New Member

[mtrt012]

Hi Guys,


I just signed up on the website.

Im from Nebraska.

I was on here a long time ago but forgot my credentials of my associated email so I just signed up again.

I have an 84 750 turbo project that I’ve been working on over the last few years.

It currently has a hayabusa front end, a billet turbo upgrade from Charlie, a clutch basket from Roger etc.

I’m currently working on finishing up an aftermarket megasquirt 3 ecu swap to get rid of the factory dfi system.

I have the aftermarket system configured to give full sequential injection, (had to add a cam sensor for full sequential) and waste spark using 2 gm dis coils and wide band o2 sensor.


The bike starts runs and rides and I’m currently working on tuning the spark and fuel tables.

Does anyone know or actually checked on a dyno what the stock ignition timing is at full boost and full load.

The supplement manual says about 30 degrees from 3600 rpm on.

This seems like a lot of timing at max boost. Especially in race mode.

(I’m getting around 22-23 psi boost but my timing is setup to ramp down from 30 btdc to 10 btdc as the boost ramps up)

I’m curious if the stock ecu can actually control timing or if it’s all done by the stock igniter.

Anyway maybe I need to start a new topic in a different place of the website but I wanted to introduce myself and my project to you guys.

Thanks,

Ryan

[Lorcan]

Welcome back Ryan!

In an email to you I stated that the ignition went from 30 degrees at idle to 10 on boost - it's the other way around! . 10 at idle and 30 as the revs go up, I think the standard GPz750 goes to around 36 degrees so the turbo is effectively retarded 6 degrees on boost.

How much advance you run on elevated boost is highly dependent on the fuel you use. What do you plan on using? On 120 octane (leaded) race petrol I ran the full 30 degrees and it was fine, but for unleaded fuels you'd need to run less.

[georgew4714]

Welcome back Ryan
Very interesting project , good luck

[mtrt012]

Thanks George.

The project has been fun and I’ve learned a lot so far.

Lorcan,

I’m using 91 pump gas but I’ve got the timing set to go from 30 to 10 deg as the boost comes in. This should be pretty conservative compared to stock timing.

Hopefully it will be a little insurance while I’m tuning.

My initial fuel tune is targeting an afr of about 13:1 under cruise light load and 11.3 at max boost.