2.7 ETA Performance; Chips vs. Motronic upgrade vs. ?

[ForcedFirebird]

Putting an "i" cam in a stock eta head is a waste, the head flow characteristics are all wrong for the cam.

Open exhaust and all the parasitic accys removed an eta will make about 120whp, the 885 head on an eta bottom end will make about 10-15 more with everything still stock (we have gotten as much as 145whp with the 2.7i tuned). For comparison, my chip-only b25 with 200k miles makes 148whp.

We have done all the combinations, and have dyno sheets on all of them. Best time/money spent on an eta is to just drop the 885 top end and electronics on, hands down.

[603Racing]

If you are going to do 4 or 5, you might as well just do the whole i head swap. If you don't want to do the whole head swap then just get a SSSquid chip or MarkD chip. I was given a MarkD chip for free and it really woke up my 250k mile eta. I would have gone with the SSSquid chip if I didn't get the MarkD for free from a friend.

[AwakenNoMore]

seriously consider a head swap. After dealing with having to replace the head on my car I can tell you from experience its worth it. These engines are retarded simple to work on.

[brahbarian]

Putting an "i" cam in a stock eta head is a waste, the head flow characteristics are all wrong for the cam.

Open exhaust and all the parasitic accys removed an eta will make about 120whp, the 885 head on an eta bottom end will make about 10-15 more with everything still stock (we have gotten as much as 145whp with the 2.7i tuned). For comparison, my chip-only b25 with 200k miles makes 148whp.

We have done all the combinations, and have dyno sheets on all of them. Best time/money spent on an eta is to just drop the 885 top end and electronics on, hands down.

i have a 85 eta. just to make it clear. i read a lot on this but im still not clear.
all i have to do is swap the whole top end from a "i" engine and not touch the bottom end.
i head, TB, exhuast, and the computer?

i was under the impression that you would have to swap the bottom end off a 88 seta so that the piston match the i head?
or is this not necessary?

[fiveightandten]

A chipped ETA definitely isn't 90% of a tuned 2.7i.
A chipped ETA is great for daily driving, absolutely nothing wrong with it. You'll enjoy a higher rev limiter, (5000-5500 depending on what you decide to go with), and better performance, but it doesn't quite compare to the higher power and rev limit of a 2.7i (6800+ rev limit depending on tune).

Stock [1.3] Motronic (I assume you meant 1.3) on a stock ETA will definitely not bring you to stock m20b25 performance, if that were the case there would be absolutely no reason to swap the head over, there are quite a few differences with the engines that just software wouldn't offset the differences. The 885 (B25) head is better flowing, has dual valve springs, a better cam, and is just a better over-all system.

A 24v swap will be more time consuming, more expensive, and more work, but a lot of people are very happy with it, and as long as you go M50TUB25 it will be a noticeable gain over a 2.7i. Some people however feel disappointed after doing an M50 (non vanos) swap and the results aren't astonishing.

From the factory the M50 only has about 20hp on the M20, albeit a better power curve and a better tq:hp ratio.

I was just putting up arbitrary and meaningless numbers to illustrate my thinking, which is really centered around time/cost investment on performance return. I don't know how these different options compare (hence the thread). But thanks for putting some qualitative reference in. That definitely helps put things into prospective.

just keep that eta up to date and chip it if you like, and save your money for a swap. even a good condition stock m50 will walk all but a extensively modded m20. ive been offered multiple complete s50/s52 for under 1.5k. a running drop in m5x ready with all swap parts etc should run you 1-2.5k.

Thanks for the insight.

My math tells me that an M5x swap would put the car in the P/W ratio range of my E36 M3 and 330ci. That's great, but it doesn't need to be that fast to be fun. An M5x, IMO, may not be worth the effort for a 2.5i car. But coming from an ETA, it's huge. It's something to consider. A swap isn't something I would do this season. But smaller powertrain work would make sense to do now if that's where it would end.

A chipped eta, with exhaust restrictions removed goes pretty well. I autoX'd my first season with just a chip, exhaust and a 3.73, and had a ball. The 2.7i conversion is the way to go IMO. I used the EU323i 731 head, and the car is a torque monster. Squids tune for the 2.7i is awesome. I spent the day yesterday giving rides at our Performance Driving School to students, and scared the crap out of them all on course. "What the hell is in this thing?" is the most common comment pulling back into grid. I'm usually 1-2 seconds off the BSP Vettes times, so I'm happy.

So you're running a 731 head with 323i manifold and intake components, stock cam, Squid tune with exhaust? How much weight is pulled out of the car? How would you compare the power to an M5x swap and stock 2.5i?

A couple things to keep in mind.... The standard eta head, #1264200, comes with a 4 journal cam. The "i" camshaft is a 7 journal. Modifying / drilling the additional oiling holes is not a big deal, but I wouldn't do it with the head installed. (just imagine where all those chips could get!)

