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12.5 comp on stock ECU pump gas

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bullettdsm

N/T DSM Wiseman
DSM Wiseman
2,609
35
Dec 17, 2004
East Hampton, Connecticut
There is a lot of conversation about how high of a comp you can run on the stock ECU and pump. As I suspected, you can run 12.5 comp on stock ECU and pump gas (93oct).

The set-up I have is 12.5 comp, Crower 2's, MP60mm, LTH, lightly ported head, ported stock intake, Stock ECU.

Here's a quick, crappy vid I just made (don't mind the stumble at the end, I have a vac leak I haven't addressed yet).

12.5 comp, C2's, LTH, MP60mm, stock ECU, pump gas - YouTube

MB
 
How's the butt dyno? I have a 2.4 with 10.5:1 and Crower 3's running a stock ATX ecu.

With a 6500 rpm rev limit and a 3.55 transmission, she still surprised me.

If I had to do it again, I'd probably would have gone long rod 12.5:1.

It's reassuring that the stock ecu can still maintain compression that high.

Any dyno time in the future? And not to jack, but how's the ITB & 16:1 build going?
 
How's the butt dyno? I have a 2.4 with 10.5:1 and Crower 3's running a stock ATX ecu.

With a 6500 rpm rev limit and a 3.55 transmission, she still surprised me.

If I had to do it again, I'd probably would have gone long rod 12.5:1.

It's reassuring that the stock ecu can still maintain compression that high.

Any dyno time in the future? And not to jack, but how's the ITB & 16:1 build going?

Butt dyno notices the extra pop. Burnouts are super easy (but I could do that with a stocker set-up, this can chirp and hold a spin in 2nd gear), and she pulls nice in the upper rpm's. I just haven't gotten into the 7k+ pulls yet. I still gotta get more miles on her.

I want to do dyno time when I switch her to MS, so I'll probably do a base pull on the stock ECU then (I have my MS set-up as a piggyback because of emissions. I have two quick disconnects from MS to Stock and back so it takes about 20 seconds to switch back and forth).

As for the ITB's on the 16:1, I probably won't do that, because of the previous history with the ITB's. They don't show to make any more power, so there's no real advantage on a 1/4 mile race car.

As for the 16:1, it is in the car right now. I got a quick tune on her (with a "close to race ported head" on it. My race ported head somehow got water stuck in it over the winter, and cracked :( ) just before the SO, so I could at least give her some runs in Norwalk. Unfortunately, those runs were with a bad tranny, so when I tried to do a full-on run, the tranny locked up and sent her to about 11.5k rpms, LOL.

The power level was only 216whp, but I don't have the race head on there and I have a little electrical break up in my MS to find. I expect the levels to be much higher with the new Fierro ported head I have and the MS fixed.

MB
 
You should boost it, I'd love to see what it does. But not at the expensive of grenading a perfectly good N/A motor.

Still waiting for Mike to build me one of his LTH's because I'd love 200whp or close to that.
 
I still plan on boosting it. But because I already paid Mike for the header, I wanted to see what I could crank out of the motor N/A. I'd love to be on the 200whp list.... And then the 400whp list. Lol.
 
You should boost it, I'd love to see what it does. But not at the expensive of grenading a perfectly good N/A motor.
I've tried boosting, its just not in my blood :notgood: I get no kicks from "slapping on" a turbo ;). But I did set-up the 12.5 on a 150 shot one time and I kinda liked that :D

Of course, the challenge of turbo'ing a 12.5 motor sounds interesting.........

I still plan on boosting it. But because I already paid Mike for the header

This disappoints me to no end :notgood: I hope there is at least some kind of communication.

MB
 
Ok, so current update on the 12.5 engine; got some miles on her (idk how many. I'm upstairs right now maybe in the 60 -70 mile range. I haven't had a lot of time to run her around). When I first got her on the road, she seemed to have quite a bit of pick up and go. But as the computer started getting involved, she is defintiely getting more "loggy". I believe that that stupid ECU is pulling timing and richening up the mxiture. Is it as bad as stock? No, but I don't really see the difference between my 10.5 and the 12.5. Now she'll still spin into 2nd gear (with a Quaife in there too), but it seems to have gotten slower since the ECU. Now, if I reset ECU, I start back at the quite a bit of pick up and go. I should be tuning her thursday on MS (weather permitting).

MB
 
Yea, the stock ECU blows. I'd imagine whenever I got around to installing my MS, it would be like driving a whole new car.

And the 6.5 rpm redline sucks also.
 
So newest update; got her on the dyno today (not real successfull. Trying to teach a new tuner MS. He's a real good tuner just doesn't know MS so we have wasted a lot of time so far trying to teach him).

The stock ECU has now effectively been "taught". Put her on the dyno for numbers, and they weren't very impressive, LOL.

135.5whp with 117torque @6000rpm.

Now I wanted to log timing numbers, but his equipment was malfunctioning. So here's what I think was happening. I think the stock ECU was seeing events and freaking out. I think (judging from the instant power gains when I reset the ecu and then the power loss as she "learned"; as well as the dark spark plugs) that the stock ecu was pulling timing and pumping in fuel.

I believe I got better numbers on the stock ECU and 10.9 comp. I just haven't got the memory (or the time to search) to come up with the info.

So the long and the short of it is; yes, you can run 12.5 comp on pump on stock ecu (I'v egot plenty of miles on her now as a daily), but your gains wil be limited by the stock ECU (and this is an engine with all the NA bells and whistles).

MS tune on this set-up yet to come.....

