Log in

View Full Version : Tuning Problem. Would like suggestions.


Low-Speed
04-24-2019, 08:25 AM
First off, my mods -

S2 w/Toys
255 HP Walbro
DTEC FC w/TunerXS Wideband
NGK Iridium's, 1 heat range colder.

When I was on the Dyno, I was able to get consistent 12.5-13.0 AFR's, even higher. I did not have the Walbro yet, nor the Iridium (fine-wire) plugs.

After I installed the Walbro, I could not get the car to lean out. It runs up to 11.5, sometimes 12.0, then richens up as you try to lean it out. Initially, I thought it was simply an issue with spark blow-out.

So, I went with the fine-wire plugs. Gapped them nice and tight. This allowed me to get sections of the range back to 12.5, but other sections still won't make 11.5....

I was looking at the boost, and it seemed a bit high. I've taken the pre-load out of the S2 Wastegate. The boost is down some, but it still won't lean out enough. (I'm still seeing spikes well in excess of 20 psi, and the result is 11.5 AFR's @ 4500-5000 RPM. My current thinking is that I have extremely high IAT's, and knock retard is holding down my AFR's.

Has anyone had this kind of a problem? Do I simply have too much fuel? How can I lower the boost more?

punkrokdood
04-24-2019, 09:06 AM
its really hard to say what is going on without more info. have you tried one of the OBD II scan gauges to see what your overall timing advance, and what your knock retard is? that would be my first step... also, i'd seriously look into a FMIC since I don't see one on your mod list

Stage2BlackSRT4
04-24-2019, 10:56 AM
x2 aeroforce scan gauge

whiteACRsrt05
04-24-2019, 11:11 AM
I tossed my rings running that kind of A/F I would suggest getting lower than 12's IMO I hold my a/f at 11.2 and get 0 knock all the way through teh rpm range.... If i set my dtec up leaner then i start to get knock at around 11.9-12.4



my setup
stg 0 ecu
gt3147 turbo
rc 750's
dtec
devils own W/I
new block
valve grind
planed head
STOCK I/C:thumb:
STOCK fuel pump:ftard: walboro on the shelf wainting for the stocker to die:thumb:

punkrokdood
04-24-2019, 11:17 AM
I tossed my rings running that kind of A/F I would suggest getting lower than 12's IMO I hold my a/f at 11.2 and get 0 knock all the way through teh rpm range.... If i set my dtec up leaner then i start to get knock at around 11.9-12.4



my setup
stg 0 ecu
gt3147 turbo
rc 750's
dtec
devils own W/I
new block
valve grind
planed head
STOCK I/C:thumb:
STOCK fuel pump:ftard: walboro on the shelf wainting for the stocker to die:thumb:

that's why you can get away with it :thumb:

Stage2BlackSRT4
04-24-2019, 11:40 AM
I can run a 12.0 with W/I but I'm not getting a lot of upped timing because I use the return line to lean it out mostly and then the sfac to fine tune (15-17%). But you really, really need a scan gauge to dial a good tune it and know your running safe. Injector duty %, Knock timing retard, Long term fuel trim, AIT, Timing, ect ect

On a side note: I also had lots of extra flow uptop after getting my 255 ended up turning my base on the return way down (35-36psi), and dialing my sfac down (pulling less)==for me==better tune, god forbid my w/i should ever fail though

Low-Speed
04-24-2019, 11:52 AM
I can run a 12.0 with W/I but I'm not getting a lot of upped timing because I use the return line to lean it out mostly and then the sfac to fine tune (15-17%). But you really, really need a scan gauge to dial a good tune it and know your running safe. Injector duty %, Knock timing retard, Long term fuel trim, AIT, Timing, ect ect

On a side note: I also had lots of extra flow uptop after getting my 255 ended up turning my base on the return way down (35-36psi), and dialing my sfac down (pulling less)==for me==better tune, god forbid my w/i should ever fail though

Yeah...that makes sense. I get Injector cycle with the DTEC. As well as a form of knock detection. I don't have timing, or how the factory computer is reacting. I'll wait, and get a scan tool before playing much more.

But, I have 10-12% alteration of the MAP signal, up top, and I end up with too much boost @ redline. (pulling low 10 AFR's no less) For that matter, my trouble area is where it's trying to spike 20+ psi. (Hard to tell how much with the factory gauge, but, it spiked it to the needle the other day!) And the air fuel when that happened fell from 11.4 to 10.9. (I think it pulled timing and added fuel to compensate for knock. Showing 5 on the DTEC, but I've seen it spike to 12 before.)

Basically, for now, I'll shoot for 11.0 and see what happens.

Stage2BlackSRT4
04-24-2019, 12:04 PM
Yeah...that makes sense. I get Injector cycle with the DTEC. As well as a form of knock detection. I don't have timing, or how the factory computer is reacting. I'll wait, and get a scan tool before playing much more.

