Out of Fuel with 650's on a 16G?

[andymoraitis]

Hi All,

I've been having some tuning issues lately and while I'm to the stage where I could use some help. This is going to be pretty long so please be patient when reading. Here's the current setup:

Big 16G - 25psi
Walbro 190
FIC 650's
Comp 200 Camps
Dejon Sidemount
2.25" Upper and Lower IC Pipes
Crushed 1G BOV
Injen Intake
Full 3" Exhaust
Keydiver Stage III (12:1 A/F 18 Timing Advance)
All else stock

Prior to my cam install, I was able to run with 550cc injectors to 25-26psi on an average of 98 octane unleaded with only 3-5 counts of knock at the top of third. The settings in that chip were 11.7:1 A/F and 19 degrees of timing. Since the cam install, knock counts have risen dramatically to 10-13 on the old chip and I bought and installed new injectors thinking that I was running out of fuel with the 550's.

I re-tested yesterday on the same octane and boost levels with the new chip and 650's. At 25psi, knock at the top of third is close 15 counts. There's no reason I should be outstripping 650's considering that I'm not seeing massive airflow out of a small turbo. At the same time, I'm hearing strange noises from the front of the motor. It sounds as if someone is letting the air out of a balloon in a high pitched whine. This happens under vaccuum while cruising and continues if I pop the car out of gear and stop. I know it's a not a mechanical noise since it tapers off and stops a few seconds after I stop.

So that we can isolate some issues, I've done the following:

1. Boost leak tested to 26psi.
2. Read the plugs: They show up dark brown (octane boost) with some blackness (rich)
3. Tried raising octane - Knock persists
4. Replaced the O2 - Knock persists
5. Replaced all injector seals with new Viton seals
6. Fuel filter and 190 pump are 8K miles old.

To me, this almost sounds like a fuel delivery issue. Since I have a 2G, there's no way that I can log IPW and IDC. Just for kicks, I'm going to pull the lower heatshields and Seafoam the motor today and see if I can spot any manifold or O2 cracks or leaks as this could be the pinhole noise I'm hearing. I'm also thinking of replacing the FPR with an adjustable and ripping apart the pump to see if the o-ring is causing an issue. Maybe I'm not getting a 1:1 rising rate on fuel under load.

Any other suggestions would be appreciated.

Thanks,

Andy

 

[dnhieu]

i was about to say are you sure your not over running your stock fuel pressure regulator? i know i did with my 190 and it made tuning hell. it would probably be worse for you because dont have anything to tune with but burnt chips....

 

[andymoraitis]

David,

You may be right. Before I get to that, let me follow up with a few tests I ran this morning.

1. I removed my wastegate shims and re-set boost to 22psi with the 12:1/18 advance chip. There was zero knock at this boost level on the same fuel I've been running. The car pulled like a beast and felt great all the way up to 7200. Just for kicks, I may try the more aggressive chip at 12.5:1/22 advance and see what it does.

2. Seafoaming the motor without the lower heat shields on revealed TONS of smoke from the front of the motor. Now all of my manifold, manifold to turbo and manifold to O2 bolts are tight so that tells me I either have leaking gaskets or cracks in those areas. Since there was so much smoke, it was hard to tell, but it looked like gaskets were leaking more than anything else.

I think at higher boost levels (around 25-26psi), the stock FPR simply can't keep up and I'll likely either find the boost limit for 3-5 counts and stay there, or upgrade the FPR with the bolt on from Import Evolution. In the meantime, I need to replace all of the turbo gaskets and do a port job while I'm in there to see if I can stop the leaks before the O2 as these are likely the source of my pinhole air leak sounds.

I'll let you guys know what I find.

Andy

 

[dnhieu]

when i put sea foam in my car it always smokes at least a little bit from the turbo area. i thought this was normal??? anyways do you think you are just simply running lean from a 12:1 afr? i know you run half race gas and half premium unleaded but do you think this can be the case??? also i think at thoes boost levels are are starting to over run the evo 3 16g do you think the inter cooler just cant keep up from all the hot air comming from the turbo? im just shooting some ideas at you to get the mind moving .


hope that helps
david

 

[CanadianTSi]

You might be running out of fuel pump...

