Max Boost/Timing? 440cc Injectors w/ A/R .60 t3/t4

[83turbo280zx]

Been doing some reading here and there but haven't stumbled across anything concrete yet so I figured I'd ask here.

 

First off, here is my setup. I will be installing 440cc supra injectors on a pallnet rail, with an Aeromotive Regulator, thinking maybe base pressure 40-45psi, and installing a a/r.60 t3/t4 garrett turbo.

 

Here is my current engine setup

 

F54 stock dished turbo pistons

N42 head with P79 "A" cam

12x32x4 FMIC, 2.5" piping

93 octane pump gas

MS2.2 16x16 tables

Walbro 255 Fuel pump

Glowshift Digital Wideband

 

I'm trying to get an idea of how much boost and timing I can run safely with this setup. Sure I can just keep upping it 2psi at a time and watching my wideband and listening for knock, but I'd like to get a baseline from other's experiences. I am familiar with megasquirt, I am running a "street" tune with my Z31 T3 at 12psi on stock injectors at the moment.

 

For now I plan to retain the stock internal wastegate as the WG flange will bolt to the back of my t3/t4 i'm going to install.

 

Anyone have their previous experiences they'd like to share to give me an idea of what to start setting my base map at? Currently I'm running really retarded timing at 12psi on the stock injectors, close to 14 degrees at full boost from 4k rpm and up, not sure if thats going to be the same with the 440cc injectors or not.

[280zex]

I keep mine at a maximum of 20 deg advanced @ 15lbs boost, however my Z is NOT fuel injected. I found some megasquirt timing tables around here some where that showed some timing curves. What I seen was about what I run in total timing under boost. I did see a few that were at 17 deg timing at 15lbs boost as well.

IF your still unsure, play it safe. IF you don't play safe or tune to aggressive then you go BOOM!!!!

[280zex]

this is a pic of my ignition timing map for my 123ignition programmable distributor. I start at 20 deg at 500rpm, and advance up to a total of 36 deg at 3000rpm.

I do not tune for any vac advance yet. I start to pull timing at 0 inches vac (100kpa) all the way thru 15lbs boost. so at wide open throttle (WOT) and 15lbs boost my timing is only 20 deg.

 

just know my setup is not fuel injected.

 

you can try bing image search for megasquirt timing maps, I found a lot of useful information that way.

 

every engine is different, and so is the ignition and injection tune.

 

NOTE: if you are not boosted the most VE is only about 78-80% depending on how much head work you have done, or had done. Stock Z heads are not known to have a good VE (volumetric efficiency). when I was using megasquirt FI the best VE I had at WOT was 80% and I have some light head work/port matching/custom valves......

[83turbo280zx]

this is a pic of my ignition timing map for my 123ignition programmable distributor. I start at 20 deg at 500rpm, and advance up to a total of 36 deg at 3000rpm.

I do not tune for any vac advance yet. I start to pull timing at 0 inches vac (100kpa) all the way thru 15lbs boost. so at wide open throttle (WOT) and 15lbs boost my timing is only 20 deg.

 

just know my setup is not fuel injected.

 

you can try bing image search for megasquirt timing maps, I found a lot of useful information that way.

 

every engine is different, and so is the ignition and injection tune.

 

NOTE: if you are not boosted the most VE is only about 78-80% depending on how much head work you have done, or had done. Stock Z heads are not known to have a good VE (volumetric efficiency). when I was using megasquirt FI the best VE I had at WOT was 80% and I have some light head work/port matching/custom valves......

 

Cool thank you for that. I've been downloading a few different tunes that people have shared and sort of tearing them apart as well. I guess i'm more concern at what everyone else is running timing wise, even at 20 degrees timing i was experiencing some light spark knock, that is with the stock turbo, stock injectors, FMIC, and a walbro 255. I'm sure running 45psi fuel pressure and 440cc injectors will make a huge difference in atomization and being able to have enough fuel to cool the combustion chamber.

[280zex]

think of it this way....

Ignition timing is a dynamic of fuel load. when your cruzing down the freeway, you don't want a heavy fuel load (rich).