As I see it, if you are going to change the cam, you'll need to pull the head. If you've got that far, I would just continue and change to an 885 head at that time.

You can source the head, cam, springs, rockers and shafts all ahead of time, have all the machining done, and the head assembled prior to pulling the old head off. Very little, if any down time. Just get all your gaskets and other small parts (head dowel pins) ahead of time.

As a time reference, I just finished a head R&R. One weekend to disassemble and pull the head, one weekend to replace and re-assemble. Could have been faster, but work interferes at times!

Ahh, I did read about the cam journals in the sticky thread. I had forgotten about that, and it definitely defines priorities a bit. I recall people also talking about clearance issues between ETA pistons and the 885 head, if i'm recollecting that. I'll have to read through that thread again.

Putting an "i" cam in a stock eta head is a waste, the head flow characteristics are all wrong for the cam.

Open exhaust and all the parasitic accys removed an eta will make about 120whp, the 885 head on an eta bottom end will make about 10-15 more with everything still stock (we have gotten as much as 145whp with the 2.7i tuned). For comparison, my chip-only b25 with 200k miles makes 148whp.

We have done all the combinations, and have dyno sheets on all of them. Best time/money spent on an eta is to just drop the 885 top end and electronics on, hands down.

Excellent info, and this is what i'm looking for.

So, basically to get power comparable to a stock b25, i'd need the following:
Stock 885 head mated to stock 2.7 bottom end
Motronic upgrade to swap electronics over + tune
b25 intake components, manifold, pulleys, etc.

So, if I might make some pretty generalized statements to put things into prospective. I'll use the common ~15% drivetrain loss to try and put things in comparable terms.

A) Stock b27 no mods: ~120 BHP (~100 WHP)

B) Stock b27 with chip and exhaust, no PS, no AC: ~140 BHP (~120 WHP) for ~$400-$500 and very minimal work/downtime

C) 2.7i with stock 885 head & stock b27 bottom end, motronic upgrade, b25 intake components, pulleys, etc. and tune: ~155BHP (~135 WHP) for ~$700-$900 and a decent amount of work, but moderate downtime.

D) M5x swap with stock engine: ~190 BHP (~160 WHP), for $1500-2000 and a lot of work and a lot of downtime


Is that at least somewhat accurate? This is the type of mental prospective i'm trying to gather together to see how these options stack up against one another.

If you are going to do 4 or 5, you might as well just do the whole i head swap. If you don't want to do the whole head swap then just get a SSSquid chip or MarkD chip. I was given a MarkD chip for free and it really woke up my 250k mile eta. I would have gone with the SSSquid chip if I didn't get the MarkD for free from a friend.

Thanks for the insight. :up:

[squidmaster]

The head swap is less work than you'd think. It can easily be done in a day, or an afternoon if you have an extra set of hands. The m20 is a great and simple engine to work on.

You have to think about the power curves between the ETA and 2,7i as well. With the ETA you can't go past 5200ish (tuned) and the TQ has dropped off quite a bit before then, with peak HP touching just around 5000-5300, whereas the 2.7i holds a good amount of tq to 6000rpm, and peak HP is right around there as well.

[Lyfesideways]

Thanks for the data point. Are you running a totally stock i head? How would you put the power in, in comparison to a stock 2.5i and, say, an M50 swap?


Thanks for the reply.

With the ETA, i'm not willing to touch the bottom end, and I would strongly prefer to not pull the head off. I'm willing to swap the cam, and obviously springs will come with that as well, and a Motronic upgrade is doable. Swapping i intake components and manifold is no big deal. But IMO, getting into bottom end work, and pulling the head off for an i head that will have to go to a machine shop, add to downtime and cost ect, doesn't seem worth it. It seems that effort would be better spent just doing a cheap 24V (which would, however, take away from some of the old raw mechanical quirkiness of the car).

This is a 3rd car for me. I have an E36 M3 that's reasonably modified, and an E46 330ci that I DD (keeping that stock). I've done transmission swaps, clutch jobs, headgasket job, manifold swaps, full suspension refresh (every piece of rubber under my M3 has been replaced) etc. in my somewhat small garage. I'm capable of doing this stuff. But it's a matter of return for investment with this car. I want it to be faster, but i'm trying to get an idea of the cost/time investment to benefit ratio for my options.

The E30 is something I bought as another fun car. I searched for almost 6 months to find one without rust. This is very difficult around here. I happened across this 69K mile, bone stock 1986 es. The car is pretty nice. By far the nicest one I looked at. I'll be keeping it as long as i'm physically capable of driving it.

My goal is to get the car some more power. But I do intend to keep it for quite some time. I'd like to do things right the first time, but I have no idea how some of these mods stack up to, say, a stock 2.5i, or a 24V swap (where they stand in the mix).

I'll use some arbitrary comparisons...If a Motronic upgrade on a stock engine gets me to 2.5i performance, I think that's worth the effort. If a chip gets me 90% there for a fraction of the time investment, then the Motronic isn't worth it. If a Motronic upgrade with an i cam and breather mods gets me 90% to a 24V swap, it's a complete no brainer.

