Manifold difference??

Rx-7fetish · 04-23-2009, 02:57 PM

Ill get pics tonight but While taking my turbo off looking for an axhaust leak i discovered that my manifold is cracked. I have an extra one but when i went to get it i noticed that the one of the car has an extra pencil sized hole in it and a flap thing and a big actuator for the flap. The one without is off a jdm car so im assuming that its emissions junk. I just want to be sure. So if anyone know the difference let me know. My car is an 88 s4 tenth ann. The jdm turbo is also s4. Also how freely should i be able to spin the turbo by hand. the one off the car spins really easy but has no side to side or back and forth play, neither does the jdm one but its a little stiff to spin, is this do to it not having any oil in it to lubricate it?? Oh and when is it neccessary to port the waste gate? Im running stock boost but have a more freely flowing exhaust. And whats the difference between a recirculating blow off valve and an atmospheric one, besides one venting back before the turbo and one venting to air. The sound is cool but it recirculates for a reason right? this is my first turbo anything lol

I forgot to mention that one manifold has k5 stamped on it and the other has k7 on it

NoDOHC · 04-23-2009, 10:05 PM

Porting the wastegate when you have the turbo off is always a good idea.

I think that you are talking about the twin scroll actuator (gives you faster boost response) a picture of it would help.

The stiff to spin may be due to lack of oil. if there is no play, you are probably ok.

The recirculating blowoff valve is quiet, while the open one is louder (Pssssht when shifting gears). The open one will dump boost more quickly and is better for higher boost applications.

TehMonkay · 04-24-2009, 12:04 AM

As long as the turbo manifold has the same flange you can use it. S5 is divided s4 is not.

Rx-7fetish · 04-24-2009, 10:36 AM

There both s4 manifolds, the one at the top is from a jap car the lower one is off my tenth ann

Rx-7fetish · 04-24-2009, 11:05 AM

Also the one off the car has this little hole running through it (bottom left in the opening in the pic.) the jap one does not have this hole

Rx-7fetish · 04-24-2009, 11:07 AM

Mostly i just want a 100% sure answer on what the flapper thing is and do i need it, what difference is it going to make without it. The manifold is cracked all to h377, and i only have the one extra, i dont want to buy another one if i dont need to, and my dad is taking a turbo to work to get it ported for me monday

Rx-7fetish · 04-25-2009, 07:47 PM

?? Nobdy knows what it is? im trying to have this car back on the road by next week

antman0408 · 04-25-2009, 10:30 PM

It's the twin scroll flapper. It's not needed, but it helps spool the turbo below 3000 rpms.

04-23-2009, 02:57 PM	#1
Rx-7fetish Blue Blur Join Date: Jan 2009 Location: Windsor Posts: 211 Rep Power: 0	Manifold difference?? Ill get pics tonight but While taking my turbo off looking for an axhaust leak i discovered that my manifold is cracked. I have an extra one but when i went to get it i noticed that the one of the car has an extra pencil sized hole in it and a flap thing and a big actuator for the flap. The one without is off a jdm car so im assuming that its emissions junk. I just want to be sure. So if anyone know the difference let me know. My car is an 88 s4 tenth ann. The jdm turbo is also s4. Also how freely should i be able to spin the turbo by hand. the one off the car spins really easy but has no side to side or back and forth play, neither does the jdm one but its a little stiff to spin, is this do to it not having any oil in it to lubricate it?? Oh and when is it neccessary to port the waste gate? Im running stock boost but have a more freely flowing exhaust. And whats the difference between a recirculating blow off valve and an atmospheric one, besides one venting back before the turbo and one venting to air. The sound is cool but it recirculates for a reason right? this is my first turbo anything lol I forgot to mention that one manifold has k5 stamped on it and the other has k7 on it Last edited by Rx-7fetish; 04-23-2009 at 03:48 PM.

04-23-2009, 10:05 PM	#2
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin Posts: 855 Rep Power: 17	Porting the wastegate when you have the turbo off is always a good idea. I think that you are talking about the twin scroll actuator (gives you faster boost response) a picture of it would help. The stiff to spin may be due to lack of oil. if there is no play, you are probably ok. The recirculating blowoff valve is quiet, while the open one is louder (Pssssht when shifting gears). The open one will dump boost more quickly and is better for higher boost applications. __________________ 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)

04-24-2009, 12:04 AM	#3
TehMonkay Rotary Fanatic Join Date: Apr 2008 Location: Louisville, KY Posts: 302 Rep Power: 18	As long as the turbo manifold has the same flange you can use it. S5 is divided s4 is not. __________________ My car blows up everytime I start it, it's rotary

04-24-2009, 10:36 AM	#4
Rx-7fetish Blue Blur Join Date: Jan 2009 Location: Windsor Posts: 211 Rep Power: 0	There both s4 manifolds, the one at the top is from a jap car the lower one is off my tenth ann

04-24-2009, 11:05 AM	#5
Rx-7fetish Blue Blur Join Date: Jan 2009 Location: Windsor Posts: 211 Rep Power: 0	Also the one off the car has this little hole running through it (bottom left in the opening in the pic.) the jap one does not have this hole

04-24-2009, 11:07 AM	#6
Rx-7fetish Blue Blur Join Date: Jan 2009 Location: Windsor Posts: 211 Rep Power: 0	Mostly i just want a 100% sure answer on what the flapper thing is and do i need it, what difference is it going to make without it. The manifold is cracked all to h377, and i only have the one extra, i dont want to buy another one if i dont need to, and my dad is taking a turbo to work to get it ported for me monday

04-25-2009, 07:47 PM	#7
Rx-7fetish Blue Blur Join Date: Jan 2009 Location: Windsor Posts: 211 Rep Power: 0	?? Nobdy knows what it is? im trying to have this car back on the road by next week

04-25-2009, 10:30 PM	#8
antman0408 Rotary Fan in Training Join Date: Jan 2009 Posts: 61 Rep Power: 17	It's the twin scroll flapper. It's not needed, but it helps spool the turbo below 3000 rpms.