Adjusting aftermarket camshafts - 7mgte
- Thread starter BLACKCAT
- Start date
I go strictly by the degree wheel on the crank, and actual movement of the cam followers.
This is because of manufacturing tollerances in both the cam gears, and cams (especially BC cams) will vary from one set to another.
I run between 114 to 116 degrees between lobe centers.
And the lobe centers strait up (this means that the lobe centers are equally spaced from crank top dead center)
Then advance/retard to get the power band where I like it.
Hint: record where you have cam gears at to achive 'strait up'.
Then you do not have to put a degree wheel on, and pop the cam covers off every time you want to fiddle with them,
you will always know where 'home'' is.
Any less split between lobe centers, will yeild greater peak HP, but less power band width.
On bike engines, with very good trans ratios (little RPM drop between shifts)
I run as low as 106 degrees split.
But our trans drop the rpm from one gear to another quite a bit,
so less overall power/wider power band is actually faster than more peak/narrower power band.
This is because of manufacturing tollerances in both the cam gears, and cams (especially BC cams) will vary from one set to another.
I run between 114 to 116 degrees between lobe centers.
And the lobe centers strait up (this means that the lobe centers are equally spaced from crank top dead center)
Then advance/retard to get the power band where I like it.
Hint: record where you have cam gears at to achive 'strait up'.
Then you do not have to put a degree wheel on, and pop the cam covers off every time you want to fiddle with them,
you will always know where 'home'' is.
Any less split between lobe centers, will yeild greater peak HP, but less power band width.
On bike engines, with very good trans ratios (little RPM drop between shifts)
I run as low as 106 degrees split.
But our trans drop the rpm from one gear to another quite a bit,
so less overall power/wider power band is actually faster than more peak/narrower power band.
I have the same cams in my 88 7mgte. heads worked over w 1mm os valves, port and polish. curious what the setting would be if i just popped the old cam gears off, put my adj fidanzas on, the crank is at 0 and the original cam gears both pointed straight up. how far would i want to retard/advance each cam respectively with this position. i wouldve used a degree wheel and done this proper but the company i gave my cyl head to with the bc cams in the box somehow managed to keep my cam timing tag, didn't realize it once i got it back, and therefore put the motor back together under the assumption no degreeing was necessary as per bc told me(until i asked about the adj cam gear to a bc rep. told him my engines symptoms and he gave me a base correction.)
Where exactly are you retarding/advancing ur cam gears from? TDC of the crank, or .050" lift with a degree wheel? Im interested in how I can adjust my gears from TDC of the crankshaft @ 0 degrees. Right now, according to BC, I was advised to try -2 intake +2 exhaust. then timed the engine about 9-10 deg BTDC to keep my idle about 750 ish. But my car under a load studders bad, runs way lean. i haven't gotten to WOT to check it cuz its studdering like it does. dont have a timing light accessible atm so i tried moving the intake another degree but made the problem worse actually. any advise BLACKCAT?? my car is fully worked, cyl head : os 1mm precision valves, port and polished, BC264's, BC springs/retainers, HKS stopper head gasket, ARP torqued to 115lbft.(alot i know, but they can take it and i dont wanna blow that 350$ H.Gasket.). Engine: bored .060", new pistons, stock rods, crank mag particled and balanced, new bearings everywhere, Driftmotion 60-1 turbo .70 AR, tubular t4 flange manifold, ext. 50mm wastegate, 3in intercooler w/ alum piping, godspeed radiator, dual flexalite puller fans, turbosmart gbcv elec. solenoid operated two stage manual boost controller, AEM uego, APEXi Neo, Aeromotive AFPR, fuel dampner bypass, Walbro 255lph, Lexus AFM, RC 550cc injectors, new coil packs, elec tested every possible sensor/assy on the car, repaired alot of the harnesswhere wires were cracked at plugins, pretty much pulled entire harness apart, inspected, and re antichafed the whole thing and taped it back up, ive taken the motor apart three diff times after i had installed everything chasing down little problems. my buddies had six of these cars, the seventh was mine but he never got around to fixing it, in a round about way i bought it. anyways, he has never tuned one with cams in it, or played with this NEO but done lots of tuning with SAFC I and II so i have confidence, but were all exhausting our local supra resource of combined knowledge. The only way for me to get a degree wheel on the car and be able to remotely read/install it correctly is to pull the radiator. if thats what you suggest the best way is(i know it is the best way i just dont want to fucking do it) then i guess so be it. please help!!BLACKCAT;1393732 said:
