First real drives single turbo auto... questions

ok, so I have done quite a bit of work to my supra over the past 6 months or so and today was MOT day. Ok, it failed on 2 tyres which I knew it would but I've got new alloys to fit so wanted to check that was all before I fitted them. Also failed on NS rear seatbelt mech not working which was annoying as I have been through the car totally but that was one thing I didn't check/fix/

Anyway, my questions...

I have not had an auto supra before (single turbo this one approx 500 rwhp at present) . Turbo is good for maybe 650rwhp ish I reckon but mapped to protect the auto box on a link ECU.

The car goes like a scalded cat when I use L then shift to 2 but when I set off in Drive it seems very sluggish indeed. Now, I have not had enough time in the car or clear roads (busy roads saturday daytime) to test if it starts going full on when on boost in 'D' but at 2k rpm it seems to be turgid. at the same rpm in L it is far more reactive, then into 2 and it is also pulling much harder.

I tested it from a stop in Drive and it seemed like setting off in 4th gear in a 'normal' manual car. Whether this is because it needs a high stall or not I don't know. Or does my box have an issue? (it was a 'new used' box fitted when I got the car but as it needed a new engine I never got to test drive it so have no benchmark.

Can any single auto guys help with out with how the car 'should' drive please.

Any pointers?

thanks

In D on an auto you will be starting in 2nd gear, this causes a delay in the turbo spooling up a bit, what ECU are you running and where was it mapped, did the mapper notice anything

As above they pull away in second unless your stamping on the throttle, not sure at what point it selects first, the stock stall flash speed is 2000rpm or there abouts, imho if you have a larger turbo anything over 62mm a hi stall would be a must if you want a responsive street car.

I'm pretty positive mine pulls away in first whilst in 'D'. From pull away, it pretty much changes instantly to to second, then 3rd. I can feel it drop into overdrive at around 30 ish mph, if driving sensibly

In fact since having the built box fitted at the beginning of this week, the change from first to second is very harsh. I'll have to stick it in manual mode, and pull away in '2' to see if it feels better

Mine (MKIV Facelift) pulls away in first when in 'D'.......... unless snow is selected then it will pull away in 2nd

Certainlt not 'sluggish' when running in 'D' but being able to hold the gears in manual via tiptronic certainly livens things up even more....

Maybe its the single turbo? So if the torque converter is 2k as stock, then am I right in thinking that I won't see much action till after 2000 rpm?

I will do some more testing tomorrow.

I basically ended up using the box like L then into 2 then into Drive to cruise afterwards, which felt like the equivalent of putting a manual into 5th!! To be fair I didn't have the pedal to the metal at that stage as I couldn't really get clear road ahead..

Soooo, is it the big (ish) single that causes the delay when starting in D (if so I would have thought it would be the same in L?)

I am in the fortunate position of having a nearly new Titan stage 2 auto box and a hi stalll titan Torque Converter. But I didn't want to fit them yet as the car should drive sweet with the current box (Chris Wilson fitted it so I know it ran sweetly)

The other question, ECU is a Link G3 LEM, mapped on dyno dynamics. It is a good fast map I have been very reliably informed.

thanks.

Does manual mode work? Is it on but the light doesn't work? That might make the box start in 2nd?

If there really is a massive difference from a stand still then for some reason the autobox when in D isn't selecting 1st?

Try it in D and when sluggish check what speed it changes gear, it should get to the redline in quick time and at a relatively low speed if in first, 2nd gear redline change is I think over 70mph or at least around that so it should be easy to tell what gear it starts in.

Maybe its the single turbo? So if the torque converter is 2k as stock, then am I right in thinking that I won't see much action till after 2000 rpm?

I will do some more testing tomorrow.

 

I basically ended up using the box like L then into 2 then into Drive to cruise afterwards, which felt like the equivalent of putting a manual into 5th!! To be fair I didn't have the pedal to the metal at that stage as I couldn't really get clear road ahead..

 

Soooo, is it the big (ish) single that causes the delay when starting in D (if so I would have thought it would be the same in L?)

 

I am in the fortunate position of having a nearly new Titan stage 2 auto box and a hi stalll titan Torque Converter. But I didn't want to fit them yet as the car should drive sweet with the current box (Chris Wilson fitted it so I know it ran sweetly)

 

The other question, ECU is a Link G3 LEM, mapped on dyno dynamics. It is a good fast map I have been very reliably informed.

