st 204 turbo Options

[thorshammer]

Hi I have a st204 Celica with 5fse engine and am wanting o turbo it. I have read 1bwilson's and Shid's posts on turboing a 5sfe and list of components needed and this seems to be the best way to go. In my neck of the woods CT26 turbos are hard to come by, T3/T4 turbo is easier to sourc.e My question is what T3/T4 do I need and other than a CT26-T3/T4 adaptor is there anything else I need. I live in Australia so Mustangs and other American cars are not common here but plenty of Japanese sources. Thanks

[delusionz]

I didn't know the megasquirt interpolates values, i'm not sure if my ecu does that or not

but i do know that for example if boost references are 5psi apart... and say you had references -5, 0, 5, 10 etc, then optimal timing would be at those points, but 1,2,3,4,6,7,8,9 etc psi levels will have less than optimal timing

i'm betting if i had 50x50 over 20x20 i'd have more overall torque and smoother power, and my highboost where i run out of resolution would be alot more punchy

[lagos]

I didn't know the megasquirt interpolates values, i'm not sure if my ecu does that or not

but i do know that for example if boost references are 5psi apart... and say you had references -5, 0, 5, 10 etc, then optimal timing would be at those points, but 1,2,3,4,6,7,8,9 etc psi levels will have less than optimal timing

i'm betting if i had 50x50 over 20x20 i'd have more overall torque and smoother power, and my highboost where i run out of resolution would be alot more punchy

They all interpolate the values.
The only real benefit to larger maps is that you can add different fuel or timing values in very odd cells, like 10 kpa to slightly smooth out the transition during throttle lifts. Or you can add specific cells for very high boost levels your car will never run.

If you look at your boost gauge, the transition from 0psi to 7psi to 10psi to 15psi happens almost instantly. So you only really need to tune the car for those values, with one extra row for something like 20psi, should you decide to up the boost to a crazy level. If you dial you boost to 13psi, its just going to use the interpolated value between 10 and 15, and since the changes in timing and fuel are linear, that value will be correct.

Personally I think 16x16 for both fuel and timing is perfect. No one is going to dyno tune their car at 1psi, 2psi, 3psi, 4psi, 5psi, 6psi, 7psi + and need some specific settings in each of those to warrant some 50x50 ignition table.

say you had references -5, 0, 5, 10 etc, then optimal timing would be at those points, but 1,2,3,4,6,7,8,9 etc psi levels will have less than optimal timing

Thats actually not true. The transition is linear. No professional tuner takes the time to tune each psi level, because 1) it would take a lot of dyno time and 2) the values they would find would be somewhere in between of the highest and lowest cell they already tuned for.

This post has been edited by lagos: Jul 27, 2013 - 1:06 PM