Anyone else using a PSD CNC cylinder head?

Robga · June 14, 2009, 05:26:05 PM

Did you have to have a custom map to suit this head?

Ive tried 2 chips now and its running very lean on light throttle/ low revs (AFR 18+) lean enough to make it cough and splutter until i give it more throttle and off it shoots.

I have a feeling that when i bought the head Steve PSD said that it flows better than a big valve head at low revs but cant remember for sure.

Has anyone else had this problem with a CNC head and had to have a custom map to sort it out?

Cheers

Rob

Dan · June 14, 2009, 09:46:33 PM

TBH I didn't know anyone who has had a CNC head. Either way it won't be the head causing it cough and splutter.

You don't need need a custom map to suit a modified cylinder head as such. It's only really if you go big valves and a totally different cam that things might need tweaking for optimum with the map.

hayesey · June 14, 2009, 09:55:24 PM

hmm, your issue kind of sounds like the same thing I'm getting with my polo since the turbo conversion. I put it down to needing a remap which it's getting this week. I also want to get a fuel pressure gauge on it

Nick_S · June 14, 2009, 11:55:40 PM

Same happens on mine with a PSD map and red top injectors. Idles spot on and revs well, but slight partial throttle it stalls the engine.

Custom map time.

Tommo · June 15, 2009, 04:48:51 PM

I know its a bit off topic but does someone sell some software so you can map the digifant system your self?

Robga · June 15, 2009, 06:53:01 PM

Dan - like i said i think a cnc head flows more than a big valve at lower revs, so map might just need a little tweak. I have also just fitted a four branch too.

hayesey - I read your post about you problem i thought it sounded like mine! I removed the boost gauge from the vacuum pipe just to see and there was no difference.
Is Andy mapping it? Wonder how long it would be before he could map mine as i know he is very busy.

Nick - defiantly sounds like the same problem, its so annoying as it does it at cruising speed! Idles good, pulls away good then just as you are cruising it wants to cut out

Tommo - you can buy the software / hardware to do it but ive no idea where.

hayesey · June 15, 2009, 08:44:29 PM

mine does it most as you set off and below about 2.5k rpm, above that it cruises fine. Tonight I unplugged the lambda and it's a lot more drivable now, kept the AFRM connected to the probe and it's showing more sensible afr too. So I'll keep it like this till it gets remapped on friday. That's only going to be an initial map done on the road though, at a later date we'll hire a proper rolling road for a day and do it properly.

vwmk3jon · June 15, 2009, 11:23:27 PM

Bit like mine at the mo too.

Pull out of a junction and its spluttering until i floor the acclerator. If i'm lucky, the engine picks up. If not, the engine stalls.

Looks like Andys gonna be busy for a while

hayesey · June 16, 2009, 09:26:34 AM

mine doesnt stall and if anything picks up better if I'm really gentle on the throttle. I'm sure Andy will make himself as busy as he wants to!

Andy · June 16, 2009, 12:37:50 PM

Quote from: Tommo on June 15, 2009, 04:48:51 PM
I know its a bit off topic but does someone sell some software so you can map the digifant system your self?

Yes, not just software - but hardware too. At the very least you'll need a suitable chip emulator and a wideband lambda setup on top of the software. Not cheap.

Robga · June 16, 2009, 06:55:18 PM

hayesey - yours does sound different to mine now if it revs better the lighter you are on the throttle.

Anybody know what voltage the narrowband lambda sends to the ecu?
Ive got a aem wideband controller that ive set to emulate non-linear nernst cell 0-1v is this right?

Tommo · June 16, 2009, 09:56:31 PM

Quote from: Andy on June 16, 2009, 12:37:50 PM
Quote from: Tommo on June 15, 2009, 04:48:51 PM
I know its a bit off topic but does someone sell some software so you can map the digifant system your self?
Yes, not just software - but hardware too. At the very least you'll need a suitable chip emulator and a wideband lambda setup on top of the software. Not cheap.

I already have a descent wideband setup. Having to use a chip emulator is a ball ache, With Nistune you plug it into your ECU and map that directly. Not to worry.

hayesey · June 17, 2009, 09:42:46 AM

yes 0 - 1 volt is right for a narrowband. Although I think people have struggled with the narrowband emulation before, prob best to weld a 2nd boss into your exhaust and have both lambdas in at the same time. I've already welded 2 bosses into my downpipe, just not bought a wideband yet!

Tommo · June 17, 2009, 09:29:35 PM

Hayesey, I can reccomend the AEM wideband setup. A god bit of kit, comes with some good instructions, everything you need, quality bosch probe, and some stickers for your toolbox!

. I got it because a mate has had one for years in numerous daily drivers and its never let him down.

Just one problem with it, on startup the central display reads 'poo'. I have no idea why

jez1272gt · June 18, 2009, 10:52:22 AM

Quote from: Tommo on June 17, 2009, 09:29:35 PM
Just one problem with it, on startup the central display reads 'poo'. I have no idea why

So they rate their products then!!

Did you source it from the UK or get it shipped over? I looked at these a little while ago after a few people said the Innovate LC-1 was tempremental. Is it the full kit with gauge you have?