More Torque: 2.7 eta or supercharger?

[docazani]

To all sifus,I have read the various threads on forced induction and 2.7 eta engine.But I cant find any recommendation or comparison for my specific needs which are as follows:E30 325i cabrio auto, presently stock standard as far as I know. Cabrio is heavier due to reinforcements to bodyshell and I find moving off could be improved. Car is a daily driver, stop start traffic in KL, highways to Shah Alam. Weekends or free days I like to drive along trunk roads off the highway where traffic volume is low and enjoy a good blast. Overtaking response is probably blunted by the weight of cabrio. I doubt that I would go for a blast on a track with this car. My fuel bill presently is about RM200 every 5 days... Ouch!!My conclusion is I obviously need more torque. I dont need a high revving engine with top end power. Practical options are 1) 2.7 (stock) eta conversion2) 2.7 eta block with 325i head 3) aftermarket supercharger - been to see Turbo SangSo... those are my requirements and options. I would appreciate your views and recommendations. Advice on costs involved, reliability and ease of maintenance/parts will obviously be a factor.Thanks in advance. Much appreciated.Docazani

 

[Alvin]

Doc

Depends on the price of the SC conversion. I would say go with the 2.7 with B25 head. FI is ok but the M20 is a really old engine with wear & tear (Unless you have already rebuilt it). FI will accelerate the life of the engine. If you run low boost then no use. To have a bit of fun with the Cabrio, I thk you need at least in the region of 180 ~ 210bhp. I know if it was me i would go engine upgrade & if still not enough, then FI.

 

[Zoggee]

Doc,

I suggest you pm Chris Cab E30. What he has done on his E30 is superb. Or you consult Calvin Tan. Both cars are just simply Awesonme.!!!

If you are to use the 2.7 short block,then use the 2.5 pistons and a bigger injectors for higher compresssion. But there are downsides of the combination. moolah is one of them....you have to total rebuild from scratch.
WPyin is running on that combination. pm him for the details.

I've blown 2 units M20 2.5 engine in 1 month. Was wondering what happened.
Found out what happened. And I dicided to total the engine. COST A BOMB...!!
I spent 13K on it.

Here's my rough list...

1. HIOP Cams 280 deg. rm2.8K
2. Port & polish rm2K
3. Mustang Injectors rm1.9K
4. Bosch MAF rm 1.5K
5. Overhaul Parts( such as Rocker Arm shaft,Gaskets,Lifters,water jackets,vealve springs,engine bearing,all new hoses,Big Bore throttle body piston and the rings, connecting rods..argh..!!! too much can't remember)7+K
6. FSE adjustable for E30...tried the japanese brand but got problems.RM750
7.SMT6 piggyback RM 1.8K
8....and the list continues.... :cry:


run-in the engine, dynoed and simple tune ( still not refined) gives me 191bghp on engine at 5800rpns,140.1bhp on wheels.
253NM at 3800 rpms.a bit higher then the M54 Double vanos if I'm not mistaken.

Doc thats only for the engine....
with help from Calvin Tan and Fabian , we manage to get some refinement form the engine. A lot still can be done.but reliablility is the the main concerns.....NOW,I'm running back stock without the smt6 and went to HPC to test the engine. Superb.

the money spent dun get you near and M3 S14 torques...

I advise you either get the M50 or get the S50 conversion. ask those who have them in their engine bay...now thats worth it.

pm those Local Sifus like Calvin Tan,Alvin,Teejay,Pussy,Loneranger. me too ..
if not I suggest you go aftermarket tuners in US...they'll advised you what to do....

I've tried everything that you can think of on a M20 engine...believe me la..Stock is the best.They(BMW) optimised everything for you liao.

There's more then meets the eyes...!!!!!!!!

Nothing Personal ..ok???

 

[Zoggee]

When I run on stock M20B25i Motronics 1.3 with 240 getrag manual tranny and 3.73 rear diff...she runs fine!!!

until the day when the MODs starts..... headaches at the time.

