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View Full Version : DYNO'D 03 AGAIN TODAY



matt-max
03-08-2003, 11:43
(refer to previous post in late january "dyno'd 03 today')

went back to the dyno with the freshly cleaned k&n fipk and the kennedy 4" system mounted and the updated uprated hot juice box from edge. (oil pressure gauge works now which is nice!)

also added spa digital gauge reading egt and boost. this gauge stores the peak values until reset for each function.

when i called to set up the dyno appointment for a diesel truck the owner asked if this was the guy with the chevy duramax. i replied no, it's a gmc, good-naturedly. he said the guys in the shop last time still hadn't stopped talking about the figures the truck pulled down a month or so ago!

dyno operator (dubbed 'son of fat b*st*rd' by my friend along for the ride) asked what my goal was for the day. i thought for a second or two and said '375hp.' he gave me a condescending look, saying 'that's alot of power, buddy.'

run 1 was stock with no box on the truck but with the 'improved' intake and exhaust. three runs were made, from 232-240hp. highest figure was the last run of the day with the box off and once engine was at its highest operating temp. peak boost was close to 20lbs i believe.
(previous run in january without intake and exhaust mods or box yielded 245hp stock with 18 degreee higher air temps, a difference of 5-12hp less.)

run 2 was new level 1 juice, the old level 2. peak hp was 287. this is a gain of 47-54hp on the day.

run 3 was new level 2 juice, old level 3. peak hp gained 19, up to 306, a gain of 66-73hp on the day.

run 4 was new level 3 juice, the top of the heap for the old juice. peak hp gained another 27, up to 333, gaining 93-100hp from stock on the day. previous run in january without exhaust or intake in old level 4 was 332hp, up 87hp from that day's stock run. perhaps the exhaust and intake mods were starting to work on these higher power levels? or maybe the old level 4 didn't hit quite as hard as the new 'identical' level 3? definitely the old level 4 feels stronger than this level 3, something others have noticed as well. apparently the seat of the pants dyno and the dynojet don't always agree!

run 5 was the new level 4 hot juice, advertised as adding 125 rear wheel hp. peak hp was 374, backed up by subsequent runs at 3/4-7/8 throttle (truck feels faster at smaller throttle openings than 100% to me) giving 366 and 367hp and a fourth run with foot to the floor yielding another 374hp reading. this is a gain of 134-141hp from the baseline on the same day on the same dyno less than an hour apart, and 41hp up on the old level 4.

boost peaked at 24.1 lbs on these hot juice runs. egts stayed under 650 and were not a concern. i had reached 28.4 lbs of boost the previous day cruising around and trying to get the allison accustomed to the hot juice. since the dyno runs i've seen a peak of 29 lbs and heard from others that 30 is not uncommon. does this mean that the peak dyno figures are a lower than what we are actually seeing on the road? it only takes a couple of seconds for the run, maybe not enough to reach full pressure...

the exhaust and intake both definitely make a difference in seat of the pants power and a bigger difference in the amount of time it takes from mashing foot to the floor and the rocket acceleration to follow. but to say either one or the other or both adds power was not proven on the dyno. peak egt's have not hit 800 degrees driving around in new level 4 all the time so maybe they help out some.

anybody know how i can access the torque readings from these runs? i've got the dyno jet viewing software downloaded and the disc of my runs but have not been able to figure it out yet.

matt

[ 03-08-2003: Message edited by: matt-max ]</p>

Burner
03-08-2003, 13:26
Hey Matt,


GREAT RUN! I like the way ya did that. How long did it take to do the runs? Did you time the stock run and the JUICE run? I'm guessing the stock truck took about 7 seconds to reach full power and the JUICE took maybe 5? Did you get to run all of those juice numbers for a flat price or did they anti-up to ya on each? tongue.gif



I can't wait to do mine!!!!!!


Burner

TN farmer
03-08-2003, 16:30
What did the guys at the shop say when you hit 374hp, I bet they were surprised.

I have seen 31# of boost with my wastegate closed and I have been meaning to ask if this is to much boost.

CleviteKid
03-08-2003, 19:36
Disclaimer: This idea is FOR DISCUSSION AND CONSIDERATION ONLY. No guarantees.

Running on an inertial dyno like this or the Mustang Dyno with a really hot truck does not allow enough time for full boost to develop, so here is a way to buy more time: Ride the brakes while you are accelerating on the roller.
Right foot all the way down to open up the engine,
left foot modulating the brake
to allow a s - l - o - w time-consuming run so the intake pressure can peak.

But then, I'm not paying for your new rear brake linings and warped rotors (you Duramax guys do have rear disc brakes standard, don't you?) and don't have to put out the flames coming from your overheated tires.

And also, it is not air that makes power, it is fuel that makes power, and the difference between 24 psi and 29 psi may make no difference to the fuel. If you are only seeing 650 F EGT, you clearly have PLENTY of air and may not need any more.

Food for thought, from a guy who does not even OWN a turbocharger, and doesn't want one ! !

Dr. Lee ;)

hoot
03-08-2003, 19:51
650 EGT seems low. Where is your pyro mounted? Post turbo? I see 900 EGT stock on a hard run uphill.

CPMac632
03-08-2003, 19:54
Hoot a dynojet doesn't load a truck as hard as accelerating unloaded on flat ground so that is probably the difference in egt.

Trippin
03-08-2003, 20:58
Matt-Max,
I'm assuming you have a chart of your run showing horsepower at different rpms.
We know that (Torque x RPM)/5252 = HP.
Therefore, Torque = (HP x 5252)/RPM.
Get that calculator out and have some fun. :D

Kennedy
03-09-2003, 10:26
I think that the low EGT's are indicative of the slow response of the pyrometer probe. I have been working on tracking down the early "needle" type probes used by SPA. They are WICKED fast, but weren't reputed to be long lived. I gotta brush up on my Cajun talk as the tech guy I need to talk to is definitely from the bayou!

