Lusting for a twin turbo setup, and would like (helpful) ideas - Page 9

reboticon · 07-08-08, 12:08 AM

Quote:

Originally Posted by Dethred

No. The compressed air is going to the same throttle body. There will just be more lag with one further away (how much is yet to be seen). There's a reason that people buy a pair of headers to gain power and keep their engine running smoothly. When you have two different exhaust gas paths with differing flow rates/velocity you going to have different combustion situations therein, which is not ideal.

You may be right, but your reasoning is off. If he has equal length runners to the X-pipe after the headers and before the turbos, then the combustion situations at each cylinder are equal, assuming both turbos are feeding one common throttle body.

After the crossover point, the exhaust is going to take the path of least resistance, which would be the closer turbo, then a fraction of a second later hit the other turbo since the friction of the first turbine causes resistance.

So what im saying is, i would understand if each head fed one turbo, but with an X-pipe, or both heads feeding into a Y and then branching off to each turbo as a Y (essentially making a stretched X), it seems like the lag could mimic the idea of one large and one small turbo. Basically one kicking in low in the rpms, and the other higher.

Like i said, i may be totally off here, just want to know why

Telion · 07-08-08, 01:34 AM

This makes things interesting, these are from a Porsche 996 years 99'-04

it certainly looks close.

DandDEE · 07-08-08, 01:48 AM

hope that works ima watch just to see if i can do the same thing

Dethred · 07-08-08, 02:18 AM

Quote:

Originally Posted by reboticon

You may be right, but your reasoning is off. If he has equal length runners to the X-pipe after the headers and before the turbos, then the combustion situations at each cylinder are equal, assuming both turbos are feeding one common throttle body.

After the crossover point, the exhaust is going to take the path of least resistance, which would be the closer turbo, then a fraction of a second later hit the other turbo since the friction of the first turbine causes resistance.

So what im saying is, i would understand if each head fed one turbo, but with an X-pipe, or both heads feeding into a Y and then branching off to each turbo as a Y (essentially making a stretched X), it seems like the lag could mimic the idea of one large and one small turbo. Basically one kicking in low in the rpms, and the other higher.

Like i said, i may be totally off here, just want to know why

I was under the impression that the principles of velocity and sonic tuning still applied, even when a barrier such as a turbine enters the mix.

Dethred · 07-08-08, 02:21 AM

Quote:

Originally Posted by Telion

This makes things interesting, these are from a Porsche 996 years 99'-04

it certainly looks close.

99-04 Porsche 996 Non Turbo Stainless Steel Performance Headers - $300.00

~$300.

OBX are on Ebay for a similar price. It's probably going to be more of a headache hacking up manifolds that might not work and will be more work either way...

Telion · 07-08-08, 02:54 AM

I found them for 100.00 shipped

Telion · 07-08-08, 03:04 AM

Ok the porsche ones are definately out they look like they A. facing forward with the collector on the lower part will hit the alt and the PS. and B facing forward woth the collector on the topside won't clear the valve covers.

reboticon · 07-08-08, 04:08 AM

You may already know someone local who could make you some, this site lets you fill out specs and gives you an estimate. CES - Custom Headers

Telion · 07-08-08, 05:04 AM

I have decided on the 350z headers then if I need to re-work them I will

Dethred · 07-08-08, 05:33 AM

GIT R' DUN!

Telion · 07-08-08, 12:42 PM

Ok it was difficult to make the decision to spend 100.00 on an item that is in question as to whether or not it will work but I think somehow it either will or will be forced to work lol. But I have to answer the question that many of us wonder, just how close are these?

I will know very soon, let us pray

DandDEE · 07-08-08, 01:20 PM

now the true tests begin good luck ... alot of blood sweat and tears are gonna shed in this project aren't u glad u have us

Telion · 07-08-08, 01:26 PM

Indeed!

guest · 07-08-08, 05:22 PM

you do know you have to chuck those on for a NA perspective right? I'm thinking it may have to be forced a wee bit due to the fwd layout, damn engineers. As for praying, let's hope it doesn't take the biggest hammer you have

GrumpySteelMan · 07-09-08, 05:35 PM

Quote:

Originally Posted by reboticon

DandDEE - you aren't alone, this thread makes my brain hurt. Its funny the difference between one of grumpys posts here and in the lounge. Both of them make my head hurt but from different spectrums

What is that supposed to mean?

Quote:

Originally Posted by reboticon

Well, a straight six is always going to have the exhaust ports on the same side though, right?

I couldn't imagine doing it any other way.

Quote:

Originally Posted by reboticon

Question. I realize that on a racetrack, having both turbos as close to the ports of each head would be the best for optimal performance. In this case though, assuming he was going to drive it on the street, couldn't it actually be helpful to have one turbo further from the exhaust than the other? When i think of it, I see one turbo spooling earlier in the RPMs than the other. Wouldn't that actually help to increase the hp throughout the powerband, instead of kicking it all on at once? I used to drive my 7.0L on the street, and that much torque can get frustrating. Or have i got this figured wrong?

