6 port BP manifold, yes... really.

sen2two · 07-31-2010, 08:05 PM

The only reason I'm doing this is the car was kinda given to me. Motor was good but had a bad coolant seal. I'm re-using everything and is only costing me a grand total of 200 bucks for new soft seals. So It's time for some real experimentation to push the "stock" limits.

What i am doing is a FULL bridge 6 port. By full, i mean full. All 6 ports will have a decent sized bridge port. With a decent sized street port also. this WILL be done on the stock ECU. And yes i know, not many have actually gotten this to work. But I have done it with a friend a long time ago, but we knew far less than i know now. And it did work decent. That was also a 4 port though. I also remember ITO doing this a few years back with pretty damn good success. Stock ECU, manifolds, ect...

I will do some slight tuning with the stock s4 AFM which can actually get you pretty close. And do some minor tuning with a simple SAFC. These two little things can get you close, but not perfect.

OK, that's a little back story. The major problem that people have when doing 6 port BP is the stock intake manifold. Yes, switching to a TII manifold and port matching is easy, but what fun is that? What I am in the process of doing is using the stock 6 port lower (modding it slightly), and making a manifold in-between for the stock TB.

The question i have is whether i should have plenum or not. I the picture i drew in paint (i'm a much better fabricator than i am artist

) the one on the far left has no plenum. The secondary runners will have there own dedicated throttles. But the primary runners will meet just before the TB and join into one at the primary throttle plate. Just as the stock manifold would have them separated.

But the two pics to the right show all four runners joining a similar plenum just like they would come together in a 4 cylinder turbo manifold. The only real benefit making want to do it this way is i can machine out a a plate with velocity stacks. But i like the primary and secondary's being separated...

Any advice, on this would help...

Don't hate on the 6 port BP. It's just for fun... and I already did the porting. No turning back now.

sen2two · 07-31-2010, 08:07 PM

Here's ITO vids of the 6 port BP...

http://www.youtube.com/watch?v=4Zh8gqI-L_0

http://www.youtube.com/watch?v=INECtsxyZ74

vex · 07-31-2010, 08:25 PM

If I can recall correctly you can't exactly run a bridge port on a stock ECU....

[confirmation?]

sen2two · 07-31-2010, 08:44 PM

2 vids above prove it can be done, and done pretty nice.

I have also done this personally before. But never this extreme.

NoDOHC · 08-01-2010, 09:29 AM

I don't see why you couldn't use the stock ECU, it uses the air flow meter to determine fueling - this should compensate for any differences in the VE seamlessly.

The big issue that I see is the ignition. The factory ignition is notoriously weak at high revs (25% of idle ignition energy at 9,000 rpm). This means that you probably won't make any power past 7500 rpm anyway, regardless of how much air and fuel your engine can breathe.

Still, the manifold development is a good idea. The factory intake uses the elbow and intake piping as a plenum for the secondaries. I think I would put a plenum in for the primaries, you will be using them with the throttle mostly closed, which will exclude the use of the intake piping as a plenum.

This is a cool idea. I wish you the best of luck.

I wish you had posted this in the engine tech section, as it really isn't as much a generation specific question as an engine question.

RETed · 08-01-2010, 02:49 PM

Quote:

Originally Posted by NoDOHC

I don't see why you couldn't use the stock ECU, it uses the air flow meter to determine fueling - this should compensate for any differences in the VE seamlessly.

I guess it would never be possible to "peg" the stock AFM and then the stock ECU has no idea how much air the engine is ingesting...

-Ted

sen2two · 08-01-2010, 12:02 PM

I got this idea when i was trying to adapt a FD TPS to a set of GSXR ITB's to use for this set-up. Making it possible to run a full ITB set-up on stock ECU. But I don't like the idea of real ITB's with the stock AFM. Plus, I really think I would be pushing the stock ECU limits a little to far with that one. If this set-up works out good. I might try the GSXR ITB's after. I have these parts laying around. Might as well try it out...

Our TB's come with 3 throttle plates. So, basically the secondaries are individual, and the primaries ports are the only one sharing a throttle. So using the stock TB in this way, gets you close as you can get to ITB's still running mostly stock stuff.

NoDOHC · 08-01-2010, 01:34 PM

That is the way it is configured from the factory too.

NoDOHC · 08-02-2010, 12:06 AM

Ok, I see your point... still they must have left some safety factor. Maybe use a turbo AFM?

