home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > performance & modifications

Reply
 
Thread Tools Display Modes
Old 10-24-2017, 08:47 PM   #1
740atl
educator monkey
 
740atl's Avatar
 
Join Date: Apr 2010
Location: USA
Default turbo crossover pipes changes in tuning?

So I've been back and forth with supercharger/rear mount turbo/low mount twin turbos/single turbo/bigger heads/snakes on my v8 and I've seen most people do the standard flip the manifolds up or forward and join the exhaust from each side into a common t3 or T4 flange, then hero/success/boost/instant 9 second 1/4.

Like what's shown below....



PROBLEM.....I don't have room for any of that.

I've been looking at pictures of the old buick grand national and they did it differently... In case you didn't know, they take one bank from the driver's side, feed it under the engine and then send it back into the header on the passenger side. Well, it looks like this.



My brain likes option 1 with two sides merging into one. I like it better from a tuning aspect. I don't know why, my brain just likes it.

Option 2 seems like the passenger side is going to see something different than the driver's side. The entire driver side exhaust gets dumped into the passenger side while it's coming out of the head.

My brain is telling me it should make no difference 1 or 2 because pressure is pressure, but I wanted to ask the question anyways. Do buick GN people have special tuning considerations because of the way the exhaust combines or is it not anything to worry about? I mean it obviously works because GNX's ruled the Earth..

Last edited by 740atl; 10-24-2017 at 09:04 PM..
740atl is offline   Reply With Quote
Old 10-24-2017, 10:59 PM   #2
Andrewhans
Turbo LS ****poster
 
Andrewhans's Avatar
 
Join Date: Jan 2013
Location: S. Korea
Default

The hooker cast turbo manifold actually do exactly what youre asking.
https://www.holley.com/products/exha.../parts/8510HKR

Actually almost all of the log style turbo manifold you can buy are that way. KB Racing is a great example of another one that is a VERY successfull robust design.

Will something like this work as an in between?

__________________

Current setup - Aluminum L33/Summit Turbo Stage 2, Billet 80mm turbo, single Walbro 450 and Dual AEM 400's, Bosch 210's
3060lb no driver
3240lb with driver

Last edited by Andrewhans; 10-24-2017 at 11:09 PM..
Andrewhans is offline   Reply With Quote
Old 10-24-2017, 11:41 PM   #3
TurboDenny
Why am I here?
 
Join Date: Nov 2014
Location: Indianapolis, IN
Default

I don't think tuning would be any different if the o2 is placed post turbo.
__________________


Instagram: @itstotesdenny

Quote:
Originally Posted by FreeEMSFred View Post
Nothing's black magic. Basics to moderate power levels are cake, period. Start off rich and retarded, like your president.
TurboDenny is offline   Reply With Quote
Old 10-25-2017, 09:23 AM   #4
740atl
educator monkey
 
740atl's Avatar
 
Join Date: Apr 2010
Location: USA
Default

Thanks guys.

Andrew, that's very similar to what I'm thinking of doing except I might make a log manifold instead of using the stocker (lt1). I'm thinking of this. The LT1 accessory drive takes up so much room compared to the LS setup. I think I have enough room to do this and make the crossover pipe go under and behind the engine.


Andrew, what size turbo are you working with?


What will a single 3" exhaust v8 sound like?
740atl is offline   Reply With Quote
Old 10-25-2017, 09:34 AM   #5
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

this is what I did.




I should have used smaller piping.
__________________
"They bum rushed them in their own crib, they drank all their beer, they partied with their ladies and they left with the trophy"

Now with in-house Dyno tuning!

Megasquirt Tuning!
Plug and play LH 2.4 Megasquirt, now with stealth mode!
linuxman51 is offline   Reply With Quote
Old 10-25-2017, 10:21 AM   #6
740atl
educator monkey
 
740atl's Avatar
 
Join Date: Apr 2010
Location: USA
Default

Is that 2.5 or 3”?
740atl is offline   Reply With Quote
Old 10-25-2017, 11:19 AM   #7
Andrewhans
Turbo LS ****poster
 
Andrewhans's Avatar
 
Join Date: Jan 2013
Location: S. Korea
Default

Quote:
Originally Posted by 740atl View Post
Andrew, what size turbo are you working with?
I have the VS Racing 7875 non billet wheel. Billet vs non billet wont change the physical size at all. Just a bit more airflow from the compressor.

