wanted! more HP.

[Rocking-M]

From the stock 2.7 eta 6 in the 325.
First, the less expensive changes that will up the HP.
Can the cam be changed to the later 325 cam?
The eta engine puts out about 125hp but more torque than the
non-eta's. The rpm is lower too. Can the bits be changed from the
non-eta's to this eta engine and get it close to the non-eta specs?
Non-eta was about a 170 hp engine.
Thanks, Robert

PS the youngest isn't in a hurry, he's got to save a bit to be able to do
the upgrades.

 

[epj3]

In order of cheap to expensive and NOT from best to worst...


-Chip
-REAL cold air intake
-Electric fan (to replace mechanical fan)
-Big bore throttle body and higher-flow injectors
-Exhaust manifold & free-flow exhaust
-AFM conversion
-Turbo (easily best bang for buck, you could EASILY get over 250whp out of the m20 for under $1,000 total. It'll be reliable if you do it right - the m20 is a very good 'turbo' motor, though not as good as the M30 which is almost literally a motor built for forced induction but NA)

A HUGE swap is putting the "I" head on the "E" block. You retain all that torque, get a higher revving engine with a much higher flow head. This is a very easy swap too... basically an extra step past replacing the timing belt. Just have to watch for the technicalities when it comes to putting everything back together. BTW The non-eta motors are 167hp 164 lb-ft torque, eta motors are 125hp and 170lb-ft torque. You can swap cams on ETA's though swapping entire heads would be cheaper and more effective.

Honestly with an old ETA, what will make the biggest difference is general maintainence. I think all e30 owners here will agree that even more than mods, having a well tuned stock motor will give you much more power. Do everything - all sensors, all ignition (wire, plugs, cap, rotor/cap, etc.), replace ALL fluids and thermostat, make sure all fuel lines aren't cracking and that the fuel pressure regulator is in good shape. Run some seafoam through the oil about 25 miles before doing an oil change, and run it through the intake. Run some redline fuel system cleaner in a tank of gas, and make sure all the 'little things' are okay - like the engine ground strap, engine mounts, tranny mounts, charcoal canister, etc. Clean out the throttle body, idle control valve, etc.

Nothing made my cars more fun than replacing these little things. They add up and make the car feel WORLDS better. Stuff like engine and tranny mounts will run you about $80 between all 4 (if that...) and take about 30 minutes to install. Good luck, if you need any more advice feel free to ask!

 

[jrt67ss350]

A HUGE swap is putting the "I" head on the "E" block. You retain all that torque, get a higher revving engine with a much higher flow head. This is a very easy swap too... basically an extra step past replacing the timing belt. Just have to watch for the technicalities when it comes to putting everything back together. BTW The non-eta motors are 167hp 164 lb-ft torque, eta motors are 125hp and 170lb-ft torque. You can swap cams on ETA's though swapping entire heads would be cheaper and more effective.

It's not that simple. The ETA pistons are flat top pistons whereas the non-ETA pistons are slightly domed. Correspondingly, the combustion chambers in the ETA head are smaller than the combustion chambers in the 325i head. If you just swap the 325i head onto an ETA block, the compression ratio plummets and power goes down significantly. To fix this, you also have to change pistons when doing this swap.

 

[jrt67ss350]

If you want to get the power in your ETA up to the the level of that in the 325i, your easiest thing would probably be to get yourself an M20 from a 325i and swap the engines out.

 

[epj3]

It's not that simple. The ETA pistons are flat top pistons whereas the non-ETA pistons are slightly domed. Correspondingly, the combustion chambers in the ETA head are smaller than the combustion chambers in the 325i head. If you just swap the 325i head onto an ETA block, the compression ratio plummets and power goes down significantly. To fix this, you also have to change pistons when doing this swap.

Yea that makes sense.

http://www.strictlyeta.net/technical/328i_1.html

Sounds like a fun conversion though.

