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Weirdest Dyno Sessions Ever


HeavyIron

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I think I have a black cloud over my head. Whenever my car touches a dyno it breaks. I was at my dyno shop 3 weeks ago before the 24" of snow and my coolant temp snsor crapped out right after we got the dyno setup. <_< So fast forward to tuesday night and I had my new coolant temp sensor and Underdrive pulley on and I was set to go. After hooking everything up did two test pulls to 4k to see if his rpm trigger was set right and everything looked good. Then bad things happened. During the 1st run my boost gauge stopped reading - not sure why. So I thought I was making no boost, until we looked at the dyno read out and saw 30 psi!!!:blink::blink::blink: F*** me! Sure the TQ numbers are out of sight, but where the hell is my IPD boost controller when I need it. Yes, I checked all the vac hoses and on consequent runs we disabled it by pulling the electrical connection and vac hose off the wastegate hoping to run on spring only. Still was hitting 24psi. The boost is not my problem, the reason the wastegate doesn't seem to be opening as it should is a concern. Even larger is my horrible air fuel ratios. It has been freezing rain around here so I have not had a chance to track it down. Suggestions would be helpful

I have posted my original run from sept. using my old 300/70 actuator vs.all my new info using my Forge wastegate and 16-20 progressive spring.

All new info is in PDF format at the bottom

s70run1-1.jpg

s70run1-2.jpg

DC_2507358.pdf

3 pages in attachment

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Not bad afr;s on old dyno sheet, a little rich at higher rpms 12.2 being nicely leaned out.

I wouldn't even drive the car with that lean AFR, i'm suprised they didn't let off, i wouldnt even dyno a car running that lean. You were definately detonating, Low HP and Low torque.

that's crazy lean!

why is there nothing above 3.7k rpms? Did you shut it down?

Stopping the dyno at 3700rpms is the only thing that saved that motor

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Not bad afr;s on old dyno sheet, a little rich at higher rpms 12.2 being nicely leaned out.

I wouldn't even drive the car with that lean AFR, i'm suprised they didn't let off, i wouldnt even dyno a car running that lean. You were definately detonating, Low HP and Low torque.

Stopping the dyno at 3700rpms is the only thing that saved that motor

makes sense

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Car shouldn't run that lean at 24psi, what injectors and FPR are you running? Its not getting enough fuel somewhere. My car at 24psi see's 12.5 max. I would swap wastegates back see your afrs then.

You have to realize that a tailpipe sniffer isn't that accurate also

Shut down early due to lean conditions. The only parts on the car that are different are the wastegate and the underdrive. Neither of which would explain the superlean conition or excessive uncontrollable boost. Car behaves just fine under part throttle with AFr's in the 12-14 range. I am running Volvo Green injectors with stock FPR. The dyno shops Fuel pressure fitting was broken so we could not check that- next time. I would feel the lean conditon was due to noet enough fuel if it was progressive, but I am running lean even at low boost levels...

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So..... driving there, idling, driving back... what AFR's are you seeing on your wideband? How does the car respond? Did it only seem to whack out on the dyno?

No massive vacuum leaks? Does the wastegate arm move freely with the actuator disconnected? Did you pressure test the actuator to confirm base opening pressure?

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So..... driving there, idling, driving back... what AFR's are you seeing on your wideband? How does the car respond? Did it only seem to whack out on the dyno?

No massive vacuum leaks? Does the wastegate arm move freely with the actuator disconnected? Did you pressure test the actuator to confirm base opening pressure?

Afr's between 12-14 during part throttle cruising. Car boosts hard at the slightest hint of throttle above 2500rpm. no massive vacum leaks. I did not check the wastegate in the manner mentioned, but I will.

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I once had an issue with my afr's leaning out to 17.5 under cruising, it turned out to be a vacuum cap on the vac tree. I usually hold 20" of vacuum and it held 18" at idle, i just thought the loss of 2" of vacuum was the denser air, but turned out that one of my caps had ripped and was leaking

Afr's between 12-14 during part throttle cruising. Car boosts hard at the slightest hint of throttle above 2500rpm. no massive vacum leaks. I did not check the wastegate in the manner mentioned, but I will.

I'd bet that that wastegate is not opening :rolleyes: If your part throttle and boost is creeping its not opening at all

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So..... driving there, idling, driving back... what AFR's are you seeing on your wideband? How does the car respond? Did it only seem to whack out on the dyno?

No massive vacuum leaks? Does the wastegate arm move freely with the actuator disconnected? Did you pressure test the actuator to confirm base opening pressure?

I brought home a vacum pump and I am going to test the wastegate both by hand and with the vacum gauge. I am also going to trace all the vac lines and caps on the vac tree, clean the MAF and.... any other suggestions?????

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I brought home a vacum pump and I am going to test the wastegate both by hand and with the vacum gauge. I am also going to trace all the vac lines and caps on the vac tree, clean the MAF and.... any other suggestions?????

Rob, do you have a wideband Meter? What does the car feel like driving? Does it idle normally? That chart is so lean it's hard to believe there's not some sign of what's going on..

EDIT: Have you (or access to) a fuel pressure gauge? How old is the fuel filter?

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Rob, do you have a wideband Meter? What does the car feel like driving? Does it idle normally? That chart is so lean it's hard to believe there's not some sign of what's going on..

EDIT: Have you (or access to) a fuel pressure gauge? How old is the fuel filter?

I have a wideband in the car and that is the weird thing. Under normal (part throttle) the car is great no problem between 2500-5k rpms with AFR's running between 12-14. But, do anything but roll smoothly and slowly into the throttle and the boost comes on stupid hard above 2500, car goes lean and misfires. Car is great and happy running 5-10 psi. Drives and idles smooth, does not run hot or any other signs. Fuel filter has about 5k miles on it. Yes I have fuel pressure gauge at work. On the dyno, we could not hear it misfiring, but we got codes on 2 out of 3 runs

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