Intake idea
Posted: Thu Nov 23, 2017 6:44 pm
First off... Happy Thanksgiving everyone! Now, on to my idea. This is for the 2.8-3.4 V6 crowd, a Helmholtz resonance intake. I'm not sure how many of you (if any) are familiar with what that is, so I'll explain it as best I can. Basically it is an intake that changes shape internally to keep the air moving at higher speed at different rpm ranges. The result is not necessarily more power, but, instead of having a single peak you move the peak around a little bit, it actually moves the TQ lower and higher in stages. This is not for the "just stick a 3.8/LS/572bb in it crowd," it's also not VTEC for your Chevy, this is for NA only V6 and someone adventurous that wants to experiment. That said you should feel a difference, you definitely notice a lack of power or bog if a solenoid fails. It is something I believe can be adapted from v6 Mazda engine, or maybe someone crafty could refine the idea better. I just want to put the idea forward. I have no idea about hood or strut bar clearances.
The stock Chevy V6 intake is one box (?) with 6 runners, TB at one end. The Mazda intake I'm referring to has 2 intake boxes (engine side of TB, that look like 1 box,) 3 runners on each box. There is a TB at one end, and a runner like tube at the other end of the intake with a valve that opens and closes connecting the 2 intake boxes. There is a second tube in the middle of the intake also connecting the 2 intake boxes with a valve that controls.
At low rpm, the valves are closed, all runners pull air from the TB side. Simulating a longer intake path.
At mid rpm the far valve opens and air gets pulled from the TB but also can be pulled from the far and the other box. Shortening the path to the runners.
At high RPM both valves open and air can be pulled from the TB, far end and middle to feed all the runners a larger amount of air faster.
There is also air getting pulled in all directions sawing around the intake back and forth, getting pulled down runners until the valves shut, at which point the air slams into the back of the intake valve compressing and then springing back up the runner, back into the intake. That air bouncing back gets used to help charge a runner with a valve open. At different rpms the air spring effect changes, is less or more effective, this is why vlaves and changing the shape works. This isn't theory, it works.
Both valves are vacuum operated by solenoid by the ECU. No biggie there are aftermarket switches, called window switches, that can be used and set to open and close these valves (with some JY solenoids,) based on rpm with whatever computer you have. You'd have to find the rpms that work best for you, and whatever combination you have.
The short of it. Cut a Mazda KL v6 intake at the runners in a way that it can be mated to the bottom part of the Chevy V6 runners, weld together or use a bunch of couplers. The Chevy intake sits in the V, whereas the KL intake (there are 4 different ones,) hangs over the rear valve cover. It's really tough trying to get an idea through pictures. From project 91 "SS" 3400/5spd engine bay pic with engine and strut bar it looks like there is room.
Runner spacing is even on the KL and looks offset on the Chevy I don't know if that makes it a no go or not, maybe it's close enough to fudge. I'm thinking 2 cuts at an angle to match up at the longer runners. There may also be more of that fudge room considering the OHV covers probably sit lower
2 of the KL intakes have oval runners, the other 2 have square runners. Oval would probably match up better, those are easier to find. The 2 oval port intakes also work better for lower rpms, which would probably work better with 2 valve engines. KLs are 2.5l v6, the oval port ones (intake heads) make 164hp 160tq or 170hp 160tq. Stock TB is 60mm, 65 can be fit, hourglassing can be done, and possibly twin tb from a Mustang can be adapted or fit. But the best of all the intakes makes 200hp, 170tq NA I believe still using a 60mm TB. Supplying enough air shouldn't be an issue with these intakes, any can be ported to support 200 NA. Not familiar with the Beretta's TPS, idle air, or egr setups. Worst case adapt a Beretta TB to fit. Anyway, I've written a novel here, hopefully a good read. I have a video that shows all 4 intakes and can probably give measurements or show specific angles if someone is interested in that information.
https://www.youtube.com/watch?v=mVcCTana4vw Headphone warning at the end, last 5 seconds or so!
The stock Chevy V6 intake is one box (?) with 6 runners, TB at one end. The Mazda intake I'm referring to has 2 intake boxes (engine side of TB, that look like 1 box,) 3 runners on each box. There is a TB at one end, and a runner like tube at the other end of the intake with a valve that opens and closes connecting the 2 intake boxes. There is a second tube in the middle of the intake also connecting the 2 intake boxes with a valve that controls.
At low rpm, the valves are closed, all runners pull air from the TB side. Simulating a longer intake path.
At mid rpm the far valve opens and air gets pulled from the TB but also can be pulled from the far and the other box. Shortening the path to the runners.
At high RPM both valves open and air can be pulled from the TB, far end and middle to feed all the runners a larger amount of air faster.
There is also air getting pulled in all directions sawing around the intake back and forth, getting pulled down runners until the valves shut, at which point the air slams into the back of the intake valve compressing and then springing back up the runner, back into the intake. That air bouncing back gets used to help charge a runner with a valve open. At different rpms the air spring effect changes, is less or more effective, this is why vlaves and changing the shape works. This isn't theory, it works.
Both valves are vacuum operated by solenoid by the ECU. No biggie there are aftermarket switches, called window switches, that can be used and set to open and close these valves (with some JY solenoids,) based on rpm with whatever computer you have. You'd have to find the rpms that work best for you, and whatever combination you have.
The short of it. Cut a Mazda KL v6 intake at the runners in a way that it can be mated to the bottom part of the Chevy V6 runners, weld together or use a bunch of couplers. The Chevy intake sits in the V, whereas the KL intake (there are 4 different ones,) hangs over the rear valve cover. It's really tough trying to get an idea through pictures. From project 91 "SS" 3400/5spd engine bay pic with engine and strut bar it looks like there is room.
Runner spacing is even on the KL and looks offset on the Chevy I don't know if that makes it a no go or not, maybe it's close enough to fudge. I'm thinking 2 cuts at an angle to match up at the longer runners. There may also be more of that fudge room considering the OHV covers probably sit lower
2 of the KL intakes have oval runners, the other 2 have square runners. Oval would probably match up better, those are easier to find. The 2 oval port intakes also work better for lower rpms, which would probably work better with 2 valve engines. KLs are 2.5l v6, the oval port ones (intake heads) make 164hp 160tq or 170hp 160tq. Stock TB is 60mm, 65 can be fit, hourglassing can be done, and possibly twin tb from a Mustang can be adapted or fit. But the best of all the intakes makes 200hp, 170tq NA I believe still using a 60mm TB. Supplying enough air shouldn't be an issue with these intakes, any can be ported to support 200 NA. Not familiar with the Beretta's TPS, idle air, or egr setups. Worst case adapt a Beretta TB to fit. Anyway, I've written a novel here, hopefully a good read. I have a video that shows all 4 intakes and can probably give measurements or show specific angles if someone is interested in that information.
https://www.youtube.com/watch?v=mVcCTana4vw Headphone warning at the end, last 5 seconds or so!