Dyno'd the 77 today!

[blazinchuck]

after some aggravation with the steering column, decided to ride out to my buddy's shop. they wanted to put the bronco on the chassis dyno...so i said ok




she put down 210hp/245tq...i was hoping for more, but thats still not bad,


anyway to figure out what my loss is going thru a nv3550,d20,9"(4.56) and 33" tires? so i can kinda put a number on the motor.


they printed out my run, but my scanner is down.


fuel pressure held 42, and the wideband showed my running a touch rich...i think 12.8

[SC74]

Hell yea Chuck. What do you think motor only is?

[chuzie]

Chuckles and I went back and forth on that last night. Typically looking at 15% loss from crank back for street cars with manual. Fellas on classic range from 20 to 28%. I would venture to say 24% is a fairly decent estimate for chuck since he does not have crazy tires or anything. So with 210 @ wheels we might estimate 260 HP @ crank. I know he was hoping for more though with the bore, came, etc. Could be simple mods though.

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[SC74]

What do you think a stock 5.0 would be - at crank and at rear wheel?

[broncosbybart]

My guess on the stock 5.0 is about 200??

That is really cool chuck!!

[chuzie]

Actually the stock 5.0HO (MAF + 60mm TB 1989-1992) was 225HP (FWHP) @ 4,000 RPM which was beaten by the Cobra variant in '93 with 235HP (according to the government) but it was really more like 265HP.

[blazinchuck]

im not digging the power curve tho...it should 1500-2000 lower for rock crawling...oh well guess i got a mud rig now lol

[chuzie]

I wish there was an app so we could dual post between forums with one click.

[blazinchuck]

as soon as i can finish the steering column, cruise control, ac/heater...my boy shawn got me a chip/flip switch/data cable...so i need to get up to his shop so they can write a custom tune for the 77. might net a few more ponies!!

[blazinchuck]

Thought id bring this back up. Dynoed the 77 again last night. I fixed a leaking brake booster and got the 65mm throttle body/70maf now. My buddy got me a chip/switch/data cable. So base run was 213/246. Found fuel too learn now- so he tweaked it up a couple times, then on 3rd run added 2° of timing.I'll post pic of the computer screen. The last row of numbers were a comparison to my buddies stang. Guy told me I can easily run 87 now or anything. I was worried bout that and have been running mid grade since installing the 306. He also added another tune for a9l...since I'm using a a9p now. So if eec crashes I can use either and still have the tune. Ended up with 242/275 at the tires! Not bad at all. And just for kicks... I brought a pair of my f150 tires/wheels(235/75/15) another run show only 6hp/11tq increase.

Now what's interesting my buddy's stang has gt40heads/intake/tf stage 1 cam(same as me) and shorty headers.

I have same intake/tf alum heads, same cam, more compression w/dome pistons. His before and after 240/289...260/306 with a 5sp.

So I'm sure my motor is making more power...but I'm losing a good bit thru 9",d20,nv3550... so hope this sheds some light on things.

Getting a tune if very good!!! I could have hurt my motor running as lean as I was I think.


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