3D Printed Intake Manifolds

[michaelmount123]

As a side question, what do we theorise the real difference to laptimes between ITBs and a single throttle? Obviously a pretty broad question open to speculation. I get it with n/a cars but wonder on the real world differences with a boosted engine? Especially now with dbw being an option.

Interesting question. Since it's all about laptimes, peak power may be irrevelent. It would come down to average power within the rev ranges determined by the gearing, driver skill to efficiently manage the potentially dissimilar power profiles, even racetrack configuration which may be suited to one power profile over the other.

All conditions being the same, the quickest laptime would probably be the configuration that provides the highest HP within the RPM range utilized. If your gearbox is set up for 4500 to 7500 RPM, for example, the higher average HP within that range would be quickest. The dyno will therefore show which will be quickest, keeping in mind that peak power may be irrelevant.

[gruhsy]

Drive By Wire mentioned earlier;
the AT power have that option.

[333pg333]

As a side question, what do we theorise the real difference to laptimes between ITBs and a single throttle? Obviously a pretty broad question open to speculation. I get it with n/a cars but wonder on the real world differences with a boosted engine? Especially now with dbw being an option.

Interesting question. Since it's all about laptimes, peak power may be irrevelent. It would come down to average power within the rev ranges determined by the gearing, driver skill to efficiently manage the potentially dissimilar power profiles, even racetrack configuration which may be suited to one power profile over the other.

All conditions being the same, the quickest laptime would probably be the configuration that provides the highest HP within the RPM range utilized. If your gearbox is set up for 4500 to 7500 RPM, for example, the higher average HP within that range would be quickest. The dyno will therefore show which will be quickest, keeping in mind that peak power may be irrelevant.

It was a bit of a silly question of mine but I suppose now that we're here.

So in this hypothetical if we had the same car, same engine and just swapped intakes (ITB and single throttle) with the same size / length runners into the same sized ports then would that be a fair comparison? Perhaps the ITB version would be better served with a different turbo? Maybe different tuning and boost ramping? I'd always read that ITBs gave better throttle control and more immediate response...but in a forced induction motor perhaps that difference isn't nearly as obvious as on an n/a motor? I guess JME and others did it for a reason though.

I know you had a design in the wings Michael. Did anyone ever run that in a turbo car?

[michaelmount123]

I never ran any of my intakes on a turbo car. Interesting, however, that Porsche turbo racecars (and even the NA racecars) used the ITB's. 944GTR, 924GTR, all the water cooled R's and RSR's, 956, 962, etc, etc. This doesn't mean a single TB won't work well, only that Porsche saw some advantage to using ITB's. That said, there's an advantage to applying the KISS principle with a single.

[michaelmount123]

Here's another thing I did on a few 951 intake manifolds which seemed to work well: I'd cut the 951 plenum in half to access the individual inlets. I'd rework the inlets to give them a more radiused entry, then weld the plenum back together. Admittedly, I never did a back to back test, but these engines made good power with tuning.

[Tom]

Here's another thing I did on a few 951 intake manifolds which seemed to work well: I'd cut the 951 plenum in half to access the individual inlets. I'd rework the inlets to give them a more radiused entry, then weld the plenum back together. Admittedly, I never did a back to back test, but these engines made good power with tuning.

I've seen that done where they take a big section of the top off, leaving the throttle body flange in place. That apparently gives enough room to open up the ports. Have any pictures of where you cut?

[333pg333]

On a previous motor they modified the stock intake with some internal diverters I suppose is the best term. I have no proof of improvement vs stock.

[michaelmount123]

Your intakes are certainly appealing to the eye, Patrick.

Here's what's going on in New Zealand. The intake will be CNC machined to fit an ultra modern fuel/air mixing device that uses no electronic control. Currently finalizing design detail. The mismatch at the intake entry will be addressed.

SethIntake.png (554.81 KiB) Viewed 1333 times

[333pg333]

"Ultra modern fuel/air mixing device that uses no electronic control" Almost sounds like a carburetor Michael. Glad to see someone is working with your design and developing it. Our neighbours do some good stuff across the ditch.

[michaelmount123]

Here's another thing I did on a few 951 intake manifolds which seemed to work well: I'd cut the 951 plenum in half to access the individual inlets. I'd rework the inlets to give them a more radiused entry, then weld the plenum back together. Admittedly, I never did a back to back test, but these engines made good power with tuning.

I've seen that done where they take a big section of the top off, leaving the throttle body flange in place. That apparently gives enough room to open up the ports. Have any pictures of where you cut?

This is approximately where I cut, Tom. I didn't disturb the TB flange.

951IntakeMan2.jpg (509.87 KiB) Viewed 1287 times