The turbo version of this engine prefers around 20* BTDC.

I'm dumping too much fuel initially. That's why it will start an run if I have the throttle open passed 75%. No more fuel is injected beyond that point.

Gotta adjust my fueling and my pulse width settings.


Also need to confirm that my injectors aren't leaking.


She's getting too much fuel initially. That's why it wont idle.


Tomorrow I will continue and see what I can accomplish.

20* is like a damn diesel lol

how much advancement are you getting throughout the RPM range?

Haha! yup. My 2 stroke outboard also likes 20* initial timing.


I once had a copy of the L28ET* timing curve that was published by someone but it was on paper and long lost. Anyone remember paper? Even better joke if you are a "Waterworld" fan Full advance was in at 3000 and what I've found to be a good starting point for tuning for pump gas (the quality could make a BIG difference) was a total of about 22-24* @ 15psi boost. If you follow a simple, linear map to retard 1* per 1psi boost, then you would want the full advance to be about 37-38* to have 22-23* total at 15psi boost (38* advance - 15* retard = 23* total). So, with an initial of 20*, you can then build a linear map to ramp the timing up to 38* advance at 3000. Since I will not likely to have 15psi boost below 3000 rpm, it should be acceptable.

All the maps are linear in the example and that can be refined later when fine tuning if I feel the need to ramp differently on the way to full advance. You can also get more aggresive with the timing if there is no detonation..... However, I fully believe more boost and less timing nets more power (with these engines) than less boost and more timing, as long as you are not detonating. Also, if you are not detonating and the EGTs are low (rich) you have the option to run more timing, turn down the FP or turn up the boost. Hmm, tough choice.


Obviously there are many different ways to think about, and approach, it.




*my motor is not a L28et, but instead a higher compression turbo'd N/A motor. So obviously this is not gospel.

This post was edited by OldAndyAndTheSea on Sep 3 2015 09:35am

you guys and your silly turbos that i know nothing of


who wants to put a turbo on the latemodel motor?

I've got a pair of twin 88's or a single 116 sitting in the box new (also have a few used s480s, s400s, and an aurora 8000) Those are babies though

Either of those should get you enough of a boost to win a race

i already win races lol


why dont we put them all on it?

two 88's pushing a 116 would be a hell of a set up lol.

Use some 2" rod for head studs

What frame and brand 88s are they?

The new in the box are the Percision 88-84's with ball bearings.

The other 88's I have are from a motor building shop that I can't name at this time. If i did, I wouldn't be able to stand my mirror image

the 116 is also a custom fab that i've used on pulling trucks and I had one left over.

So yeah...... The car I built actually runs.....on its own!




Go Figure.


Lots to do yet, but holy shit...this is a big deal.