is smooth & precise. Really impressed with it & he is just finishing his own shifter. I can see that on my wish list

Great news! That 3.90 trans will probably be fine for you. FYI if can't resolve the trouble with the speedo you can send it back to Speedhut and have it converted to GPS...I had the same issue so that's what I did.

Enjoy it!