final check

[mini-sprite]

Well the car is finished and just doing the final bits before mapping in January. This is where i am now. could you have a look and see what you think, just anything glaring really. The car starts and runs great, but haven't had it through the rev range (not road legal)

Its still really rich at idle i know that

I had a bit of a set back as my trailer was stolen a few moths ago. I've sorted another and collect at the weekend.

Paul

[Dennis_Zx7r]

Your injectors seem to be really big as PW is only about 1.5ms in idle despite the really rich mixture. On deceleration it's down to 1.2ms. If you don't already use sequential this may be beneficial.

[Matt Cramer]

I see you've got PWM current limiting on with a 75% current limit - what sort of injectors are these?

There's an odd "ledge" in the VE table between 20 and 25% TPS at low RPM - what's the deal there? Timing map is also a bit weird; at high RPM, it's pulling timing as the load drops, while low load timing would normally advance.

This engine pulls great vacuum at idle - any particular reason you're using alpha-N?

[mini-sprite]

It's a 1.8 Mazda mx5 standard. I'm using Mazda RX8 injectors It's eventually going to be forced induction. It's gone from 265cc standard to 450cc.

I'm using Alpha N as I'm using tps for load. This is because don't know enough about the different choices

I'm already running semi sequential.

I'll have a look tomorrow at the things you have

Thank you

[mini-sprite]

I see you've got PWM current limiting on with a 75% current limit - what sort of injectors are these?

There's an odd "ledge" in the VE table between 20 and 25% TPS at low RPM - what's the deal there? Timing map is also a bit weird; at high RPM, it's pulling timing as the load drops, while low load timing would normally advance.

This engine pulls great vacuum at idle - any particular reason you're using alpha-N?

These are the things that i'm talking about. I don't have a massive amount of experience with this. I can see what your saying about the PWM% Should i take this back to recommended 30%? I have no idea why it ended up with that figure

I can see the ledge you are speaking of and will have a look.

So ive just been out quickly to the workshop and set it to "speed density" this brought the idle AFR to 13.5 - 14.0.

cheers

[grom_e30]

i thought rx8 injectors were high-z so wouldn't need current limiting

[mini-sprite]

i thought rx8 injectors were high-z so wouldn't need current limiting

Its the other way around isn't it? The Mini i did with the Suzuki swift GTI engine in it had low impedance injectors and this needed a Ballast resistor as the DTA ECU could only use high impedance injectors.

Paul

[grom_e30]

how many ohms are the injectors?

[mini-sprite]

13.8 ohms

[grom_e30]

that's high-z so you don't need current limiting so best to turn it off

[mini-sprite]

that's high-z so you don't need current limiting so best to turn it off

Ok got it. That's a setting to use between high and low impedance. I'll turn it off then

[mini-sprite]

Now running speed density

turned off current limiting

This tune is using the last restore point from a few weeks ago before i started messing with the fuel and spark.

idle speed is higher and a bit unsteady also there is a flat spot in the middle of the map now.


Went back to Alpha N for a short data log and revs freely. the idle is much more stable and lower.

Cheers

[grom_e30]

it will run like a dog if you just switch from a semi tuned alpha-n setup to a totally un tuned speed density setup

[mini-sprite]

it will run like a dog if you just switch from a semi tuned alpha-n setup to a totally un tuned speed density setup

Non of it is really tuned

[grom_e30]

if you spend a bit of time with it in speed density and tune it a bit, it will usually be a bit better mannered at small throttle openings compared to alpha-n also the speed density will be better for tuning once the car is boosted.