LPG on 325/335 with megasquirt

[deian]

Hi again, still thinking ideas here so don't laugh if they are silly ones...

So if i get a 325i, how does it run on LPG? And if i make a conversion to an M30, how does that run on LPG.

On top that... how would they run with an aftermarket ECU such as Megasquirt? I know what your thinking why convert to a beefy 3.5 only to zap some power by putting lpg on it, it would certainly justify running it as a daily driver. And then... how about 3.5 turbo lpg megasquirt? I'm very particular to what I want so I want the bad news now as i'm thinking about the whole project so i can rethink.

Thanks a lot guys. Glad to be back.

[Ant]

Lpg and MS= no worries

you can use dual tables, so one for Petrol @ 14.7 AFR, and another for LPG @ 15.7 AFR, dual fuel not a problem

as for 335 and lpg, no issues, turbo on lpg, good idea as the gas will pull the intake temps down to lower than ambient

in short, decide what you want and go for it !

[deian]

Excellent, sounds good, Can you also have dual ignition tables with MS (will have the add on to control ignition too), one for petrol and one for lpg (as it's over RON 100)

i think i will do it in this order...
1 get a bmw
2 convert it so lpg
3 convert the ecu to megasquirt
4 drop a 3.5 lump to it
5 slap a turbo on

[gareth]

oh no, you you've got me thinking.....

supercharged LPG M30B35!!!!

[deian]

lots of money for the project, but maybe the savings of running the car will make the project more satisfying in the end

[miniblob]

I know what your thinking why convert to a beefy 3.5 only to zap some power by putting lpg on it

I've read a bit about lpg and i believe it is a higher octane fuel than petrol, so will give better performance if tuned correctly!!!
Apparently you can get much better performance if you convert the car to lpg only!!

[ollielsd]

yes lpg has a much higher calorific value, but car needs to be set up to best utilise it

[LittleT]

I've got a C220 merc I've just fitted with a LPG system - uses 1 x LPG injector per cylinder and a programable piggyback ecu. The software is easy to use - downloaded onto laptop and just plugs into the ecu with a patch lead. The car runs so much smoother and no power loss (although I'd like to get it on the rolers to verify it). Will use the same system on my M50/318is conversion.

Oh yeah, I use a 70 litre tank as well, so its got some range!!!

[e21Jason]

Hi

Were did you buy the merc lpg parts and did you do the conversion your self.

Jason

[Jos]

oh no, you you've got me thinking.....

supercharged LPG M30B35!!!!

Funnily enough....

Thats EXACTLY what I am in the process of doing :p

[deian]

Hi,

Supercharged? Wow, will you run Megasquirt on it? You are a crazy man! How long has it taken so far? And how much longer?

Thanks

[Jos]

Looking at your order I would do it differently so you are not doubling up on work/installs

1) Get a BMW - done
2) Drop in an M30 and get it running on petrol/stock ECU - engine is getting a full rebuild 1st
3) Install MSnS system
4) Supercharge it - I am using a centrifugal supercharger but you could also use twinscrew/roots depending on what you wanted.
5) Convert to LPG very quickly afterward
6) Get setup and enjoy, I think I would use a normal basemap for the non S/C engine and then only get the final maps done once the LPG is in, leaving the SC belt off for the time with no maps.

As far as progress goes not much has been happening, started the idea a fair few months ago. I have the engine but I decided to strip it and see what condition it was in as it had been sitting for ages, glad I did as 1 cylinder had water in it and had seized the engine. Got it free after taking the head off and this allowed me to inspect the block and head, it needs bath cleaned really so while I get that done and pressure tested I thought I may as well get it reringed and rehoned (will have to for the seized one anyway) So I dropped the crank, it all looks good but will reshell it anyway, seeing as it's off. Just randomly collecting information at the moment to minimize issues when it comes to assembly.

Need: supercharger (not sure on ATI or Vortech at the moment but will be intercooled regardless of what Vortech say, also hard to get ATI compressor maps as they don't publish them, which is a pain..)
Was going to use Emerald, a former m8 of mine from Uni is the Emerald dealer for NI but I am thinking toward the MSnS more at the moment.
Need new sump and oil pump pickup as its a Generation 2 Engine and don't fit in the e30 as it stands.
Need 1 new piston and a full set of rings for all 6
Need full set of shell barings
Need a gearbox
Need to make a front crank pulley of the correct size (got access to a workshop lathe for that)
Probably need a set of bigger injectors looking at toby's duration on his

Estimate once funds become available about 8 weeks for it I think depending on availability of parts. My dad does work in Penbrooke so should be able to get some mainland stuff too.

Still very much in planning stages but I do like to think things through an awful lot, and it's been 6 months since I last looked at all this, bit of a refresher needed.

