Need a builders help

[2broke2gofast]

About 8months ago I accidentally shifted from 3rd to 2nd at high rpms and warpped some exhaust valves on my afr 165's. After tearing into the car, and letting it sit for a few months I decided to do a complete rebuild. I let a reputable builder in the are port and polish the heads, replaced valves, guides, and all that. He also took the block .030 over and installed a set of flat top d.s.s flat top pistons. Decided to take .030 off the heads for compression and put it back together.

Before the build up I was running a stock cam with the out of the box afr's and the trick flow street intake. with a tune made 262rwhp and 286tq on a mustang dyno. Now, after the build and about 700 miles of break in, I returned to the same dyno, on a cooler day, with the ported and polished heads, same trick flow street intake, new lunati 51014 cam...This round I made 256rwhp (6hp less than berfore) and 301tq.

The tuner says the intake is a likely culprit, but I don't see gaining 30+ rwhp with an intake.

Suggestions, thoughts, comments?

 

[GDTrumbo]

It might take a few hundred more miles to get it broke in good. It'll loosen up over time. Besides, even at this point, it appears you lost 6hp but look at the torque you've gained. Can't complain too much. Go back to the dyno at 5K and see what you get.

GT

 

[Paul]

If I were to hazard a guess, the guy who ported the heads isn't as good as the CNC program that did it in the first place, and you actually lost performance.

 

[2broke2gofast]

If I were to hazard a guess, the guy who ported the heads isn't as good as the CNC program that did it in the first place, and you actually lost performance.

the heads did flow better after the port job. Also, if that were the case would I have seen the increase in torque?
The tuner said I had that intake maxed out before the build and that the overlap with that cam is where I'm actually seeing the loss. He has a great dislike for the trick flow street upper. Is it worth changing out just the upper for the track heat version?

I can tell you that hp and torque start to fall off at about 5,200rpm's. The street upper operating range is idle to 5500. Should I change to a complete new intake or just swap out uppers?

 

[LAFENATU]

It could be a thousand things dude..

How much timing and what was the air/fuel ratio?

Something doesn't add up. Your torque seems good but the HP is a little low.

Flat tops should raise your compression also...what was the final compression with the heads?

Could be your bottom end was built to tight..

Keep in mind with the heads, flow is good but velocity is what you want.

 

[2broke2gofast]

a/f was 13.0:1
on 6 dyno pulls timing was changed between 10 to 17*
cam was set at 107
compression is ~9.75:1

again, would torque increase if the port job was the problem? Also, the intake and intake ports on the head were aligned correctly.

 

[LAFENATU]

Did they straighten the intake ports on the AFR's?

 

[2broke2gofast]

not sure. could be the issue. cars for sale now anyway, I'm done with it....it's just not what I want or need anymore.

 

[2broke2gofast]

I know that street burner intake is rated to 5500 rpm, but would power just stop there?

 

[LAFENATU]

what do you mean by the cam was set to 107?

It was advanced?

BTW, just for info...

My car has stock compression, 165's, GT40 intake, Crane 2031 cam and I made 285/296....through an automatic.

 

[2broke2gofast]

what do you mean by the cam was set to 107?

It was advanced?

BTW, just for info...

My car has stock compression, 165's, GT40 intake, Crane 2031 cam and I made 285/296....through an automatic.

Mustang dyno or dyno jet?

 

[ProKiller]

is the engine throwing any codes? i can't believe its running 100% and lost power....

what injectors and maf? has it been tuned?

 

[2broke2gofast]

No codes, yes it was dyno tuned. I actually gained 16hp with the tune.

 

[LAFENATU]

My car was tuned on a dynojet with diablosport chipmaster revolution software but, it is a newer dynojet that has a load bearing option.

 

[2broke2gofast]

My car was tuned on a dynojet with diablosport chipmaster revolution software but, it is a newer dynojet that has a load bearing option.

The tuner said I would be looking at around 280-290 on a dyno jet, but that doesn't make me any happier as I was hoping to see 290 on his dyno. I'm really fed up with the car, this whole process has been nothing but trouble. I've got the car sitting for sale outside the store now.

 

[LAFENATU]

Keep in mind dude...numbers arnt everything.

 

[Paul]

Keep in mind dude...numbers arnt everything.

+1

Do you have the before/after head flow numbers? Also, flow isn't everything since increased port volume will virtually always result in more flow, but does not necessarily reflect increased velocity or any other number of fluid dynamic properties that I'm too dumb to explain.

Paul.

 

[2broke2gofast]

Keep in mind dude...numbers arnt everything.

I agree, but LESS horsepower pisses me off to the point of frustration
Power isn't everything, but if wasn't worth something we'd all be in civics and neons (non-turbo of course, b/c they make more power than most of us)

 

[GDTrumbo]

Keep in mind dude...numbers arnt everything.

+1

Do you have the before/after head flow numbers? Also, flow isn't everything since increased port volume will virtually always result in more flow, but does not necessarily reflect increased velocity or any other number of fluid dynamic properties that I'm too dumb to explain.

Paul.

Your good Paul! Velocity plays a large role in this equation. It's almost like putting a carb. (or throttle body) on an engine thats too big.
Vacuum readings go down and idle quality suffers. Most times power output suffers also.

GT