Setting timing for turbo w/dizzy
 

I got ahold of an old haltech f9. It only controls the fuel not timing. So I'm planning on using a distributor and putting a vacuum retard/boost advance canister on it.
Just wondering what a good starting point would be for timing. Running 10-12psi with 9.7 rotors 6-port turbo. Pump gas. I've been running the stock s4 turbo ecu with an rtek 1.5 and stock timing and never had a problem.

since you're running an S4 T2 ECU, you could just run stock timing on the distributor and it would be like 10 degrees retarded already...

what i found worked best using a dizzy on a boostd applacation is to set the timming at 0* at idle with the vac unhooked, than connect the vac line to MANIFOLD vac.

iirc vac advance is 10* and mech advance is10*

this will give you 10* at idle/low rpm 20* under cruse and the boost pressure retards it to 10* when your under boost. i found this to work very well for power and fuel econemy, way better than the locked dizzy a lot of people use.

Yeah, i didn't want to do a locked dizzy for driveability sake.

Indeed. The locked dizzy was a big part of the reason I gave up on blow-through. I never tried the stock dizzy because no one seemed to know what it would do when exposed to boost.

I never knew what it would do. All I've ever read about boosting with a dizzy is to use an older volvo 240 turbo advance/retard can and adapt it to a stock dizzy. I guess, when I get my stock one I could pump a couple psi to it and see what it does.

subscribed;there's some good info here for reference
i also have a f9 ecu & plan on using a similar setup

Mankdrake
can you update this thread as you proceed/progress?

I'll do my best. I'm kinda playing it by ear. Information is very scarce. My goal is to have it in Thanksgiving weekend. The motor it came off of was a similar setup so, hopefully it won't take much to get it going based on that map.

leave the t2 ecu in it .. it sort of retards correctly with the boost .. and uses direct fire and decent coils.. it already does the job much better than any dizzy

wire in the f9 to do fuel only .. take the ignition pulse signal from the leading coils .. it should essentially see the same as what it does when hooked to a dizzy

That's been suggested but I need the T2 setup for my FC project. Planning on going direct fire leading with an MSD 6A. The reason I'm doing the haltech is to simplify. I don't need 2 wire harnesses going through the firewall.

the distributor curves are in the FSM. unless you find a turbo distributor, it can only advance with vacuum, it won't retard at all with boost.

you should compare the logs people have of the T2 ecu with the distributor curves, the T2 ECU is more aggressive

Just to add, ruining your timing from an ecu will be better than a dizzy, but a dizzy will also work fine


A lot of people here will repeat what they heard... Us dizzy has vac advance and jdm 12at dizzy has boost retard... This is wrong, they may have differant advance curves but any one that gets both dizzys next to each other on the bench as I have can see what they do and don't do.

Then they will understand what I first posted, what the 12at dizzy dose is de-advance the timing the same way a usdm dizzy will when connected as I described

I.m assuming you.re refering to the leading plugs. what about the trailing side?

using a stock dizzy the leading has a vac pot and the trailing have a vac pot, you "tee" them together . then your leading and trailing will advance and de-advance together. your split will be what evet you set it at, i think i set mine at 10* split

Fantastic info here, I love search

Good info, im running a standard dizzy locked at 15 btdc for 10-12 psi on my blowthrough. I would like to try something a bit better for fuel economy. I will try the canisters to manifold vacuum to to see what it does.

Armyofone is your dizzy welded for no mech advance? Or did you just rev the motor up to initiate mech advance and then set timing to 15? Thank you

I spot welded the weights in place. I have also seen people just pull the springs off but I needed insurance.

I am also thinking of going back to firing the leading through the cap to lose the wasted spark, I'll let the dyno chart tell me what is best.

subbed

I just pulled the springs off of mine and set leading to TDC. It still advances about 10 degrees when I hit the throttle. So I'm guessing the arms aren't fully extending at idle. Still, I don't think there's any danger in just removing the springs as long as you know what the max advance is and tune for that.

I hooked up the vacuum advance (ported vacuum) and it had no effect whatsoever. I thought this system was independent of the mechanical system?

FYI this setup hasn't seen boost yet, still N/A until I get another manifold made.

Lizard mind sharing some info on how to LOCK the dizzy at tdc or the method you did.

Put simply:

Remove it, pull it apart, remove the springs, put it back together, reinstall, time L1 to the TDC mark on the pulley with a timing gun at idle. Or you can experiment with more advance if you want. I left mine at zero since that's where it idled the best.

Make sure you mark the orientation of everything before you pull it or you'll just be guessing at your timing when you're done.

That drift without the springs is the reason I wel the mechanism in the advanced position.

and a very good reason to do so.. timing drift on a turbo motor can hurt you in a bad way!
and going through the cap instead of waste spark will make more hp..
waste spark= fires coil twice as many times so the coil had half the time to recharge.. not good at high rpm.. the dyno will tell you this