 

thanks.

Yeah the flash stall speed it 2000rpm so you not see much action prior to this unless your normal driving , flooring it will see it jump to 2000rpm selecting first and away you go, when selecting first/L it will seem more responsive as you have aleady selected it with half throttle as I dont quite think thats enough for a first gear select in D.

What hi stall have you got because wrong selection on this can kill the driving experience also, as well as a rediculous size single turbo, but you can always fit a smaller turbine housing to aid spool being auto and stock box you really only want 550 bhp and torque,

I have a 67mm with a 0.68 turbine which sees me spool in first from a stand still around 3300 and way over 1 bar by 4k, but if I had a 0.96 my spool would be much latter but able to make more top end power, which I dont really want extra lag and top end piwer in a street weekend toy

Does manual mode work? Is it on but the light doesn't work? That might make the box start in 2nd?

 

If there really is a massive difference from a stand still then for some reason the autobox when in D isn't selecting 1st?

 

Try it in D and when sluggish check what speed it changes gear, it should get to the redline in quick time and at a relatively low speed if in first, 2nd gear redline change is I think over 70mph or at least around that so it should be easy to tell what gear it starts in.

Thanks guys, much appreciated

@Scooter..

It does indeed sound like it has been in manual mode!!

Unfortunately I can't test again till Tuesday as fixing a few minor issues on the car before it goes for retest but I will report back as soon as I have checked that manual was definitely off.

Am I correct in thinking that if manual is selected, once the car is turned off etc then the next time it is restarted it would be in normal auto mode?? or does the manual button stay 'on' once its pressed?

I read the supra bumph about manual mode driving and it pretty much describes precisely the experience I had

@mellonman

thanks.

Its a 3800rpm hi stall.

But its not installed presently, I'm just running stock box and TC at the moment.

In D on an auto you will be starting in 2nd gear, this causes a delay in the turbo spooling up a bit, what ECU are you running and where was it mapped, did the mapper notice anything

Just found this

1996 Toyota Supra owners manual, page 60 said

(g) Driving in manual mode

 

In the manual mode, the transmission system stops automatic gear shifting. Use this mode when starting your vehicle on a snowy or slippery road, when driving up steep inclines, and down with engine braking.

 

To set the manual mode, push the "MANU" button. In the manual mode, the "MANU" mode indicator light comes on and the transmission shifts up or down as follows.

 

"D" Position--The transmission is locked in third gear.

 

When your vehicle speed drops down, the transmission will shift to second gear for smooth accelerating.

 

"2" position--The transmission is locked in second gear.

"L" position--The transmission is locked in first gear.

 

Quote

NOTICE:

 

Be carefull not to overrev the engine when using "2" or "L" position.

 

If the automatic transmission fluid temperature becomes too high, the "MANU" mode indicator light flashes for several seconds and goes off. The driving mode then automatically changes from manual mode to normal driving mode.

 

To cancel the manual mode, push the "MANU" button once again. The "MANU" mode indicator light will go off and the transmission system will work in the normal driving mode.

 

The manual mode automatically cancels out when the ignition switch is off.

So in manu mode it starts in 3rd gear! or kicks down to 2nd if needed. All a learning curve for me

:blink:where are you getting this info from, mine always pulls from 1st in drive

Unless you floor it I am positive that it starts in 2nd

Unless you floor it I am positive that it starts in 2nd

Mine has always started off in 1st when selected in D, just changes at very low RPM into 2nd when lightly on the throttle.

Mine has always started off in 1st when selected in D, just changes at very low RPM into 2nd when lightly on the throttle.

Its all dependant on how fast you press the loud peddle,

I bet the public havent seen so many supras launching from the lights with all us lot out testing

Unless you floor it I am positive that it starts in 2nd

if you have a car doing this, i'd say you have an issue somewhere.

Its all dependant on how fast you press the loud peddle,

I bet the public havent seen so many supras launching from the lights with all us lot out testing

I have to respectfully disagree

Even with the lightest of pressure on the loud pedal in D, mine still starts off in 1st gear.

I did think the same until I tried

Might not be able to notice so much in a tt but a everyday driving pull away its in second

No, mine 100% starts in 1st.

No, mine 100% starts in 1st.

Mine too