ST vs BT

Cousen · **Posted:** Tue Jun 12, 2012 9:19 am

I know we all know one is black and one is silver, one runs with toothpicks and eats bearings, the other one is cheap and dirty.

Anyways, I want discuss the electronics. The ST came out with an AFM, for me that changes allot. I never really thought about it. It's not just some rods and squish areas that is different, but even the electronics. That last bit makes the two engines worlds apart for me and pretty much the only thing they have left in common is 20valves, but even that is not the same because the cams are also different.

What I know now about AFM is that it's nasty and I never really understood it. I think the ST was designed with more tolerance levels and the BT is more of a precision instrument.

I'm wondering how different the ECU's are now. I'm thinking with some changes to the fuel pressure and AFM trickery you could maybe tune it yourself a bit. Wonder what they do to the AFM on the stock 5M's and 6M's when they boost them?

Useless info and musings for the day done.. :thumb:

Boksie · **Posted:** Tue Jun 12, 2012 9:56 am

Honestly to mess with the AFM and/or standard ECU if you want to boost that car is just working backwards. Replace it with an aftermarket ECU and get it over and done with.

ScrappyDoo · **Posted:** Tue Jun 12, 2012 9:58 am

They will do what the Uno's do. Remove the AFM and fit an aftermarket fuel management system. It will be way less hassle to do this!! Why mess with an old system??

Cousen · **Posted:** Tue Jun 12, 2012 11:37 am

I agree with you guys. Looking at the other forums, this thing of chipping the 20valve always comes up, I don't understand it. As you guys said just fit a stand alone system. Besides that, these guys wan't to make there NA 20valves "fast", allot of money for very little gains.

rxi18675 · **Posted:** Tue Jun 12, 2012 11:41 am

Yes no reason to complicate it! go aftermarket ecu! blacktop and silver top almost with engine parts only share the same block casting! head design is also different! throttles, ecu rods pistons cams thermostats not the same flywheel ,timing belt covers different oil pump different . 1 has a oil cooler 1 does not! so ya quite a few differences. as for chipping because of the closed loop system it doesnt take well to the 20v so goes back to standard so to say! Aspirated spend alot of money yes but there is a thrill to it! and the engine is capable but comes with a price tag to modify!

rxi18675 · **Posted:** Wed Jul 18, 2012 2:09 am

Just to add some info here.. the crankshaft gear is also different on black and silver top... there of by a few degree's
doing another build here currently for some1 else.. blacktop bottom end.. but silver top oil pump.. and blacktop head.
So whats need for it to work is.. use the silvertop crank gear and a silvertop timing belt which is 111-teeth opposed to black tops 110-teeth timing belt. cam timing remains as per oem marks..

Bang'DUp · **Posted:** Wed Jul 18, 2012 9:46 am

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ST vs BT

ST vs BT

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