M112 snout reversal?

[David2009]

I will be using a GE exhaust cam and choose between GE or GTE inlet cams, I suspect the GE is the better?

I have adjustable camshaft gears and am informed that +1° inlet -3° exhaust are 'ball park' settings for stock cams on both 2JZA80-GE and GTE.

Is there a camshaft Guru here who could advise which inlet cam to choose and supercharger ball-park settings please.

Exhaust cam. (common)

Lobe separation 114° TDC
Exhaust Duration 236°
Exhaust Camshaft lift 8.4mm
Exhaust valve diameter 29mm
Exhaust Valve timing - Opening 52° BBDC
Exhaust Valve timing - Closing 4° ATDC


Inlet cam choices

GE 10:1
Lobe separation 114.5° TDC
Intake Duration 235°
Intake Camshaft lift 8.3mm
inlet valve diameter 33.5mm
Intake Valve timing - Opening 3° BTDC
Intake Valve timing - Closing 52° ABDC


J spec GTE 8.5:1
Lobe separation 113.5° TDC
Intake Duration 224°
Intake Camshaft lift 7.88mm
Inlet valve diameter 33.5mm
Intake Valve timing - Opening 3° BTDC
Intake Valve timing - Closing 41° ABDC


Export spec GTE 8.5:1
Lobe separation 113.5° TDC
Intake Duration 233°
Intake Camshaft lift 8.25mm
Inlet valve diameter 33.5mm
Intake Valve timing - Opening 3° BTDC
Intake Valve timing - Closing 50° ABDC

For reference;

1G-GZE 8:1 camshaft spec

Lobe separation 113° TDC
Exhaust Duration 240°
Exhaust Valve timing - Opening 53° BBDC
Exhaust Valve timing - Closing 7° ATDC

Lobe separation 112° TDC
Intake Duration 228°
Intake Valve timing - Opening 2° BTDC
Intake Valve timing - Closing 46° ABDC

[David2009]

The Dyno-day of reckoning arrived for the conversion, here's a clip of it running on stock ECU before the set-up.




However, before we bolted it to the hubs, it sucked the guts out of the Idle Control Valve and trashed the brand new M112.


(Pics won't upload)


What idle control valve is going to be man enough for the rebuild?

[vinces427bb]

i would look into the ICV on a stock toyota-car/truck, ford-mustang/truck-lightning, or GM-car that was supercharged
great to see it running, hope you corral the issues keeping you from driving and enjoying it

[Michael]

Nice video, thanks for posting. Glad to see the project has made some good progress... at least until the IAC's guts laid waste to the M112; sorry to hear.

But I especially liked the shot of the smiling builder at the end of the video...LOL!!! That was gold!!!

Keep us posted on the rebuild.

[David2009]

The ICV used was same as the stock Toyota 1G-GZE set-up and I'm not trusting that again.

Looking for a strong valve and to fit a safety net system too.

[David2009]

For the rebuild I used a Bosch ICV from an Audi.

With the present belt configuration it's boosting to 12lbs, yet I am adding another idler up close and friendly with the supercharger pulley to gain more wrap and reach the target boost of 15psi.

[vinces427bb]

sounds great
which cams did you use, and are you happy with that choice?

[David2009]

I am running stock N/A cams, the 15lb pulley is slipping @ 12lbs and it's on a temporary map until the new idler is installed, I will let you know.

[David2009]

It's working properly now and boosting to 11.5lbs. :)



rollers 024.JPG

It's a hub dynograph, flywheel figures are 30 more.

The cam timing is stock, I'm just happy to have it working at last.

After I have completed the water/meth installation, I'll fit a 3.6" pulley (14lbs?) and have it remapped.

[David2009]

The conversion has been my daily drive for 6 months now with no failures. :)

Now the winter is easing, I'll soon have the opportunity to complete the transmission modifications and then go for a re-map with a 3.6" pulley, 14 lbs boost?

If there's anyone with input to my camshaft choice post above, now's the time please.

[David2009]

I will be using a GE exhaust cam and choose between GE or GTE inlet cams, I suspect the GE is the better?

I have adjustable camshaft gears and am informed that +1° inlet -3° exhaust are 'ball park' settings for stock cams on both 2JZA80-GE and GTE.

Is there a camshaft Guru here who could advise which inlet cam to choose and supercharger ball-park settings please.