Doc,

I suggest you try manual tranny first ,match it with a correct rear diff. Thats a whole lot fun then modding the engine.

 

[Zoggee]

Now if I am to buy anuder BMW ,???

I will get the M3....but now I'm in love with anuder German Marque with flat 4.


The Porshce...!!!!!

 

[Jipster]

Doc.... engine swap may be the key.... probably same amount of money but less head and heart ache.... less twiddling too.... if you keep it stock there will be room for future improvement as well.... 2.7, 2.8, 2.9 M20 strokers probably test the envelope of what is possible already (metric mechanic quotes a 3.2 though) and they will be engines which require a lot of tlc.... forced induction is similar, lots of tlc required..... if its your daily driver, reliability and driveability is and should be your priority.

 

[bmwky]

doc....take zogs advice. you dun want no headache, money spent is not the issue but the angony of a bad job is too much to bear for us mere mortals. research througly before you embark on your mods. Ask from the been there dunnit guys. zogs is not the only one who have change/destroy countless M20 engines, ask calvin tan, his E30 doesn't get to where it is today on a single mod. If you still quench for torque, probably the best option is to change to a E36 328iC, I know of one of these fine species for sale.

 

[Zoggee]

Originally posted by bmwky@Jun 28 2006, 05:39 PM
doc....take zogs advice. you dun want no headache, money spent is not the issue but the angony of a bad job is too much to bear for us mere mortals. research througly before you embark on your mods. Ask from the been there dunnit guys. zogs is not the only one who have change/destroy countless M20 engines, ask calvin tan, his E30 doesn't get to where it is today on a single mod. If you still quench for torque, probably the best option is to change to a E36 328iC, I know of one of these fine species for sale.

Thank you ..... I tot you dun understand engerlish

 

[docazani]

Thanks guys...

Daily driver...so reliability is paramount.

No time or energy to run around with headaches... so looks like stock is best.

Next question is.... for my needs stock 325i or stock 2.7 eta? Any forummers have a stock eta in their cars willing to let me have a try??

I have driven an E28 525eta in UK once but that was like almost 20 years ago...cant remember what its like..

Docazani

 

[skar19]

Originally posted by docazani@Jun 28 2006, 05:56 PM
Thanks guys...

Daily driver...so reliability is paramount.

No time or energy to run around with headaches... so looks like stock is best.

Next question is.... for my needs stock 325i or stock 2.7 eta? Any forummers have a stock eta in their cars willing to let me have a try??

I have driven an E28 525eta in UK once but that was like almost 20 years ago...cant remember what its like..

Docazani

bro the stock eta isnt that nice to drive and in a way you are down grading.

- AFAIK most etas where ljet, but there are some motronic.
- The engine produces less power than the 2.5
- on the eta ecu the revs are limited to somewhere around 4000rpm
- the eta engine has bigger displacement but is actually less advanced compared to the 2.5 engine
- even by using the 320 oe 323 ecu the mapping wont be sufficient to manage the eta....your fuel consumption will go.

if you still want the eta engine, then sell your 2.5 to me

this is what i suggest you to do.

- convert to a manual gearbox (big difference compared to auto)
- find out what your current rear differential ratio is and go for a slightly higher ratio
- you may also want to add a performance chip the change the characteristics of the car.
- drop in a K&N element, Big throttle, exhaust headers, piping and muffler
- upgrade the suspension system, springs absorbers, antiroll bars, strut bars.
(go for something like bilstien tuning kit and eibach ARB, strut bars ask fabian)
- get some good tyres
- i have driven a 2.5 manual before and it has lots of torque and its fun to drive serious.....even the 2.0/1.8 is fun to drive.

but seriously the 2.5 is anyday better than the 2.7 eta

if you really want more reliability and power, then go for the m50 conversion.......it is worth the money spent. but be advised that you need to uprate the suspension , brake system and chassis.