You're thinking about a sequential turbo setup. A very effective layout, but for all intents and purposes this will be a 'biturbo' setup. The differences between piping distances will have a negligible effect.

Quote:

Originally Posted by Dethred

No. The compressed air is going to the same throttle body. There will just be more lag with one further away (how much is yet to be seen). There's a reason that people buy a pair of headers to gain power and keep their engine running smoothly. When you have two different exhaust gas paths with differing flow rates/velocity you going to have different combustion situations therein, which is not ideal.

If you think about the volume of the entire intake (pipes, i/c, etc) the extra distance is pretty insignificant. The exhaust side matters, but until you start causing large thermodynamic differences...like a turbo 12" from the head, and a turbo 12' from the head...you are unlikely to have any serious issues.

Thanks for understanding the need for balance on the exhaust side.

Although I think you oversimplified your example.

Quote:

Originally Posted by Telion

Ok I picked up a gasket from an 05' 350z and it looks fairly promising the shape and size of the holes are virtually identical to our cars. The difference as we pretty much knew was in the spacing between each port. in order to best determine the spacing I centered the two center holes which line up nicely and measured the variance on the outer holes. Each outer hole on the 350z is a hair over 1/2" wider than the Legends gasket. So I am thinking this could be worth a shot. At the price these are available for it would cost more than that just to buy the material for a custom set to be made not including labor, and even better I will not have to hack up my OBX headers. One thing I do need to consider though is the amount of stress that 1/2 would cause. I think it would be best to heat them up and correct the variance. here's the pics.

The stress at the collector won't be the biggest issue looking at the design. I would consider enlarging the outside manifold bolt holes to account for the expansion of the metal...remember stainless experiences heat expansion about 2x what mild steel does.

Heat bending is probably an ok idea, although personally I'd cut them apart and 'rebuild them' with some extra pipe.

Most importantly I'd cut the 350Z flange off, bend (or rebiuld) the pipes to the proper spec, and then have the pipes decked on a milling machine before I welded the Legend flanges on, and then have it decked again after welding. I suggest this because you'll want those joints and welds to be very strong, and you'll want to minimize the effect welding has considering warpage on the final product.

07-08-08, 01:34 AM	#122 (permalink)
Telion Of the Telion Chip Join Date: Feb 2006 Location: Hopefully In your ECU ;) Posts: 4,333 Car 1: White 91 KA8 5spd W/3.5, TII Cams & Manifold Car 2: White 91 KA8 JDM TII iTrader: (38)	This makes things interesting, these are from a Porsche 996 years 99'-04 it certainly looks close. __________________ \/Provider of The Telion Chip click here\/ http://telionsite.com or search Telion Chip 3.5, TII cams,pnp mani & springs,Telion Chip,HID's,H&R's/Koni's,Addco Sway bars,TII calipers,RH C2's,R.J. shifter,DV8 EGR plate,CAI,OBX headers,2.5" exhaust,hi-flow cat,K2 muffler,Stage III clutch,S&D rotors, KVR pads, blackend damper, a CF hood, AFC NEO, 3.5 Aluminum pulley, & Web cams. C&R Racing radiator and more to come.

07-08-08, 02:54 AM	#126 (permalink)
Telion Of the Telion Chip Join Date: Feb 2006 Location: Hopefully In your ECU ;) Posts: 4,333 Car 1: White 91 KA8 5spd W/3.5, TII Cams & Manifold Car 2: White 91 KA8 JDM TII iTrader: (38)	I found them for 100.00 shipped __________________ \/Provider of The Telion Chip click here\/ http://telionsite.com or search Telion Chip 3.5, TII cams,pnp mani & springs,Telion Chip,HID's,H&R's/Koni's,Addco Sway bars,TII calipers,RH C2's,R.J. shifter,DV8 EGR plate,CAI,OBX headers,2.5" exhaust,hi-flow cat,K2 muffler,Stage III clutch,S&D rotors, KVR pads, blackend damper, a CF hood, AFC NEO, 3.5 Aluminum pulley, & Web cams. C&R Racing radiator and more to come.

