first 408 dyno report
01-15-2005, 11:12 PM
#1
first 408 dyno report
video soon >> http://www.1320video.com/videos.php
not totaly happy with how today went.
first thing today i put on the fixed up header. this part went well. puting the turbo, header, down pipe, oil lines, air filter, some other stuff all only took about an hour. the design of this kit is real easy to work on. no hard to get to bolts or anything. then i slaped in some br7 plugs, one range colder than stock. the truck fired right off but ran like crap. it does not like those plugs at all. i had to turn up the idle and some tuning would need to be done if i was to run those all the time. off to the dyno!
straped it down and hit it with 9psi closed exhaust, the numbers were not fantastic. 436hp/473tq. this seems a little low looking at the 6.0 numbers at 10psi on the chart below but i was running race gas and conservative timing, 18deg max. 18deg on race fuel might be too low.
the chart on that one looked a little off and i thought i heard some wheel spin but wasn't sure. we opened the cut out and hit it again. from here on out we couldn't get anything to work right. power was up a little, then down a little, add timing, pull timing. didn't much matter. numbers were all over.
it wasn't completely clear to me at the time but it apears we were fighting wheel spin the entire time. on some of the runs it was clearly shreading the tires so we could tighten up the straps or adjust the air presure and try it again. we got it better but looking back i dont think we had a single run that didn't have some or alot of wheel spin. having wheel spin seems like it would make prety much all the data useless. we figured out a few things about mustang dynos. wheel spin totaly messes things up. the dyno trys to hold you at 300rpm/sec rise but when you spin the rpms go up to fast so it adds load and ends up making the wheel spin worse. it was all just a FU mess.
i was out of money by this time but the last run we made they switch the way the dyno controls the load. they turned on a fixed load instead of an rpm dependant load. with a fixed load we still got some wheel spin but the chart and pull was much smoother. the numbers were still lower than i expected but with wheel spin i dont know that i can make any conclusions at all. the chart below only has the last pull on it. by this time i was at ~14psi and back up to 22deg of timing. after leaving the dyno i turned the boost down a little to about 13psi and beat it all the way home. it pulls like mad, i rolled into the throttle at 65mph on the interstate and lit up the tires. i just dont buy the 519hp with as strong as it is pulling.
we saw minimal knock retard or no knock retard at all, if we were seeing nice gains or any gains for that matter i would have cranked it up more. there was a guy there that thinks my q trim is a serious restriction for this many cubes and he may be right. a 3" down pipe can't help either. we did get up to ~85% duty cycle. doing the math backwards it apears we were using 814fwhp worth of fuel (66lb injectors at 85% = 56lb's of fuel x 8 = 448lb's of fuel / .55 = 814hp worth of fuel). seems like that should have been 600rwhp to me. the maf was flat lining hard.
here are the screen shots.
not totaly happy with how today went.
first thing today i put on the fixed up header. this part went well. puting the turbo, header, down pipe, oil lines, air filter, some other stuff all only took about an hour. the design of this kit is real easy to work on. no hard to get to bolts or anything. then i slaped in some br7 plugs, one range colder than stock. the truck fired right off but ran like crap. it does not like those plugs at all. i had to turn up the idle and some tuning would need to be done if i was to run those all the time. off to the dyno!
straped it down and hit it with 9psi closed exhaust, the numbers were not fantastic. 436hp/473tq. this seems a little low looking at the 6.0 numbers at 10psi on the chart below but i was running race gas and conservative timing, 18deg max. 18deg on race fuel might be too low.
the chart on that one looked a little off and i thought i heard some wheel spin but wasn't sure. we opened the cut out and hit it again. from here on out we couldn't get anything to work right. power was up a little, then down a little, add timing, pull timing. didn't much matter. numbers were all over.
it wasn't completely clear to me at the time but it apears we were fighting wheel spin the entire time. on some of the runs it was clearly shreading the tires so we could tighten up the straps or adjust the air presure and try it again. we got it better but looking back i dont think we had a single run that didn't have some or alot of wheel spin. having wheel spin seems like it would make prety much all the data useless. we figured out a few things about mustang dynos. wheel spin totaly messes things up. the dyno trys to hold you at 300rpm/sec rise but when you spin the rpms go up to fast so it adds load and ends up making the wheel spin worse. it was all just a FU mess.
i was out of money by this time but the last run we made they switch the way the dyno controls the load. they turned on a fixed load instead of an rpm dependant load. with a fixed load we still got some wheel spin but the chart and pull was much smoother. the numbers were still lower than i expected but with wheel spin i dont know that i can make any conclusions at all. the chart below only has the last pull on it. by this time i was at ~14psi and back up to 22deg of timing. after leaving the dyno i turned the boost down a little to about 13psi and beat it all the way home. it pulls like mad, i rolled into the throttle at 65mph on the interstate and lit up the tires. i just dont buy the 519hp with as strong as it is pulling.
we saw minimal knock retard or no knock retard at all, if we were seeing nice gains or any gains for that matter i would have cranked it up more. there was a guy there that thinks my q trim is a serious restriction for this many cubes and he may be right. a 3" down pipe can't help either. we did get up to ~85% duty cycle. doing the math backwards it apears we were using 814fwhp worth of fuel (66lb injectors at 85% = 56lb's of fuel x 8 = 448lb's of fuel / .55 = 814hp worth of fuel). seems like that should have been 600rwhp to me. the maf was flat lining hard.
here are the screen shots.
