Is there a difference between bt and st 20v head???

[Sam-Q]

what do you mean by angles riojin?

[Frak]

I think the ST head is underrated, I quite like the squish zones

ST combustion chamber for NA

[Sam-Q]

on a blacktop you could machine the edges of the combustion chamber to be a constant angle all round and then do the F1 trick of having matching upward quench zones between the piston and the head. Moving onto the real world yeah I have wondered why they changed that, any ideas Frak?

[Frak]

I think this would be a good idea, but like you said real world.

you know lately, bloody 20v's have had me pulling my hair out! as you know there is an early and a late ST, they really respond like two different engines. I think the open chamber of the BT really has to do with what Toyota were using the engine for at the time with regards racing, chasing hp at really high rpm, reducing valve shrouding and using pistons with high dome.

Technically if you look at the extra work they did on the BT compared to a later ST, it was a lot of work to get very little hp for the road engine, racing obviously very different, the ST throttles are more than big enough for the hp a road engine puts out, there was no need for the bigger BT throttles, unless you needed more airflow at the sort of rpm they were using in racing. The BT is very much a totally different intake port/combustion chamber/exhaust port compared to a ST for a gain of only 5hp on a road car.....there was a bigger picture at Toyota(racing)

I just finished dynoing another ST with cams etc and it's really bloody easy to go backwards

Once the new electronics are up and running on the engine dyno I'm planning some serious ST dyno time

I'm not kidding these are a very tempremental engine with regards getting good hp or low hp once you start changing cams etc.

[slider4life]

Can anyone recommend a good 20v tuner with a haltec??? I'm from port Macquarie but I will travel.

[FoldKing86]

You could ask Just Engine Management but you'll be waiting a while. Pathetic customer service in that joint. But its your car.

Sounds like you need anybody other then your current tuner. Pretty sure there's a tuners guide on DC somewhere9i couldnt find it). Maybe SAS or Uni group.

[Sam-Q]

makes sense, although what doesn't is I thought they never put any serious work into getting the most out of one of these, that is unless they realised later it was a total flop because of the flawed 5v design.

I also shake my head when people say you gain power by fitting blacktop throttles, I mean they are bigger!!

So is it true there isn't a more tempremental engine in terms of collector design?

[Vance]

talk to wideslider on these forums. hes getting 96rwkw out of a standard blacktop+trd headgasket+t3 trumpets running on a haltech. pretty sure his tuner is in the south-east sydney area

[Matt]

If you take your car to JEM expect to be waiting 6 weeks, and then have to take your car away on the back of a tow truck...