eta performance

[Bav///Motorworks]

ight just got the chip in and must say wow... huge difference
but i want more!!! i just want more up top.
i would like to kno, the I intake manifold and throttle body will help? and what about a I exhaust manifold and back? anything to let this motor wih the chip breath better. thanks
i kinda wanna add another 20hp if its possible without doing any major mods such as p&p the heads and etc.

[X2theZ3]

ight just got the chip in and must say wow... huge difference
but i want more!!! i just want more up top.
i would like to kno, the I intake manifold and throttle body will help? and what about a I exhaust manifold and back? anything to let this motor wih the chip breath better. thanks
i kinda wanna add another 20hp if its possible without doing any major mods such as p&p the heads and etc.

20 more hp will be very hard. do major mods if you want power. Stroker.

[James Crivellone]

When I had an ETA motor in my car, I had the following which put quite a few smilies on my face.


M20B27
Jim C Chip
I Intake Manifold
I Throttle Body
I Exhaust + Manifolds
3.25LSD out of a 535is.


It was a very fun car, 2nd and 3rd had a decent grunt, however the lack of top end that the eta motor has didn't help..Needless to say compared to the original configuration it helped a TON.


I now have an M20B25, Mark D, 13.5LB Fly (I would do this on the eta as well, would help), No AC, and a 4.10LSD and the difference is amazing...

You could also look into not so popular options, such as a 323i 731 Head, which helps the motor out a good amount, or Turbo, or some have even done an I Cam with I valvesprings (requires some machine work on the head) as well with I Motronic and that has really opened the motor up.

However for around the price of getting all those parts you can find a used I motor as well with decent mileage...

My

[Jon '92 325ic]

For more power up top

As was already suggested, switch to the I intake manifold, plus have it Extrude Honed. Your performance above 3,500 rpm will be noticeably better. You can get a used i head with throttle body for $25 - $50 on eBay. Having it Extrude Honed I think goes for $600 - $650 nowadays.

A 4.10 rear diff will also improve performance (acceleration, not HP or torque), but more so on the low end. You'll be noticeably quicker off the line and will get to higher rpm quicker. Using a 10-speed bicycle as an analogy, a 4.10 rear diff would be like taking off from a dead stop and racing to top speed in 9th gear whereas a 3.73 rear diff would be like being in 10th gear. Eventually, the rider in 10th gear will catch up to the guy in 9th gear (while pedalling less) and reach a higher maximum speed, but the guy in 9th gear (4.10 rear diff) will be quicker off the line and will reach his maximum speed first. You'll give up a little fuel economy going to a 4.10. You can get a good used open 4.10 on eBay for $75 and up. Joel at EuroDepot sells used open 4.10 diffs for $150 I believe. His have been sandblasted and repainted and I believe a new mounting bushing is installed also. A used limited slip 4.10 go for $300 - $450.

[James Crivellone]

As was already suggested, switch to the I intake manifold, plus have it Extrude Honed. Your performance above 3,500 rpm will be noticeably better. You can get a used i head with throttle body for $25 - $50 on eBay. Having it Extrude Honed I think goes for $600 - $650 nowadays.

A 4.10 rear diff will also improve performance (acceleration, not HP or torque), but more so on the low end. You'll be noticeably quicker off the line and will get to higher rpm quicker. Using a 10-speed bicycle as an analogy, a 4.10 rear diff would be like taking off from a dead stop and racing to top speed in 9th gear whereas a 3.73 rear diff would be like being in 10th gear. Eventually, the rider in 10th gear will catch up to the guy in 9th gear (while pedalling less) and reach a higher maximum speed, but the guy in 9th gear (4.10 rear diff) will be quicker off the line and will reach his maximum speed first. You'll give up a little fuel economy going to a 4.10. You can get a good used open 4.10 on eBay for $75 and up. Joel at EuroDepot sells used open 4.10 diffs for $150 I believe. His have been sandblasted and repainted and I believe a new mounting bushing is installed also. A used limited slip 4.10 go for $300 - $450.

Jon this is an ETA we are talking about here, with a stock redline of 4800, and a chipped of 5200, he will have ZERO topend with a 4.10, let alone a 3.73.

a 3.46 is even pushing it.

Considering stock ETA's made after 04/86 had a 2.93 Gearing in them, a 3.25 is a nice upgrade to give it a little more oomph, especially if he has an 84/85 which came with 2.7X Geared diffs.

[Bav///Motorworks]

do u really notice the difference with the I intake manifold/throttle body and exhaust/manifold? i can pick those up...

[Bav///Motorworks]

i have an 86 which has the 2.93's.... where can i find the 3.25 off teh 5 series... i don't go on 5 series boards



edit: aslo i would like upgraded cams if there any available. i luv the rough idle and etc and of course the gains

[Jon '92 325ic]

Thanks James

Didn't know Es came with 2.93 rear diffs. So James is correct, going to a 4.10 is not recommended. Like James suggests, if you have a 2.93, going to a 3.25 would be the way to go. Don't even think about going to 4.10 from a 2.93.

Thanks James.

[formula driver]

I have an I intake manifold and throttle body that I will sell. The intake manifold is painted with sanded ribs. PM if your intrested. Ill give you a great deal.