Comparing Aftermarket Porsche 928 Intake Options
The right intake manifold can make a huge difference on a 928. But is modifying another brand’s intake better than buying a custom-built one?
There comes a point in (most) everyone’s life when they simply want more power. And coaxing power from any Porsche is a simple matter of selecting the right parts and the right tune. With an abundance of options available in the aftermarket, choosing the right ones can be daunting, however. So thankfully, we’ve got plenty of first-world testing available at our fingertips in the Rennlist forums. Like this recent Porsche 928 intake manifold showdown started by mark kibort. Namely between a custom modified Aston Martin manifold and Carl’s new hi-rise piece.
“Carl’s intake looks amazing and is just what we have all been talking about for sometime. It seems more convenient than the CF intake system, in that it more resembles the stock configuration (TB feeding from underneath and plumbed rearward).”
Of course, the OP doesn’t just speculate as to what this new intake can do. They also post some real (and impressive) dyno results!
“The HP gains vs the stock manifold are even more than what the CF produced. I am wondering if that is due to the engine management system used or the design of the manifold. The CF manifold installations were using stock MAF and dual TBs. Carl’s manifold (654) showed near the same HP at 4,000 to 4,500 rpm. But once 4,600 was hit, the power was 50 hp gains (the gain I got from going from a 5-liter to stroker). And then, it took off from there.
ALL in the range you use the engine at the track. 4,500 rpm to 6,500 rpm is where you use the engine if you are racing. NEVER does your RPM go lower, unless you are either coasting into or through a turn. At the exit of ALL racing turns, the RPM will always be in this sweet spot range of RPM. So WELL done Carl!”
Impressive results, indeed. But the OP openly wonders if they can do even better with their own custom design.
“Now the questions of comparison to what I have been working on with the Aston Martin intake. I would like to do a comparison to what might be a more cost effective solution, what would just plain work better, or even be an easier project.
A quick review of what I’ve planned:
1. Use a modified AM V8 intake that has the legs cut off and mated with a wider footprint set of legs mated to the Hans adapters.
2. Use an aftermarket 90-100mm TB.
3. Use the stock MAF.
4 Use a cone filter with an entrance just in front of the radiator.
5. Modify oil filler area components.”
The hard part, of course, is making it fit. But the OP seems to have that covered.
“As far as the AM intake goes, I’m pretty confident based on measurements that it will fit. The only mods I need to make are to the oil filler. Not that difficult, but Carls doesn’t need to make that mod. And, with the location of the TB in the near stock location, refitting the stock throttle linkage would be easier as well.”
Despite how “simple” this sounds, Hacker-Pschorr wonders out loud if it’s really worth the effort.
“Maybe give Carl a call to get all of your questions answered. This is a custom intake build for a custom motor. You have a custom motor. Ask Carl to make you a custom intake.”
Of course, that would be the easy way out. And what follows is a fascinating and lengthy conversation surrounding the intricacies of things like torque curve and intake design. And it’s well worth the read! Be sure and check out the entire thread by heading over here, and chime in with your thoughts on intake options for the Porsche 928!
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