FRS / BRZ Intake Manifold - Development Thread - FT-86SpeedFactory by Velox

[nelsmar]

Originally Posted by Captain Snooze

@NotEric6
Can you explain in non technical terms why you suspect the bellhorns are the wrong height for na applucations?
Ta.

Runner length & volume changes the power band / efficiency. Typically a extending the runner is more efficient at a lower RPM, and shortening the runner is increases efficiency at high RPM. This is why ITB's have short runners as they are usually used on high RPM setups. And if you look at the stacks on a hot rod they are typically longer.

There is a lot involved with this topic... But the logs we were seeing were showing a fairly flat engine load at basically every RPM vs the stock manifold having a peak power. If you extend a runner typically you increase peak at a point and then add a curve to the power band. Just like what happens with the crawford manifold spacers. By extending the runner length it pushes the efficiency of the stock manifold to a lower RPM but costs power at the top end. And as the logs were showing some "interesting" bits at even 8,000RPM extending the runners could cause a similar effect to that of the crawford spacers by giving a "peak" at a lower RPM. So if we increased the runner length and the falloff landed at say 7800RPM then you may see more gains throughout the rest of the power band. This is why this manifold was made with multiple runners for testing. To see which ones would work best using the most efficiency design on every other aspect of the manifold that they could come up with. And then dial in adjustable parameters in the real world to see what actually improved the performance.

Here is an example plot that shows what happens when someone was testing runner length on I want to say a rotary platform (I don't even remember what it is from):


This is why the Yamaha R1 had a variable length runner at one point so that way it would move the runner to match the RPM and attempt to keep a more neutral power band, while still achieving the gains of a long runner at low RPM.

[johan]

Originally Posted by Captain Snooze

@NotEric6
Can you explain in non technical terms why you suspect the bellhorns are the wrong height for na applucations?
Ta.

Originally Posted by nelsmar

Runner length & volume changes the power band / efficiency. Typically a extending the runner is more efficient at a lower RPM, and shortening the runner is increases efficiency at high RPM. This is why ITB's have short runners as they are usually used on high RPM setups. And if you look at the stacks on a hot rod they are typically longer.

There is a lot involved with this topic... But the logs we were seeing were showing a fairly flat engine load at basically every RPM vs the stock manifold having a peak power. If you extend a runner typically you increase peak at a point and then add a curve to the power band. Just like what happens with the crawford manifold spacers. By extending the runner length it pushes the efficiency of the stock manifold to a lower RPM but costs power at the top end. And as the logs were showing some "interesting" bits at even 8,000RPM extending the runners could cause a similar effect to that of the crawford spacers by giving a "peak" at a lower RPM. So if we increased the runner length and the falloff landed at say 7800RPM then you may see more gains throughout the rest of the power band. This is why this manifold was made with multiple runners for testing. To see which ones would work best using the most efficiency design on every other aspect of the manifold that they could come up with. And then dial in adjustable parameters in the real world to see what actually improved the performance.

Here is an example plot that shows what happens when someone was testing runner length on I want to say a rotary platform (I don't even remember what it is from):


This is why the Yamaha R1 had a variable length runner at one point so that way it would move the runner to match the RPM and attempt to keep a more neutral power band, while still achieving the gains of a long runner at low RPM.

Several production cars have and have had multi-length runner intake manifolds. Toyota did it in the 80's (most popularly in this car's namesake), Honda in the 90's (Integra GS-R), and it's quite common in many commuter cars still today.

I'm very interested in the flow dynamics of the different bellhorn lengths and their resultant power band effects. This whole thing doesn't quite correlate to a standard intake manifold design, nor an ITB setup - since all of this is post TB, yet we have these individual plenums and then individual velocity stacks as well. This is by far one of the most interesting IM designs I've ever seen. It's like an inverted 1-2-4 header design

It will be interesting to see how this works with aftermarket UEL vs EL header designs. Since one flows better in the midrange and the other up top. Running complementing vs contrasting parts combos could yield very interesting results. I'm hoping that you guys can incorporate some of these factors into your dyno testing.

[Captain Snooze]

Thanks Nelsmar for your detailed reply.

[nelsmar]

Originally Posted by johan

Several production cars have and have had multi-length runner intake manifolds. Toyota did it in the 80's (most popularly in this car's namesake), Honda in the 90's (Integra GS-R), and it's quite common in many commuter cars still today.

