What fuel ratio for boost transition?

Nistune topics related specifically to the 6303 cpu

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vincentav8
 

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Joined: Sun Jul 22, 2012 9:33 pm

What fuel ratio for boost transition?

Post by vincentav8 »

Hi, I have an R33 with 550cc inj /z32 AFM, all supporting fuel / air mods etc.
My Nistune board was tuned recently and at top end it runs great ... but around boost transition it feels sluggish. Looking at the fuel maps it's set at around 15:1 to 14:1 in the transition area. In fact it only drops below 14:1 at 4500rpm/tp52 (O2 feedback disabled across the whole map).

Seems a bit lean to me?

any views?
bachig24u
 

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Re: What fuel ratio for boost transition?

Post by bachig24u »

I would be pulling lamda down to 0.9 to start with, maybe even 0.85 if it responds well.

Whats the timing like at full load and zero vacuum?
vincentav8
 

Posts: 16
Joined: Sun Jul 22, 2012 9:33 pm

Re: What fuel ratio for boost transition?

Post by vincentav8 »

Hi, thanks for the response ... I need to take it out and run a log to get an accurate reading, but on the timing map I'm set at about 33 - 24 degrees around transition .. here's the map
timing.JPG
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bachig24u
 

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Re: What fuel ratio for boost transition?

Post by bachig24u »

a log of boost against the load in the map would tell a story.
vincentav8
 

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Joined: Sun Jul 22, 2012 9:33 pm

Re: What fuel ratio for boost transition?

Post by vincentav8 »

sorry for the delay ... I ran a few log files but can't confirm what I need to yet.
For some reason when i play the logs I'm not logging speed? will try again, maybe a software glitch?

But, back to the more important stuff I guess I need to work out if I can take a feed off my boost controller to log boost.
AEM wideband going in next week so I can get some accurate AFRs
Matt
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Re: What fuel ratio for boost transition?

Post by Matt »

Make sure speed is selected in the register list when you connect to consult

If speed = 0 at all times then the ECU isnt seeing the signal (normally speedo > dash cluster > ECU)
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