BAD300

This thread will be dedicated to my project long in the waiting. Alot of research. Alot of new ground work. A few performance forums attributed to get this far An excellent workshop found also.

Will start with some pics in the next post of when I brought the beast home in January of this year.

To begin with. Bought this 300E from a disillusioned seller who allowed poor workshop to build the car & eventually poor workmanship & little knowledge led to destruction of performance built engine along with most of the running gear & turbo equipment to be replaced from scratch.

Hope this thread will be informative & maybe stir a little discussion for those interested in stretching the boundaries a bit

Below are some pics of the car when I brought her home in January. It was running LPG set up with only 1 convertor. Running a Garrett T03 highflowed to T04 specs. Pretty stock exhaust manifold I think off a diesel? Not sure now. Exhaust was anywhere from 2/14"-3" ike a dogs breakfast. All looked good but it was destined to blow up.......it did!



















Purchased items & work to be done commencing last week:

Running Gear:

Low km M103 3.0L in VG cond' left stock 9.2:1 comp (aid in spool time)
GT3540R .63 A/R billet comp wheel; ceramic bearings (all lowering spool time)
Microtech MT8 timing only ECU
3" turbo back mandrel exhaust
Larger FMIC & fabricated mandrel aluminium piping to suit
Custom Inlet inc 3" bell end runners & Boxy Plenum
Custom Steampipe Exhaust Manifold with 45mm external wastegate
Reco'd 400 Mixer (older style were better) & Twin Vapour/Convertors & larger lines to suit
Rebuilt Trans with shift kit & 2300rpm stall convertor
New engine Mounts
New Trans Mount
New Behl Radiator & all hoses
New Front Flex Plate......will add later any other gear I've forgotten

Boost will begin @ 10psi, then 12, then hopefully 14

Will be installing LPG primer sensor & oil filter between engine & turbo

Looking realistically @ between 260-290rwkw depending on boost I run? I was going for 290 solid but I feel @ this stage I would have to use .84 A/R housing to gain the top end needed I think? This would mean a trade off of more lag & less linear powerband.

BAD300

Decided to raise the boost in increments when we, eventually do get to tune car Initially do a run @ 10psi using a 45mm external wastegate then @ 15psi @ see how she fairs & what hp we can achieve @ this boost. As I've said before, hp will be down due to small turbine housing but the trade off is quicker low down response so I can live with that I won't be running a BOV as the auto's stalled @ 2300-2500rpm so unlike manual gear changes where you would definitely run a BOV, gear change will be pretty much instantaneous & BOV in this case would be for the **** effect only. Back pressure will be negligible & the large wastegate will do that job well. Also the larger comp wheel ensure large volume of airflow & counter the back pressure anyway. All in the set up @ this stage.

Also @ this stage I think I'll call it a day @ 15psi for reliability purposes more than anything. The LPG will work in my advantage in this area with it's higher octane ability however, this hp will be a big enough shock I think for the stock car including running gear, brakes, suspension per se.

The MT8 has to be made up especially & will be a few weeks wait bugger it. Hopefully there is enough to be done in the meantime with fabrication anyway?

P.S. I may still run a BOV. Plumbed back though but awaiting workshops call

BAD300

For those interested parties. When considering LPG running high output engines. You must first choose the right set up in order to achieve desired results from a stock engine, or even performance built engine for that matter. I have owned LPG on both purpose-built & stock engines & there are pitfalls for both! Like any good engine guy will agree. once you are guaranteed consistent AFR's. It's all in the tune!

I want to say @ this early point. I am fully aware of the LPI injection available & vapour injection systems but chose not to go down these paths due to 4 things. Cost, availability & poor manufacturing of certain parts & finally that car was already set up this way so I wanted to simply finish what was started so many years ago. This along with fact the blow-through mixer systems we use down here are the best you can get & are actually producing better results in high output applications than injection rivals.