 

so what you can do is ADD ignition to a particular engine running dynamic like this. 60mph in 5th gear and say 15 INHG vac, you would want to burn a bit lean by your VE map for the injector fuel pulse AND how much ignition timing to burn off that bit of extra fuel you don't need.

 

I have seen some ignition maps with about 40 deg +/- 5 deg total timing at 3000 rpm with about 12 to 15 INHG vac

 

AS your system builds boost you want to LOOSE timing = richer fuel load = attempt at removing ping.

 

However you can only add so much fuel, and remove so much timing to avoid ping that your engine will loose power!!

 

be safe with them ignition maps. learn to read your engine. there are many things you can do to help with staying away from the ping monster!!

[83turbo280zx]

think of it this way....

Ignition timing is a dynamic of fuel load. when your cruzing down the freeway, you don't want a heavy fuel load (rich).

 

so what you can do is ADD ignition to a particular engine running dynamic like this. 60mph in 5th gear and say 15 INHG vac, you would want to burn a bit lean by your VE map for the injector fuel pulse AND how much ignition timing to burn off that bit of extra fuel you don't need.

 

I have seen some ignition maps with about 40 deg +/- 5 deg total timing at 3000 rpm with about 12 to 15 INHG vac

 

AS your system builds boost you want to LOOSE timing = richer fuel load = attempt at removing ping.

 

However you can only add so much fuel, and remove so much timing to avoid ping that your engine will loose power!!

 

be safe with them ignition maps. learn to read your engine. there are many things you can do to help with staying away from the ping monster!!

 

Yea i think I'm seeing right about 35 degrees timing at cruising speeds, seems to do well, maybe I'll kick the timing up a little more and see how it does. Thanks for all the pointers, every bit of information helps. I also bought a couple of tuning books a while back that seemed to clarify a lot about the subject. I think it's time to refer back to those lol.

[280zex]

Honestly I use Bing/Google search for ignition timing maps for any possible info I can get.

your best bet is a dyno tune session, and be able to actively tune your ignition during actual load conditions. I did this yesterday, and was able to eek out another 20 rwhp, and pull some cruze fuel load out. I should be seeing about 20mpg in stead of 15mpg at cruze. My Z cruzes @ 64mph @ 3000 rpm, so I took the time to clean up that part of the engine dynamic and ignition timing.

 

My engine now gets between 40 deg and 35 deg timing, between 12inhg and 18ingh. That's the sweet spot for my cruze dynamic, and the wide band on the dyno pegged right at 15afr on a light cruze @ 60mph.

 

That cost me 85$ for 1 hour of dyno time. it was worth every penny!!!

[83turbo280zx]

Honestly I use Bing/Google search for ignition timing maps for any possible info I can get.

your best bet is a dyno tune session, and be able to actively tune your ignition during actual load conditions. I did this yesterday, and was able to eek out another 20 rwhp, and pull some cruze fuel load out. I should be seeing about 20mpg in stead of 15mpg at cruze. My Z cruzes @ 64mph @ 3000 rpm, so I took the time to clean up that part of the engine dynamic and ignition timing.

 

My engine now gets between 40 deg and 35 deg timing, between 12inhg and 18ingh. That's the sweet spot for my cruze dynamic, and the wide band on the dyno pegged right at 15afr on a light cruze @ 60mph.

 

That cost me 85$ for 1 hour of dyno time. it was worth every penny!!!

 

Yea i may consider doing that. I already talked to a local speed shop who is familiar with megasquirt, they get $130/hr, i may just have them fine tune everything for me.

 

Unfortunately I am down for an extra week though. Had to order an internal wastegate flange to bolt to the turbo. The nissan t3 and garrett t3 5 bolt flanges look identical at first glance until you go to bolt it together, nothing lines up lol. Perfect excuse for a custom v-band downpipe now.

 

I did get all of my AN lines, my FPR and pallnet rail finished, very satisfied with those results.

[280zex]

This is an updated version of my ignition timing map, from dyno tuning this last weekend.