6G Celicas Forums

Hi guys im thinking about going turbo, i have a stock 7afe motor, im currently running a 3 row all aluminum radiator and a big transmission oil cooler with an electric fan on it. I have a brand new torque converter inside the transmission. I got about 140k on the motor and tranny. i also have 440cc injectors (not installed), got a cheap aem piggy back (not installed). i will go have it dyno'd and tuned by a shop if i do get a turbo setup but im curious what 7afe stock motors can handle (my guess is not very much). i dont want to kill the motor just want to bump up the hp and tq as much as i can without going forged.

I think it'd be more cost efficient to swap in a 4agze. Is it being auto essential to you?

Personally I do prefer auto for daily driving because in hawaii traffic sucks. And I don't fancy driving stick for an hour in traffic.

But I think I read 3 to 4psi is fine in stock internals, But I believe that was with a manual transmission. Not sure how much extra the auto can handle.

http://www.6gc.net/howto/turbocharge_your_7afe Stock injectors max out at 14 psi.

http://www.6gc.net/forums/index.php?showtopic=64431

While I'm sure you'll get appropriate and correct answers from other members... Hafkai is pretty much the boosted 7A guru on here as far as I know.

Now i feel dumb, thanks box

I swear i read 3-5psi was safe and anything more was dangerous on stock internals.

Then again I know very little.

Just depends on the engine, internal components strength and compression etc... Most engines stock are good for around 6, some can do 10-12. Just depends.

I see thank you :-). im pretty scared of running up boost lol. I think if i have a good tune i will do no more than 14 psi. even that is pushing it. Its going to cost me $400 to get it tuned, i dont know if they dyno it while tuning i think they do, then again i never had it done so i dont know. i will start with the standard 7 psi then work my way up but wont exceed 14psi. Seems like a manual tranny wont take 14 psi without getting a stronger clutch, im running an auto :-(, i wonder how much it will take before slipping and such. hopefully 14 psi wont be too much for it.

I see thank you :-). im pretty scared of running up boost lol. I think if i have a good tune i will do no more than 14 psi. even that is pushing it. Its going to cost me $400 to get it tuned, i dont know if they dyno it while tuning i think they do, then again i never had it done so i dont know. i will start with the standard 7 psi then work my way up but wont exceed 14psi. Seems like a manual tranny wont take 14 psi without getting a stronger clutch, im running an auto :-(, i wonder how much it will take before slipping and such. hopefully 14 psi wont be too much for it, although i really doubt it lol.

This post has been edited by rapid36: Feb 24, 2015 - 11:10 AM

If you want faster accelleration you can always go with a smaller torque converter so the stall speed will be higher and will be closer to peak torque (it'll make it feel ALOT faster when you start getting pulled at 4400 rpm lol) also it will help to make the car to idle smoother since there won't be much of a load at idle or even when your foot is just on the brake and you're in drive. There's no real mechanical connection until the "clutch" engages when the rotations match each other to stop slipping. Not too sure if anything AFTER the the torque converter might break though. Anyone know the strength of the auto st drive shafts? Lol

Also I put clutch because it has a clutch like function And is operated by fluid pressure, but I can't remember what that part is called...


This post has been edited by Noahwhite2014: Feb 24, 2015 - 4:45 PM

Totally makes sense, anyone know the compression a stock 7afe is suppose to have Per cylinder?

It's 9.5:1 if memory serves me correctly.

thats not very high compression i would imagine i could get away with 12psi pretty easily if i had a good tune on it. however im still unsure if the tranny will be able to handle it. doesnt anyone know how much an auto tranny can hold as far as HP goes for the 7afe?

Also ive been thinking about re doing the valve seals on the car, seems like that is a problem recently on the car, so i was gonna put in a more agressive cam, would this be a good idea for my turbo idea down the road?

To be honest, if you're wanting to stay automatic you'd be better off doing a 1MZ swap out of a Camry, ES300, Avalon, etc... They have the torque and power to make an automatic halfway bearable and there's no guesswork or worrying if things will last or work.

The 7A-FE is notorious for stuck oil control rings and consequently burning oil.

The compression of the motor doesn't have a lot to do with it. The real problem is in having an ecu where you can adjust the timing map. Most piggy backs can't do this, and you're stuck running 20-30 degress of timing advance under boost, where as timing under boost should be in the 15 degree range. At 30 degress of timing advance, even 7 psi is bad.

^It has to do with dynamic compression which can limit total boost, but I know that you know that obviously.

Another thing to to think about is you'll have to run higher octane fuel, but if you're willing to spend the money for a turbo conversion then that shouldn't matter. Also you'd probably need a higher stall torque converter as mentioned earlier to get the most from it, but I doubt anyone makes one for your given application. To do it right you really need forged components, and better computer management like lagos mentioned. Just look at what all Hafkai went through in order to do it right.

Really, look into the 1MZ swap. There's a lot of info here on it and it'll give you the end result with stock reliability. That or go with the 3S-GTE from a Caldina.

This post has been edited by Box: Feb 27, 2015 - 12:31 AM

Awesome thanks guys!

I am running 10psi with 6 degree static retard and safc I do daily ecu resets. I have ran up to 14psi

It has been a long time since I have been on here. I use to run 14psi on my 7afte auto all the time. The most I sent through it was 27psi. Blew my couplers apart!! Lol
Now before anyone says bs! I had a greddy black box on it then. I also was running 110 octane that night at the track. I did 3 runs on it. First one my wheels spun to much on the launch. ... I went in the burn out box & did not know to clean my tires. So I ran a 15 sec the second run I avoided the box & ran a 14 flat. The third I blew the couplers on & came in with a 16.5 lol!!
Now fast forward to now & I am still running the same motor & transmission in the car. Only thing is I sold the turbo kit back in 2008/9. Bought a house & had kids. Now the kids are older & I am going to turbo it once again. I just don’t plan on racing it. So 7 psi on a good tune is the plan. Just for show.