With that high of boost the 190 might not be able to keep up and your losing FP up top effectivly decreasing your Fuel Injector size...just a though.

 

[BaddAssGst]

You might be running out of fuel pump...

With that high of boost the 190 might not be able to keep up and your losing FP up top effectivly decreasing your Fuel Injector size...just a though.

This would be my guess as well as I've seen the support claims of 400hp out of the 190 to not be so true. It does make sense that on 22-24psi your within your knock spec of 3-5 counts but once you start running more boost, the pump can't simple keep up.

Let us know what else you find Andy.

 

[steve]

He's getting really close to where the pressure relief valve on the fuel pump opens.
Base presure + boost pressure + line losses < relief pressure.
Depending on the voltage to the pump, the pressure drop/line loss, and his IDC the 190 might not be able to keep up. It's only puts out about 150 lph at 70 psi on 12v.

Steve

 

[andymoraitis]

Well guys, here's where I stand right now.

As I mentioned above, there's zero knock at 22-23psi and she runs like a champ. If she's running that well on a 12:1 A/F and 18 degrees of timing, then it tells me that I can make more power by leaving the boost alone, upping the octane slightly and using my more aggressive tune at 12.5:1 with 22 advance.

That being said, it might be the case that the 190 just isn't enough past that level. The motor is certainly asking for more fuel as a result of adding the cams and the 650's seem to have it covered just fine. Most tuners trying to squeeze the most from their setup are at leasting running an AFPR on the 190 and I may do that, but for now, I'll probably track it and see what it does at 22-23psi. I may play around a bit more and see if she can handle 24, but at least I've turned the corner.

On a final note, the IC isn't a problem and after multiple back to back pulls, it's still hot on the inlet and cool on the outlet.

I'll keep at it and let you know what I find.

 

[steve]

Andy,

Do you have a wideband in the car to verify actual A/F?
Was the A/F staying constant on the problem pulls?

Steve

 

[andymoraitis]

Steve,

Nope, no wideband installed, but I'm thinking about one of these as well. I know that Jeff's tune is based on DSMLink style maps and I've talked to close friends with custom chips and widebands and they're almost dead nuts.

I think what this all comes down to is fuel supply. I'm sure that 190 is close to the edge. Turthfully, I haven't even re-wired it yet so that may be having a minor effect. I'll be re-testing tomorrow and see how much she'll tolerate before she starts knocking on my current octane level (98). At that point, I'm either going to drop the boost a bit and get more aggressive with the A/F and timing, or spring for a 255 and an AFPR and have at it again.

For now though, the knock is gone with less boost and that tells me she's just not getting enough go juice to run the 26-27psi I was trying to go after.

Andy

 

[BaddAssGst]

Steve,

Nope, no wideband installed, but I'm thinking about one of these as well. I know that Jeff's tune is based on DSMLink style maps and I've talked to close friends with custom chips and widebands and they're almost dead nuts.

I think what this all comes down to is fuel supply. I'm sure that 190 is close to the edge. Turthfully, I haven't even re-wired it yet so that may be having a minor effect. I'll be re-testing tomorrow and see how much she'll tolerate before she starts knocking on my current octane level (98). At that point, I'm either going to drop the boost a bit and get more aggressive with the A/F and timing, or spring for a 255 and an AFPR and have at it again.

For now though, the knock is gone with less boost and that tells me she's just not getting enough go juice to run the 26-27psi I was trying to go after.

Andy

Very good points Andy, although a recommendation I would have, would be to opt for the 255 and regulator. I feel like you would make power upping the boost 3-5 psi then you would with trying to lean it out while keeping your 22 degrees of timing.

Another thing I would try would be to rewire the pump and see where that stands. You could be close to over-working the pump and it's possible that this could give you that edge. If it does, it's a very cheap fix but if not, at least you can it's rewired.

 

[andymoraitis]

Very good points Andy, although a recommendation I would have, would be to opt for the 255 and regulator. I feel like you would make power upping the boost 3-5 psi then you would with trying to lean it out while keeping your 22 degrees of timing.