The sound varies depending on how you run the exhaust and with yours being an LT1 itll be difficult to give you an example of sound. Turbo V8 IMO almost always sound awesome.

Andrew
Andrewhans is offline   Reply With Quote
Old 10-25-2017, 11:20 AM   #8
Andrewhans
Turbo LS ****poster
 
Andrewhans's Avatar
 
Join Date: Jan 2013
Location: S. Korea
Default

Quote:
Originally Posted by linuxman51 View Post
I should have used smaller piping.
Thats is pretty damn big it appears. Wont be hurting for flow thats for sure.
Andrewhans is offline   Reply With Quote
Old 10-25-2017, 11:34 AM   #9
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

Quote:
Originally Posted by 740atl View Post
Is that 2.5 or 3”?
2.5

2.25 or 2 would probably have been plenty, and easier to work with.
linuxman51 is offline   Reply With Quote
Old 10-25-2017, 11:35 AM   #10
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

Quote:
Originally Posted by Andrewhans View Post
Thats is pretty damn big it appears. Wont be hurting for flow thats for sure.
my awesome merge right there at the turbo probably kills half of whatever I gained by going that large (which, I think, was largely because it was the same size as the manifold after the flange was cut off...)
linuxman51 is offline   Reply With Quote
Old 10-25-2017, 11:39 AM   #11
Andrewhans
Turbo LS ****poster
 
Andrewhans's Avatar
 
Join Date: Jan 2013
Location: S. Korea
Default

Quote:
Originally Posted by linuxman51 View Post
my awesome merge right there at the turbo probably kills half of whatever I gained by going that large (which, I think, was largely because it was the same size as the manifold after the flange was cut off...)
Lol that merge isnt that bad at all, really.

I used 2" vbands welded straight to manifolds and then it necks down a smidge to 1 7/8 for the majority of the crossover. Hopefully velocity stays up without choking. Should work great for my goal (550whp to 600whp)

Minus the vbands themselves the crossover is 100% reused exhaust off the Volvo haha

As a huge bonus it was very easy to package
Andrewhans is offline   Reply With Quote
Old 10-25-2017, 12:13 PM   #12
740atl
educator monkey
 
740atl's Avatar
 
Join Date: Apr 2010
Location: USA
Default

Quote:
Originally Posted by Andrewhans View Post
I have the VS Racing 7875 non billet wheel. Billet vs non billet wont change the physical size at all. Just a bit more airflow from the compressor.

The sound varies depending on how you run the exhaust and with yours being an LT1 itll be difficult to give you an example of sound. Turbo V8 IMO almost always sound awesome.

Andrew
I guess because I have a dual 3" exhaust right now, I was curious as to what it would be like with all of it crammed into a 3" single exhaust.

The 3" dual gets noticed... even by police.


just looking at the specs for the 7875. That's probably more turbo than I need... (or sadly... afford). I hate to say it but I think I'm going to try to use this old holset I have lying around... he351cw and see what happens.
740atl is offline   Reply With Quote
Old 10-25-2017, 03:18 PM   #13
Andrewhans
Turbo LS ****poster
 
Andrewhans's Avatar
 
Join Date: Jan 2013
Location: S. Korea
Default

Yeah 3" duals are probly very noisy. A single turbo with 3" straight pipe will probly be quieter than what you have now.

The 7875 is a great budget turbo, check the sloppymechanics classified facebook page. People are dumping the cast wheel 7875 for super cheap now that the billet 7875 is out.
Andrewhans is offline   Reply With Quote
Old 10-25-2017, 03:28 PM   #14
740atl
educator monkey
 
740atl's Avatar
 
Join Date: Apr 2010
Location: USA
Default

Quote:
Originally Posted by Andrewhans View Post
Yeah 3" duals are probly very noisy. A single turbo with 3" straight pipe will probly be quieter than what you have now.

