dyno'd the 2.7i

[eta]

Definatley use the "i" maifold. The two ports on the eta manifold that join to the downpipes are 1.5" in diameter on the eta manifold and 1.7" on the "i" maniolfd I beleive if memory serves. Unless your U.S maniolds are different to the euro ones.

[StereoInstaller1]

I should dyno my poor old POS.

Everyone thinks it is a badass because it sounds so mean...but it is a 320,000 mile bone stock M20 (well, AFAIK) with an ebay exhaust that was loud when it was new and is about 300X worse now.

I bet I get nowhere near 134 HP, and it runs OK.

Keep posting what you get as you build this thing. You are gonna keep the M20 with the GM ECU? Do you have a Tech2, or something better?

[ForcedFirebird]

The plan is to do the GM ECM swap as my "standalone",and turbo the m20.

I think I know why the fueling is off, the fuel pressure regulator is going bad. I hooked up an adjustable one and guage, and the stock regulator is not doing it's job. Bumped the fuel pressure up to 50psi, and idles a little better, and revs much quicker. Going to see how she feels on the way home from the shop, but still guessing until I get the WB hooked up.

[rThor432]

Yup, manifolds themselves are the same.

No, like Mitch proved with part numbers and 'eta' from the UK mentioned they are quite different. You can easily spot the difference by looking at the outside of the manifold. If you look at the ports, the difference is huge. They flow much, much better.

[eta]

I have posted RR data in the "school me on the 731 head" post, showing the exhaust system can make a big difference. This is what I am doing next on mine. 325i exhaust mated to a 528i or 535i exhaust system (I have an E28). Why E28 comes up with the cool emoicon I don't know but this board know they are cool.

I am reposting the relvent bits from this thread here.

"Dyno plots.

First a E30 327i using an 10.2:1 CR, Miller MAF and a bottom end with 731 head (giving 10.2:1 CR) port matched to an 325i inlet manifold with a 325i cam installed, 325i inlet manifold, 325i TB, 082 AFM, motronic 1.3, 173 ECU with a chip from A-tech in the U.K, hottuning exhaust maniold on 325i exhaust system. A powerful motor, flywheel fiqures shown. Wheel figures not posted but dynodymanics RR here seem to record 28% drive train loss for these cars so wheel fiqures would be~ 138whp/148wtq. The owner of this has finally fitted the 731 cam and his peak power has moved nearly 500 rpm to the right (I can't find the RR plot atm) but no loss/gain in power, he also has a Miller MAF conversion on it as well.

Second
E30 327i.

Spec, 10.2:1 eta bottom end, stock 885 head (ging a CR of 9.34:1), 325i intake manifold, BBTB, motronic 1.3 with A-techs chip, alpina 6 branch exhaust manifold on a scorpian E30 exhaust system. Again no wheel fiqures so est wheel figure are ~135whp/148wtq. This is done on Dynodynamics RR as well.

Third. E28 527i


This is my car. The spec when it was put on the RR was;
Eta bottom end, 885 head (9.34:1 CR), 325i intake, eta TB (the garage that done the work fitted this by mistake oops), motronic 1.3, 173 ECU with A-tech chip, stock eta exhaust maniold and eta exhaust system. On the day it ran rich (AFR 11.5:1 at WOT). This did not help. With the proper TB fitted and a chip retune it feels like it has a bit more power but no RR data on the new set up. However I believe the main differance between the my engine and the above is the exhaust system. The reason why I think mine is down on power and therefore why your Force firebird is also down on power is because of our eta exhaust systems. Some evidence coming up.

An E28 527i from the U.S

U.S eta bootom end, 885 head (8.35:1 CR I believe), 325i inlet mainfold, 325i TB and motronic 1.3 (unkown chip). It makes similar numbers to mine with the eta TB showing the TB is not a big restriction. Wheel numbers shown here.

Another E28 527i.

U.S eta bottom end with 9:1 forged pistons, 885 head, 325i intake mainfold, 325i TB, 3.0 bar FPR, motronic 1.0 running some sort of Dinnan chip, headers (unkown brand) and 2.5" exhaust. Wheel figures again.

So a decent exhaust on the 731 head equipped 2.7i, the second E30 885 head equipped 327i, and this last 2.7i seem to make 135-140whp and plenty of torque.

Mine makes less hp but torque is good and normal compared to the other plots. So a 731 equipped 2.7i head on the same type of RR (dynodynamics) makes more than 885 equipped 2.7i! Although the RR are run by different opperators I stand by my asseration for a simple 2.7i build using stock eta bottom ends, 325i intake manifolds, 325i TB, motronic 1.3 it does not matter much with cylinder head you pick 885 or 731, either will do as the high flow potential of the 885 head is not realised. It is only realised if you 325i pistons and deck the block to achieve sensible CR. With the stock 325i intake system, TB e.t.c builds like this can push out c.210 fhp and 210+ftq. A-tech build them all the time.