Another thing I would try would be to rewire the pump and see where that stands. You could be close to over-working the pump and it's possible that this could give you that edge. If it does, it's a very cheap fix but if not, at least you can it's rewired.

Kyle,

I agree. More boost will certainly make more power than leaning out and adding a bit of timing. Since I might as well upgrade once, I'll likely grab a 255, an AFPR and work with that instead of keeping the 190. I'll test a few things in the morning and see where I stand.

Thanks bud,

Andy

 

[steve]

Nope, no wideband installed, but I'm thinking about one of these as well. I know that Jeff's tune is based on DSMLink style maps and I've talked to close friends with custom chips and widebands and they're almost dead nuts.

What Jeff and the rest of us do is modify the open loop fuel enrichment maps.
If everything else in the car is spot on then the target A/F we set will be the actual A/F but if your closed loop fuel trims are less than perfect then it's likely that your actual open loop A/F won't match the target values either.

The wideband would have told us if you were running out of injector/pump. Anyway from the flow measurements on the Stealth316 site using the 190 pump with 650/680 injectors is marginal at those boost levels. I'd suggest getting the HP version of the 255 when you make the swap. If can support the higher fuel pressures that come with additional boost.

Steve

 

[andymoraitis]

Steve,

Thank you for clearing that up. What I don't understand however is how people are running low 12's or high 11's on high boost, 16G variants and stock FPR's with 190 pumps. I likely will upgrade as a larger pump will certainly take care of my issues, but it just doesn't make sense unless either the pump or FPR is on it's way out and not working correctly.

Andy

 

[mavisky]

Andy if you've not re-wired the pump I'd advise that. With the 18g on the 510's I noticed a change in top end with re-wiring the 3000gt pump. We'll have to see how it handles the 18g and 650's this year, but I won't be surprised If I have to jump up to a 255 on race gas. Another thing to try is to just add in real 110 octane instead of your pump gas + octane booster. This would alleviate whether or not its a fuel octane issue or actually a fuel flow issue.

There's a pump in downtown Fort Wayne that has 110 available.

 

[gman991057]

Correct me if Im wrong but aren't those modifications to the open loop maps based on flow numbers on others cars depending mostly on what turbo your running. Can the maps really be accurate for all setups, even with the same turbo. ex. different exhaust, intake, intercooler, or even cams? by varying the parts i just mentioned, flow will be greatly effected at certain points in the RPM band, causing variation in tune and A/F ratio. What I am trying to say is that if you are going to be running a chip to tune, I would at least have a wideband to make sure everything is running properly. -Griff

 

[steve]

Can the maps really be accurate for all setups, even with the same turbo. ex. different exhaust, intake, intercooler, or even cams? by varying the parts i just mentioned, flow will be greatly effected at certain points in the RPM band, causing variation in tune and A/F ratio.

The way I understand it (or don't) that's the great part about using a MAF to measure air mass. It takes VE and everything else out of the picture.
Assuming your MAF and fuel injection system is accuate, your A/F will be pretty close.

If you have a good wideband you can check your actual aganst the target and tweek the MAF compensation tables. This is why the current thinking for chip tuners or link users is to get your fuel trims as close to neutral (0 or 100%) as possible.

Steve

 

[andymoraitis]

Andy if you've not re-wired the pump I'd advise that. With the 18g on the 510's I noticed a change in top end with re-wiring the 3000gt pump. We'll have to see how it handles the 18g and 650's this year, but I won't be surprised If I have to jump up to a 255 on race gas. Another thing to try is to just add in real 110 octane instead of your pump gas + octane booster. This would alleviate whether or not its a fuel octane issue or actually a fuel flow issue.

There's a pump in downtown Fort Wayne that has 110 available.

We have 110 here in Auburn at the S&S on Main (Citgo leaded). I'm going to load up on some after a pump re-wire and I'll try the more aggressive chip and see what it does to knock. If I'm still not where I need to be, I'll look into the larger pump and AFPR.