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The mkiv Supra Owners Club

About mapping single turbo Supras


Jake

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This is probably a stupid idea and feel free to shoot me down in flames....

 

It seems like all the guys with TT-to-single-turbo conversions have difficulties mapping it around about the 4000 rpm rev range because the stock TT ECU does all its clever stuff when it's expecting the second turbo to come online, right so far?

So I was wondering if it would be a good idea to use the ECU from a NA.

Or would it be totally wrong due to ignition timing reasons, or what?

 

I'm sure there must be a good reason why this wouldn't work, I just can't think of it at the moment.

 

Any thoughts?

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Guest Terry S
This is probably a stupid idea and feel free to shoot me down in flames....

 

It seems like all the guys with TT-to-single-turbo conversions have difficulties mapping it around about the 4000 rpm rev range because the stock TT ECU does all its clever stuff when it's expecting the second turbo to come online, right so far?

So I was wondering if it would be a good idea to use the ECU from a NA.

Or would it be totally wrong due to ignition timing reasons, or what?

 

I'm sure there must be a good reason why this wouldn't work, I just can't think of it at the moment.

 

Any thoughts?

Jake this is only a problem with certain piggybacks. Standalones wont suffer this, and I *believe* Chis now has the sussed on the E-Manage

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I've gone the emanage route with the ignition and injector harness.... whether this would be suitable for a NA-T conversion using the stock ECU or not I don't know, but I would have thought so....

 

I would suggest possibly looking at modifiying the ignition system and getting rid of the distributor and putting in some electronic ignition system somehow....

 

But that might start moving beyond the capabailities of the stock ecu, in which case, something like an AEM might be the best route to go, as you can do most of the stuff with it, however be prepared for doing a lot of loom modification to suit the turbo application.

 

Gav

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Jake this is only a problem with certain piggybacks. Standalones wont suffer this, and I *believe* Chis now has the sussed on the E-Manage

 

Aye, just the airflow fudgers :)

 

It's certainly do-able, I've just been slack in chasing down all the last load sites - throttle vs rpm vs load on engine (gear), lots of variables, lots of tweaking.

 

-Ian

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I personally don't think the E-Manage has enough resolution to properly re map ignition nd fuelling when trying to fudge a stock TT ecu to run a single. Other people disagree :)

 

I think it has :p Anywhere outside of 3000-4000rpm is comparitively easy, in the range it's nasty. I don't know if you knew this but you can change the load sites, so I've actually got 5 rpm load sites in that range for uber-resolution, that's 80 cells for the airflow adjustment, and then you've got the additional injector table for load-related adjustments, which gives me another 80 cells for that.

 

It's taking me HOURS though, and many datalog runs and map iterations. However, once the map structure is in place, other TTs are a lot easier :D

 

I'll get some data for you at some point Chris, part throttle datalogs, afrs, the map itself etc.

 

-Ian

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To begin with, I doubt that the n/a ECU could even understand the meaning of 'boost' (positive intake pressure at the intake manifold)
So how do they manage when fitting single turbos to NA Supras? Do you have to replace the ECU for a NA/T conversion?
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As for signal 'fudgers' like piggybacks etc, all is not always 110% perfect behind the scenes.

Yes the signal amplitude and frequency may be within reason, but the shape of the 'amended' signal is not always good enough. (that is if you manage to change the correct signal up to the desired degree, which is not always possible)

 

You need a scope to see this, ideally one with dual display, and compare incoming and outgoing. Sometimes the outgoing is so distorted that it makes you wonder how the ECU interprets it.

 

Just me 2 Eurocents... ;)

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As for signal 'fudgers' like piggybacks etc, all is not always 110% perfect behind the scenes.

Yes the signal amplitude and frequency may be within reason, but the shape of the 'amended' signal is not always good enough. (that is if you manage to change the correct signal up to the desired degree, which is not always possible)

 

You need a scope to see this, ideally one with dual display, and compare incoming and outgoing. Sometimes the outgoing is so distorted that it makes you wonder how the ECU interprets it.

 

Just me 2 Eurocents... ;)

 

My 3 eurocents is my car with a SAFC-1 and ITC did pretty well against many £1000's of standalones last year , dont believe the hype guys untill you get to the highest level piggybacks are fine , im only running a standalone as the inj size has got silly , i could run 9's with an SAFC !!!!! :complain: :complain:

 

Dude :cool:

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Just to add that my comparisons were for different 'interceptors'.

 

It could be that the Toyota ECU is quite resilient when it comes to signal shape.

Honda ones are more particular.

 

It's just a 0-5v signal, how hard is that to intercept and send on? :blink:

 

Karmann Vortex airflow sensors maybe a differnt story :)

 

-Ian

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