Ignitin timing w/turbo

[2eighTZ4me]

I've been told by a "turbo" friend of mine that I should run almost 0 degrees ignition timing on my turbo setup. Says the boost will "handle everything else". Well - I took the car to the exhaust shop last week with the timing set at 0 initial, and 6 degrees total at 3K. The turbo blanket was smoking like a chimney when I got there. My AFR's were still down in the 10's and 11's, but I suspect the severely retarded timing caused a lot of heat.

 

I have the Electromotive HPV-1 crank fire ignition/coil setup. I have since bumped it up to about 4 degrees inital, and 10 total. Car runs "better" - but really would like to have it set properly for the turbo setup. As much as possible without detonation.

 

Garrett T04 .60 trim

AZC Intercooler w/3" piping

MS 1 (fuel and boost - no spark)

Lonewolf intake

AZC 440cc injectors

240SX TB

Bone stock 80ZX "mule" motor w/130K on it.

 

I looked at Cygnus' spark table. Looks like he starts around 9 initial and goes up through 36 "all in". His setup is similar to mine. I don't want to "assume" anything with a turbo setup though. This is my first - and hopefully my last!

 

So - timing #'s capable of withstanding 18+psi and holding the stock motor together......???? Anyone??? Bueller????

[lowrider]

I am running my turbo setup with the mechanical advance welded up and 10 degrees advance at idle. I still have my vacume advanced hooked up so that it does advance some when im not on boost. I havent encountered detonation yet, and it feels like i could advance the timing to 15 degrees with no ill effect. But you have to take my advice with a large grain of salt (more like a rock) because this is my first turbo set up as well and i am just running 8 psi of boost... Hopefuly someone with a ton of experience chimes in.

[Nigel]

Zero advance? Tell your friend to keep his opinions to himself! That's nuts! Try 20 deg initial at idle. That's about what the factory timing was set to for the L28 turbos. That's what mine runs at. It doesn't like much less. From there, the general rule of thumb is to ramp it up to ~38 deg at 3000 RPM and then pull out a degree for every lb of boost, which would put you back at 20 deg total at 18psi. Keep in mind, that's just a rule of thumb. You may need more or less timing than that, and a dyno is really the best way to figure it out. I'm running ~22 deg total advance at 15psi with no detonation. Remember, these engines only have 7.4:1 compression.

 

 

Nigel

'73 240ZT

[cygnusx1]

Stock long block? Run factory spec initial timing for your engine. The advance curve is up to you. I keep max around 36 with around 42+ at light cruise. Pull timing out during boost, 1 or 2 per psi.

[2eighTZ4me]

Thanks all. I do have a bit of a dilemma. The HPV-1 has an "initial" timing set, and an "all in" timing set. I guess it plots its' own curve accordingly. To my knowledge, there's no way to adjust timing when boost comes on. So, with that kind of boost, would you think that 10 initial and 20 total would at least cover the largest area?

 

My MS has been setup to drive 3 dual coils. I wonder if there is a way to control the HPV-1 from the MS unit......

[cygnusx1]

Limit boost to about 14, set inital to about 18 and max around 25. You are giving up major power. You could lock it at 25.

Edited April 19, 2010 by cygnusx1

[2eighTZ4me]

So, I'm basically screwed with the HPV-1 as far as timing is concerned? I won't be able to go above 14psi until I can back down timing at certain RPM ranges? My goal is 400rwhp, and it's going to require more boost than 14psi to get me there. Rats!!!

[cygnusx1]

So, I'm basically screwed with the HPV-1 as far as timing is concerned? I won't be able to go above 14psi until I can back down timing at certain RPM ranges? My goal is 400rwhp, and it's going to require more boost than 14psi to get me there. Rats!!!

I'm not familiar with the HPV1. Time to sell and upgrade. Welcome to the sickness!

[2eighTZ4me]

Bah!!! Here it comes... let the spending ensue yet again..... Thanks Sid!

[2eighTZ4me]

OK, so there is "some" salvation. It appears with the HPV-1, I can set initial timing at idle, then "all-in" timing at 3000. Then - from 3000 to 8000, I can either add 10 degrees advance, OR retard 7 degrees.

 

http://www.directignition.com/pdf_files/hpv1.pdf

 

See the top of page 15 of the above document for a graph.

 

That being said, I can run say 12 degrees initial, 27 degrees at 3000, and then retard the 7 degrees back down to 20. I guess that's the route I'll have to go for now until I can figure out a way to control the advance curve from the MS unit. Sound about right?

[Scottie-GNZ]

IMO, Nigel's method is dead-on on how it should be done. HOWEVER, note that timing control is based on not just RPM, but also on boost and once in boost, RPMs is not much of a factor in timing control. The HPV-1 is obviously designed for N/A applications and your method will work but with shortcomings. Since it is pointless pushing a stock L28ET pass 6500, you need to keep the advance at 3000 very low which is going to make the initial power hit somewhat soft. I would definitiely salvage what you can get out of what you have and look for a full-tilt MS or used TEC-2 if low on coins. Z-Gad and I ran out TEC-2s well over 750rwhp (look at the pic in my sig).

Edited April 19, 2010 by Scottie-GNZ

[Scottie-GNZ]

That being said, I can run say 12 degrees initial, 27 degrees at 3000, and then retard the 7 degrees back down to 20. I guess that's the route I'll have to go for now until I can figure out a way to control the advance curve from the MS unit. Sound about right?

That's right IF you were running up to 8000. Since you will probably run to 6500, my math says about 22* and based on the document, it would retard 3.5* at 5500.

[Nigel]

IMO, Nigel's method is dead-on on how it should be done.

 

Guess who I got that method from?

 

Many thanks, BTW!!! It saved me a lot of headaches back when I was new to tuning.

 

Nigel

'73 240ZT

 

 

 

[Pyro]

I run 28 degrees total with 13 psi (7.4:1 cr, msa turbo stage 1 cam)

 

For 18 psi, stock cam, and 7,4:1cr. I would lock the ignition at 20 degrees and try that first. Add more if you can, I would think 24 would be about max.

[Mayolives]

Nigel and Scottie are spot on. Follow their advice or you could go Ca...Boom!!! The HPV-1 is probably what you don't need.

Edited April 23, 2010 by Mayolives

[2eighTZ4me]

I realize it's not the "best" ignition-wise for this setup, unfortunately, it's what I've been dealt and I must work around it. I'm getting it tuned Tues. of next week by one of the best tuners in the Southeast, I'm sure we'll be able to make something work without any destruction.

[Matt Cramer]

Thanks all. I do have a bit of a dilemma. The HPV-1 has an "initial" timing set, and an "all in" timing set. I guess it plots its' own curve accordingly. To my knowledge, there's no way to adjust timing when boost comes on. So, with that kind of boost, would you think that 10 initial and 20 total would at least cover the largest area?

 

My MS has been setup to drive 3 dual coils. I wonder if there is a way to control the HPV-1 from the MS unit......

 

Sure is! Unbolt the coils from the HPV-1, wire the coils and sensors to the MegaSquirt. One of our customers sent in a write up on how to convert a GM DIS module into a coil mounting bracket and it will probably work with the coils on the HPV-1; they are based on the GM coil design:

 

http://www.diyautotune.com/diysotm/diysotm_2009-12.html