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EFi VE map vs TPS
Posted: Fri Aug 30, 2024 8:34 am
by PeterK
Anyone have a good VE map vs %TPS and ignition vs %TPS that they can share please. Any cold start enrichments would also be appreciated.
I suppose a supplemental question is, how close will a VE Map from one car be to another ? My assumption is that all cars will be different, but close enough for an initial start and to get me to a rolling road. I have found a set of maps on Pelican that I am slowly typing into my tune software, but it would be good to compare with others, especially tunes that people have found to work well in the real world.
My SC is a 3.2 SS, 10.5CR single plug and with 964 cams tuned for torque. It will have Triumph ITBs with Bosch 375cc injectors and Nissan 370X CoP, all controlled by a MaxxECU Sport (the one with built in bluetooth). I now have all of the parts except the ECU (on order), with an expectation of doing the conversion from CIS during the autumn / early winter. Watch this space.
Re: EFi VE map vs TPS
Posted: Fri Aug 30, 2024 8:51 am
by Gary71
Get in touch with Tim (impmad2000) he’s running the Triumph ITBs on his car that I had planned to fit on mine but never got working!
Different spec engine, but should get it started at least
He runs megasquirt if I remember correctly so the maps are easily accessible
Re: EFi VE map vs TPS
Posted: Fri Aug 30, 2024 1:03 pm
by PeterK
Thanks Gary
Re: EFi VE map vs TPS
Posted: Mon Sep 02, 2024 3:20 pm
by MikeS911
Hi Peter.
Another one to check my be PHIL on hear, he did the Triumph/Mega conversion, if I remember correctly on a 3.0lt He had Shawn do some of the setup and my still have his maps.
Are you just doing the Injection and Mega or going ignition as well?
Regards MikeS
Re: EFi VE map vs TPS
Posted: Mon Sep 02, 2024 3:57 pm
by PeterK
I'm going all in Mike - MaxxECU controlling fuel (Triumph ITBs) and ignition (Nissxan 370 CoP).
GT two has Phill's old SC now - we've been talking and now I'm getting close, I've messaged him
Re: EFi VE map vs TPS
Posted: Mon Sep 02, 2024 5:37 pm
by Bruce M
Are you connecting up the vac ports to get a MAP signal? Even if you use TPS for load it’s helpful to have the MAP signal as the injector flow rate changes based on the ratio of fuel pressure to manifold pressure. The ECU accounts for that.
I use MAP based VE table below 80% then switch to a second VE table using TPS above that cut off.
Re: EFi VE map vs TPS
Posted: Mon Sep 02, 2024 5:40 pm
by PeterK
I am connecting the vac ports to the ECU, but hadn’t planned to use it, given interweb comment on ITBs. I’ll check whether / how I might use TPS & MAP
Re: EFi VE map vs TPS
Posted: Mon Sep 02, 2024 10:10 pm
by impmad2000
My system samples atmospheric MAP at start up and uses that as a factor in the calculations. Some systems take regular reading of this, but generally you don’t climb too high in one go, but Pikes Peak might be an exception! My vacuum ports are connected together and act as reference to fuel pressure regulator, also provide vacuum for brake servo .
Re: EFi VE map vs TPS
Posted: Tue Sep 03, 2024 7:39 am
by PeterK
Thx for all the inputs. I'd rather be thinking about details now than wondering why things aren't working well later.
I have a bigger bore take-off from the manifolds for the brake servo, and small bore from each ITB will be linked to a small manifold. This will go to the ECU and probably also to the FPR.
Re: EFi VE map vs TPS
Posted: Tue Sep 03, 2024 9:18 am
by Bruce M
Haltech have some good videos on ITBs and VE tuning. This one is particularly good (motorbike ITBs on a Honda).
https://youtu.be/aFtB2g0I86A?si=yaNbik_xeAnoocS3