01-15-2005, 11:51 PM
#3
Originally Posted by BigTex
That does sound low. Too bad you didn't catch the traction problem earlier.
0 KR, thats impressive by itself. Things have progressed so much since fighting KR on our 99 trucks.
0 KR, thats impressive by itself. Things have progressed so much since fighting KR on our 99 trucks.
do you see that dead on airfuel. the wideband airfuel targeting kicks ***.
01-15-2005, 11:56 PM
#4
Yes, it looks like a dead on tune. What rpm was that peak HP number on? Is the sharp drop after peak from getting off the throttle?
I saw in another post where you were using a gas tank sensor input to log your wideband. How are you logging fuel pressure and boost? I assume you have sending units hooked up somehow. That sure looks nice having those prime readings all in EFI live.
I saw in another post where you were using a gas tank sensor input to log your wideband. How are you logging fuel pressure and boost? I assume you have sending units hooked up somehow. That sure looks nice having those prime readings all in EFI live.
01-16-2005, 12:00 AM
#5
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IF you look at the compressor map of the T-76 you can see its way off for that 408. Considering a lot of things I would not take the dyno numbers to hart. ITs time for a larger t-4 flanged turbo. At least a 81 or so. Also just a exuast housing change might help you along for now.
01-16-2005, 12:04 AM
#6
the peak hp was at 5800 and it was still climbing prety fast. i did not let off the gas at that point, it just droped off hard. i could hear it missing. either valve float or spark blow out i would guess but neither seems all that likely. patriout gold springs and brand new plugs gaped at .025. just one more thing to figure out i guess. from past experience i would expect that drop off point to come down as the boost goes up so it will be a problem.
i am using the autometer presure sensors. 5v input and a ground and then come off the output. the output is a 0-5v wich i took right to the gas tank sensor. then used efilive to scale the voltage to the presure. it wasn't too hard to hook up and is real nice to have loged.
i am using the autometer presure sensors. 5v input and a ground and then come off the output. the output is a 0-5v wich i took right to the gas tank sensor. then used efilive to scale the voltage to the presure. it wasn't too hard to hook up and is real nice to have loged.
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01-16-2005, 12:16 AM
#8
You hooked up just the electric sender, not the control box between the sender and gauge? I'll do a little research on this. I may have some questions.
I had a reason for asking about the sharp dropoff on your dyno. Not many 500+ hp truck dynos around. Late in 2003, I talked to a shop who had just done a big heads/cam job on a SS truck, then added a direct port. It needed more bolt-ons to really open up, and cam was about the same as you have now. N/A dyno looked normal, but when they hit it with a 200 shot, power hit a brick wall. Their thought was the intake just being too restrictive at that power level. They didn't let off the throttle either. Take a look, I'm interested in hearing your opinion: http://z71.net/ssdyno.jpg
I had a reason for asking about the sharp dropoff on your dyno. Not many 500+ hp truck dynos around. Late in 2003, I talked to a shop who had just done a big heads/cam job on a SS truck, then added a direct port. It needed more bolt-ons to really open up, and cam was about the same as you have now. N/A dyno looked normal, but when they hit it with a 200 shot, power hit a brick wall. Their thought was the intake just being too restrictive at that power level. They didn't let off the throttle either. Take a look, I'm interested in hearing your opinion: http://z71.net/ssdyno.jpg
01-16-2005, 12:23 AM
#9
i have the control box too since i am running the gauges on my pod but i am 99% sure you wouldnt need the control box. do a search for that post i had a decent write up i think about how i hooked it into the truck. i used the rear 02's for inputs for some things but had to get the signal down to under 1 volt for those inputs to work.
i really dont know about he power drop off. i could hear mine missing so i dont think that is an intake issue.
i really dont know about he power drop off. i could hear mine missing so i dont think that is an intake issue.
01-16-2005, 01:21 AM
#10
You're making more torque...you're bound to with that big C.I. motor. What turbine housing do you have on it now - a .96? It looks awefully small in the pics you have on your site. I know it's also a 4-bolt housing, right?
I say straighten out the minor things and give it a shot again. Maybe this time pop on a buddy's set of drag radials so they will grab a bit more. Those stock tires don't have much meat on them from the factory.
At 600-700rwhp, you should see a gain of 30rwhp or more going to a 3.5" downpipe.
Or, forget the dyno, the track is the best determining factor. Your making over 125 ft.lbs. of torque by 2400 rpm, your 60'ft. time has got to get better with that.
I say straighten out the minor things and give it a shot again. Maybe this time pop on a buddy's set of drag radials so they will grab a bit more. Those stock tires don't have much meat on them from the factory.
At 600-700rwhp, you should see a gain of 30rwhp or more going to a 3.5" downpipe.
Or, forget the dyno, the track is the best determining factor. Your making over 125 ft.lbs. of torque by 2400 rpm, your 60'ft. time has got to get better with that.