I hope this settles it for everyone and the data is useful to people".

So your car Force firebird gives good numbers. Don't worry about swapping injectors it is accepted here that the 325i one are good up 200hp. From the above plots you are not going to get close to that without serious work.

[eta]

I have just measured the internal diameter of the 325i down pipes. Bad news for those who have eta sxhausts on their 2.7i's, the i.d is 1.5". The i.d of the exit ports on the 325i exhaust manifold is 1.7". So it reduces. The bad news is the exit ports on the eta manifold are 1.5". As my eta down pipes are on the car I cannot at present measure thier i.d.

This is a shame as i was going to put the 325i exhaust manifold on mine with down pipes weldd to a 528i echust system. Now I won't bother as the 325i downpipe i.d is not better than the eta manifold.

[digger]

Why does it say "E30 2.7 with miller MAF" on the 1st graph but in the text that it uses A-tech chip and AFM?

[eta]

It a mistake. I should have it has a Miller MAF with modified miller chip (it was done about two-three years ago before Miller supported stroked M20 with the MAF kits).

[digger]

It a mistake. I should have it has a Miller MAF with modified miller chip (it was done about two-three years ago before Miller supported stroked M20 with the MAF kits).

So the 731 build has a MAF conversion and the 1st 885 does not?

[nando]

why do you UK blokes always use reverse calculated flywheel figures? so the power figures can be inflated any way you like? :p

22% drivetrain loss on an E30 is 100% imaginary. Most of those power figures are sad (especially given the mods), there are stock M20B25s here that make more power with everything 100% stock.

example:

http://www.r3vlimited.com/board/member.php?u=13411

there was also a guy with a 200,000+ mile, stock B25, with just a dinan chip, that had both a better powerband and better peak power than any of those motors.

[mattdk318i]

more info on teh homemade wideband? Ive got a good idea about how. Just would like to see your version/interpretation.

[ForcedFirebird]

why do you UK blokes always use reverse calculated flywheel figures? so the power figures can be inflated any way you like? :p

22% drivetrain loss on an E30 is 100% imaginary. Most of those power figures are sad (especially given the mods), there are stock M20B25s here that make more power with everything 100% stock.

example:

http://www.r3vlimited.com/board/member.php?u=13411

there was also a guy with a 200,000+ mile, stock B25, with just a dinan chip, that had both a better powerband and better peak power than any of those motors.

Not hardly stock. First post in his dyno thread...

We spent several hours on a DynoJet yesterday tweaking a pair of Spec E30's. At the end both cars were making peak numbers of 162hp & 155 torque (in 100F temps). That is about as good gets for a stock M20B25. Both my car and and the other have blue printed engines with stock components. The Spec E30 rules impose pretty severe limits on what we can do, so the tuning was mostly a matter of finding a good DME (we had eight or so to play with) and tweaking the AFM to richen the mixture below 4500rpm.

I've learned over time that the choice of DME is pretty important. Several times now I've seen a change in the DME make a marked difference in the power output of the engine. You pretty much can't tell that there is anything wrong with the DME from driving the the car, but it sure is obvious on the dyno. Given that the DME's are 20'ish year old and that the analog portions of the DME do age, that isn't a surprising finding.

more info on teh homemade wideband? Ive got a good idea about how. Just would like to see your version/interpretation.

They aren't made anymore, but I bought 3 kits from 14point7.com The first I fried when accidentally letting the 12v touch another lead - DOH! The second one was built and works great, the third is still yet to be assembled. Mine are the JAW (just another wideband), then he came out with NAW (not another wideband), now he has a line of products called SLC. I paid $150 for the kits several years ago which included a digital readout, 3 programmable outputs (plus db-9) and AFR vs RPM dattalogging. The logarithms are outstanding and since the JAW doesn't have any surface-mount components, they are easily repaired/diagnosed by the novice to average electronics geek hehe.

[nando]

okay, blueprinted stock, but any motor you put together should go through that.

everything else about that motor is stock, the cam, the chip, the intake, the exhaust, everything. with a MAF, headers, intake, exhaust, and hours of dyno time with a custom chip, you'd expect more from a motor, no?

[ForcedFirebird]

True. I expect a lot more once tuned. I am buying an emulator as we speak ;)

[briansjacobs]

not showing any numbers on purpose, I just wanted to show the sexy curves we are making. on later runs we got the AFR flat and numbers got a little better but I never printed that sheet out. For the most part I dont have a need to rev past 6k because the torque is more usefull than the HP