07-31-2010, 08:05 PM	#1
sen2two KTEC Join Date: Jan 2009 iTrader: (2) Posts: 642 Rep Power: 0	6 port BP manifold, yes... really. The only reason I'm doing this is the car was kinda given to me. Motor was good but had a bad coolant seal. I'm re-using everything and is only costing me a grand total of 200 bucks for new soft seals. So It's time for some real experimentation to push the "stock" limits. What i am doing is a FULL bridge 6 port. By full, i mean full. All 6 ports will have a decent sized bridge port. With a decent sized street port also. this WILL be done on the stock ECU. And yes i know, not many have actually gotten this to work. But I have done it with a friend a long time ago, but we knew far less than i know now. And it did work decent. That was also a 4 port though. I also remember ITO doing this a few years back with pretty damn good success. Stock ECU, manifolds, ect... I will do some slight tuning with the stock s4 AFM which can actually get you pretty close. And do some minor tuning with a simple SAFC. These two little things can get you close, but not perfect. OK, that's a little back story. The major problem that people have when doing 6 port BP is the stock intake manifold. Yes, switching to a TII manifold and port matching is easy, but what fun is that? What I am in the process of doing is using the stock 6 port lower (modding it slightly), and making a manifold in-between for the stock TB. The question i have is whether i should have plenum or not. I the picture i drew in paint (i'm a much better fabricator than i am artist ) the one on the far left has no plenum. The secondary runners will have there own dedicated throttles. But the primary runners will meet just before the TB and join into one at the primary throttle plate. Just as the stock manifold would have them separated. But the two pics to the right show all four runners joining a similar plenum just like they would come together in a 4 cylinder turbo manifold. The only real benefit making want to do it this way is i can machine out a a plate with velocity stacks. But i like the primary and secondary's being separated... Any advice, on this would help... Don't hate on the 6 port BP. It's just for fun... and I already did the porting. No turning back now. __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

07-31-2010, 08:07 PM	#2
sen2two KTEC Join Date: Jan 2009 iTrader: (2) Posts: 642 Rep Power: 0	Here's ITO vids of the 6 port BP... http://www.youtube.com/watch?v=4Zh8gqI-L_0 http://www.youtube.com/watch?v=INECtsxyZ74 __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

07-31-2010, 08:25 PM	#3
vex RCC Loves Me Not You Join Date: Jul 2008 Location: Influx. iTrader: (6) Posts: 2,113 Rep Power: 19	If I can recall correctly you can't exactly run a bridge port on a stock ECU.... [confirmation?] __________________ The Official FC Radiator Thread My Project Thread: Cerberus CCVT Virginia Rotary Group

07-31-2010, 08:44 PM	#4
sen2two KTEC Join Date: Jan 2009 iTrader: (2) Posts: 642 Rep Power: 0	2 vids above prove it can be done, and done pretty nice. I have also done this personally before. But never this extreme. __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

08-01-2010, 09:29 AM	#5
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	I don't see why you couldn't use the stock ECU, it uses the air flow meter to determine fueling - this should compensate for any differences in the VE seamlessly. The big issue that I see is the ignition. The factory ignition is notoriously weak at high revs (25% of idle ignition energy at 9,000 rpm). This means that you probably won't make any power past 7500 rpm anyway, regardless of how much air and fuel your engine can breathe. Still, the manifold development is a good idea. The factory intake uses the elbow and intake piping as a plenum for the secondaries. I think I would put a plenum in for the primaries, you will be using them with the throttle mostly closed, which will exclude the use of the intake piping as a plenum. This is a cool idea. I wish you the best of luck. I wish you had posted this in the engine tech section, as it really isn't as much a generation specific question as an engine question. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

08-01-2010, 12:02 PM	#7
sen2two KTEC Join Date: Jan 2009 iTrader: (2) Posts: 642 Rep Power: 0	I got this idea when i was trying to adapt a FD TPS to a set of GSXR ITB's to use for this set-up. Making it possible to run a full ITB set-up on stock ECU. But I don't like the idea of real ITB's with the stock AFM. Plus, I really think I would be pushing the stock ECU limits a little to far with that one. If this set-up works out good. I might try the GSXR ITB's after. I have these parts laying around. Might as well try it out... Our TB's come with 3 throttle plates. So, basically the secondaries are individual, and the primaries ports are the only one sharing a throttle. So using the stock TB in this way, gets you close as you can get to ITB's still running mostly stock stuff. __________________ what I have: 1985 Gs:12a All motor Drag car - 1973 Rx2: Play car What I had: 93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2

08-01-2010, 01:34 PM	#8
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	That is the way it is configured from the factory too. __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

08-02-2010, 12:06 AM	#9
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	Ok, I see your point... still they must have left some safety factor. Maybe use a turbo AFM? __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)