Pretty weak dyno results (Diagnose please)

[Icepick]

All mods are in my sig, please help with ideas.

Max power 255 rwhp @ 5300rpm
Max torque 280 with a pretty flat curve, went from 230 @ 2200rpms to 280 @ 4300rpms, at 5300rpm where torque and hp curves meet it was at 255 along with the HP.

a/f was a very steady 13:1


The only excuses i can make right now are that i was at stock timing with 87 octane and it was VERY humid today. If i bump the timing to 16 and run premium it was mentioned by a couple of people that with my Edelbrock heads i may see upwards of 15rwhp gain.

Any ideas anyone?

 

[Scorpion91GT]

IMO, that's not bad for a N/A car, keep in mind you can lose anywhere from 20 to 30 percent hp from engine to wheels...according to my calculations, with you losing 25 percent hp to the wheels, you're running about 318.75 hp at the engine. That's pretty good, and yes, if you bump your timing a bit and use better gas, I'm sure you'll gain a couple of more hp.

 

[drgn5.0]

stock cam? stock injectors? these make a difference. get a cam and some injectors you will notice a difference, turn the timing up too.

 

[D347643]

no reason for premium unless you need it.

 

[tmoss]

The HP numbers probably have more to do with the cam, and torque is down probably due to the larger intake manifold and head runner sizes. I made a little more HP but significantly more torque with my combo. You'd make more power and torque with the right cam.

 

[5.0guy]

mustang dyno or dynojet?

 

[Jo_885o]

stock cam? stock injectors? these make a difference. get a cam and some injectors you will notice a difference, turn the timing up too.

 

[25thmustang]

I have to agree in here, if you didnt tune it, have stock injectors, and a stock cam it is going to hurt. I made 272/316 on my combo with stock heads (GT-40 valves) stock cam, and a Cobra intake. The heads are hurting your tq, as well as the intake, and Im sure the cam is hurting the power up top! Id say tune it, I went from 255 or so rwhp to 272 in 3 dyno pulls by playing with FP and timing!

 

[Icepick]

To answer questions:

Dynojet
Stock fuel system
Stock ignition
Stock cam (1.72 rockers)

I'm wondering if i can run a decent cam with my rockers or if i need to switch to 1.6's to run a nice cam.

 

[kn7671]

To answer questions:

Dynojet
Stock fuel system
Stock ignition
Stock cam (1.72 rockers)

I'm wondering if i can run a decent cam with my rockers or if i need to switch to 1.6's to run a nice cam.

You can stick an E303 cam in the engine without clearance issues with the 1.72 rockers. With those rockers your effective lift will increase to .535", from .471" on the stock cam. Besides the lift, the most important is the duration increase on the E303 over stock. Combined with 24lb injectors, and at least a 155lph pump, your power should be close to 300hp at the wheels.

On my older Mustang I was running a Cobra intake, Edelbrock Heads, E303 cam, 1.7 rockers, with 24lb injectors, and all the other normal stuff, I put out 317hp with 342lbft tq to the rear wheels with the drive accessory belt off, and 304hp, 335lbft tq with the drive belt on.

On street tires with 3.55 gears on a T5 trans, I would run 13.30's at 106mph all night long.

Curious, with all the work to install heads and intake, why did you not change the injectors and camshaft at the same time?

 

[Icepick]

Curious, with all the work to install heads and intake, why did you not change the injectors and camshaft at the same time?

Cool, thanks for the info.

About your question, i've heard the stock ignition and fuel system can usually get to 300 rwhp before you really have to upgrade it. As for the Cam, that's another story, the shop that did the heads, intake install was supposed to do the cam also, i was told by them it would fit, but during the install they said it had clearance issues so they put the stock on back in without calling and asking me, or i would have told them to put 1.6's in and use the cam but i wasn't called (i really wanted the cam) and that's what i'm stuck with for now.