I was watching Carter’s car on the Dyno. At about 4500 RMP’s his AFR went lean for a little bit and then came back to normal. The tester said that he had observed that same problem on a few other E30’s that weekend. I am wondering if a certain ECU model is causing that problem? For the guys that did have the dip what ECU do you have? Any other thoughts on what would cause that dip in a few of our cars?
Dyno Runs At VIR
screwynewy
#2
I don’t know what ECU I have but the dyno operator said that my AFR curve was the cleanest of any of the E30’s that he had run. That would be the only bright spot in my dyno results as my numbers were the lowest of all those tested at 147 bhp and 145 torque. There were a couple cars in the 160+ hp range :ohmy:
mskeen
#3
Interesting, it would be nice to compare all the sheets. From what I remember, Ken, your car pulls pretty well. It must have good area under the curve even if not the highest numbers.
screwynewy
#4
Most everyone I have dragged down the straights can pull on me, some cars more than others. I have to have a pretty good run on them to get the pass.
Carter did get the dyno results for all of the SE30 cars that were tested. I am pretty sure he will make them public at some point.
leggwork
#8
if Carter hasn’t done anything with his AFM yet, it is likely a worn area on the AFM sweep arm.
bruce
trentmw wrote:
Carter
#9
I’ll scan and add dyno sheets from the following cars.
Carter
Carlton - if I can get a copy
Brandon
John A.
If I can’t figure out how to post them, I’m sure my good friend and neighbor Ken will help.
Carter
Elephant4
#11
I’ll post mine from Mid Ohio when i get a chance, it made 150hp/150tq (140000) mile engine.
MikeD
#12
Elephant4 wrote:
FWIW this dyno read about 10hp higher than our dyno hear in norfolk. It’s in their best interest to have their million dollar dyno spit out good #'s though.
screwynewy
#13
MikeD wrote:
[quote]Elephant4 wrote:
FWIW this dyno read about 10hp higher than our dyno hear in norfolk. It’s in their best interest to have their million dollar dyno spit out good #'s though.[/quote]
Mike, while I agree with your assertion that the mobile dyno would want to have positive results for customers I had my car dyno’d in the spring on a dynojet at a local shop and got almost identical numbers. So I can’t really say whether or not the trackside dyno was higher or not, at least in my case.
Carter
#14
Keith Smith’s car [file name=72807KeithSmithVIR.pdf size=141994]http://spece30.com/media/kunena/attachments/legacy/files/72807KeithSmithVIR.pdf[/file]
Carter
#15
Carter Hunt car [file name=72907HuntVIR.pdf size=148273]http://spece30.com/media/kunena/attachments/legacy/files/72907HuntVIR.pdf[/file]
Carter
#16
Jon Allen car
[file name=72807JonAllenVIR.pdf size=140027]http://spece30.com/media/kunena/attachments/legacy/files/72807JonAllenVIR.pdf[/file]
Carter
#17
David Herrington car
[file name=72807HerringtonVIR.pdf size=138113]http://spece30.com/media/kunena/attachments/legacy/files/72807HerringtonVIR.pdf[/file]
Carter
#18
When comparing my dyno sheet (second lowest numbers of the cars tested that day) to Jon’s dyno sheet (highest numbers) it’s clear that his engine is strong. His air/fuel ratio is also much better and the hp and torque lines are very smooth.
My hp and torque lines are very jagged, my air/fuel is lean up to 5000 rpm and then goes more rich, then lean at 5500, then rich at 6000 rpm.
At 3650 rpm, Jon has 100 hp
At 3650 rpm, I have 88 hp
At 4000 rpm, Jon has 118 hp
At 4000 rpm, I have 105 hp
At 4500 rpm, Jon has 135 hp
At 4500 rpm, I have 117 hp
At 5000 rpm, Jon has 145 hp
At 5000 rpm, I have 115 hp
At 5500 rpm, Jon has 161 hp
At 5500 rpm, I have 150 hp
At 6000 rpm, Jon has 162 hp
At 6000 rpm, I have 153 hp
From what we have seen on other dynos, I do think this one was reading about 4 hp high.
I’m thinking that the problems with my engine (other than having 257k miles on the clock, are as follows.
Vacuum leak somewhere in the intake - I know that one of the metal pressed-in fittings is a little loose and other gaskets are surely old and leaking
The airflow meter should be replaced.
The ignition might be causing the jagged lines, although the cap and rotor are two racing seasons old, the plug wires are three years old, and the plugs are new.
Also, Steven Canterbury’s and Keith Smith’s lines are smooth like Jon’s and their air/fuel ratios are good. David Herrington’s lines are jagged like mine, and his air/fuel ratio looks like mine as well. Lean up to about 5000 and then rich.
Any advice from the group?
Carter
mskeen
#19
You might have a problem with your TPS. If the computer doesn’t know you’re at WOT, it will try to keep the AFRs at stoich, which is right where you are.