true twin turbo mod
 

hey does anyone know how much boost the true twin conversion puts out without a boost controller? i have a boost gauge but its broken. i have the heavy duty intercooler boots for deisels and they keep slipping off so i need to know how much boost it is putting out. please let me know guys thanks

Both true twin, and (oem) sequential mode, put out about the same boost level without a boost controller (approx 11.5psi without a downpipe, and about 13psi - 14psi with a downpipe)...also depending on mileage & 'health' of your engine & turbos.

i just bought the motor it had 47000 miles on it i know this because i bought it jdm and saw the car before it was taken out. i have a greddy fmic and downpipe with 3.5 inch exaust all the way back. i also have another problem with the ttc. first gear does fine but after that it starts popping like its not getting enough fuel.

How many miles since you have changed the spark plugs?

I havn't done it since i bought the engine about 8 months ago so i will try it, do you know what kind are the best for a supra?

If you want plugs that don't need to be changed very often, just get stock plugs (platinum) and gap them down to about .032". Note: be VERY careful about damaging the tiny center electrode while gapping platinum plugs...the slightest scratch, scuff, or 'nick' on the edge of the electrode, will radically reduce the service life of the plug.

If you want copper plugs that need to be changed about every oil change, NGK 6097's are ideal for a 'bpu' Mkiv tt, imho...also gap them down to about .032" (depending on the max boost you plan to run, how old your coilpacks are, and whether you have an ignition amplifier (eg. HKS DLI)). Note that copper plugs are MUCH easier to gap than platinum.

i changed my plugs and i got the platinums and it didnt change at all, i think i may need a fuel pressure regulator, what do you guys think? my old plugs were disscolored and i looked at the chart and it said that i was running too lean.

Are you using a us-spec ecu or a jdm ecu?

u.s. at the moment i have a jdm 5 speed turbo but i need a clutch pedal assembly to use it because im auto

Is there such thing as a jdm 5 speed turbo? Afaik, the 2jz-gte only came with the 6spd.

Also, why are you changing to the jdm engine? Is there something wrong with your current engine? ...or are you only swapping ecu's and if so, why?

You said "...first gear does fine but after that it starts popping like its not getting enough fuel...". Does it also do that when you put it back to oem sequential mode?

Please fill us in on all of the details of the Supra you're currently driving with the "popping" problem', including all of the modifications.

i blew my old motor and the new one does not boost when it is only in sequential mode because my water pump went out a while ago and fried the vsv's, but befor my water pump went out it ran fine. the guy i bought the motor from went to japan himself and they rarly sell the 2jz with the 6 speed he said he could get the five speed turbo for me because it is best for drifting and that is what i enjoy doing. as of mods currently installed on my car i have, a greddy turbo timer, greddy blitz fmic, 3.5 inch greddy trust exaust, it had an hks boost controller but it was broken when i bought the car (you couldn't read the screen), and im still running the u.s. ecu. sorry if ive been kinda annoying lol, but im pretty new with supras thanks for all ur help

Honestly I think he is/was stringing you along. As far as I know the 5spd was never offered with the 2jz-gTe in the Mkiv Supra (aka jza80) because it doesn't handle the power as well. PLEASE make him prove me wrong here...I'd rather be wrong about this than have you stuck with a covertly-swapped tranny from an n/a Supra or Aristo... Oh and why on earth would he say the 6spd isn't as good for drifting? Imho, that doesn't make any sense at all either.

Not annoying at all...just trying to help you get to the bottom of the problem with your Supra.

It may pain you to hear that I'm going to suggest you go back to the drawing board here. Using true-twin mode as a band-aid to cover up faulty electronic components/wiring is a recipe for disaster, imo. I have to suggest that you not only get your oem sequential VSVs working, you also need to troubleshoot all of the wiring & other electrical components in the area where your water pump blew. For example, your crank position sensor wiring is also in that same location!!! Although I don't know for sure your Supra's popping/leanness issue is related to a wiring issue in the area of your water pump, that my best guess at this point in time is that it very well could be related. At the very least, getting those vsvs working again would allow us to test whether or not the popping problem also happens in sequential mode, right? Lastly, I'm sure you'd admit that you would rather your oem sequential VSVs were working perfectly, and if you decide to you can go to true-twin by choice rather than by necessity.

Oh, one last thought: how many miles are on your coilpacks?

the guy said that the 5 speed has longer gear ratios than the 6 so that is why it is supose to be better. and my coilpacks are the same ones that came with the motor so around 80,000 miles

That's not true either. Here are the ratios:

GEAR_RATIO_Between_V160 vs.
_____________Gears____W58
V160
_1____3.827
_2____2.36_____1.467____0.076
_3____1.685____0.675____0.056
_4____1.312____0.373____0.098
_5____1________0.312____0.095
_6____0.793____0.207

W58
_1____3.285
_2____1.894____1.391
_3____1.275____0.619
_4____1________0.275
_5____0.783____0.217

As you can see in every (!) case the gear ratio is longer in the 6spd.

They may be overdue for a change, along with your "fried...vsv's".