Exhaust cam. (common)

Lobe separation 114° TDC
Exhaust Duration 236°
Exhaust Camshaft lift 8.4mm
Exhaust valve diameter 29mm
Exhaust Valve timing - Opening 52° BBDC
Exhaust Valve timing - Closing 4° ATDC


Inlet cam choices

GE 10:1
Lobe separation 114.5° TDC
Intake Duration 235°
Intake Camshaft lift 8.3mm
inlet valve diameter 33.5mm
Intake Valve timing - Opening 3° BTDC
Intake Valve timing - Closing 52° ABDC


J spec GTE 8.5:1
Lobe separation 113.5° TDC
Intake Duration 224°
Intake Camshaft lift 7.88mm
Inlet valve diameter 33.5mm
Intake Valve timing - Opening 3° BTDC
Intake Valve timing - Closing 41° ABDC


Export spec GTE 8.5:1
Lobe separation 113.5° TDC
Intake Duration 233°
Intake Camshaft lift 8.25mm
Inlet valve diameter 33.5mm
Intake Valve timing - Opening 3° BTDC
Intake Valve timing - Closing 50° ABDC

For reference;

1G-GZE 8:1 camshaft spec

Lobe separation 113° TDC
Exhaust Duration 240°
Exhaust Valve timing - Opening 53° BBDC
Exhaust Valve timing - Closing 7° ATDC

Lobe separation 112° TDC
Intake Duration 228°
Intake Valve timing - Opening 2° BTDC
Intake Valve timing - Closing 46° ABDC

After much head scratching; I've decided to swap in a GTE Export spec inlet cam and run it @ -1°?


My reasoning is;

This will reduce the overlap by 1° without increasing lobe separation.

The resulting 2° less duration and lower lift should be more than compensated by the boost and from less of it lost.

This configuration also weighs towards a more dominant exhaust cam profile and is a smallest angle lobe separation configuration of the bunch.

[vinces427bb]

after thinking on this;
knowing it is hard to pick an exact winner cam without knowing the airflow values for your heads intake and exhaust....
i would go with the J-spec GTE cam on intake=due to the lower rpm performance it will give as the boost will easily fill the cylinders..

although i do think it should run hard which ever cam you pick

[David2009]

In preparation for a remap into the 400 club, I've been working on the A343/0E Hybrid transmission, upgrading the valve-body and fitting IS250 flappy-paddles which put a mind-bendingly random Gremlin into the manualised gear-changes.

It would appear they're not simple momentary switches and must have a gizmo of some sort inside, there are 4 different combinations for the electrickery and it was of course the last configuration of re-soldered joints onto the microswitch terminals to be tried that worked properly.

I've been out and made a vid-clip, it took an hour of B road stalking to find 20 seconds of peace and I only managed one run.

A rough uphill straight that proved a bit lively north of 90 Leptons causing my tools and things to leap about a bit in the back, but it was that or nought.

The gauge shows full boost by 3k but I'm sure it's lagging behind, the AFR shows a nice steady 12 and the mil light is telling me that it doesn't like the cat overheat sensor living behind the radio.

The copper plugs haven't been touched since it was mapped 8k miles ago and they're no longer happy over 6k revs, so was aiming for changes @ 6k.

WOT stresses cause slower changes and 1st to 2nd takes the longest, I was a nodger late with the first two, but not too bad for my first blast with the new setup.

Constant thrust change times @ WOT are down to around; 1st to 2nd 0.9 sec, 2nd to 3rd 0.2 sec and 3rd to O.D. 0.3 sec.

Suprastick is set @ 0.1 sec lock-up delay which can be reduced to 0 for faster changes, but that 100 milliseconds 'softener' gives the best traction on dry tarmac.

The 2nd to 3rd actuator has the strongest pair of springs and gives the fastest change, so when more important jobs are out of the way, I'll fit stronger springs into the others and see if I can get them all down to around 200 milliseconds for road use and 100 ms for the strip.

[David2009]

Seeing in the real world what the stock cam can do before swapping.

I've mastered the belt traction and fitted a 3.2" pulley, it should now be pumping enough air for my 500 ftlbbhp target. :)

However, there's a blow in the exhaust manifold that's also a random suck and the intermittent air getting in is causing the O2 sensor to have fuel cutting fits. :(

I've tried 2 used ones now only to learn that 18 years old crank sensors are wooly and it needs a new distributer.

Videos and data.

First test spin with the 3.2" pulley and I told Dan to do his damnedest to make it slip.

[David2009]

Here's the boost pressure and induction vacuum graph. :)







I didn't get away until 7pm and we had no time to tinker with the water/meth, yet without it, the max-temp of post heat-soaked charge-cooled air after retiming the cams back to stock was 36°C @ 6.5k rpm.

Here's a bunch of info if it means anything to you?