Twin engine GTP project progress thread

[Turbocharged400sbc]

yeah we should be around 300 or so as well I know we're set up for full line pressure at TCC apply.

by the way this is the oversized boost valve from Sonnax. I've got a few bags of springs over the years from transmissions I'm sure I'd be able to find something in there or at McMaster that would bump up pressure over the OEM
http://www.sonnax.com/parts/2337
Tools.
http://www.sonnax.com/parts/2877

[91parkave]

Will your force motor current table help out inmaxing out the pressure?

[Turbocharged400sbc]

he's not using the OEM PCM I'm not sure but he may be running 0 EPC current all the time

[TwinV6GTP]

he's not using the OEM PCM I'm not sure but he may be running 0 EPC current all the time

The Magnashift controller has a line pressure adjustment with a LED that shows the actual pressure. It's max pressure right now.

BTW we are back running again, yes !
And best of all, the Aurora Converter is looser after all.
My rear engine now spools quicker than the front. That's perfect...
I only need 2.5 seconds to spool for a decent launch off the line.
That means this weekend at the airstrip, I'm ready for armdrop racing.

[TwinV6GTP]

yeah we should be around 300 or so as well I know we're set up for full line pressure at TCC apply.

by the way this is the oversized boost valve from Sonnax. I've got a few bags of springs over the years from transmissions I'm sure I'd be able to find something in there or at McMaster that would bump up pressure over the OEM
http://www.sonnax.com/parts/2337
Tools.
http://www.sonnax.com/parts/2877

Would you lock TCC under full throttle once off the line ?

[TwinV6GTP]

New trans in action.
I finally let passengers in the car.
Here's Momo our newest addition to the team. He's used to powerful cars so he really enjoyed it !

[Turbocharged400sbc]

The Magnashift controller has a line pressure adjustment with a LED that shows the actual pressure. It's max pressure right now.

BTW we are back running again, yes !
And best of all, the Aurora Converter is looser after all.
My rear engine now spools quicker than the front. That's perfect...
I only need 2.5 seconds to spool for a decent launch off the line.
That means this weekend at the airstrip, I'm ready for armdrop racing.

yeah any time you take a converter from a lower tq motor and put it behind a motor with more tq the stall speed increases, if you need more you can go for the 4.5/4.9 converters.

speaking of converters i found the bit for the cf clutch conversion of the vcc 80e's
http://www.atraonline.com/gears/2008...5/2008_5_6.pdf

did you find out what fdr? it should be 3.48 though the up package (autobahn) had the 3.71

Would you lock TCC under full throttle once off the line ?

with the boost limiting feature of the 7 stage controller, yes i would, but i didnt design it for that, the TR is a racecar, but its a well mannered street machine.
i designed it to use the GMR Oringless IS with a modified converter hub to save quite a bit of coin over buying a new 900$ non lockup converter. the pressure is for the release side as our converter is more efficient than many here run and we dont need any dragging of the clutch while loading it, while at the same time being able to max out 3rd gear to 167mph.
now it seems like we have a 2.93 fdr so we dont need to drop as much tq down low. so now with tcc locked he could hit over 185 in third tcc locked, but should put us through the traps at 140+mph at no more than 6000-6500rpm.

you cant really use much of my setup advice im afraid as the whole package was built for our terrific low/mid rpm breathing geometry, where the motor is most at home...instead of winding it out to 7k.

build it for tq, and you get hp, build it for hp, and you dont always get the tq.

in regards to the pump pressures, be aware that 300 was the high end of oem, dave boosting it over 300 isnt much, over oem, the mods to no longer limit the pressure apply is what does the trick (****in NVH garbage).

keep in mind the 80e is a different animal...its not one pump, but 4 of them. while two are scavenge pumps, the primary pump and secondary pump seem to double act on the boost valve to limit the second pumps contribution only to the high hydraulic load situations.
like 1st, where there is a whole lotta apply volume and pressure required to keep all the circuits activated-the 80e's hunger for fluid is one reason many tech's point to the unserviceability of the primary filter as the leading cause of premature failure, that thing is barely sized for one pump...and it has to feed two of em.

looking at the pressure valve, you could increase tq signal pressure and/or increase the spring force to up the pressure, but it appears that it would do little to up the pressure and volume since the 2nd pump seems to be limited by the shape of the spool valve. so a new valve with more taper on the secondary pump section looks like it would up the secondary pump pressure, but at the same time youd have to extend the shoulder of the primary section to prevent it from bleeding off.

if you test at the pressure port it looks like you should see ~250-300 main line pressure. the problem is that its limited past that....really it makes sense, cant have anyone complain about hard shifts in a cadillac...yay NVH compromises!

[TwinV6GTP]

yeah any time you take a converter from a lower tq motor and put it behind a motor with more tq the stall speed increases, if you need more you can go for the 4.5/4.9 converters.

speaking of converters i found the bit for the cf clutch conversion of the vcc 80e's
http://www.atraonline.com/gears/2008...5/2008_5_6.pdf

did you find out what fdr? it should be 3.48 though the up package (autobahn) had the 3.71



with the boost limiting feature of the 7 stage controller, yes i would, but i didnt design it for that, the TR is a racecar, but its a well mannered street machine.
i designed it to use the GMR Oringless IS with a modified converter hub to save quite a bit of coin over buying a new 900$ non lockup converter. the pressure is for the release side as our converter is more efficient than many here run and we dont need any dragging of the clutch while loading it, while at the same time being able to max out 3rd gear to 167mph.
now it seems like we have a 2.93 fdr so we dont need to drop as much tq down low. so now with tcc locked he could hit over 185 in third tcc locked, but should put us through the traps at 140+mph at no more than 6000-6500rpm.

