Dyno this morning, advice needed.
Thread Starter
Le Mans Master
Joined: Nov 2001
Posts: 6,905
Likes: 205
From: Kern County CA
Dyno this morning, advice needed.
2002 Z06, only power mod is the Blackwing, 5900 miles, Ambient temp 80 degrees, Barometric pressure 29.10 inch Hg, Correction factor 1.03, Elevation 550 feet.
1st run: 356.7 hp, 343.4 tq, oil 210, coolant 221
2nd run: 351 hp, 344.3 tq, oil 235, coolant 221
At this time, I turned on the AC full blast for 4 minutes, then shut down AC
3rd run: 362.9 hp, 353.7 tq, oil 228, coolant 217.
My observations: turning on the fans definitely helped big time. So I will get a davinci fan controller kit. I noticed that the curves for runs 1 & 2 have a significant dip at 4500 rpm and from then on, there are lots of squiggly dips until redlline. The 3rd and best run does NOT have the 4500 rpm dip and there are significantly less squigglies. Up until 4500 rpm, all 3 curves are smooth. If some one can let me know how to post the graphs I will do so, I have them scanned into my hard drive already.
Thanks,
RT
1st run: 356.7 hp, 343.4 tq, oil 210, coolant 221
2nd run: 351 hp, 344.3 tq, oil 235, coolant 221
At this time, I turned on the AC full blast for 4 minutes, then shut down AC
3rd run: 362.9 hp, 353.7 tq, oil 228, coolant 217.
My observations: turning on the fans definitely helped big time. So I will get a davinci fan controller kit. I noticed that the curves for runs 1 & 2 have a significant dip at 4500 rpm and from then on, there are lots of squiggly dips until redlline. The 3rd and best run does NOT have the 4500 rpm dip and there are significantly less squigglies. Up until 4500 rpm, all 3 curves are smooth. If some one can let me know how to post the graphs I will do so, I have them scanned into my hard drive already.
Thanks,
RT
Drifting
Joined: Feb 2000
Posts: 1,922
Likes: 0
From: Boulder, Colorado
Re: Dyno this morning, advice needed. (Rapid Transit)
I noticed that the curves for runs 1 & 2 have a significant dip at 4500 rpm and from then on, there are lots of squiggly dips until redlline. The 3rd and best run does NOT have the 4500 rpm dip and there are significantly less squigglies. Up until 4500 rpm, all 3 curves are smooth.
If some one can let me know how to post the graphs I will do so, I have them scanned into my hard drive already.
If you don't have one, email me the pics. I'll put them on my forum homepage and post the links here.
Le Mans Master
Joined: Nov 1999
Posts: 7,695
Likes: 51
From: Imperial Beach CA
Re: Dyno this morning, advice needed. (Rapid Transit)
I've got three or four dyno sheets with similar clitches. Seems that third run always is the best. With our last 3 dyno days in Gardena CA there were a lot of graphs that way. Spark retard seems to be the concensus.
Drifting
Joined: Feb 2000
Posts: 1,922
Likes: 0
From: Boulder, Colorado
Re: Dyno this morning, advice needed. (Rapid Transit)
What causes spark retards in this case? Or in the cases that you've seen at Gardena?
Bad gas, too much heat, or the engine running too lean can cause pinging.
Pro
Joined: Jun 2002
Posts: 687
Likes: 0
From: Wichita Falls Tx
Re: Dyno this morning, advice needed. (Miles in Michigan)
I dont know if it is spark retard though.I had my car dyno tuned and my knock retard was desensitized and the dip was still there. I had a friend dyno his 00C5 right after I did and the dip was about 200 rpm lower than mine but still there. My car is modified though and the guy couldnt answer what it was. I am still confused though :crazy:
Thread Starter
Le Mans Master
Joined: Nov 2001
Posts: 6,905
Likes: 205
From: Kern County CA
Re: Dyno this morning, advice needed. (Rapid Transit)
Here's the link to the graph, let's see if it works: http://www.ofoto.com/PhotoView.jsp?U...id=26208042105
Thanks for any input!
RT
Thanks for any input!
RT
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Melting Slicks
Joined: May 2000
Posts: 2,161
Likes: 17
Re: Dyno this morning, advice needed. (Rapid Transit)
Due to the low octane of CA gas, you are getting spark retard when the engine gets too warm. You need two things: a hypertach 160 thrmostat and a fan controller (or hypertech) to change fan settings. This should take away the problems........
Le Mans Master
Joined: Nov 1999
Posts: 7,695
Likes: 51
From: Imperial Beach CA
Re: Dyno this morning, advice needed. (Rapid Transit)
Mine look the same. Had that on the 00 and my just bought 02. May have something to do with just clearing out the sysem on the first runs. I did note that cars that had been run hard or real fresh motors it wasn't as apparent.
Thread Starter
Le Mans Master
Joined: Nov 2001
Posts: 6,905
Likes: 205
From: Kern County CA
Re: Dyno this morning, advice needed. (jimman)
OliverM5:
Your recommendation of a 160 thermostat will open up an entirely new discussion (I've read all of them and it only confuses me more). Why do you want a 160? vs 172, or some other numbers I see?
jimman:
So you're saying my car hasn't been run hard enough? That's easy to take care of! :D
Thanks guys,
Your recommendation of a 160 thermostat will open up an entirely new discussion (I've read all of them and it only confuses me more). Why do you want a 160? vs 172, or some other numbers I see?
jimman:
So you're saying my car hasn't been run hard enough? That's easy to take care of! :D
Thanks guys,
Drifting
Joined: Feb 2000
Posts: 1,922
Likes: 0
From: Boulder, Colorado
Re: (Rapid Transit)
Sorry it took me so long, I forgot that my corvetteforum info has my work email address instead of my home address. I didn't see your email until today.
It does look like spark retard. Redynoing with a bottle or two of octane booster (or race gas) would tell you for sure, if the retard goes away after that. I don't really know what to suggest to fix it.
It does look like spark retard. Redynoing with a bottle or two of octane booster (or race gas) would tell you for sure, if the retard goes away after that. I don't really know what to suggest to fix it.