super high EGTs but WBo2 says good

[Flowgoode]

Ok my problem is around 5k-5,500 rpm to 7k rpm my egt's skyrocket past 1600 degrees and my knock goes crazy. I have dsmlink and i've tried adding sooo much fuel and still no change.

My PLX wideband o2 says my air fuel ratio is like 11.0 - 11.5:1 then the egts start shooting up at like 5500rpm and the air fuel goes to like 12-13:1. But i've added even +20 fuel on dsmlink and the wideband said like 10-11:1 and I still got knock and super high egts. I also turned off my knock sensor thru dsmlink and still got high egts and lose of power.

I have my fuel pressure at 40psi and 550 injectors. My mods are on my site. http://www.cardomain.com/id/flowgoode i'll list them anyway.

I really need help its killing me not being able to pull all the way through an entire gear and my power cutting out right in my powerband. The only other thing i can think of is my sidemount I/C is creating so much heat. Thanks!


MODS:
Free Mods
K&N no can
Magnecor Wires
NGK plugs
DSS 2.5" UIP w/Greddy Type-S BOV
Extreme Tech. 3" Catback
2.5" downpipe w/ eliminated cat
2g exhaust manifold
Ported o2 housing
ACT 2100 Clutch
XACT Streetlite Flywheel
Greddy Profec-B Boost Controller
Dejon Tool Intake pipe 3" - 2.5"
Dejon turbo outlet elbow
FP BIG 16g turbo ported w/ 34mm wastegate upgrade
Walbro 255lph HP fuel pump
RC/Eng. 550cc injectors
6bolt engine swap

TUNING:
1G DSMLink Engine Managment
PLX Devices Wideband o2 (M-300)
PocketLOGGER
SX Peformance Adjust. Fuel Press. Regulator
Autometer Phantom: Boost, Air/Fuel, EGT gauges
Jegs fuel pressure gauge
Apexi S-AFC

SUSPENSION/LOOKS:
Ractive Front Upper Strut Bar
RoadRace Engineering Rear Strut Bar
Rota Subzero 17x7.5 Wheels Bronze
Kumho Ecsta Supra 712's
Power Slot rotors

 

[97TSIAWD]

I would say too much fuel. It seems like your a/f goes up when you start seeing knock. Let's see what some other people think first though.

 

[Nanan]

Well with out knowing what boost your at in this range I can not tell you an exact answer.

It looks like you are going beyond the abilities of your 550 injectors which wouldnt be to hard if you are pushing 18+ psi boost at that rpm range. The 1600+F egt will only come from running lean which is why you are also getting knock. The ecu will try to raise fuel ratio and retard timming if it starts seeing knock. By bypassing the knock sensor you are putting your engine at serious risk of detonation damage which can result in damaged pistons, valves, cyl head, and block.

To much fuel would cause lower then normal egt's not higher.

 

[Flowgoode]

Well with out knowing what boost your at in this range I can not tell you an exact answer.

You can crank up the fuel on the dsmlink all you want but if you are going beyond the working range of the injectors you will not get the extra fuel.

It looks like you are going beyond the abilities of your 550 injectors which wouldnt be to hard if you are pushing 18+ psi boost at that rpm range. The 1600+F egt will only come from running lean which is why you are also getting knock. The ecu will try to raise fuel ratio and retard timming if it starts seeing knock. By bypassing the knock sensor you are putting your engine at serious risk of detonation damage which can result in damaged pistons, valves, cyl head, and block.

To much fuel would cause lower then normal egt's not higher.

I've tried upping the fuel with the dsmlink and still does the same thing and it says im only using about 80-85% injector duty. Also, I only disabled the knock sensor to do the test once, I didnt keep it disabled.

I am running 18psi on my big 16g 255hp rewired, 550s and 40 base psi of fuel pressure, can I really max that out? on average i only see in the range of 1800 to barely 2000 hz airflow and thats during the midrange where the car pulls good.

 

[Nanan]

An 80%ish duty cycle is getting rather high up there, you shouldn't really go over 75% at your max usage point. You are hitting a fuel flow restriction in your injectors, it doesnt matter if they are on constantly with the volume and density of air going through the engine at that rpm@psi range, you just lack the ability to push the required fuel.

Think of your injectors like a garden hose nozzle; turn the water on full blast, nice hard stream right? now hook your hose up to a fire hydrant, your going to see about the same stream. Why? you have hit a point where the opening is not large enough to flow the volume even with increased pressure due to extreamly turbulant flow right at the tip. How do you solve the problem? simple put a bigger nozzle on the hose which in your case would be a set of 650+ injectors.

