cam grinding for a 6m

**pete05** · 01-04-2007, 07:21 PM

Does anybody know what size regrind cams i could run on the factory ecu of a 5m/6m with out getting into trouble with the ecu?

**pete05** · 02-04-2007, 09:58 AM

can anybody tell me are the cams shown in this thread mild?http://forums.toymods.org.au/index.p...t=0#msg_616845

**CrUZida** · 02-04-2007, 10:48 AM

Nothing wild, but you wouldn't get the benefits of the grind on the stock ecu.

**pete05** · 02-04-2007, 10:52 AM

yeah bit of research has shown that the stock ecu is useless above 5300rpm at which point it just goes super rich.

**CrUZida** · 02-04-2007, 10:54 AM

You can 'tweak' some of that with playing with the AFM.
But to do that you'll need dyno time.

**pete05** · 02-04-2007, 10:58 AM

yeah was planning on putting it on the dyno once the 6m is run in, i got the 6m rebuilt so be interesting to see what i can get from it. some of the guys on the supra forum are getting around the 150rwhp with an exhaust so i would be happy with that

**ViPeR_NiPPleX** · 02-04-2007, 12:22 PM

problem with the 5/6/7m afm is its maximum flow reading is exceeded when above a certain rpm at full throttle. So manipulating the afm by adjusting spring tension or doing it electronically wont help when trying to go up high in the revs. It will probably lean out.

A problem with the heads and reground cams, unless material is welded onto the cams and then ground back to the factory base circle, the hydraulic lifter will try to take up the slack because the base circle is reduced and might possibly either come out or run out of travel. If you get cams reground, measure the factory base circle and then the reground cams circle, take the difference and remove that measurement from the bottom of the cam tower, this should in theory bring the valvetrain geometry back inline.

There is more information on the topic on www.celicasupra.com/forums

**CrUZida** · 02-04-2007, 01:12 PM

Originally Posted by pete05

yeah was planning on putting it on the dyno once the 6m is run in, i got the 6m rebuilt so be interesting to see what i can get from it. some of the guys on the supra forum are getting around the 150rwhp with an exhaust so i would be happy with that

There are also guys on the forums getting more rwhp than factory flyhp, and these are just rebuilds, not worked.

I'd say 100rwkw would be a nice figure to get.
Anything over that would be a bonus.

**CrUZida** · 02-04-2007, 01:14 PM

Originally Posted by ViPeR_NiPPleX

problem with the 5/6/7m afm is its maximum flow reading is exceeded when above a certain rpm at full throttle. So manipulating the afm by adjusting spring tension or doing it electronically wont help when trying to go up high in the revs. It will probably lean out.

That doesn't compute, as you can force 5-6psi of boost into a 5M and the AFM doesn't max out (it still runs rich as fuck)

**pete05** · 02-04-2007, 02:22 PM

from what i have read once it passes the air flow meter max open, it goes to set map values based on rpm and i believe it goes very rich in the mixture. Once the 6m is in it will go on the dyno and i will see how it runs.

**brett_celicacoupe** · 02-04-2007, 07:01 PM

you need to realise that the power made by an engine is proportional to the air consumed.

its something like 10lb/min of air per 100hp. (imperial units FTL)

the airflow meter has a maximum volumetric flow rate probably 15-20% higher then the stock engine at redline. this allows for the differences in air density, less dense air (higher temps) means the AFM will see a larger volume of air flowing through it for the same hp.

the ECU can calculate the mass/time of air entering the engine based on the volume/time and temperature.

since toyota run all their engines uber rich, power can be gained by leaning them out safely towards stoich, or just under. tampering with your AFM spring may cause more headaches then its worth.
making the spring tighter will only squish the curve in the negative X direction. im still trying to understand all the relationships but you may be able trick the ECU via the temperature sensor. placing a resistor in series maybe? depending on how the temp sensor works, youd want to make it think there is less air entering then there actually is (lean it)

or.... taunt the spring (to avoid maxing the AFM) and lower the temp signal. the taunting would lean it and you could richen it by lowering the temp voltage.

some info here http://www.geocities.com/MotorCity/P...ct/Engine.html

just some thoughts