The issue is, i'm having a hard time finding comparisons of these things to yardstick these mods against things i'm familiar with. Do I just slap a chip in and call it a day, because the extra effort of a Motronic upgrade only gets me 10% more power? Do I not waste my money on a chip because the Motronic upgrade is vastly better? Just trying to get a feel for what the best course of action is.

I hope that explains my thinking. Apologies for the novel. ;)

In comparison two of my buddies have m50 swaps one with getrag one with zf tranny.
I only raced them with either stock eta or chipped eta ecu setups.

But I can honestly say I will never in my life do a 24vswap...
To each their own, I raced one of my buddies m50 from a dig to about 130, he pulled on me by about a car length or so .. And that was before the new cam,valve springs, and motronic upgrade.which really remedied all the issues I was having before.
That was also wth 2.93lsd not 3.73lsd..

It's all up to you. M50s pack a totally different punch then m20s and they are a lot of fun don't get me wrong.

[fiveightandten]

The head swap is less work than you'd think. It can easily be done in a day, or an afternoon if you have an extra set of hands. The m20 is a great and simple engine to work on.

It's the electronics of the Motronic upgrade that seem to be the worst part of the job. I haven't read up on timing the engine, and I haven't read through to distinguish the clearance issues I saw some people mentioning. So i'd need to do more reading for sure.

That option isn't out of the running. But based on ForcedFirebird's post, i'm surprised it doesn't make more power. Putting a b25 head with b25 electronics onto a b27 block should effectively make a stroker i motor with higher compression. I'm surprised it barely makes stock i power. The exhaust is clearly a restriction. But that's easily swapped out.

[fiveightandten]

In comparison two of my buddies have m50 swaps one with getrag one with zf tranny.
I only raced them with either stock eta or chipped eta ecu setups.

But I can honestly say I will never in my life do a 24vswap...
To each their own, I raced one of my buddies m50 from a dig to about 130, he pulled on me by about a car length or so .. And that was before the new cam,valve springs, and motronic upgrade.which really remedied all the issues I was having before.
That was also wth 2.93lsd not 3.73lsd..

It's all up to you. M50s pack a totally different punch then m20s and they are a lot of fun don't get me wrong.

Good info. So you're running a 1.3 update with a b27 head and i cam/springs?

Would you say your car is about comparable to a stock 2.5i? Also, is there a big difference between the chipped ETA and the 2.7i setup(s)?

Yeah, M5x swap doesn't make the car into a rocket. It seems to be diminishing returns when compared to a 2.7i setup. They're still pretty quick IMO, but S5x is a healthy bit stronger for sure.

[squidmaster]

Its lower compression actually.

[Gary Horneck]

I built my motor for torque. Since I Rallycross it, helps to have 80% of your torque below 2,500 rpms. Also gives massive dig coming out of corners on AutoX course. I get the car in 2nd and it has so much torque I never have to shift.

I am running all '89 i components other than the EU 731 head. I have the 323i intake and distributer also, but once you plunk a 4-barrel Holley on it, there is no weight savings.

I did the head swap in one weekend, alone, two weeks after lumbar spinal fusion operation, so its a breeze.

[squidmaster]

2012! That's old! You need a new dyno ;)

[Gary Horneck]

I have last years around here somewhere. And I do need to do some pulls this spring. But the torque curve was very similar, it goes WHAM.

[squidmaster]

Seriously! You can't ask for much of a better torque curve than that!

[Lyfesideways]

Good info. So you're running a 1.3 update with a b27 head and i cam/springs?

Would you say your car is about comparable to a stock 2.5i? Also, is there a big difference between the chipped ETA and the 2.7i setup(s)?

Yeah, M5x swap doesn't make the car into a rocket. It seems to be diminishing returns when compared to a 2.7i setup. They're still pretty quick IMO, but S5x is a healthy bit stronger for sure.

im running 1.3 on b25 head on a 2.7 block...

its a drift car and the mid range torque it puts down is amazing!

3 of my buddies have stock b25 motors with 3.73 diffs and ive been in their cars numberous times, i really don't see them beating my setup or coming close!

chipped eta is fun but it does not breathe up top very well..
2.7i is the best of both worlds.
low to mid range is greatly improved, and the i cam pulls a lot better up top than the 4 journal eta cam..

if my buddy wouldn't have sold his m50 swapped e30 i would ask him to line them up again and im not too sure he would win..
my other buddy has also went thru 2 m50s and only gotten to drive the car for a month and one track day...

if i was the OP i would stick with m20 motor whether it be b25 or some stroker variant..

ive put over 60,000 miles 15+track days (no trailer mind you)and the bottom end still looks like it came from the factory with original crosshatching. 220k+ and it still purrs like a kitten.



just my 2 cents tho