Through discussions with other performance forum members, the issue of the inlet manifold came up big time. Fact that the inlet manifold was manufactured as a dry flow only manifold but now is having to act as a wet flow! Simply ensuring the set up is right so enough LPG feeds all 6 cylinders to prevent leaning out. Whilst LPG resists detonation very well due to it's higher octane rating (110), thus, allowing higher boost levels than pump gas, you must ensure AFR's are constant! Enough fuel/air gets is supplied through entire powerband.

The way previous owner had LPG set up was pathetic. Ignorance played a huge part in purpose-built engine (low comp forgies etc) leaning out in a few cylinders & causing head gasket to corrode & eventually head to warp & finally driven for too long in this state which ended up scoring the bores & actually corroding engine block between combustion chambers Electrolysis played a bid part also when car was left to sit for too long in between driving. Head was a mess when I pulled it off.

My workshop will be running new thicker LPG lines & reconditioning Mixer & boring out venturi chamber for greater flow volume & fitting larger main jet, coupled with twin converters.

Next. Customised inlet manifold is being fabricated (almost finished) whereby runners were cut down to about 3" in length & then turned bell ends fitted onto each & then mated to a custom boxy plenum that's welded onto these. The Mixer will now sit sideways, acting as also as the tb fitted to front of boxy plenum instead of the middle of the old stock manifold as previous owner had done. Modified inlet will then be bench flow tested to ensure even distribution of gases. Also by positioning the tb @ front of engine allows for much shorter intercooler inlet piping so less volume has to be forced around the intercooler circuit = quicker spool time.

This is probably the main custom work that will ensure reliable LPG flow rate.

Hope this is helpful to anyone either interested in this mad project or contemplating LPG use in the future. I personally wouldn't have willingly undertaken this challenge if it weren't for the predicament I found myself in due to this poor cars fate & the huge potential of a much-luved car that ended up pushed aside through ignorance & despair.....

BAD300

I've decided to take a members advice on another forum who has worked on & owns 4 of these turbocharged 300E's. Concerning the dynamics of these engines & how they work up top & not so much down low so, in order to take advantage of their inherent performance characteristics, I've decided to swap turbine housings. I will run with the .84. & not the .63. I may as well swap it now while it's sitting on bench than later after it's fitted to the car.

I don't want the back pressure & accompanying heat on the turbine wheel & inlet parts that the smaller housing would create. Besides. The better economy & higher hp I think kinda speaks for itself

Just so happens workshop has an .84 housing from a commodore they worked on so it isn't a big deal.

speedracervroom

where did u get the engine cover?

BAD300

It was fitted to car when I purchased it. It's fibreglass same as the boot cradle. Previous owner had them custom made from who knows sorry? Nice accent I thought but don't think it'll fit with new mods being done unless I grind bits off here & there maybe & bolt it somewhere solid once engine bay works completed?

speedracervroom

dang i wants!!! looks clean would do it black tho

Shoomakan

Nice. My car is headed to the garage in a couple of weeks for a manual swap, finally got all the parts together.

I also plan on fitting a turbo, but I haven't found enough online M104 literature to do so. Lots of people have turbo'd M103's, haven't found many M104s though.

So far it looks like I'm going to flip the exhaust manifold and mount the turbo on it, and upgrade my injectors, fuel pump, and get a rising rate fuel pressure regulator to tune. It'll be a ***** to tune, but it should work.

Any input? Your help would be greatly appreciated. I really don't wanna blow my engine.

Cheers, Shoomakan

the_widebody

make sure your rising rate regulator is of good quality, and has a 1:1 ratio

Shoomakan

Is flipping the exhaust manifold a good bet? If not, do you know anyone who makes them?

the_widebody

not sure, i suppose if you have good fab skills, and cast iron weldin ability, you could mod the exaust manifold.

there is a bunch of threads on hear and benzworld, on how to mate the euro cast desil manifold to the 103.

roman at turbobandit, sweeden, make manifolds, look on peachparts, but they aint cheep.

if you can weld, wht not have a bash at making your own fron scratch?

