318is m42 project update

[Gunni]

How about some wideband closed loop control?
I´m having the same issues even with having MAP compensation and throttle angle fuel map,
if I move slightly within the same cell the afr goes straight to 19:1.
I could spend more time in the MAP map to fix it but I´ll be turning this into FI setup soon enough,

[stuartgallafant]

glad to see you're making such good progress tim...

that MS business sounds well confusing! Ant made it sound simple! im quite worried about doing it to mine now in case i start something that i just cant finish...

[tim_s]

woah this is an old thread! might dig out some more recent pics on the wknd.
I actually got MS working pretty well in the end. I did use some EGO control, but I wanted a really good base map without using any wideband feedback, which I got pretty close to getting. MAF was the answer to quite a few of my problems, I'm a fan of this setup with MSNS. I used 2 maps too, one for part throttle, one for high throttle, as I wanted different AFRs at smae site depending on whether I was nailing it or not.

It still had a few lingering issues:
-idle was not as smooth as motronic, and as I never got pwm idle working, it used to dip on the PAS and lowered a bit when temps hiked up. Personally I reckon that with the injectors I was running (about 3.5ms idle) and MS standard code, the idle wasn't going to be as good as factory. Hopefully the hi res code will help.
-AFRs in traffic were a bit wonky, EGO correction really helped, but still wasn't perfect and couldn't use it on idle cos it made the idle more wonky. again hopefully hi res would help that, and I reckon I needed to spend more time investigating the relationship between IAT and AFR on my setup with my MAF.
-timing in traffic was never as smooth as motronic. everywhere but around the city the timing felt pretty damn close to facotory, but coming off throttle and driving around in town it was never great. but hey i was running it on huge ITBs so par for the course i reckon.
-AFRs in general were never as smooth as motronic - i think this was mainly a limitation of MSNS, but without ever getting a pro (read ant) to do some mapping, I don't know and certainly some of it might have been down to my (lack of) experience.

Considering I ran MS for about 6 months, I reckon I got pretty close.
I'm holding out hope for the hi res code, which I never got to use while on megasquirt.

For the moment things have changed quite a lot. As some of you know, my brand spanking engine decided to eat its small end bushes within 10k miles.

Good news is there was no other damage done to the engine, and the engine shop repaired it for 5/8 of f all, and while there I added a new oil pump, new pressure release valve, new rear crank seal (one from last time was seeping a bit), got another engineering firm to lighten and balance all the rotating components, and now have some lightweight pins in there and some extra strong bushes. also provided a really good opportunity to check that all was well with the bores which were re-measured and cleaned, as was the crank. I fitted a nice new late spec head with the lighter valve gear etc, relapped valves and new stem seals etc while there and had the flanges of the exhaust manifold welded up as they were starting to go on cyls 1 and 4. I seem to have screwed the cam timing (difficult to get right because my performance inlet cam doesn't actually line up on the square bit on the back of the head) which I'll sort this wknd but otherwise everything is sweeet again. lpg's still not running though, has been sidelined for a bit.
As a result of the engine stuff, I've removed the ITBs for the minute until everything has settled again on the new engine. I've made some neat little mods to motronic and now it runs 13.2:1 on WOT, and 17:1 on cruise with the 2.1 and performance inlet cam etc. - factory motronic setup was at 15/16:1 on mid throttle (never dared try full throttle!) and off the scale lean on cruise. It drives like factory now on the modified engine, and this is a nice, and damn fast setup, if a hell of a lot more boring than on the ITBs. When I find some more time, I'm going to re-hash the ITBs learning from the mistakes of the first time, and with hi-res megasquirt code. but for the meantime I wanna get her r/r'd as she stands.

[CaesarBob]

Sorry to hear about the probs with your original "new" engine. Just goes to show there will always be opportunities to have another tinker even after a substantial project.

[ShepsEvo3]

Tim, you've been busy But you seem to be getting things sorted

We have a new dyno being delivered next week. You should pop up for a run on it soon, you will be impressed

Your AFR's are looking good too, especially on WOT. I'm not sure I would have gone so lean on cruising but does she run smoothly at 17:1?

Good work though

[tim_s]

Hey Paul, yes have been a bit busy with it, didn't see that one coming!
funny you mention the dyno, i've been talking to Si, Andy (with the white S2) and Pete (chavrocco and S4) about us all doing a sesh on your new rollers, they all seem quite excited about it! In fact I may come along for the ride with Pete this Monday (he's having that rocco tuned with you) depending on how things pan out.
17:1 is about what the M42 cruises at on the motorway with factory fuelling running properly. It runs and fuels pretty similar to factory at the moment, a touch richer everywhere basically. With the ITBs and MS it depended on how much advance you pushed as to whether you could go much further than 17:1 staying smooth, but you could go a fair bit leaner with the right advance, although without measuring exhaust temp i never really pushed it - i wanted to get EGT gauge to set that up.

