325e

Fri Mar 27, 2009 11:41 am

Will a 28 pin chip for a US 'super eta' type 154 ECU be compatible with my type 173 ECU and if not will the entire 154 ECU plug into my wiring loom?

I have done some research on the net and got conflicting information about Motronic 1.1 & 1.3 compatibility.

The reason I ask (and I'm sure some of you will think I'm mad!) is that I quite like the idea of turning my humble 320i into a 325e which will give me a chance to do a few things to my 731 head in readiness for a full 327i conversion.

If I like the way it drives I might end up keeping it a 325e - I used to own a 525e which was a super old girl.

Fri Mar 27, 2009 6:19 pm

I am a bit confused,325e never came to the UK...the 'super eta' used the 885 head with the larger 325 type valves...the longer stroke of the eta engine requires very different fueling and ignition to a 320,when I built my 2.7 Ant supplied a chip suited to my engine spec,did not cost too much either.What spec are you thinking of building?

Sat Mar 28, 2009 9:59 am

Well the plan is to do a straight swap and drop the eta engine in as it is (with a longer diff) and once the 2.0 engine is out I can take the 731 head off to fit 325i valves and shape the inlet ports to match a 325i inlet manifold

If I like the way the 3er drives as a 325e I might just not bother with a full 327i set up because I'm much more interested in flexibility than outright power

The reason I ask about 154/173 ecu's is because I think late American 'Super' Etas were equipped with Motronic 1.1/1.3 and it would be nice if I could just remove my 2.0 chip and replace it with an eta chip

Sat Mar 28, 2009 10:37 am

Sounds like a good plan!You will need a modified chip of some sort to run the eta engine of course,best way would be the later,all electronic system so you can eliminate the dizzy.If you have the American spec chip it may be worth trying it,but not worth the risk of buying one! As I posted,Ant can write you chip to suit your spec. 731 head with bigger valves is best head for the eta piston,I keep meaning to try it myself.What cam are you thinking of? Once again,I have a 323 cam 'in stock' for my next head build...I found that stock 731 head with 325 cam,eta stock short motor gave me 178bhp and a flat torque 'curve' from 1500rpm.In real terms on the road this means that the gearbox is virtualy redundant once the car is up to main road speed,I can pull out to overtake trucks and accelerate from 55mph to 80 in 5th..in complete safety.I would expect that the stock 200 eta head/cam will give all the bottom end that I have but not the grunt above,say,3500rpm that I enjoy.I am running a 3.64 diff,BTW.

Sat Mar 28, 2009 10:52 am

178hp is that at the flywheel or wheels?

Sat Mar 28, 2009 11:03 am

m_jermyn wrote:178hp is that at the flywheel or wheels?

Hehehe....fly! Not a lot over a stock 325 but it's the torque that counts out on the road.I rarely use the area above 3000rpm,why I think you have a good idea just sticking the standard eta motor in with motronic.

Sat Mar 28, 2009 11:11 am

so you get 178hp with a 731 head and a 325i cam??? Didnt change the inlet manifold, chip, air filter or 325i computer?

Sat Mar 28, 2009 11:26 am

Ah,full spec...stock eta short motor sat on E30 alloy sump. 731 head with stock 320 valves, 325 cam.325 inlet manifold,fuel rail,fuel pressure regulator.(head/manifold matched) Miller MAF with K and N cone filter.Chip supplied by Ant,modified by Miller to suit their MAF.In this spec I got 178.3bhp and 190ft.lb torque,180ft.lb torque from 2000rpm,peaking at 190 at 4000rpm and tailing off to 170 at 5250rpm.Peak bhp at 5250rpm.Since this dyno run(24 Nov 07 at Evolve,Luton) I have added a hottuning 6 branch that does seem to boost the top end a bit.Ran it for ages with a 320i badge on the boot,very confusing!

Sat Mar 28, 2009 11:32 am

lol im looking at a 325e tomorrow and thinking of a 885 head ported and polished 325i inlet manifold matchflowed to head, maf K&N cone extractors somesort of chip and I think I need a 325i computer also some sort of big throttle body

Sat Mar 28, 2009 11:35 am

Oh its the perfect scam I told my misses im buying the car for her so she can get rid of her old sh1tta swift. I will sell the swift let her drive the E until she saves for a new car.... In the mean time im slowley collecting the parts to turn the humble 325e into a 327i weapon...

Sat Mar 28, 2009 1:37 pm

m_jermyn wrote:Oh its the perfect scam I told my misses im buying the car for her so she can get rid of her old sh1tta swift. I will sell the swift let her drive the E until she saves for a new car.... In the mean time im slowley collecting the parts to turn the humble 325e into a 327i weapon...

I like your thinking....just hope the little lady does not get too attached to her new toy!

Sat Mar 28, 2009 3:52 pm

I'm just going to stick with the standard 320i camshaft as I don't really see the point of spending £x00 on a sports cam that will increase emissions and decrease low down shove and I might even just use the 731 head as it is complete with standard valves and 320i inlet manifold.

Should be picking the engine up next week, just hope it's not a bag of nails!

The reason I want to buy an eta chip is because a 2.7 chip is set up to work with a 325i afm and injectors so I guess it wouldn't work on an eta which has the same afm and injectors as the 2 litre engine