My Dyno results

[MSPi]

That is pretty good numbers for the mods you have. What kind of dyno is it?

I dynoed my 96 auto with header,exh, and intake with 4.10's and 33's and it made 128whp in 4wd on a 220k motor. This seemed about right for the mileage and drivetrain losses.

As for the 1 to 1 for dynos that doesn't really matter. I owned a shop with a AWD dynojet dyno and had over 30,000 runs on it in 7 years. On inertia based dynos it is just a simple calculation of accelarating a fixed mass over a speed range over time. So if you use 2nd gear you will accelarate faster (lower time) but you will only go from like 20 to 60mph (lower speed range). So if you use 3rd (closer to 1 to 1 on auto) it will take longer (longer time) but you will go from like 30 to 100mph (bigger speed range). You should get very similar numbers. Hope this made some sense. Most dyno user will do the higher gear so you get a longer smoother pull from the engine.

 

[Super mud]

With a 30% loss from the auto wouldn't that mean about 230 at the crank? 230x0.7=160. Thats great horsepower. Actually more than I think would even be possible out of that setup?

 

[Talyn]

No, he doesn't have 230 HP. An exhaust + throttle body will not gain 35 hp over stock. He would be lucky to have 10 over stock.

 

[Porch951]

Typically accepted figures are auto = 20% loss, manual = 15% loss.

 

[FunkRider]

He might put down 120hp on one dyno and 170hp on another. You can NOT compare dyno numbers from one to another. From the sounds of it that machine has the settings goofed with. Especially being at a school, someone likely wanted to walk around with a dyno sheet boner. For me a dyno is only useful for tuning so you can tell IF you have gained or lost power.

 

[IXNAYXJ]

That's a lot of HP, but I suspect that's the dyno reading high rather than the motor being a monster. Do you know the type of dyno it was on? Here's our last run for reference:

Dyno Video

The Jeep has a conical filter, bored Renix TB, ported H.O. head, mild cam, 19 lbs Ford injectors, aftermarket header, no cat (it's a race car, that's allowed), more or less straight pipe through a CherryBomb, 2WD AW4 and 26" tall tires. Mustang Dyno.

 

[Super mud]

He might put down 120hp on one dyno and 170hp on another. You can NOT compare dyno numbers from one to another. From the sounds of it that machine has the settings goofed with. Especially being at a school, someone likely wanted to walk around with a dyno sheet boner. For me a dyno is only useful for tuning so you can tell IF you have gained or lost power.

Thank you for enlightening me.

 

[whitexj98]

The dyno was set for a 1998 jeep cherokee @4200 pounds and it is a Mustang dyno.

 

[jeeptec]

those numbers are right on the ball park for rear wheel torque and horse power. add 23% for drive train loss and your hp is 195 and your torque is 223.

 

[CTeunuch]

That's a lot of HP, but I suspect that's the dyno reading high rather than the motor being a monster. Do you know the type of dyno it was on? Here's our last run for reference:

Dyno Video

The Jeep has a conical filter, bored Renix TB, ported H.O. head, mild cam, 19 lbs Ford injectors, aftermarket header, no cat (it's a race car, that's allowed), more or less straight pipe through a CherryBomb, 2WD AW4 and 26" tall tires. Mustang Dyno.

Aren't the 19lbs slightly less than factory 4.0 injectors? Any problems with it going lean? I though the OEM Jeep's were somewhere around 21lbs....

 

[IXNAYXJ]

Aren't the 19lbs slightly less than factory 4.0 injectors? Any problems with it going lean? I though the OEM Jeep's were somewhere around 21lbs....

I believe it varies by year. I think the Jeep injectors are also 19#, but have a lower flow rating.

http://www.lunghd.com/Tech_Articles/Fuel_System/Fuel_Injector_Upgrades.htm

At peak hp (134hp 160lb/ft) we were 14.3 A/F. It actually smelled a little fat at the top end. It looks like mainly we were limited by our TB , but we have a 63mm one on the way to fix that. I forgot to mention we've also done a 99+ intake.

-Matt

 

[comanche91]

Here are my readings on the HESCO dyno from 2008. Still going strong. Specs:
4.6 Hesco stroker
Unichip
99+ intake manifold
31" tires
Readings taken w. AW4 in 3rd gear

Got the 2001 WJ intake manifold mounted and the Unichip wired in on my 4.6L Hesco stroker and had the Unichip programmed and was dynoed at Hesco today. The dyno peak HP vs. torque BEFORE readings last year were 207.5 HP @ 3950 RPM, torque was 243.0 at this RPM. Peak torque was 280 @ 3600 RPM. The AFTER reading, manifold only, was 219.5 HP @ 3916 RPM, torque at 294.9. The AFTER reading w. manifold and Unichip, was 261.1 HP @ 4400 RPM, with torque at 312.8. Peak torque was 345 @ 3500 RPM. All readings are at the rear rear wheel of course.

That's a HP increase of 53.6 (although at a higher RPM, 3950 vs. 4400) and a torque increase of 65 ft. lbs. at about the same 3500 RPM, even w. the 20%-25% power robbing AW-4. Just the updated intake w/o the chip gave impressive gains. Very worthwhile mods. Actually improved mileage a bit too, about 1-2 MPG.