When good is not enough, Camshaft time again.
- Thread starter Kent mosby
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PRH
Well-Known Member
That would be the preferred sequence of events.
Can you post a pic of a datalog from the track, right before and after the launch, that shows the rpm?
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I will later tonight.
need any other parameters as well?
Here is some good talk on Solid Roller Cams
Description, Pros and Cons
For those that would like to know.
* * * * *
Description, Pros and Cons
For those that would like to know.
* * * * *
PRH
Well-Known Member
Is there a a TPS position indication on the datalog too?
I’m looking to see what the rpm trace looks like right before, and after you step on the gas.
I’m looking to see what the rpm trace looks like right before, and after you step on the gas.
I mean, rpm and mph for the whole run would be good. Need gearing and tire diameter as well. Just to calculate slip percentage.
90% is max throttle and the blades are wide open. Last race 11.7 or so. I don't have the time slip. This is shifted manually with transgo 2 shift kit. Sorry, this one was with the bad o2 sensor. AFR was spiking. I will get another
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PRH
Well-Known Member
I’m not looking at datalog screen shots very often…….but, to me……on those two it looks like the converter is flashing 4000 on the first one, and 4000-4200 on the second one.
Based on the fall back numbers after the shift, it doesn’t appear the engine is “driving thru” the converter during the gear changes.
That being said, sometimes what’s fast down the racetrack doesn’t look great on a graph.
There could easily be .1-.2 ET in a different converter, but imo, the current one doesn’t present any obvious problems.
The 60’ times are kinda weak for the “sum of the parts”, which often points towards something left on the table, converter wise.
I’d still try changing the cam and testing, before changing the converter.
The other thing is, I’ve seen situations where a looser converter shows less power on the chassis dyno, yet runs a quicker ET in the car.
Based on the fall back numbers after the shift, it doesn’t appear the engine is “driving thru” the converter during the gear changes.
That being said, sometimes what’s fast down the racetrack doesn’t look great on a graph.
There could easily be .1-.2 ET in a different converter, but imo, the current one doesn’t present any obvious problems.
The 60’ times are kinda weak for the “sum of the parts”, which often points towards something left on the table, converter wise.
I’d still try changing the cam and testing, before changing the converter.
The other thing is, I’ve seen situations where a looser converter shows less power on the chassis dyno, yet runs a quicker ET in the car.
I do not have mph. Typically at the end of the race it is 116-117mph. 88.6 in circumference. 3.911 rearend.
TT5.9mag
Two atmospheres are better than one
You’re doing a wonderful, methodical job of focusing on a plan and moving through the steps it takes to get through it. Some people want to breeze through the thread and not read everything and suggest nonsense after you’ve made a decision and then tell you you’re wrong. You don’t need a solid roller, you don’t need a carburetor (maybe for testing, and that’s a big maybe). Just keep doing what you’re doing. This is one of a few threads where someone asks for help, the helpers ask for data, and you’ve responded to it with actual good data. Props to you. Don’t close the thread, keep pushing forward. Ignore the bullshit.
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TT5.9mag
Two atmospheres are better than one
Kent, do you have close up pictures of the spark plugs at any point in your time running the engine when the O2 sensor was good? The posted pics are not helpful as you’ve described the O2 sensor failing causing the rich condition. Any pics from dyno runs or track runs?
This is from the dyno run a couple years back, nothing since then
TT5.9mag
Two atmospheres are better than one
Can you post a screen shot of your timing graph please. Those plugs all look very short on timing.
This is the most recent. Timing used to start at 25. Those plugs were from a while back.
TT5.9mag
Two atmospheres are better than one
So 34-35 degrees at wot if I can see that clear enough on my phone. Did you run timing loops on the dyno? I’m not familiar enough with the TF 240s to know if that’s a normal range but I do know I’ve tuned some NA big block mopars with cast iron heads and they liked 37-39 degrees and sometimes in to the 40s if cylinder pressure was really low. I guess the question is how much tuning was done on the dyno?
I can’t see the graph very well on my phone evening I blow it up but 34-35 would need to be at 7k plus for those heads.
That’s a pretty fast chamber.
If he’s under 6500 I’d think 32 total would be tops unless I’m missing g something.
TT5.9mag
Two atmospheres are better than one
Look at the plugs he posted in #189. I know it’s hard to see but don’t they look short on total to you?
Is the wire is clean to the shell? It’s hard to see in the picture.
And I can’t see the graph well enough to see if he has a curve in it.
If he does it looks like the first line is his initial and his cruise timing.
I need to look at it on my iPad. Maybe I can see it more clearly on that.
I am not sure at all what the timing or fuel were at with that plug. I will be getting new plugs when all is ready to go with the new cam. Since it is so easy to change the tune during a dyno test, what changes would you like to see for that test. I will make a few tunes to prep for that.
TT5.9mag
Two atmospheres are better than one
There’s a curve, but only a few degrees. Looks like about 30 initial and 34-35 total.
TT5.9mag
Two atmospheres are better than one
Not necessarily changes but more so actual tuning. Making runs at different wot timing and seeing what the engine responds to. If your tuner or dyno operator are not doing that they are not doing you any favors.
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