Shoomakan

How about a centrifugal supercharger? I have one lying around, good for the 3.0 displacement. That should be the easiest to install as well.

BAD300

M104's have been successfully turbocharged as well. Thumbs down to the SC idea unless you research it well. These engines work better up top-end rather than down low where a SC offers it's benefits. Also you would have to strengthen the bottom end considerably with the SC. With turbocharging, no need to if you do it right! Besides, turbos offer easier to achieve high end power/torque imo. SC would be interesting less info around for our engines I'm afraid

As mentioned, Roman form Peachparts forum & a few others over there like Joreto, Eric400 & kynsi will be good members to liase with. I warn you though Roman & kynsi are not for the faint hearted but will be good to guage what can be had from these engines.

The M104 is a little more difficult to turbo & probably not as tuff as the M103 if you want HUGE hp. Moderates OK though but it's mainly the CIS you have to work with & it's a bit complicated to tune with. Can do it mind you but a stand alone ECU is best obviously.

Word of avice. I wouldn't go making my own exhaust manifold if you weren't an excellent welder. Turbulence in the pipes caused bu poor merge collector will limit power & damage the turbo &/or engine. Leave it to a fabrication workshop. Roman does make them. They are $800 Euro. Freight charges to you from Sweden will kill you though due to the weight

PM me if you want Romans details or threads

EDIT: I just realised your in Beirut! There is a member on Peachparts that lives there. Jayrash. Get onto him & your set!

Shoomakan

You make a good point with that S/C. I think you're right, turbo is the way to go.

I was doing some research, and apparently the 3.5 Diesel turbo manifold mounts right on to the M104's head. If that's true, all I'd need to do is adapt the flange to T4 (apparently it comes with a T3 flange).

I'll also PM you for roman's details.

Shoomakan

Also, I found a Mosselman TT kit over here, but it's for the M103. Would it need expensive modding to mount to my engine, or is it relatively easy?

BAD300

Yes that's correct. They will fit although, a custom manifold would allow turbo to perform better through the powerband.

I'll PM you RBYCC's details & some thread links to another who has the TurboTechnics TT kits installed. I'm sure RBYCC has the kit on an M104 & only issue was tuning the CIS

Keep in mind the going twin turbocharging was used when larger turbos weren't that responsive. Large turbos now are alot more efficient. Also, TT is more expensive & doesn't yield better results.

RBYCC

I run the TurboTechnics UK twin turbo kit on a M103-12V.

Best search to do for the M104-24V install would be NickGed in the UK ( early M104 with CIS-E ) and Ortolan Australia/Canada ( late M104 with HFM )

If I recall JayRash in Lebanon may have had a Mosselman install.

Different fuel enrichment theory between what ***** Mosselman did compared to TurboTechnics.

Mosselman did it electronically with a piggy back controller using the stock fuel delivery system where as TurboTechnics used additional injectors fired by their semi stand alone controller.

Mosselman had a much better electronic control, but the additional injectors used by TurboTechnics can make a lot of power fired via a modern stand alone controller such as the Split Second AIC1.

Shoomakan

I spoke to Jayrash, his kit is the 12V and apparently won't mount with my head. Shame, too. He offered it at a decent price.

If the 350SD turbo manifold would fit, but isn't that efficient anyway, that's also a dead end to me.

I guess I'm gonna go to a workshop and custom design my own turbo manifold. Seems like the safest bet...

BAD300

Stock manifolds will always be limited in efficiency. They do support up to a certain hp but will never perform like a steampipe equal length runner type. But you have to get a pro to build one as runners need to all join up to a 'merge collector' so turbulence is avoided. These manifolds support much higher hp as well as provide better boost, quicker spool, better flow = less backpressure = less heat & hinderance to power gains.

You do however have to weigh up the cost of the whole build. What you can afford in the end & what performance you want from your car. You don't want your set budget to blow out.