CaesarBob: you're not wrong. it also shows that with a custom build sometimes you have to beware that things like this can happen. In the end it wasn't too bad for me though, i needed to do a partial rebuild for tweaking anyway, so this was a good excuse to check everything over and make some improvements.

[stuartgallafant]

stick some more pictures up tim, i'd be interested to see how everything looks now

[tim_s]

here you go mate:

before with ITBs and LPG


new head


new engine in, this pic was taken today, so is exactly as she stands at the mo.

[appletree]

looking good tim! bit different from when i saw it

bit off topic but what are the bungs for in the exhaust runners?? any one know?

pressure testing or somthuing like that??

[jkarran]

Individual cylinder lambda or EGT test points would be my bet though I didn't think you could do individual cylinder spark or fuel maps in MS yet. Or maybe something less exotic... heat shield mounts

Shame some of the old pics seem to be broken, it's an interesting thread.

jk

[Demlotcrew]

How well does the engine run on LPG? Performance wise.

Andrew

[stuartgallafant]

bit off topic but what are the bungs for in the exhaust runners?? any one know?

they're there for use on the DIS machine to help diagnose air and/or fuelling problems

[tim_s]

Andrew, i'm afraid i don't know about the LPG, has been purely ornamental for the last few months, various other things have been keeping me busy. it was all ready to go, i just needed to get the lines leak-tested and get her certified by autogas-worldwide in wales, but then I got the tapping noise! want to get it going over the next few weeks though now that the car's back to health, I'll let you know how it goes. I went in a friend's IS200 with the same kit and it went pretty nicely; i guess a lot of it is down to the tuner. Thankfully I still have the wideband in the car so will do some tweaking once its in.


good news is i have 1000 miles on the engine now since the second rebuild, all seems really good. i'd forgotten how smooth the car was with motronic and the 2.1 (much smoother than the 1.8 ). bad news is im bored already, the performance is off a bit too as the inlet cam timing is not perfect - its not 'barking' or feeling like its on cam at any sensible rpm. i'm either going to get another inlet cam reground, or go for some wilder cams next week when im in germany. Think I can go a bit wilder and keep a good idle, but its a bit of a risk and an expensive experiment if they're too wild! I'm also considering how i can get some more factory-based ITBs that will run on moronic, which will undoubtedly prove to be a bit of a mission. am thinking of standard airbox and miller MAF onto a newly designed plenum. won't give the same performance but should give a good compromise between the two setups I have at the moment. If i did so, i'd try not to compromise as far as the dbilas setup which runs far too short runners and a crap plenum.

[Demlotcrew]

What was the exact cause for the first 2.1 to go wrong?

Andrew

[stuartgallafant]

did you get the cams reground from piper? i was thinking of getting mine done by piper but someone who builds a lot of high-spec engines told me KENT would be a btter option

what do you think on yours tim?

[tim_s]

What was the exact cause for the first 2.1 to go wrong?

Andrew

one of the phosy bronze small end bushes gave up (some play developed against the pin) for no apparent reason. have some much tougher steel-backed bushes in there now, new pins too. the pins/pistons had done a few miles in a (6 pot) race engine which threw a rod (the piston for that cyl was binned though) before being put into my engine first time around, so maybe the pin for the small end that went had some undetected wear on it, or maybe I just got unlucky with one of the bushes - shit happens. All the pins are brand new lightweight efforts now, and the small ends are toughened, so all should be well.

As for cams Stu just go with the company you want to use. I've had cams from both kent and piper in the past, and have a lot of time for both companies. I used to have a GS2 and a 285 piper for my golf.
Neither company's regrinds will give a perfect idle on the standard short stroke engine, but on the other hand if you want to make big power you're gonna have to go wilder than cam regrinds.

[stuartgallafant]

i was thinking of using the piper regrinds. there really isnt a lot out there for the M42 unless you're spending silly money! the Schrick set are about £600 or something ridiculous like that

[tim_s]

there's lots out there mate, you need to budget £400-500 for a proper set of new cams if you're sticking with the 1.8. you can even use regrinds to get a harsh profile if you swap to solid lifters and shims to make up where they take so much off the base circle. the shrick profile is crap value for money.