Dyno tuned kenne bell 331 stroker.

[bell55]

So I had my 331 tuned and the results where heart breaking. 205hp@4380 & 327tq@2097. Can this be right? 331 stroker,AFR 185 heads, comp 35-351 cam,JBA headers, MSD Dist & ingnition,kenne bell 2.1 running 6lbs of boost. Timing was set at 10 and ran about 17 during the run. I would think the numbers would be a little higher. Should I go to a different Dyno shop? Does anyone have HP numbers on there 302.

 

[ponyracer]

That engine should close to double that n/a. The stock 5.0 efi was around 200.

Was that on a chassis dyno or an engine dyno? Tranny, tires?

 

[bell55]

On a mustang chassis Dyno. 35" tires,c-4,Detroit locker in the 9"

 

[Thunder26]

If that was done in your bronco with big tires that sounds really good actually.

 

[av8rds]

yeah do a search for dyno results here and I have my engine vs chassis info posted, it was a BIG difference.

 

[Viperwolf1]

Timing was set at 10 and ran about 17 during the run.

Are you saying the ignition didn't advance with rpm? That will cause lots of power loss.

 

[bell55]

It starts to then the computer starts pulling it out due to the air charge temp.

 

[Viperwolf1]

The air temp will be higher because of the SC so the ACT must be in the intake? The ECM is thinking the hot air will cause detonation so it backs off the timing to the point where the SC isn't really helping.

I'd say the tune needs to be changed or the ACT needs to be moved outside the TB or both.

 

[StnePny]

If you want to see real numbers put on an Engine Dyno (not a Chassis Dyno)

 

[csjr]

I had my rig dyno tuned many moons ago. It was sporting a mostly stock 1974 vinatage (probably had been rebuilt, but no proof) 351W, NP435, 35 inch radials and 4.10 gears. The tuning improved the driveability and throttle response as my timing was screwed up among other things. The final numbers were not earth shattering--something like 160hp and 290 ft. lbs. With a lifted bronco I think you can subtract 25% for driveline drag, but I would have to agree that your motor should be in the 400hp range. Minus 25% should still be around 300hp at the wheels. I would think the tuning shop would be able to tell you that though and invistigate your setup to make recommendations.

 

[Mr Rags]

I had mine ran on a chassis dyno about 3 to 4 years ago. The owner said the bronco will have about a 30% parasitic loss. Still, mine was just an old 302 with a big cam, chevy valves and porting in the stock heads, Duff's long tube headers, a Holley T/A 670, 33" tires w/ 4.11. it was about 190 bhp. I don't remember the TQ numbers.

I had a 100hp shot of NOS on it at the time, and with it, it ran about 270 bhp.

I too think you should be much higher.

 

[Nightstick]

Here's that other thread with some dyno numbers.

 

[trailpsycho]

OK, so those are the numbers, but how does it feel to drive. I bet its a blast. As long as you are having fun driving it, who cares what the HP/TQ #s are...you will likely still smoke mot of the ricers out there anyway. Its not a competition, is it? If the seat of the pants feel is good, roll with it...or find someone who knows how to dyno a SC-ed 5.0.

 

[bell55]

That's the issue, it doesn't feel that much different prior from the supercharger install.I would think adding 6-7 lbs of boost would of made a drastic change.

 

[Thunder26]

Where in the rpm range does it not feel different? I think it might be that your pulling out timing up top.

 

[Broncobowsher]

I remember driving some other low boost blower engines. They did run better but it wasn't a completely different animal type of different.

You are stating the ACTs are going up. How much ACT rise are you getting? With such mild boost I wouldn't expect that much. Depending on the temp rise that 6 Lbs of boost would be more like the power gain from only 3 or 4. And you still have the parasitic loss of the drive. Is the blower too small for an engine that big? (thinking it was only for a stock 302)

I have also heard of issues with a Kenne Bell and cams with too much overlap just blowing air/fuel out the exhaust. Lots of glowing headers.

 

[73stallion]

On a mustang chassis Dyno. 35" tires,c-4,Detroit locker in the 9"

what gears?

 

[mavereq]

i'm basing everything i say here off the 03 cobra setup since that's where my experience with twin screw superchargers is from. if it doesn't apply then just ignore me.

you should be running 2 iat sensors, one before the throttle body and one after the supercharger. if you datalog you should be able to see the difference and where it starts spiking. the system is designed to pull timing when your iat's get too hot or you'll get detonation. with only 6 pounds of boost you shouldn't be seeing crazy iat's unless something is wrong. a 2.1 kb is a little on the small side but you shouldn't be overspinning it at that low of an rpm. then again, you shouldn't be getting your peak hp at that low of an rpm either.

is your water pump for the intercooler working properly? at what temp is your tuner having it pull timing? if you have a properly working intercooler then your temps shouldn't be spiking high enough to pull timing that low.

 

[Bituman]

I had similar experience recently. Without getting into all the engine details, mine is very similar to OP, although I'm carbed and have no S/C. Running 33" tires, C4, 4.11 gears. Had it tuned at Lopers, a local speed shop here in Phoenix with dyno, and ended up with just over 200 RWHP. Was a little disappointed, thought I'd at least be 250 or so. While reflecting on the unexpected low HP numbers I had to admit that the tuning helped my truck run much better so I decided not to worry so much about the HP. Like TrailPsycho says, good seat of the pants feel.

Bob

 

[KennyB]

You can lose 30% and More with Tranny, Transfer, gearing....

Engine Dyno, my Brand New GT-40 Crate Motor with Iron heads Stock Cam, Windage Tray, Performer Manifold, & Carb, HEI Ignition put out 302hp and 322 Torque. (For Sale)

My NEW Motor, Aluminum heads, and a Weiand 174 Blower at 9lbs is guessed at 525hp.... and prolly 300 at the Wheels