i Valve Springs in my Eta head?

[nando]

why don't you have your stock injectors cleaned and flowtested? your car would probably run a lot better than doing big injectors on a stock e motor.

[Jand3rson]

why don't you have your stock injectors cleaned and flowtested? your car would probably run a lot better than doing big injectors on a stock e motor.

Once I get done building the new head with all of the modifications, it won't be a stock e motor. Larger injectors with an AFPR, and tuned to the correct settings will only benefit the new top end.

[E30 Wagen]

Once I get done building the new head with all of the modifications, it won't be a stock e motor. Larger injectors with an AFPR, and tuned to the correct settings will only benefit the new top end.

what kind of top end are you hoping for?

Also, i'm wondering if there are piston upgrades for the eta, anything at all like that?

[Jand3rson]

what kind of top end are you hoping for?

I'll be rebuilding and modifying a stock eta head, as well as upgrading the intake system. This will include:

- Dual 325i valve springs
- 3 angle valve grind
- All new valves, guides, etc.
- 325i cam
- 325i intake manifold and throttle body
- Intake ports enlarged to match 325i intake

In the meantime, I also plan to install a full 325i exhaust from the engine back, with my current Magnaflow muffler. Once the new head is built and all the new components are installed, along with the chip, I'm hoping for around 160-170 hp, with torque around 180-190. A shop here in town recently installed a dyno, so I'll be able to get accurate numbers then.

[SpecM]

That sucks. So what can I use? Is there anything besides the E28 M5 units?

-Use m50 injecters from an e34/e36. About 17 lbs/hr, all you will need.
-I have an '88 super-eta, the one with an "i" head from the factory. Im planning on useing an b25i cam, dual springs, intake man/TB, m50 injectors and a 173 dme with Motronic 1.3.
-I have to replace the head gasket so maybe ill shave the head a bit too...does anyone know how much can be safely and reasonably removed?

[EtaSport]

It would be fine to use m50 injectors, thats what I'm running. But he is keeping the eta motronic which uses low impeadance injectors instead of the high impeadance ones from the m50.

[SpecM]

-What's the difference between high and low inpedence injecters? Ive hear those terms thrown around before...
-Oh, btw guys, I just stared posting here. A newbe to r3vlimited but Ive been at bf.c for a while. Both are great sites

[EtaSport]

The high impedance injectors have high resistance. If you think of ohms law which states: 1 volt will push 1 amp through 1 ohm, you can see if you change the resistance value you would change the equation. I think the high impedance injectors are 16 ohms resistance, and the low are around 3-4? Since the injector is a solenoid that works on magnetic principles, it opens when current is applied to it. Typically higher resistance circuit steps down voltage more than a low resistance circuit. It could be that the low impedance injector needs more voltage to activate the magnet than the high impedance.

This is as much as I know about it, havent got too far into fuel injections yet at lincoln tech. Someone else can chime in if they've got anything to add, or correct.

[Jand3rson]

Well, unless anyone can figure out what other low impedance injectors there are that I could use, I'm probably going to just end up using the E28 M5 units. I know they'd be a bit overkill, but would there be any serious side effects to using them? I'd be using an AFPR along with my setup.

[SpecM]

-I wouldn't thinks so. The car may have trouble adjusting at first but it will eventualy narrow the pulse width enough to cut down flow from the over-sized injectors.
-Sorry...at bit off topic... but how much is OK to shave off the head?

[mr.happy]

My ideal set-up would be a 323i head on the 2.7 block, and motronic 1.3. I believe this would put out at least 170 maybe 180 crank. Hopefully if we ever get to it I'll be able to get my car on the dyno soon and tell you how it does.

What is the diff. between the 323i & 325i heads?


Thanks Robert

[EtaSport]

The 325i head has much larger intake and exhaust ports, it also has larger valves, as well as a better cam and dual valve springs. It would have been too easy however for BMW to make the E and I car similar so us power hounds could just grab a 325i head to clamp on to our e block, keep 9.0:1 compression and have at least 170 hp with the right software.

I have thought about the injector question before, yes it will flow more fuel, but the computer will adjust the pulse width like specM said. I'm not sure how much it can adjust it though. Another way to help is if you lessened the fuel pressure, or at least kept it around 37psi (2.5 bar). That way you wont have too much at idle, but it can make better use of it at high rpms since they should have less pulse width elsewhere.

[Jand3rson]

I have thought about the injector question before, yes it will flow more fuel, but the computer will adjust the pulse width like specM said. I'm not sure how much it can adjust it though. Another way to help is if you lessened the fuel pressure, or at least kept it around 37psi (2.5 bar). That way you wont have too much at idle, but it can make better use of it at high rpms since they should have less pulse width elsewhere.

This can be done by using an adjustable fuel pressure regulator, correct?

[EtaSport]

I'm pretty sure that you can adjust it down. Just use an in line fuel pressure gauge to determine what pressure your at.

[e30bimmerdude]

So Eurospeed, are you using the stock eta motronic, or are you going to be switching over to the "I" 173....sorry if i missed something...also so you will be using bigger injectors, with a FMU (bmp, has a good one with a gauge)....

http://www.atpturbo.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=tp&Category_Code=FUL

these guys have some good injectors, maybe something to think about...

also is this something i can do at home, ie swapping the cam, valve springs etc, or would it be wise to take it to a shop, i know you are using the eta head, which as we have talked about earlier needs to have the additional 3 oil journals drilled, but other than that is it possible to stay away from a shop?....thanks fellas...