But, I have 10-12% alteration of the MAP signal, up top, and I end up with too much boost @ redline. (pulling low 10 AFR's no less) For that matter, my trouble area is where it's trying to spike 20+ psi. (Hard to tell how much with the factory gauge, but, it spiked it to the needle the other day!) And the air fuel when that happened fell from 11.4 to 10.9. (I think it pulled timing and added fuel to compensate for knock. Showing 5 on the DTEC, but I've seen it spike to 12 before.)

Basically, for now, I'll shoot for 11.0 and see what happens.

That might be, I found that by logging RPM in relation to knock I can see the areas in the band that need a little more fuel or less timing. If you have a dyno look at the area with the big spike in TQ that should be your peak boost area and try pulling less fuel on your detc though that range of the RPM band.

(for me is 4100-4750 I pull about 2-3% less but it will be diff for every set up, im not really stock turbo).

Low-Speed
04-24-2019, 12:55 PM
That might be, I found that by logging RPM in relation to knock I can see the areas in the band that need a little more fuel or less timing. If you have a dyno look at the area with the big spike in TQ that should be your peak boost area and try pulling less fuel on your detc though that range of the RPM band.

(for me is 4100-4750 I pull about 2-3% less but it will be diff for every set up, im not really stock turbo).

Hmm...If I'm reading this right, run it rich in that 4200 RPM area, so that I don't detonate due to high boost (IAT's), and hopefully, it will quit de-tuning me in the 4500-4800 RPM range when it's too much pressure/too lean for the engine speed?

I like that idea. Wish I'd found this board sooner. You guys are actually helpful! Over on - that other forum - they'll flame you for asking a question like that.

I very much appreciate the input so far. I have a couple of things to try now, and I'll post up what seems to be working when I get a chance to do some tuning.

Thanks.

Stage2BlackSRT4
04-24-2019, 01:04 PM
Hmm...If I'm reading this right, run it rich in that 4200 RPM area, so that I don't detonate due to high boost (IAT's), and hopefully, it will quit de-tuning me in the 4500-4800 RPM range when it's too much pressure/too lean for the engine speed?

I like that idea. Wish I'd found this board sooner. You guys are actually helpful! Over on - that other forum - they'll flame you for asking a question like that.

I very much appreciate the input so far. I have a couple of things to try now, and I'll post up what seems to be working when I get a chance to do some tuning.

Thanks.



RPM range when it's too much pressure/too lean for the engine speed?
Yes

Run it richer (it might be a lean area already anyway becaue of the extra boost in the spike) so that your not using the detc as much (so your geting less timing) though the point were you have the most boost, not sure were it is on your set up might be in the same area might be less. If you don't have a dyno sheet its hard to tell for sure. Take a buddy out with you so he can watch you boost and RPM while you drive. But yes thats basicly what I was saying to try... a scan gauge really cleans this guess and try up to a more defind tune



Post a pic of a recent dyno sheet if you have one

Low-Speed
04-27-2019, 05:39 PM
Let me put this another way:

Currently, with about 12% alteration of signal with my DTEC, the car is still running PIG rich.

The problem I'm seeing is a MAJOR boost spike, meaning, it is pegging my stock boost gauge.

My basic question is, do you feel I'm simply sporting too much timing, or is the heat from the turbo bouncing the choke line what is hurting me?

My DTEC isn't showing a lot of knock. Just a small amount (4-5). I'm wondering if the computer is compensating ahead of time due to high IAT's from the superheated air/stock intercooler, or is it more likely it's trying to pump in too much timing, and it's hitting a point of the knock sensor causing knock retard there?

Basically, what should I try first, lowering the boost, or killing off some fuel so the DTEC doesn't have to compensate so much?

Thirteens420k
04-27-2019, 06:11 PM
Let me put this another way:

Currently, with about 12% alteration of signal with my DTEC, the car is still running PIG rich.

The problem I'm seeing is a MAJOR boost spike, meaning, it is pegging my stock boost gauge.

My basic question is, do you feel I'm simply sporting too much timing, or is the heat from the turbo bouncing the choke line what is hurting me?

My DTEC isn't showing a lot of knock. Just a small amount (4-5). I'm wondering if the computer is compensating ahead of time due to high IAT's from the superheated air/stock intercooler, or is it more likely it's trying to pump in too much timing, and it's hitting a point of the knock sensor causing knock retard there?

