whats the crack with 16v turbo?

[kazi]

I've been thinking about this for a bit now but I'm not 100% what way to go. turbo 16v or ITB the 16v. I'm leaning towards turbo as I miss the power and think turbo with 86 chassis would be a good match.

anyway!! I have my old 3 rib Big port engine doing nothing and in need of a rebuild but whats everyones consensus with the building a turbo 16v.

I would aim (if i go the turbo route) for 240WHP. Not used for drift, more fast road and occasional track/sprint use

whats best?

3 rib / 7 rib (I know this is an on going thing but WHY? is there any real life experience from both sides?)

would 4AGZE pistons stand 240hp or go forged?

crank size? would the 40mm crack work from the 3 rib?

Transmission... People say the T50 is weak. but would it stand grip use

Rear diff... same as above.. if not what do people use.

I'm not wanting this to snowball into a house deposit but equally i know this isn't going to be cheap. I want good power (240 ideally), good reliability and a good cost. Hard to get all 3 i know!

[Bean]

The power itself isn't the real issue it's the increased torque of a turbo build that will drastically decrease the life of your drivetrain.
With an ITB build you'd struggle to get 240whp that's pretty much up there with the most powerful NA 4AGEs in existence (so difficult and very expensive).

If you really want to achieve good value and some sort of reliability I'd aim lower with the power or consider a different engine all together

[kazi]

(07-31-2017 10:57 PM)Bean Wrote:  The power itself isn't the real issue it's the increased torque of a turbo build that will drastically decrease the life of your drivetrain.
With an ITB build you'd struggle to get 240whp that's pretty much up there with the most powerful NA 4AGEs in existence (so difficult and very expensive).

If you really want to achieve good value and some sort of reliability I'd aim lower with the power or consider a different engine all together

Yes sorry, should have made that clear that I'm not after 240hp going NA. Would be nice but damn near impossible. I'm going to stick with 16v. At the moment I can't bring myself to put anything else into an 86 apart from the 16v. As much as I'm wanting to turbo and as backwards as my next line is, I want to keep the car as original (in terms of engine anyway) as I can.

[Bean]

4AGZE? if you can get one for a good price it'll have over 50% more torque over the old bigport, as I assume that's what your missing.
To get figures like that NA you're looking at a couple of grands in parts alone + tuning

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[oldeskewltoy]

kazi - "as I miss the power", what kind of power/car are you more use too??

Have you driven an AE86 with 170-180 crank hp? It isn't supercar quick... but it is a great compromise between mashing the throttle and accelerating... as opposed to either... mashing the throttle and not moving... OR having so much power that mashing the throttle only gets you a violation of one kind or another.......

If you are looking for torque and power and keeping it n/a, look into building a 7AGE.


Now on to turbo builds... 250whp should not need much more then a set of pistons, a mild cam, a set of performance valve springs, a properly sized turbo, and proper management (with knock monitoring).

Pistons - you could use OEM Toyota 4AGZE pistons, but they are very old technology. The original 4AGZE pistons are just too low a compression, and while the 2nd gen pistons are better, I'd look for a custom piston with a static CR of about 9.5:1, or 10.0:1 for best results.

Mild cam - Stock cam duration is 240 overall, and 204 @ .050". I'd keep duration @ .050" to 212 or less. Big lift cams will require big $$$ work to get them to "fit", I'd keep lifts to 9mm, or less. 9mm lifts will fit many of the "performance" valve springs.

Valve springs - for the intake side a MINIMUM of 32# + #'s in boost you plan on running (15#s of boost = 15 + 32 = 47#s of seat pressure on the intake side). Exhaust side doesn't have to contend with boost. Now for a but... although the exhaust side doesn't contend with boost, a performance spring will accommodate larger lift, longer duration cams better then stock springs.

Engine Management - Keep it simple... decent resolution, ease of tuning, knock monitoring, data logging.

Turbo - something with quick spool, that will make a max of 330-350hp pumping to a 4AG. This will allow you to make your goals, with a little bit extra for "turn'n up the wick"

[kazi]

Thanks for that reply!!

Previous power output in used to is 300hp in a st206 celica. Was quick but weight of car killed it. And my last car before importing the 86 was a 221hp Starlet Glanza. Around the same weight as the corolla on a 1.3 4efte running 0'9 bar on a TD04L. That was a quick car but not over quick that I couldn't use the power.

As for being in a 170 crank power 86.... no I haven't been in one. I have the only 86 in about 200 miles at least.

That's the information I'm after about pisto viability and head etc etc.

300 in an 86 I can imagine would be pretty quick with a sorted chassis.