chaplin

I plan on installing the APR S3 in a couple of weeks.

Yippers®

For example, the DBW ports are considerably smaller than the nDBW yet the two kits make about the same power.
Gasket matching may be worthwile tho.

xr4tic

The nonDBW ports are plenty big, the cam is the big restriction.

I wouldn't go any farther than port matching to the gasket, that's all I did to mine.

Brent V

smoothing out the inside of the intake manifold can actually have a negative effect on performance. Throttle tip-in injects more fuel to account for condensation of the fuel on the intake manifold walls...changing the surface of the inside of the intake manifold changes the amount of fuel that sticks to it and thus the overall amount that makes it into the engine.

Silvant

the inlet side of the turbo on mine is as big as it can get without tapering down to the turbo..

VAP

it's not necesarily to hog out or take gobs of material off the the intake manifold, tho they will if asked (for a modest fee). It's primarily for polishing/smoothing/radiusing the internal runners, casting webs and straight-to-bend transitions with as little material removal as possible. Less than .008" were removed from my intake I.D. while closer to .018" was removed from the gasketed ports with no optically-perceptable port-to-runner angles... perfectly smooth transition. And if a Level II Extrude hone is chosen they will gasket-match both inlet/outlet ports to a gasket that you send them at the time of work. When done the internal intake manifold looks like glass/liquid mercury. I have a brand new, never mounted 225 TT intake manifold thats been Level II EH'd if ya like I can post pics of it's internals. It is friggin GORGEOUS!!

And I've heard all the rumors associated with the desirable affecfts of sand cast intake manifolds, fuel condensation and "cling" of fuel to intake walls and atomization et al. And they're probably true on normally aspirated applications to a greaer/lesser degree. But in the 4 years I've ran EH intakes I've noticed nothing but positive improvement/gain in all situations from idling to the local road course on EVERY high-boost application I've done. No errant/abnormal readings on wide-band F/A ratios, EGT's or otherwise. I think once ya go past 20psi boost there's little hope of any intake wall fuel "cling" or less than fine-mist atomization whatsoever due to volume/velocities. In closed loop it "may" happen but I've never perceived anything but stellar results from extrude honing which has always been accompanied by better, smoother idling, fuel economy, high end grunt and all-around driveability.

On my UrS4 a Level II EH intake manifold made 16.4HP at 5800 RPM's/26 psi boost with no other modification so there is benefit to it. Tho on a smaller displacement engine at less boost how much is unknowable. But if anyone's going for maximum power and is willing to swap $500 for 7-10HP it's worth considering. Depends on how deep ones pockets are.

The exhaust manifold on the other hand is NOT worth extrude honing. Just gasket-match and go. I had my EM Extrude Honed and 6 months later all signs of extrude honing were gone... completley eroded away. Tho I could definately "feel" the IM was extrude honed I never "felt" or otherwise perceived any gain in SOP dyno with extrude honed exhaust manifold.

And of course YMMV

sportQ

Besides exhaust manifold and intake manifold?

VAP

and some high pressure 10,000 psi regulators and air transfer ports for some .177 caliber match pre-charged pneumatic air rifles I used to make for ISU, 10 meter Olympic and World Field Target competition.

The intake manifold showed more gains than the cylinder heads or compressor housings per dollar. That is to say that cylinder heads and housings were worth doing but only if you have an unlimited budget. Last cylinder head I had done ran $4500 JUST for extrude honing and now that I'm retired I simply cannot afford those numbers any longer.

sportQ

Many will sing the praises of the powerflow process, especially watercraft racers, Ford guys, etc. However, I am curious how extrude honing the turbo housing changes the performance of a turbo. There isn't really that much out there on the subject.

Thanks

VAP

Never really "felt" the difference but it was just part of my prep regimen.