A Mustang dyno can adjust the "sweep rate" or the amount of time that it takes to run the test. My next dyno session we are planning to do a "steady state" load test. This will allow the engine to give all it has at the set RPM. The only question I have is how low we can manage to hold 4th gear without a downshift...

SoCalDMAX
03-09-2003, 11:33
Those are awesome dyno numbers, thanks for the post! I bet the dyno operator was floored that you were able to predict power within 1 hp!

I ran into an RV shop owner yesterday who has a 3500 with the 8.1. He was bragging that he's never SEEN a diesel keep up or pass him uphill with his 5er. I kept my mouth shut, but it was hard!

the fact that the dyno doesn't load the engine long/hard enough explains the phenomena I've been seeing. Although increased boost doesn't add any power on the dyno, I feel it does help decrease EGTs under extreme load and allows you to use more of that power you paid when you really need it, with lower EGTs.

Regards, Steve

Billy14
03-10-2003, 00:47
matt-max,

Maybe I missed it in your post but could you let us know if you were running in 4th or was this a run from start to finish through all the gears?

I recently ran on a Dynojet & pulled 398 H.P. & 706.4 on the torque curve with the A/C left on redface.gif The peak reading was produced in 4th however, I did a power/brake start at 1400 rpm & let it run through all the gears shutting down at 85mph. Hot Juice level 4

I've caught some flack on this run from other members (which may be, or probably justified because I don't know) that a run not locked in 4th will not be accurate. :(

I do know for a fact that by chance my truck is stronger than others (stock), this has been proven. Must have been slapped together on a Wednesday. :D

Billy

sdaver
03-10-2003, 07:15
good deal.........did you lock out fifth and roll on hard at about 40 mph ?...........is that fast enough to stop the downshift to third ? :D dave

matt-max
03-10-2003, 08:34
Burner-thanks for the pat on the back, but i don't feel like i had much to do with the numbers because the rotund red-haired guy did all the piloting and all i did was buy some stuff and throw it at the truck. the real heroes are guys like kennedy and the edge boys that put in all the time to make these products work. good thing they charge for these products.... i didn't time the runs, but my best guess is maybe around 5 seconds for the stock and 3 or so for the hot juice. it literally was over before you knew it! dyno shop has a $75 for three runs (which i did last time) or $100/hr as many vehicles and runs as you want. i did 12 runs the other day.

TN farmer- i would say they were quietly surprised at first, and then opened up a bit more afterwards and became impressed when it sunk in. 'son of fat b' had planned on getting a new powerstroke to tow his drag car with but now is leaning toward a dmax instead. any feedback yet on whether or not your 31# boost is safe?

Dr Lee- i would be glad to try that dyno procedure...on somebody else's truck!

hoot-egt is mounted in the 'hoot' position i believe, directly under the mounting stud closest to the firewall on the passenger's side exhaust manifold. is that pre or post? i hit exactly 800 degrees this past weekend on a quick trip over to illinois. not sure where the trouble zone starts.

Trippin-i'm sure i have all that info on this 3.5" disc, i just haven't figured out how to access it yet. it appears i have hp on the left axis and mph on the bottom axis and nothing on the right. we did look at torque on the screen immediately after the runs but its not up on my screen now, and i haven't figured out how to grab it off the disc yet.

john-i thought that probe looked awful beefy going in...i'd like to have a faster reading, more accurate gauge, but not at the expense of having to replace it all the time. what is the magic number to stay away from?

steve-thanks, i'm glad to be able to put some more info up here so that we can all learn some more about our trucks. i have appreciated all your info too. and you'll see that guy with the 8.1 out there someday...and we all know how it will turn out! do you have your wastegate disabled?

Billy-i set the trans in tow/haul, overdrive off, and he rolled into it. they do not have a tech2 so this was the best we could do. i remember that last time the lower than expected torque figures were because the truck was in higher rpms in third instead of down in the torque bulge in fourth at the same tire speed. he did run through all the gears (1-4) but took it easy until shifting into fourth. he claims he needs a 1:1 ratio for the dyno to work best. i know when i dyno my bikes they do a 1-4 multi-gear run sometimes and a fourth gear only other times. with high power engines, it isn't unusual to see some spikes on your graph at the shift points that are due to clutch/trans slip. that may be what is up with your runs, or maybe your dyno reads a bit different (they all read different!) or maybe yours just makes a bit more power!

sdaver-loks like he hit it at about 48mph, or at least that's where he hit the trigger on the dyno to start recording data. it didn't downshift into third at that speed.

i have been driving around in level 4 on both modes since i got this new box and have not had any problems or codes. just the occassional puff of black smoke when i put my foot into it. i have been truly enjoying the on-ramp to the highway near my house. banked curve uphill leading on to three lanes going up a steep hill. even with dry clean pavement i can break the rears free and drift the tail out all the way around and then hook up and rocket up the far right 'truck' lane with the exhaust-rasp and turbo-whistle echoing off the 50' high limestone cut-aways on both sides. what a way to start the day...
matt

hoot
03-10-2003, 17:36
That's pre turbo. You are right at the exhaust exit out of the cylinders. Nice and cool. Mine runs a couple hundred if not more higher.

Kennedy
03-10-2003, 18:12
Matt,

It may be a while before I have anything on the probes. How big diameter is the probe you have?

sdaver
03-10-2003, 23:25
sounds kinda personal to me kennedy.............and you call me a bird dogger........ :D hey I got my bulbs.....thanks :D dave