Basically, what should I try first, lowering the boost, or killing off some fuel so the DTEC doesn't have to compensate so much?
Being lean off the spike and getting richer toward redline is pretty common for the stock turbo. There are ways around it though. A return line setup will do wonders as far as initial fuel tuning. Also a scan gauge will get you dialed in nicely after you get a decent base pressure and rising rate on the RL. Toward redline the timing climbs higher. So with more boost holding up top you are gonna get some knock. That knock is gonna pull some timing back and add fuel. Try not pulling so much fuel toward redline and see if it leans it out a little(i know it sounds backwards, but if your pulling timing, from too much fuel being pulled, you need to add a little more fuel and a little less timing in that rpm range. Play with that for a little while untill you can afford to get the RL and scan gauge to really see whats going on with the car.
BTW, i got your voicemail but T-mobile sevice>me.
I'll call you when i get a chance.
-Garrett

Stage2BlackSRT4
04-27-2019, 06:42 PM
x 2 what 13 said.

What the curve looked like on my old stock turbo stage 2 tune. Stage 2 Adds more fuel and timing (but less timing up top then stage 0, its programmed for more boost) as the RPM’s go up. And I had an aftermarket WG that had a big boost spike to about 23psi falling to 15psi

So JUST for example (THIS IS MADE UP JUST FOR EXAMPLE)

3000 – 15%
3200 – 17%
3400 – 17%
3600 – 17%
3800 – 17%
4000 – 17%
4200 – 16%
4400 – 15%
4600 – 15%
4800 – 16%
5000 – 17%
5400 – 18%
6000 – 17%
6400 – 15%

Low-Speed
04-28-2019, 06:13 AM
x 2 what 13 said.

What the curve looked like on my old stock turbo stage 2 tune. Stage 2 Adds more fuel and timing (but less timing up top then stage 0, its programmed for more boost) as the RPM’s go up. And I had an aftermarket WG that had a big boost spike to about 23psi falling to 15psi

So JUST for example (THIS IS MADE UP JUST FOR EXAMPLE)

3000 – 15%
3200 – 17%
3400 – 17%
3600 – 17%
3800 – 17%
4000 – 17%
4200 – 16%
4400 – 15%
4600 – 15%
4800 – 16%
5000 – 17%
5400 – 18%
6000 – 17%
6400 – 15%

Problem I'm having, is I'm not lean anywhere. (11.2 AFR on a pegged, that's right, pegged stock boost gauge on the spike.) Then, If I try and get 12% signal alteration or more towards the top, It'll easily try and hold 20+ to redline, and is indicating a "blow-out" or severe timing pull, without giving any indication of knock. Spoke with Garrett some last night.

Pretty sure the extremely high boost is giving me major spikes in the IAT's due to pounding the turbo's choke line for extended periods. Never had the problem on the stock pump, but on the stock pump, alteration of 8% on the signal yielded 20-21 psi spike, 15@redline, with 12.7-13.0 AFR across the board (given some minor tuning, like, about 6.7% on the spike, etc.)

So, I was playing last night some. Told Garrett I'd let him know my results as I went. So far, the only setting that yields me (with 0% change) low enough boost I think I might can tune is DAB 1 on the S2 WGA, 0 preload. I'm seeing a 13 psi spike, and 9 @ redline. That's far better than 17 psi spikes, and 12 @ redline with DAB 3. So, I'm going to try and tune it out on DAB 1 today, and see if I can get it to lean out some. IF I'm still having problems, I'm going to bolt on the stock WGA, and see what the boost drops to, since for me, that's the least expensive route at the moment. If I can get something working that way, my next upgrade will be an EBC, followed by one of his Fuel Returns to allow me to fine tune my setup.

Stage2BlackSRT4
04-28-2019, 09:06 PM
:0) Cool man, keep us updated :0)

Low-Speed
05-31-2019, 05:55 PM
Okay. Have had the S0 Wastegate installed for a couple of weeks now.
The ONLY problem I have is that it only runs 13psi.
Period. I don't get a spike. I just get a climb to 13 and hold.

But, with the lower IAT's, despite not having the proper boost level, I now have more power in 1st and 2nd gears. 3rd feels comparable to before, but being as I'm nowhere near the 17 psi I was holding at redline in 3rd before....

It's quite interesting really. My AFR's are now very close to what I was looking (mid to high 12's. Now, I need to creep up on the boost (MBC and S2 WGA is my current consideration, as a cheap route!) until I am just out of the range of knock. That should net me the most ideal power #'s for my setup.

I appreciate your suggestions guys. And I learned something interesting. Part of the reason for the stupid rich AFR's was timing pull/fuel increase due to knock loads. It would lean out to a point, then the boost would get too high, and it would go the other way again.

Now, with my IAT's down, I can lean it out well on DAB3. (Max Fuel Mode!) I have tons of timing now I'm sure!

I understand now why everyone goes with the AGP WGA, or boost controllers. The stock system cannot seem to find a happy compromise when you're pushing a Walbro, S2 injectors, and a S2 car! Especially not when you try leaning it out with the DTEC for the high 9 AFR's it sees stock at that point!

|