you cant really use much of my setup advice im afraid as the whole package was built for our terrific low/mid rpm breathing geometry, where the motor is most at home...instead of winding it out to 7k.

build it for tq, and you get hp, build it for hp, and you dont always get the tq.

in regards to the pump pressures, be aware that 300 was the high end of oem, dave boosting it over 300 isnt much, over oem, the mods to no longer limit the pressure apply is what does the trick (****in NVH garbage).

keep in mind the 80e is a different animal...its not one pump, but 4 of them. while two are scavenge pumps, the primary pump and secondary pump seem to double act on the boost valve to limit the second pumps contribution only to the high hydraulic load situations.
like 1st, where there is a whole lotta apply volume and pressure required to keep all the circuits activated-the 80e's hunger for fluid is one reason many tech's point to the unserviceability of the primary filter as the leading cause of premature failure, that thing is barely sized for one pump...and it has to feed two of em.

looking at the pressure valve, you could increase tq signal pressure and/or increase the spring force to up the pressure, but it appears that it would do little to up the pressure and volume since the 2nd pump seems to be limited by the shape of the spool valve. so a new valve with more taper on the secondary pump section looks like it would up the secondary pump pressure, but at the same time youd have to extend the shoulder of the primary section to prevent it from bleeding off.

if you test at the pressure port it looks like you should see ~250-300 main line pressure. the problem is that its limited past that....really it makes sense, cant have anyone complain about hard shifts in a cadillac...yay NVH compromises!

So you believe the stock 4t80e has plenty of main line pressure ?

[Turbocharged400sbc]

not likely, there's a healthy range so there seems there's plenty of tolerance variables with springs, machining, etc.

but the pressure test port is easy as ****, its right on the top. youd be able to tell where you are, the problem may be the volume required at that high pressure.

the way the valving looks in 1st is that if mainline pressure dips the 2ndary pump no longer exhausts to the pump inlet. by changing the shape of that taper you could make the 2ndary pump far more active in a performance application vs its design of keeping pump losses minimal and bringing a 2nd pump in when it cant keep up.
the 65 e pressure is nominally 240-290 iirc, ours is set to 300+
obviously if the oem is marginal, it may be wear and tear or it may be a weaker spring/dude wanted to go home early, who knows...
if your pressure is up near 300 (80e is ~250-300) then id say it might be enough. but shoot since you dont have any other means of diagnostics...go ahead and see how the pressure acts during launch. it sure couldnt hurt and would at least give you a base line.
trans guy i used to work with had both an air core and a glycerin gauge on his manifold....the glycerin can hide the pressure oscillations that he used to find with certain nvh complaints.

hell use the EGR A/D input trick to shove a simple 5v sending unit into the main port and datalog it in real time...btw while yer at it, hookup the ISS/tft/vss so we can get some rudimentary data? lol

even if all we get is some "tcc slip" and calculated gear ratio numbers we can figure out how well the converter is reacting as well is a certain gear is actually holding or if its slipping.

sure is fun blazing trails lol

[jdredd]

the 65 e pressure is nominally 240-290 iirc, ours is set to 300+

This is what I had down in my notes from something I gathered awhile back for stock..

Min Line pressure
P/R/N , 1.0 amp, 79-101 psi
4/3/2 , 1.0 amp, 74-86 psi
1 , 1.0 amp, 146-187 psi


Max Line Pressure
P/R/N , 0.0 amp , 223-271 psi
4/3/2 , 0.0 amp , 167-203 psi
1 , 0.0 amp , 146-187 psi

My issue was even at 0.0 amp, in P/R/N it was over 300psi.. but once I was in gear and moving the pressure tanked... I think around
150psi or so in 1-3rd.

[TwinV6GTP]

Interesting data, Jdredd, thanks. I will check my line pressure if my trans survives tomorrow night racing. This weekend looks like RAIN so no airstrip for me...
I'm really tempted to twin engine my 07 GP GT special edition... much nicer car and also I'd make it daily driveable.
It would be a little of a gas guzzler but who cares.. weekend cruiser.

Also thanks to TBC400sbc, always nice to see the information being shared.

[91parkave]

Why not just rear engine your 07, and tub the inside under the hood. For fuel tank etc...

[Turbocharged400sbc]

cause if one is good, then two is more betta

btw i dug out my spare vb so i can tear it apart and look at the boost valve.
it appears the sonnax might replace only the primary pump half?

regardless a new valve with a 2nd pump that comes in sooner shouldnt be hard to turn, at the least we can get the spring dimensions/rate for sourcing a stiffer spring

[darkhorizon]

I bet you would have alot of fun with a fiero... single engine has alot of potential too.

[kkehlet]

awesome work GM did some experimenting with the chevy citation

[TwinV6GTP]

Thanks but that citation has nothing on this gtp lol. But was the first to do it, props to gm for the ingeniuity.


Sent from my iPhone

[Turbocharged400sbc]

lol they were copying the terrifying toronado, as well as the other twin drivetrain toronado's (one fella was almost set to start mass producing em!) then the Hurst "Hairy" olds. there were plenty of twin and multi engine cars but most utilized custom drivetrains where the toronado transaxle made it stupid easy lol

keep in mind that was the 60's

[Mike16]

This thing is a monster. I hope to see you at luskville sometime.

Dommestics vs. imports Sept 6 at luskville dragway, if weathers nice ill be there all day.

[Neil98gt]

Fancy seeing you pop up on my news feed.

The car is a beast that's for sure.

[Russosaur]

Also popped on 1320 video if I saw it right

Sent from the Milky Way