07-08-08, 03:04 AM	#127 (permalink)
Telion Of the Telion Chip Join Date: Feb 2006 Location: Hopefully In your ECU ;) Posts: 4,333 Car 1: White 91 KA8 5spd W/3.5, TII Cams & Manifold Car 2: White 91 KA8 JDM TII iTrader: (38)	Ok the porsche ones are definately out they look like they A. facing forward with the collector on the lower part will hit the alt and the PS. and B facing forward woth the collector on the topside won't clear the valve covers. __________________ \/Provider of The Telion Chip click here\/ http://telionsite.com or search Telion Chip 3.5, TII cams,pnp mani & springs,Telion Chip,HID's,H&R's/Koni's,Addco Sway bars,TII calipers,RH C2's,R.J. shifter,DV8 EGR plate,CAI,OBX headers,2.5" exhaust,hi-flow cat,K2 muffler,Stage III clutch,S&D rotors, KVR pads, blackend damper, a CF hood, AFC NEO, 3.5 Aluminum pulley, & Web cams. C&R Racing radiator and more to come.

07-08-08, 04:08 AM	#128 (permalink)
reboticon Registered User Join Date: May 2008 Location: Knoxville Posts: 1,119 Car 1: 95 Black 4dr Car 2: 92 Blue 4dr Car 3: 71 429& 87 5.0Tbirds iTrader: (3)	You may already know someone local who could make you some, this site lets you fill out specs and gives you an estimate. CES - Custom Headers __________________ Fixing legends is easier than fixing lolcats, but the parts are way more expensive.. My Wiring Nightmare..http://www.acura-legend.com/vbulleti...59/index3.html

07-08-08, 05:04 AM	#129 (permalink)
Telion Of the Telion Chip Join Date: Feb 2006 Location: Hopefully In your ECU ;) Posts: 4,333 Car 1: White 91 KA8 5spd W/3.5, TII Cams & Manifold Car 2: White 91 KA8 JDM TII iTrader: (38)	I have decided on the 350z headers then if I need to re-work them I will __________________ \/Provider of The Telion Chip click here\/ http://telionsite.com or search Telion Chip 3.5, TII cams,pnp mani & springs,Telion Chip,HID's,H&R's/Koni's,Addco Sway bars,TII calipers,RH C2's,R.J. shifter,DV8 EGR plate,CAI,OBX headers,2.5" exhaust,hi-flow cat,K2 muffler,Stage III clutch,S&D rotors, KVR pads, blackend damper, a CF hood, AFC NEO, 3.5 Aluminum pulley, & Web cams. C&R Racing radiator and more to come.

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07-08-08, 05:33 AM	#130 (permalink)
Dethred Hi! I'm Ryan. Join Date: Aug 2002 Location: Yorktown, VA Posts: 4,296 Car 1: 2008 Honda Civic Si Coupe Car 2: 92' Acura Legend 4DR iTrader: (2)	GIT R' DUN!

07-08-08, 12:42 PM	#131 (permalink)
Telion Of the Telion Chip Join Date: Feb 2006 Location: Hopefully In your ECU ;) Posts: 4,333 Car 1: White 91 KA8 5spd W/3.5, TII Cams & Manifold Car 2: White 91 KA8 JDM TII iTrader: (38)	Ok it was difficult to make the decision to spend 100.00 on an item that is in question as to whether or not it will work but I think somehow it either will or will be forced to work lol. But I have to answer the question that many of us wonder, just how close are these? I will know very soon, let us pray __________________ \/Provider of The Telion Chip click here\/ http://telionsite.com or search Telion Chip 3.5, TII cams,pnp mani & springs,Telion Chip,HID's,H&R's/Koni's,Addco Sway bars,TII calipers,RH C2's,R.J. shifter,DV8 EGR plate,CAI,OBX headers,2.5" exhaust,hi-flow cat,K2 muffler,Stage III clutch,S&D rotors, KVR pads, blackend damper, a CF hood, AFC NEO, 3.5 Aluminum pulley, & Web cams. C&R Racing radiator and more to come.

07-08-08, 01:26 PM	#133 (permalink)
Telion Of the Telion Chip Join Date: Feb 2006 Location: Hopefully In your ECU ;) Posts: 4,333 Car 1: White 91 KA8 5spd W/3.5, TII Cams & Manifold Car 2: White 91 KA8 JDM TII iTrader: (38)	Indeed! __________________ \/Provider of The Telion Chip click here\/ http://telionsite.com or search Telion Chip 3.5, TII cams,pnp mani & springs,Telion Chip,HID's,H&R's/Koni's,Addco Sway bars,TII calipers,RH C2's,R.J. shifter,DV8 EGR plate,CAI,OBX headers,2.5" exhaust,hi-flow cat,K2 muffler,Stage III clutch,S&D rotors, KVR pads, blackend damper, a CF hood, AFC NEO, 3.5 Aluminum pulley, & Web cams. C&R Racing radiator and more to come.

07-08-08, 05:22 PM	#134 (permalink)
guest huh? Join Date: Sep 2007 Location: utah Posts: 92 iTrader: (0)	you do know you have to chuck those on for a NA perspective right? I'm thinking it may have to be forced a wee bit due to the fwd layout, damn engineers. As for praying, let's hope it doesn't take the biggest hammer you have