Yessir - two dyno charts to compare will make a world of difference and offer some new insights. Date is now scheduled as 8/1, pending any issues. I don't forsee anything so fingers crossed.Originally Posted by JeepLab
Yessir - two dyno charts to compare will make a world of difference and offer some new insights. Date is now scheduled as 8/1, pending any issues. I don't forsee anything so fingers crossed.
I still don't trust Prodigy's stock dyno run. Torque is too high, and peak power is too low and reached at too low of an RPM. The Pentastar has a nearly flat torque curve from 1800 rpm to redline, and all other stock dyno results agree that peak power happens at redline (6400 RPM), and that the peak power number is higher than the peak torque number.
Look at JeepLab's stock dyno results for comparison:
JeepLab shows torque at 175 ft-lbs vs Prodigy at 203 ft-lbs. JeeLab shows power at 189 hp @ 6400 rpm vs Prodigy at 170 hp @ ~5000 rpm.
Also, according to their dyno charts, stage 2 turbo (and therefore also stage 1) has a LOSS of torque/power below 2800 RPM. My but dyno does not agree with this. It feels similar to stock around 2000 rpm to me, with noticeable gains before 2500 RPM.
I wonder what causes that sudden drop in torque at 6200 rpm on the stage 2 dyno...
Can't wait to see JeepLab's stage 2 dyno results compared to JeepLab's stock dyno results for a second opinion.
I haven't studied the dyno graph too well but I have always been of the mindset that as long as you test the before and after on the same dyno and similar conditions that is what really matters and should give you the actual gains. I understand what you are saying but every jeep is different, how corrections are applied to the dyno and such. Regarding the sudden drop at 6200rpm, I thought I heard it mentioned that the speed limiter was hit?
I am very excited to read the full review, with driving impression video!
Variations between jeeps (or dyno calibrations, or local atmospheric conditions) will not cause a major difference in the shape of the torque/power curves. With a stock jeep, peak power should always come at/near redline, and should have a higher value than the peak torque value.
The sudden drop at 6200 I'm referring to is on the stage 2 dyno. The speed limiter is not an issue with the turbo tune installed (stock speed limit is lifted by the tune).
I have confirmed that the dyno operator lifted the throttle as soon as the power curve reached its peak and started falling. They were focusing on getting peak numbers. So the sudden dropoff at 6200 rpm is NOT representative of the power output of stage 2.
No explanation for the loss in tq/power below 2700 rpms yet. Just that it is not expected and that it has not yet been investigated because the focus at the time was on getting peak numbers.
While we're waiting for the "early August" dyno results, can we get some general thoughts on power delivery compared to RIPP and Magnuson? Still waiting to hear that blow-off valve too
I'm interested in what happens with the coolant overflow reservoir. Do you have any pics or thoughts to share on that? Is the new location reasonably accessible for checking the coolant level?
The coolant tank is black (knew you'd like that) and it mounts near the front bumper where you can check it easily. My mount was a bit more of a challenge because I have a stubby front bumper and a front skid plate. We mounted it at a slight angle and it is behind my skid for protection. Checking it is not as easy as a stock bumpered JK but it really isn't too bad to remove two bolts, drop it, and inspect.
Skid is off in this picture so it looks more exposed than it is.
FIRST DYNO CHART
This was the best run today. Here are some notes you need to be aware of.
- The stock line in this chart is not Jesse's Girl, Its Sweet Pea's stock dyno line. Sweet Pea and Black Betty were dyno'd years apart (stock) and came out in the exact same spot, so I consider the line a standard.
- Humid summer day
- 4.88 gearing. - This shouldnt alter the line as far as power to the ground vs RPM but JG is geared.
- Stock Tires. All our dyno's to date are on stock 255/75R17 BFG Km1s.
photo bump!
Trying to get a bigger image....
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