I'm very interested in the flow dynamics of the different bellhorn lengths and their resultant power band effects. This whole thing doesn't quite correlate to a standard intake manifold design, nor an ITB setup - since all of this is post TB, yet we have these individual plenums and then individual velocity stacks as well. This is by far one of the most interesting IM designs I've ever seen. It's like an inverted 1-2-4 header design

It will be interesting to see how this works with aftermarket UEL vs EL header designs. Since one flows better in the midrange and the other up top. Running complementing vs contrasting parts combos could yield very interesting results. I'm hoping that you guys can incorporate some of these factors into your dyno testing.

The integra GSR actually had two intake manifold runners, one that would open up for higher volume. But yup! It has been done many times!

As for it being different than ITB's to the engine it is all the same... vacuum is vacuum. If the manifold is 2BAR or 1BAR (Atmospheric) the engine is still in a vacuum in comparison. The only difference is you are WOT with a bellhorn in the manifold and then you are simply regulating the pressure vs regulating the flow. The throttle can restrict flow vs having a massive plenum. However there are size constraints due to factory AC lines and other bits and pieces to be able to make a fully unrestricted manifold.

Velox is simply putting the runner inside the plenum instead of adding the plenum on top of the runner... Think of the BMW manifolds... they are ITB's with stacks inside of a plenum.

Im no specialists in this art / science but I have been around the scene for a while and I have seen many intake manifolds with this design in the Honda community in the past for the B & K series.

Others have done this such as AMS, Full Blown, Skunk2... and many many others!
http://www.streettunedmotorsports.co...e_manifold.htm
http://velocityelement.com/the-veloc...ing-car-parts/

[Calum]

@FT-86 SpeedFactory, wil you be sending Velox a header to test this with? From looking at your site I see that you sell one of the top end brands, it would be a good representation to show what the combination would look like.

[nelsmar]

Originally Posted by Tim Radley

What length did you run and what rpm did that give a peak at?

lol if he responds to this I may bust out laughing. And he knows why. Eric... Maybe we should bum Brent's car this weekend... Hahahaha! (Inside joke)

[fika84]

Originally Posted by nelsmar

...
There is a lot involved with this topic... But the logs we were seeing were showing a fairly flat engine load at basically every RPM vs the stock manifold having a peak power. If you extend a runner typically you increase peak at a point and then add a curve to the power band. Just like what happens with the crawford manifold spacers....

Originally Posted by Tim Radley

What length did you run and what rpm did that give a peak at?

Based on the above, I would assume they didn't see much of a peak.

[VerusEric]

Originally Posted by Tim Radley

What length did you run and what rpm did that give a peak at?

1.25" height and seeing peak load somewhere around 7500. But for the most part its flat all the way to 8k RPM. Not sure what this translates to hp/tq wise but it feels great up there.

This was a FI intake manifold build, though for some reason most people believe we were building it for NA power. The fact it is performing NA leaves us with a lot of hopes for both platforms.

Originally Posted by Calum

@FT-86 SpeedFactory, wil you be sending Velox a header to test this with? From looking at your site I see that you sell one of the top end brands, it would be a good representation to show what the combination would look like.

No need as I'm sure we can work something out with locals or their shop cars.

One more picture:

[HUNTERANGEL121]

Will there be two versions? One optimized for NA, and one for FI?

Sent from my toaster

[Calum]

Originally Posted by NotEric6

This was a FI intake manifold build, though for some reason most people believe we were building it for NA power. The fact it is performing NA leaves us with a lot of hopes for both platforms.

Two reasons, 1) This thread is posted in the engine forum not the fi forum, 2) alot of us are still holding on to a glimmer of hope.

[VerusEric]

Originally Posted by HUNTERANGEL121

Will there be two versions? One optimized for NA, and one for FI?

Sent from my toaster

Possibly through different bellhorn heights.

Originally Posted by Calum

Two reasons, 1) This thread is posted in the engine forum not the fi forum, 2) alot of us are still holding on to a glimmer of hope.

Hold onto that glimmer... especially if you feel comfortable revving the engine .

[asnoir]

If you sell it for NA is there an specialy Ecutek Map in the bundle?

[Calum]

Originally Posted by NotEric6

Possibly through different bellhorn heights.



Hold onto that glimmer... especially if you feel comfortable revving the engine .

[fika84]

The only reason I want this manifold is for the 9k RPM redline NA motor I'm going to build...