The intercooler is another thing to factor in to cost. The larger the volume IC, the more power & reliability can be had. Everything you do contributes to the end result. Most folk build with driveability in mind.

I'm building my car to perform moreso in the mid range of the turbo's powerband. Put simple. You need to choose the right size, type of turbo for the project goal!

Smaller turbos will be better down low. Bigger better up top. If you choose the right larger turbo you can have best of both worlds but you still need to know where you want the powerband to be?

Also. Keep in mind that these engines work best up top. Not down low. It isn't best to try & get them launching hard as you'll break things in the driveline. Your best to get these things plodding along first, then hit the gas & push all way to redline (this is where the best efficiency range of these engines sit). Build the thing accordingly.

The turbo I chose for instance makes best use of the mid to high rev range of the engine whilst, still spooling down lower. Even the parts arte lightened & then this is where the custom exhaust manifold (even inlet can be modified for better flow but your starting to talk money here) comes into play Same as intercooler capacity & so on & so on.......

The more performance you seek. The more parts need to be re-looked at

Shoomakan

Very true, BAD300. I couldn't agree more with what you said.

I've basically come up with the game plan:

I'm gonna use a very good condition KKK K27. It's a big turbo that's extremely reliable and can live forever at medium boost. One of the cars it came installed on was the older 745i, which was a 3.3/3.5 litre engine. On that engine, it started spooling at around ~2200rpms, so I think it'll be ideal on my car. Like you said, mid to upper range and far more important.

The turbo manifold will be custom made since I'm not really pleased with the stock available options. I will install the SplitSecond A1C1 system to tune(BAD300, if you can tell me exactly which one to buy, I looked at the site and was a bit confused).

There will be a front mounted intercooler as well, along with a Walbro 255 fuel pump and a fuel pressure regulator. Stock injectors stay in for now, I don't need them if I have the SplitSecond injector.

So that's basically my plan. I look to open between 6 and 10 psi, on a fully stock motor. Is there anything I need to worry about? The headgasket should be fine at that pressure, I hope. Aiming for 300whp, hope it'll hit it.

BAD300

Sounds good Shoomakan Roman makes them for the M103. That's all you need to state. 16 guage Steampipe, tig welded with good runners & your set.

6 - 10psi is fine with these engines as long as you get the tune right (AFR's). Stock head gaskets are fine as long as engine is in good condition & you don't overheat it. 300whp is fine!

Shoomakan

What are the horsepower gains at 10 psi? I'm curious to know. And at 6 psi?

I'm probably going to get some ARP head bolts just in case, and maybe change the headgasket to a copper one. M104's have high compression to start with.

BAD300

Hp really depends upon turbo type/size. The GT35R I am using rates to 600+hp. This equates to approx 400-450whp mid range say, 15psi? A 10psi maybe, 350-400whp? 6psi around 300-350?

There are alot of variables though to consider. These turbos really want to work from 15-25psi so, by about 12 I figure good results for the street

I wouldn't be concerned too much about head gasket or bolts unless it needs it. Stainless multi-layer are better than copper. Roman makes them in a few different specs to order. Yes, the M104 has higher compression than the M103 but you can deal with this by keeping boost down. 10psi is OK Again. I have to emphasis getting the tune right. It's crucial to have AFR's constant on all cylinders.

Of course it's better to strengthen these engines but not necessary if they are in good maintained condition & not too higher mileage.

Shoomakan

It's done 150,000 miles. Seems to me after looking on this forum that it's still a sprightly young toddler. :P AND it was granny driven all those miles, my grandma was the first owner. And I don't think she spent her time doing donuts in the car.

So I'll limit myself to 10psi, I guess. I'll be sure to start a thread as soon as I start collecting the parts.

BAD300, you've been a huge help. Thanks a bundle!

BAD300

My pleasure

Yeah even though the engine sounds like it'd be fine. 10psi to be on the safe side. You can always go harder later if it seems to handle it. 10psi though with a decent turbo & the stock compression should be awesome