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Thread: Timing Maps for Tuning

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Posts: 11-20 of 156
2009-10-03 05:53:21
Id like to put mine up but its for a ve ecu so im not sure that its of much use to you guys?

Its a sr20ve-t with gtir t28. Running a chipped sr16ve ecu.
The usual mods front mount, 550cc, ve maf, 2.5" exhaust, STOCK sr20ve engine.

So im currently running 16deg of timing at 8.5-9psi of boost? Whats your opinions on boost vs timing on the STOCK compression sr20ve with the gtir t28?

I think thats low but obviously i dont really have experience with the stock compression ve to know how far i can push the timing up?
2009-10-03 14:07:51
Originally Posted by austingtir
Id like to put mine up but its for a ve ecu so im not sure that its of much use to you guys?
It is absolutely of use to us.
2009-10-03 14:20:36
16* total timing? Post up your timing map.
2009-10-03 14:46:14
Originally Posted by Coheed
I should put my rom dump on here. Looks like I should be around 24-25* advance according to most tunes, on around 24psi of boost.
According to most tunes? Which tunes are those exactly? 24 degrees advance timing at 24 psi sounds ridiculous.
2009-10-03 21:10:38
Coheed/Benfenner: Pm both of you EDIT: dont worry its sorted.

Free File Hosting Made Simple - MediaFire

Yeah 16deg total so im at around 100 on the TP scale at 8.5-9psi (according to consult) iv left a bit of room there for a couple more psi... probably to much room.

CAR: GTIR pulsar
ENGINE: SR20VE (stock compression GTIR T28)
MODS: 2.5" exhaust, front mount, sr20ve ecu chipped, sr20ve maf, pod, 550cc, 255lph HP,
TUNE: SAFE base map

Last edited by Vadim on 2013-05-03 at 02-18-31.
2009-10-04 02:59:03
Originally Posted by BenFenner
According to most tunes? Which tunes are those exactly? 24 degrees advance timing at 24 psi sounds ridiculous.

Yes it is rediculous. I am running 20* right now on the top end on 24-26psi(depending on temps outside) and I am running 100 octane fuel. Of course, 24-25psi up here is like 21psi at sea level when you look at total airflow. Not to mention other factors, but it is pretty close to 21psi.

Is 21psi too much to run on 8.5:1 at sea level on 100 octane? My calculations put me around 85% VE. Which sucks balls. I want to get over 100% but the setup would prob be too laggy. But for the airflow I am pushing I am making about 400whp uncorrected. Id like to make that on a lot less boost, but it may need more timing to get there. The VE map I got when I was NA was conservative by about 4*. Perhaps this map will react really well to the added timing. Or the car will blow up? LOL.
2010-05-19 08:24:56
whats up with some VE maps?
2010-05-27 14:28:09
Ethalpy Styled 10 PSI Base Tune

This map is based on the Ethalpy's Guide. I used it as a base for my other map and it works great. Big thanks to Ethalpy for posting the guide up!

Motor: DET 8.5 CR Only!
Mods:W11 T28 7psi, 91 Intake Cam, FMIC, ThermoBlok Spacers, 2.5" DP/Exhaust
Max Safe Boost: 10psi
Octane: 93 Shell
Dyno WHP: NA
Safe or Tuned Map: Base Map for the most part. This map can take more timing in the vacuum area, but be careful with the boost columns.

Since Fresh Alloy took down the old posts, here is a quote from Enthalpy's post.
Originally Posted by Enthalpy

OK, So you list timing values for over 3500... starting at 32 degrees. What should timing look like below boost? I'll have to check my map, but I think I run it pretty low down in the vacuum.