 

[ldzpstnr]

if you want to use a 325i cylinder head on a 2.7 eta engine you would need to find the 1988 325 pistons.... its the last year of the ETA engine and it had a 325i cylinder head and special pistons. Or you could get a set of customs pistons. That link EPJ3 put up will give you intructions on how to make a bad ass M20 motor... but its not cheap. Ireland engineering has a few stroker kits for the motor too.

The ETA is not really a racer motor... it was designed to get good mileage. It can be built strong, but you gotta spend lots of money rebuilding the motor and putting good internals into it.

My ETA has a hi-porfmance chip and a K&N air filter that replaced the stock paper one in the air box. It runs great I think, great for around town driving. I cannot tell you what chip I have, it was in the car when I bought it. I am leaving my car the way it is tell it dies, then its getting an M50.

If you want real power, put an M50(or variant) out of a newer 3 series.

 

[epj3]

In all honesty, and in terms of moddability, the M20 is a piece of junk. Stock, the m20 rocks and will last longer than you. but thats all it does well. Either do a motor swap, or do forced induction with the extra required work. Only reason the M30 isn't a piece of junk is because its capable of insane hp numbers reliably and cheaply - the m20 isn't. Strokers will barely put you over 200hp and thats with a pretty boring torque curve, and cost an insane amount of money. For 1/8 the price you could do an M30 swap and START OFF with 208 hp and almost 70lb-ft more torque.

 

[ldzpstnr]

How much more does tne M30 weigh? Does it have a timing belt or chain? and it takes to forced induction really well? I would like to take some weight off my car when I do the engine swap.... been looking at the alluminum M52's. Of course there are other ways to get weight off and I will do what I can. Once I get finished with college I am going to buy a new bmw, then build my E30 into one fast little car.

 

[epj3]

How much more does tne M30 weigh? Does it have a timing belt or chain? and it takes to forced induction really well? I would like to take some weight off my car when I do the engine swap.... been looking at the alluminum M52's. Of course there are other ways to get weight off and I will do what I can. Once I get finished with college I am going to buy a new bmw, then build my E30 into one fast little car.

These are engine weights and do not include drivetrain. Keep in mind that, even though a V8 could weigh more, its weight is much closer to the center of gravity. I wouldn't touch the BMW V8's with a million-foot pole, but still. These are all stock numbers for the most powerful version of each engine that reached the united states. The absolute most common swaps are M30, M50/52, and S50/52.

M20 - 258lbs (167hp 164 ft-lb) - Not very moddable, can accept some forced induction.

M30 - 315lbs (208+ hp, 220 lb-ft torque) - Probably one of the best forced induction motors EVER. It has forged pistons and rods from factory. Stock internals, it can handle over 600whp. With an S38 crank and pistons, easily near 1000 hp. Dinan or some random tuner once said it is quite literally a 'forced induction motor,' but that bmw had forgotten the turbo. Only downside is bad gas mileage.

M42 (E30 318is) 220lbs, 140hp. Very moddable naturally aspirated, though nobody really does FI on this motor. Very good motor because it is a very short block, so most of the weigh is near the firewall.

M50 189hp, 299lbs!
M52 (OBDII version of the above motor, same HP but a bit more torque), 308lbs!! Note - the US M50/52/S52 blocks were ALL iron. Only europe got the more powerful and lighter alloy blocks.

M54 (E46 3 series motor) 277lbs, 3 liter has something like 225 hp? Very nice motor though haven't heard of anyone doing the swap into an e30.



And for some M variants that people have swapped in...

S14 (E30 M3) - 234lbs (192hp) - Fairly moddable, especially as NA. But costs a fortune.

S38 (E34 3.8l version) 332lbs, 340hp, gobs of torque. Guy in sweden got something like 1100 hp out of a near stock motor! Insane.

S50/52 (OBDI and OBDII versions of E36 M3 motors, both 240bhp) S50 weighs the same as M50, and S52 weighs the same as the M52.