[deian]

i'm thinking minus everything here, no bmw, no space, no money! i want some background first you see, but i will definately do it, it's a goal in my life!!

i've had two e30 2 door 325i before, both been SE's first one was older a zinnobar red 1986, it was manual with LSD too, and was a damn lot better than my last e30 which was also a 1988 Zachs Silver 325i SE Auto EH sport type AWESOME gearbox though (80mph in 2nd!!) but it let me down in an overtaking manouvere and mauled the car (no lsd either). Both cars has the better obc, and rear blind. So i've been bitten by the BMW bug! my next car will be a 325i, the most loaded i can get. i will post a question here about which one to get.

thanks for the info, sounds interesting!

[Jos]

If you are going to do a transplant have a dig about and try and get a loaded smaller engined one, the 325s are lots more money, the only thing you need is a damn solid shell as more or less everything else will be changed, watch out for 316/318s as they have drum rear brakes. Not a major as they can be changed easy enough. Although if its a long term plan, get a 325 as you will get more enjoyment from it, or a 318is, but they are probably just as much money as a 325.

Shell quality (read lack of rust) should be the main factor for choosing a donor.

Background is a good idea to get an idea of the work involved, have a look at the other threads on here, search way back for the threads from tobyunna and andy335 as they were the 335i pioneers on here I think. Should help you avoid most of the pitfalls, ofc if you haven't already seen: http://www.e30.de/335i/00.htm
some of the information is incorrect/not important but it will give you an idea. And don't be afraid to ask, it's the only way to learn.

[deian]

I'd like a 325i first, just so I can get some enjoyment first, I think the 3.5 conversion won't follow for a while though, I will get all the parts first, then do the job over a few months (less maybe).

I have been reading some of the latest threads, but not gone back too far, I will make a note of doing that. I have seen the e30.de link before, interesting! Would you suggest I get a 3.5 donor car first? And strip that of it's parts, or a 325i first and gut that car? The plan is to inspect it ALL, rewire the lot if necessary, check all is good alignment wise and make sure the body is sound on it too. I want to go down the 325 route because when the M20 engine goes out I will keep it and strip that down and rebuild it as an NA racing engine over a period of time, then will get another e30 and turn that into another toy. With the engine that comes out of the other e30, i will rebuild that as stock and swap around as needed, by that time I should be swapping engines in a few hours!

Thanks for the info lots of print outs and highlighting now. I will print ALL of megasquirts pages out and file the lot, another thing I'm doing is tracking what 325's and 535's and relevant parts go on sale on ebay and autotrader, so I know whats out there, and what I need to budget. All taking time i;m afriad. I'm in no rush though. Again thanks for your help.

[Jos]

A 535 donor would probably be the cheapest method and the safest, you can check it's running and see how good the engine is if it's still in a car!. If you are going to check over the whole e30 shell I would get that 1st, it will be the bit that takes the most time. The engine loom is more or less completely seperate from the car loom, only the plug at the fusebox connects them together, and some overlap on the SI board. Dismantling your e30 is a good way to learn! Just make sure you can reassemble it afterwards :p

Is the 325 going to be a daily driver over the conversion period or a project car with another car for everyday use? If its your 1st conversion it would be wise to have it as a project car really, as these things never go that smoothly and you can end up with a car with no engine in it, or an engine that don't run.
Do you have lots of space, 2 half cars sitting on a driveway/in a garage irritates parents and wives with exceptional speed!

That's pretty much the same as what I am doing, lots of reading, all kept in a big file so you can reference back to it when needed. Parts costs, average donor/engine costs and a list of stuff you need to get, which you can score off as you get them.

[gareth]

if you're planning on a 3.5 conversion, startng with a good 320i will be a lot cheaper but if it's a late one it will have the rear disks etc. the shell is also likely to have had a much easier life.

i've done the swap fairly recently and am only too happy to help out. if you search under my username there will be lot of info there too.

getting to be quite a fleet on here!

[Jos]

lol, all the petroleum companies wil be rubbing their mitts with glee!!

Tourings also all come with rear discs

[deian]

I'd love a big file with loads of info i'm a control freak! i don't think it will be a daily driver either, i plan to just run a cheapy to save on fuel there, as for space i'm looking for space (aren't we all), been on to the council to hire a garage off them, but they are rare, people hold on to them. one in the garage, and something on the drive too.

As for fudging up half way and can't put it back together, i will label everything, and put things in order, and take pictures, and make notes and all sorts, real geeky way!!

So the reading begins... thanks for all the info guys! I value the words of people on this forum, and will no doubt be back fishing for more geeky bmw info.

[gareth]

taking piccies is the very best thing you can do. use a cheap/old/battered but high resolution digital camera and take hundreds of them. it'll pay for iteself in reduced headaches!

[Jeff_200]

My 335i is generally smoother on lpg than it is petrol. Pulls a wee bit harder on petrol at the top end though