 

[ichiwan2]

Skar19 mentioned something very important. U need to uprate a lot of things.

As your car is a cabriolet, I would worry most about the chassis. While it has been reinforced at the sills, it may not be enough to handle the additional torque and power, unless you are willing to weld up the doors and jump into the car through the window opening (when the top is up) or keep the top down all the time. :nyehehe:

Words like scuttle shake also come to mind. Google this.

 

[bmwky]

Originally posted by skar19+Jun 29 2006, 03:00 AM-->QUOTE (skar19 @ Jun 29 2006, 03:00 AM)

 

[ALBundy]

Yup, the only worthwhile mod to do is go for the M50 conversion.

There is only so much you can do with the M20, and money wise the returns from a M50 transplant is higher.

To do the eta conversion, basically only the crank and conrod will be used. You will still need to use the existing 2.5 pistons (need to skim a little) for higher compression together with you existing 2.5 cylinder head. Then to optimise, the new compression and stroke length, a piggback ECU is needed. All in, the cost could be as high as a M50 transplant and yet the M50B25 engine will still outperform this conversion.

 

[SAMBK]

Greets,

Under my hood is an eta 2.7 engine, have no idea if its in stock form or not. Was told by previous owner, its an ori 2.7 engine, came half-cut from Japan, used to be in an e30 wagon(325e ?). The ecu is if not mistaken a Bosch Motronic. All was transplanted etc by AutoTecknika dudes.

A bit "rojak" car as what my brothers(mechanics) told me, under the hood there's a big K&N air filter & from the $$$$$ I paid for a total new customised exhaust for it, she screams if in high pursuit.

Really all this engine stuffs are out of my league, don't really understand but 1 thing I do know, a lot TLC & I really enjoyed driving my bimmer.





Regards.

 

[teejay]

doc pm me,

we can chat as i live nearby tmn melati.....m20 upgrades are my forte, been doing research for the past 9 years....

 

[ALBundy]

Yup no other better person to speak to...the other one is Calvin Tan, the true M20 experts. 9 years wasted on the M20 research!!

 

[pussy]

Doc,

my input why i did a M50 conversion.. reliability.

i had a 3 months go with a M20B25 car 3 years ago, had much stuff to change and modify.. cost me $$
lesson learned, so my next thing is to do is to convert my M40B18 to M50B25, not M20 engine..(M20parts are not cheap this days and quite the same with M50)

My car runs fine since 6 months and so far just the normal service intervals. i dun need to worry about the air flow meter screwing up nor balancing the Co2 mixture, contact point(rotor), plug cables, timing belts, etc, cos the M50 engine is much simpler in design(refined)..

even my milage figures -fast roads and town driving gives me 11.8L to a 100km/h.. very good FC.

i m suprised that your FC is so high, better get it check.

also, consider the power output of the 2.7L M20 versus the 2.5L
M50 - 2.7L gets you about 180hp with 189hp M50 and torque is very similar of 250NM (around there)

Note also, many have said that the mod into 2.7 engine needs a lot of work to obtain that figures many modders claimed..

well enough said.. your call doc.

regards.

 

[OSFlanker]

Originally posted by ALBundy@Jun 29 2006, 10:57 AM
Yup, the only worthwhile mod to do is go for the M50 conversion.

There is only so much you can do with the M20, and money wise the returns from a M50 transplant is higher.................

M50 conversion is probably the best value for money mod, but in terms of worthwhileness, S50 has to be in the picture.........but nobody tried M60B40 kah???

 

[teejay]

Originally posted by OSFlanker+Jun 29 2006, 01:28 PM-->QUOTE (OSFlanker @ Jun 29 2006, 01:28 PM)

 

[teejay]

Originally posted by ALBundy@Jun 29 2006, 12:03 PM
9 years wasted on the M20 research!!

....c1p3k you!!!

then calvin tan even wasted all his teen years on the m20......17 years i think......