I ported my upper stock intake last week to match the 70 mm throttle body that I already had on the car expecting some decent improvement. But to my surprise, I think (seat of pants feeling) that I may have lost a bit of torque. The only improvement I noticed was a slight increase up top in rpms, but until I get to the track, I dont know if I gained enough horsepower to over weigh the loss in torque. Am I right about this thought, or should I have gained power and torque? Any input would be appreciated.
Ported Intake question
- Thread starter rdksek844
- Start date
Michael Yount
Mustang Master
The biggest flow bottleneck on the stock engine is the lower intake manifold. You can add bigger components upstream of that (maf, throttle body, opening the upper to 70mm, etc.) til the cows come home and it won't make much difference because the potential increase in flow can't make it past the lower intake. Send your lower off to tmoss (search the site) -- he'll port it for a reasonable price for a difference you can really feel.
Michael Yount
Mustang Master
rdk - unless you have back to back dyno numbers before and after the change (under similar ambient conditions), you don't really know what you've got. Seat of the pants is a terrible indicator of actual performance. And, if it is actually weaker, it could be due to any number of other things related to the work (vacuum leaks, timing change, fuel system malfunction, etc.). Do you have the bigger egr spacer as well?
Intake manifold runner length changes can directly affect torque in different rpm ranges (in general the longer the runner the better the bottom end torque at the cost of higher rpm power). But that runner length starts at the intake plenum - which is well downstream of where you made your change. The change you made can remove a flow obstruction which might help higher rpm power levels if that were the flow bottleneck in the system. IN your case, it's not - so the change should have made little difference at all. I wouldn't lose too much sleep over it - get your intake changed/ported, and then see what you've got. IN any event - what can you do about it? Not like you're gonna put another stock one on to check and see, right?
Intake manifold runner length changes can directly affect torque in different rpm ranges (in general the longer the runner the better the bottom end torque at the cost of higher rpm power). But that runner length starts at the intake plenum - which is well downstream of where you made your change. The change you made can remove a flow obstruction which might help higher rpm power levels if that were the flow bottleneck in the system. IN your case, it's not - so the change should have made little difference at all. I wouldn't lose too much sleep over it - get your intake changed/ported, and then see what you've got. IN any event - what can you do about it? Not like you're gonna put another stock one on to check and see, right?
Yeah, I'm thinking it was a mistake, but I have a spare and it is a stock intake which are a dime a dozen so the only thing I lost was a little time. But it was my first port job and I did learn alot. So all in all I'll look at it as a learning experience. I should have asked you first about it.
Bead blsting the crap off after running it through parts washer. Parts washer solvent takes the oil based crud off and the bead blast takes the exhaust deposits off the solvent won't touch.
PM me with your email address and I'll send info..........The upper won't "hurt" much after flow potential of the lower is increased. Most see 10-15HP and 15-20 ft-lbs. Some guys make the mistake of not resetting the computer memory by disconnecting the battery for at least 20 minutes and it take longer for the EEC to correct the fuel curve (now needs more fuel due to higher flows) for all driving conditions. It may take a week or two for the EEC to fully correct and for you to realize the full potential - that has been reported to me many times.
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