MB
 
yeah theres communication mark i havent ran out on anybody..... why does it disappoint u? also, the race head i did for u cracked and u expect eddies head to make much more the mine???


mike
 
Sweet so if we were useing a afx ecu we have a good bit more power if I am correct, for the fact that it's not going to be fighting aginst the set up like the stock ecu.
 
yeah theres communication mark i havent ran out on anybody..... why does it disappoint u?

Because when the head cracked, I searched over on the org and saw this; www.neons.org • View topic - AMM's Am I forgetting anybody?
Then I saw what psycho wrote and I was concerned for him because, honestly, I follow along with people that I recommend.

also, the race head i did for u cracked and u expect eddies head to make much more the mine???


mike
Nope. Absolutely not. I've NEVER questioned your ability or expertise. On the contrary, I've done nothing but tout how good your product is.

Sweet so if we were useing a afx ecu we have a good bit more power if I am correct, for the fact that it's not going to be fighting aginst the set up like the stock ecu.

Ah there's the rub. I wish I still had my AFX ECU. I would love to try it on this set-up with pump and see what happens.

In theory, it should work the same way as the stock ecu (as in adjusting for knock situations etc.). BUT it shouldn't do the crazy power pull that the stock ECU does. Good, but is it too good? How does the 12.5 comp with pump gas react to the higher timing maps and leaner mixture of the AFX ECU?

I would hope that it would react like we want it to without burning a piston, but I don't really know. I'm inclined to think that it would give us a quite a bit more power (I mean the 10.9 comp engine went into the upper 160whp's with the AFX ECU and a safc, so it seems like would), but I can't really make that statement safely.

MB
 
Because when the head cracked, I searched over on the org and saw this; www.neons.org • View topic - AMM's Am I forgetting anybody?
Then I saw what psycho wrote and I was concerned for him because, honestly, I follow along with people that I recommend.


Nope. Absolutely not. I've NEVER questioned your ability or expertise. On the contrary, I've done nothing but tout how good your product is.

MB

alrighty fair enough. im still here doing my thing and getting better then ever, just dont do it for many neon/dsm's cause of the negative feedback ive gotten over the last year..... people think im gonna rip them off. bottom line is i took on way to much work and got burned out because of it. ill be starting on chipdoggs stuff here in the next week or so after i finish a head that im working on right now. then ill just have to get with jonathan and get done what i need to for him (think its gonna be a turbo manifold) and thats in terms of parts that i owe people. then i need to get with kevin warren and nigel (turbo666) about paying them back what i own them (money)...... and thats all she wrote for owing people anything is this community. way off topic but i though i would clarify myself directly to u being that u have sent alot of people my way over the years.


mike
 
alrighty fair enough. im still here doing my thing and getting better then ever, just dont do it for many neon/dsm's cause of the negative feedback ive gotten over the last year..... people think im gonna rip them off. bottom line is i took on way to much work and got burned out because of it. ill be starting on chipdoggs stuff here in the next week or so after i finish a head that im working on right now. then ill just have to get with jonathan and get done what i need to for him (think its gonna be a turbo manifold) and thats in terms of parts that i owe people. then i need to get with kevin warren and nigel (turbo666) about paying them back what i own them (money)...... and thats all she wrote for owing people anything is this community. way off topic but i though i would clarify myself directly to u being that u have sent alot of people my way over the years.


mike
That's probably the most negative thing that's been written about you on DSMtuners. :thumb:

Let's try to stay on topic...
 
VelocitàPaola;153130678 said:
That's probably the most negative thing that's been written about you on DSMtuners. :thumb:

Let's try to stay on topic...

maybe.... but im not worried about it. back on topic


mike
 
Just some proof that this still works on stock ECU. I did a quick vid at 2300 miles (idle at 900rpm);

[ame=http://www.youtube.com/watch?v=hpOnGhE5u-s]12 5 comp C2 LTH 2300 miles - YouTube[/ame]

It does seem like it gained a little more power. I think it took a lot more time than normal for the ECU to "learn" the high comp and LTH.
 
so AFX vs MS, AFX being plug-in-play while MS requires a tune, and reading your other posts I noticed you said the AFX got close to similar results as a MS tuned by a professional tuner.

With that being said, would AFX be good for a 10.5 comp engine with a nitrous setup.
 
so AFX vs MS, AFX being plug-in-play while MS requires a tune, and reading your other posts I noticed you said the AFX got close to similar results as a MS tuned by a professional tuner.

With that being said, would AFX be good for a 10.5 comp engine with a nitrous setup.

On the set-up that I had at the time, yup the AFX did very well in a side by side dyno comparison vs a well known professional tuner. That was also on a 10.9 comp set-up.

As for Nitrous added on; if its a wet kit, I can't see why it wouldn't do fine. I actually put a wet kit on my 12.5 comp engine for a little bit (150 shot. Just to try it out). But that was on MS with 112 oct.

I would have no problems doing it, I would just watch out for detonation at first (though I highly doubt that it would be a problem if done right on a wet kit).

MB
 
So with your exact same setup, except instead of your crower 2's, you had crower 3's and an AFX, how do you think that would work out?
EDIT: Sent this message to Howell Automotive:
"Hey, had a quick question I was hoping you could answer for me. If I had a 95 mtx Eclipse 420a, 12.5:1 comp motor with Crower 3's, ported head, LTH with all supporting mods, would this ecu be safe to run? Please let me know what you think. Thanks!
This was their response:
"Yes it would"
So, I guess it will...
 
Last edited:
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