Differences between 325E and 325ES??

[Luis325]

Whata re the differences between a 1986 325E and a 325ES?

I was told that the 325es had 2:93lsd and SETA Pistons???

What else is different?

[reelizmpro]

The engine in the e and the eS are exactly the same! The 'S' is just a sport package which in the case of the eS means gas shocks/sport springs, front spoiler, rear spoiler, sport seats, OBC, premium stereo and 2.93LSD. Can't forget the M tech steering wheel and the 'S' mode instead of the '3' on the automatics lol.

[unicorn]

Purrrrfect answer!

[Leaf]

Do yourself a favor and get neather....

[kronus]

Do yourself a favor and get neather....

So what do I do once I get 'neath 'er?

[unicorn]

get "boost"ed

[ForcedFirebird]

You can get one, and put the 885 top end on it ;)

Me likey my ETA :p

[M-technik-3]

There is nothing wrong with a unloved eta or Eta Sport. Good way to find a cheap car.

[ForcedFirebird]

There is nothing wrong with a unloved eta or Eta Sport. Good way to find a cheap car.

Got mine for $3500 with 75k miles, mint interior, good paint.

Curious to see the gas mileage change after the top end. 5 speed, I get 22city, 35mpg at 55mph and 25mpg at 80 lol.

Does the es have limited slip?

[M-technik-3]

eS come with 0.25% lsd in two different ratio's 2.79 and 2.93 lsd depending on year. 3.25 wakes them right up except lack of top end unless you convert to 885 head and double springs.

[ForcedFirebird]

Got the 885 top end, but can tell these are highway gears really. Not doing the ECM swap, but am going to see if I can get a GM ECM to work. Just have to find a location where I can thread in the GM knock sensor, and modify a GM DIS wheel to work, but I have everything else worked out. Could burn a PROM for the 027 that's in the car, but I don't know how anybody is tuning that way without a dyno or a way to datalog.

[TexasTerp]

The engine in the e and the eS are exactly the same!

WRONG!! Although the vast majority of parts are the same, much like every m20 engine (I, E, or ES)....there is a significant difference between the "e" and "es" engines which the OP mentioned but doesn't know why. The seta pistons have a curvature in the head of the piston which creates a slightly lower compression that added more power to the engine. You will notice that the eta pistons are flat tops where the seta pistons are not. This is important because until BMW released the I to the US it was the fastest BMW 3 series available since the 2002tii stopped production in '77 (i think?). The compression ratio and peak HP of the engines are different so even though it's a change you don't notice visually it's the reason why people building stroker engines etc, look for the seta pistons vs the normal eta's. Also eta engines are the worst engine for boosting due to their high compression. I know I'll get flamed and some people here have done it, whatever, I don't care, but the lower the compression the better for boosting.

[reelizmpro]

eS come with 0.25% lsd in two different ratio's 2.79 and 2.93 lsd depending on year. 3.25 wakes them right up except lack of top end unless you convert to 885 head and double springs.

2.79 was used on 84-85 325e's. Then in 86 they switched to 2.93 on all 325 base model and ETA. Therefore, all 325eS models (86-87) had 2.93 gearing. How am I sure? I've owned these cars and I used to be in the business of selling differentials to Jim Blanton.

[reelizmpro]

WRONG!! Although the vast majority of parts are the same, much like every m20 engine (I, E, or ES)....there is a significant difference between the "e" and "es" engines which the OP mentioned but doesn't know why. The seta pistons have a curvature in the head of the piston which creates a slightly lower compression that added more power to the engine. You will notice that the eta pistons are flat tops where the seta pistons are not. This is important because until BMW released the I to the US it was the fastest BMW 3 series available since the 2002tii stopped production in '77 (i think?). The compression ratio and peak HP of the engines are different so even though it's a change you don't notice visually it's the reason why people building stroker engines etc, look for the seta pistons vs the normal eta's. Also eta engines are the worst engine for boosting due to their high compression. I know I'll get flamed and some people here have done it, whatever, I don't care, but the lower the compression the better for boosting.

This is where you are wrong. You see the 325eS is not the "super ETA" you heard about. The 88 325 base model is the Super ETA engine with the domed pistons.

[ForcedFirebird]

I won't flame, but I have built several turbo kits for GM V6's ranging from 8.5:1 to 9.6:1 static and one of them saw a few runs at 21psi (9.1:1). I know the v6 and l6 aren't the same, but the principal is. With the high compression, your fueling window just gets smaller. The new engine going in the Firebird is 11.5:1 and will see about 6psi through twin t04e's.

So my '86 car has the SETA pistons? It was my understanding they were the flat tops and that's why my CR was going to drop so much with the '885 head.