Funny, this is a drivability issue, and even though my timing is working out well in the the power band, I spend a lot more time driving in the range below 3000 with no boost... But it's difficult to tune that area. When I make changes at 1.5Kg of boost, I feel it. When I make changes at 2000 rpm in vacuum, its like... uhhh.... ok, did that do anything?
Alright...I am hesitant to post all this in a public forum as it is alot of knowledge learned form hard work and expensive mistakes. these are some of my personal tricks, but since there is apparently a need for the info to sort out confusion i will post it.

timing should pretty much level out over 3500 rpm, like this

for 0 boost:

500 RPM - 20 deg
1000 - 20
1500 - 22
2000 - 25
2500 - 27
3000 - 30
3500 - 32
4000 - 32
4500 - 32
7500 - 32

thats a good baseline to start with...rememeber though thats 0 boost...not full vacuum. the reason for having the timing increase as you get toward 3500 is that the actual time that the combustion has to take place gets relatively long at lower RPMs. so the igntion advane should be less. the burn time of the a/f mix is a relatively fixed time for a given intake pressure. so if the time of the compression stroke is getting longer due to low RPM then you want the ignition advance to be less so that you can reach peak cylinder pressures at the appropriate time (15-20 Deg AFTER TDC).

when i build my timing maps i keep 20 as my minimum timing all the way down to full vacuum but the 3500rpm value goes up to 40 or 42 deg. so it looks like this:

500 RPM - 20 deg
1000 - 20
1500 - 24
2000 - 28
2500 - 32
3000 - 36
3500 - 40
4000 - 40
4500 - 40
6500 - 40
7000 - 36
7500 - 34

the only weird change is that I like to roll off the timing in the high rpm high vacuum areas...just as a safety measure. when you have timing increasing as vaccum increases you get the equivalent of a vacuum advance distributor. very good for part throttle driving. vacuum advance is necessary for becasue the air / fuel mix is at a much LOWER initial energy state when it is pulled in at a high vaccum. all the molicules are pulled farther away from each other and thus your burn time takes longer. so you need to start the burn sooner to reach peak pressure at the correct time.

as the car comes into boost you will have boost retard...so say for an example of 1.0 kg/cm2 (14.7 psi) with .75 deg/lb retard you will need to take away exactly 11 degrees of timing. so your timing map at 14.7 psi should look like this

500 RPM - 9 deg
1000 - 9
1500 - 11
2000 - 14
2500 - 16
3000 - 19
3500 - 21
4000 - 21
4500 - 21
7500 - 21

the timing retards under boost for the exact opposite reason that it advances under vacuum. witht he af mix coming in at a much HIGHER energy state due to pressure you get a much faster burn rate. so you need to fire the mix later (less advance) to get peak pressure at the correct time. you can see that i would pull the timing out from everywhere. even in places that you might not ever see boost. it's more of a safeguard than anything. also it make s for very linear maps, and ones that are easy to view if you have 3-d map viewing in your EMS software (haltech e-11).

one of the things that people miss most about making basemaps and tuning cars is the linearity of the system. if you have big bumps or changes in your maps you are doing something wrong. the engine is a remarkably linear device. evene when you include turbocharging...values should always be smooth for both fuel and ignition.
Last edited by Vadim on 2013-05-03 at 02-19-28.
2010-05-27 14:34:45
Vadim's Tune V1 - 7 PSI

This map is based on the Ethalpy's Guide. I noticed Calum's maps had more timing in the vacuum areas. I adjusted and smoothed out the timing.

Map is tuned for 7 psi.

Motor: DET 8.5 CR Only!
Mods:W11 T28 7psi, 91 Intake Cam, FMIC, ThermoBlok Spacers, 2.5" DP/Exhaust
Max Safe Boost: 7psi
Octane: 93 Shell
Dyno WHP: NA
Safe or Tuned Map: Tuned Map, practically a base map based on Ethalpy's Guide. Vacuum has plenty of room for adjustment, boost areas might not.

Last edited by Vadim on 2013-05-03 at 02-19-54.
2010-11-27 22:50:10
This makes for some good reading. I have no doubt that when I start my project I'll have all the help I need the do it right the first time.
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