Jump to content
MattR

Ignition timing question

Recommended Posts

Hi guys

 

I'm nearly finished with an M54B30 swap into my E36, but I have a couple questions around some ignition maps I've been given I'm using an E36 plugin G4+, and so far have got the engine running on the M50B25 map supplied. I've been lucky enough to have gotten a tune from a guy that has run the same engine in his rally car, although he's using S50B30 ITBs & injectors, whereas I have standard B30 injectors and an M50B25 intake manifold instead. I've compared the two ignition maps and the second one is noticeably more aggressive. 

First map (Standard Link M50B25 tune)

1646751816_redpigtiming.PNG.3c45200b2029a1c550b16154353ac819.PNG

Second map (supplied M54B30 ITB tune)

151928012_eddietiming.PNG.c92113bb553c64fd1854bce647fe8812.PNG

 

Would the second map be safe enough to run, given its a road car? Also, I noticed that the second map only goes to 100kPa, is that likely to cause any trouble?

Sorry for the (probably dumb) questions, this is my first attempt at swapping and tuning an EFI engine.

 

Many thanks

 

 

Share this post


Link to post
Share on other sites

there is no answer if it would be safe or not, you need to tune your engine and find out where is the knock limit, a map from another engine setup its just a base map for starting your engine nothing more

also you said it runs ITB's how its possible to run ITB's and he uses map sensor for load ?? instead of TPS...

Edited by iceman_n

Share this post


Link to post
Share on other sites
8 hours ago, iceman_n said:

there is no answer if it would be safe or not, you need to tune your engine and find out where is the knock limit, a map from another engine setup its just a base map for starting your engine nothing more

also you said it runs ITB's how its possible to run ITB's and he uses map sensor for load ?? instead of TPS...

Yes, the donated map does use TPS as y axis. Unfortunately my budget didn't extend to ITBs (:() so I'm using traditional MAP for fuelling. 

 

Share this post


Link to post
Share on other sites

ok thats fine but the problem here is that its a totaly different thing to map an engine with TPS and different with map sensor....the alpha N method its totaly different than density method

its not as simple just to switch from TPS to map sensor just changing the axis setup on the map, thats why the second map goes until 100 and first at 105, the second map 100 is the percentage of throttle the first 105 is the kilo pascal of air entering inside the engine

 

 

Share this post


Link to post
Share on other sites
57 minutes ago, iceman_n said:

ok thats fine but the problem here is that its a totaly different thing to map an engine with TPS and different with map sensor....the alpha N method its totaly different than density method

its not as simple just to switch from TPS to map sensor just changing the axis setup on the map, thats why the second map goes until 100 and first at 105, the second map 100 is the percentage of throttle the first 105 is the kilo pascal of air entering inside the engine

 

 

Righto, that makes sense. I had a similar question regarding the possible conversion of a TPS fuel map to MAP, stands to reason that the timing maps wouldn't work for the same reasons - thanks!

Share this post


Link to post
Share on other sites

you just need to tune your engine, any respetable tuner should do a good job on a NA build like yours. I have tune some BMW engines and if you ask me they normally run from 25-28 of advance at wot with everything tune (good fuel map). The base map is always safe so is normal that a final tune has more timing and normally less fuel aswell. If you are gonna tune the engine I would start with the base map not the one from the rally car. Tune the fuel map and then go to the dyno and tune the timing.

Share this post


Link to post
Share on other sites
9 hours ago, iceman_n said:

ok thats fine but the problem here is that its a totaly different thing to map an engine with TPS and different with map sensor....the alpha N method its totaly different than density method

its not as simple just to switch from TPS to map sensor just changing the axis setup on the map, thats why the second map goes until 100 and first at 105, the second map 100 is the percentage of throttle the first 105 is the kilo pascal of air entering inside the engine

 

 

Both of those ignition tables are in Kpa. It’s a 100Kpa not 100% throttle. You don’t need to have the ignition map with TPS. Only the main fuel map has to be set up with tps and rpm when using ITB, then if it’s boosted you can use the 4D map to adjust the fuel if further required. 

Share this post


Link to post
Share on other sites

its 100 kpa because he change the axis setup just to suit in his application, so it was tps in the original map with itbs...

i disagree with you, with itbs you cant hook up map sensor with corrent readings of vacuum, tps is a must for both fuel and ignition with itbs in my experience

 

i have seen some applications with vacuum box on itbs but doesnt work right sometimes, the wave pulses make odd readings on the map sensor

Share this post


Link to post
Share on other sites
4 minutes ago, iceman_n said:

its 100 kpa because he change the axis setup just to suit in his application, so it was tps in the original map with itbs...

i disagree with you, with itbs you cant hook up map sensor with corrent readings of vacuum, tps is a must for both fuel and ignition with itbs in my experience

 

i have seen some applications with vacuum box on itbs but doesnt work right sometimes, the wave pulses make odd readings on the map sensor

Screenshots are of the map as supplied, I haven't made any changes to either 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×