I am running 18psi on my big 16g 255hp rewired, 550s and 40 base psi of fuel pressure, can I really max that out? on average i only see in the range of 1800 to barely 2000 hz airflow and thats during the midrange where the car pulls good.

What is the airflow reading going from 5500 7000 rpm? is it flat? if it is then you are likely going beyond the abilities of the stock Maf which is also likely due to the fact that 1g maf suck. A 3" GM maf and maf translator could help you out here and is also a good step for a next upgrade at your point in mods.

 

[talon1979]

If this just seemed to happen out of nowhere there is always the slight possiblity that your timing belt jumped a tooth. If all else fails make sure that all of your timing marks align up properly. I had a friend who wouldn't be on the throttle very much and his EGT's would climb like crazy no matter how much fuel he added. When the timing belt was fixed and the marks lined up everything went back to normal.

 

[Flowgoode]

What is the airflow reading going from 5500 7000 rpm? is it flat? if it is then you are likely going beyond the abilities of the stock Maf which is also likely due to the fact that 1g maf suck. A 3" GM maf and maf translator could help you out here and is also a good step for a next upgrade at your point in mods.

the air flow just varies around like 1700-1600 that i've noticed. Its like it doesnt take in more air once that stuff starts happening it starts dropping airflow and fluxuating. I do have a 3" MAFT ready to go in, I was just waiting to do the blow through setup instead of where the stock mas is. But I can install it for now in the stock location. I was also informed that it may be a heat soak problem and to adjust my timing back in the higher rpm or lower the boost a little (timing would be done with dsmlink and 500 intervals from 5500-7000rpm) and that is what is causing the high egts, but he also said not to worry so much about the egts, trust my wideband and knock sensor more. true?

 

[Flowgoode]

Hey guys thanks all for the help. But I seemed to of fixed the problem.

I installed my maft in place of the 1g mas and took away some timing uptop and now she runs great i even am in the negatives with fuel, no sky rocketing egt's and wideband says aye-okay

I guess that POS 1g mas had finally bit the dust!

Thanks again!

oh yeah now im seeing 33-34 lbs/min

Here is a picture of the new setup:

 

[Nanan]

Ah good to hear that you got it working properly. Once you said how high the maf hz were it clicked that you were overrunning the stock 1g maf.

I never considered massive heatsoak as I assumed you had a good fmic with all those mods and boost.

 

[Flowgoode]

Ah good to hear that you got it working properly. Once you said how high the maf hz were it clicked that you were overrunning the stock 1g maf.

I never considered massive heatsoak as I assumed you had a good fmic with all those mods and boost.

yeah, FMIC is next on the mods list, I ordered one almost a year ago from AHP and got ripped off big time, now im out 735 bucks and his business is shut down and I can't get my money back! GRRR Chris Anderson in Wisconsin from AHP Products IS a bad person and lies about everything he owes someone!

 

[suicidal2af]

An 80%ish duty cycle is getting rather high up there, you shouldn't really go over 75% at your max usage point. You are hitting a fuel flow restriction in your injectors, it doesnt matter if they are on constantly with the volume and density of air going through the engine at that rpm@psi range, you just lack the ability to push the required fuel.

Think of your injectors like a garden hose nozzle; turn the water on full blast, nice hard stream right? now hook your hose up to a fire hydrant, your going to see about the same stream. Why? you have hit a point where the opening is not large enough to flow the volume even with increased pressure due to extreamly turbulant flow right at the tip. How do you solve the problem? simple put a bigger nozzle on the hose which in your case would be a set of 650+ injectors.

Bad example. You wouldn't reach that point until you are at 100% IDC. At 80%, you're not flowing 550cc yet. Also, being that he has a 1g, stock fuel pressure is 38psi iirc, bumping it up to 40 would effectively increase how much fuel a 550 canf low -- but I don't know the exact number. Somewhere in the range of 575, I'd surmise.

 

[djpast]

Bad example. You wouldn't reach that point until you are at 100% IDC. At 80%, you're not flowing 550cc yet. Also, being that he has a 1g, stock fuel pressure is 38psi iirc, bumping it up to 40 would effectively increase how much fuel a 550 canf low -- but I don't know the exact number. Somewhere in the range of 575, I'd surmise.

wrong, all injectors are rated at ~43psi, so he is effectively running LESS then 550 with a fuel pressure of 40 psi, more like ~527cc.