The 7875 is a great budget turbo, check the sloppymechanics classified facebook page. People are dumping the cast wheel 7875 for super cheap now that the billet 7875 is out.
I just came off that page and did a double take. That's probably more what I'm looking for.
740atl is offline   Reply With Quote
Old 10-25-2017, 03:52 PM   #15
Andrewhans
Turbo LS ****poster
 
Andrewhans's Avatar
 
Join Date: Jan 2013
Location: S. Korea
Default

Yeah crazy cheap 750whp turbo because people want the new hotness when the old version is still an excellent turbo lol

Take advantage of other people needing the newest and "best"
Andrewhans is offline   Reply With Quote
Old 10-25-2017, 11:13 PM   #16
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

Quote:
Originally Posted by Andrewhans View Post
Yeah 3" duals are probly very noisy. A single turbo with 3" straight pipe will probly be quieter than what you have now.

The 7875 is a great budget turbo, check the sloppymechanics classified facebook page. People are dumping the cast wheel 7875 for super cheap now that the billet 7875 is out.
mine's actually a turbonetics unit, not the china clone. I kinda want one to play with on the gold car though, I may get one of the VS billet ones for it
linuxman51 is offline   Reply With Quote
Old 10-26-2017, 12:13 AM   #17
55superbeetle
Board Member
 
Join Date: Jun 2009
Location: Modesto, Ca
Default

I made this setup with a stock ls3 manifold on the drivers side and a 2.25 crossover under the torque converter, made for a super compact setup.


__________________
83 242, Turbo 6.0 LSX, E85, TH400, 8.8, 10.3@135
55superbeetle is offline   Reply With Quote
Old 10-26-2017, 12:33 AM   #18
LC4CARL
Aero challenged
 
LC4CARL's Avatar
 
Join Date: Sep 2008
Location: Vancouver, WA
Default

Holy moly.
__________________


@PDXvolvo on IG
LC4CARL is offline   Reply With Quote
Old 10-26-2017, 06:36 AM   #19
Andrewhans
Turbo LS ****poster
 
Andrewhans's Avatar
 
Join Date: Jan 2013
Location: S. Korea
Default

Quote:
Originally Posted by linuxman51 View Post
mine's actually a turbonetics unit, not the china clone. I kinda want one to play with on the gold car though, I may get one of the VS billet ones for it
They are really impressive for the money and Vren at VS Racing has bitchin customer service. Cant recommend them enough. The china s480 he carries pushed a gen 4 6.0 to 1076whp.
Andrewhans is offline   Reply With Quote
Old 10-26-2017, 07:15 AM   #20
740atl
educator monkey
 
740atl's Avatar
 
Join Date: Apr 2010
Location: USA
Default

Quote:
Originally Posted by 55superbeetle View Post
I made this setup with a stock ls3 manifold on the drivers side and a 2.25 crossover under the torque converter, made for a super compact setup.


Do you have any other pics of this? Is the crossover tucked under the passenger side manifold?
740atl is offline   Reply With Quote
Old 10-26-2017, 04:17 PM   #21
55superbeetle
Board Member
 
Join Date: Jun 2009
Location: Modesto, Ca
Default



55superbeetle is offline   Reply With Quote
Old 10-26-2017, 05:37 PM   #22
linuxman51
BRANDSCHUTZVORSCHRIFTEN!
 
linuxman51's Avatar
 
Join Date: Dec 2002
Location: mont, AL
Default

Quote:
Originally Posted by Andrewhans View Post
They are really impressive for the money and Vren at VS Racing has bitchin customer service. Cant recommend them enough. The china s480 he carries pushed a gen 4 6.0 to 1076whp.
yea, Viren's a good guy
linuxman51 is offline   Reply With Quote
Old 10-26-2017, 06:10 PM   #23
cosbySweater
Board Member
 
cosbySweater's Avatar
 
Join Date: Jul 2009
Location: Monterey/Falun
Default



I used 2.25 inch, on my Fairmont I'm doing 2 inch. Cheaper and easier to work with.
__________________
1979 Volvo 244DL 5.3/4l80e,8.8,Ms3x goldbox ecu and Mircrosquirt tcu, GTX4202r, 226/230 turbo cam, tbss intake, 11.0@128mph 9psi, 3600lbs with driver
1974 AMC Gremlin, lq4, 7875 billet, ss2 cam, 80e, 3600 stall converter, Holley Terminator x
1995 Porsche 993
2013 VW Passat TDI
Quote:
Originally Posted by bricktop420 View Post
Thank you very much everybody... i now feel sufficiently retarded and will go cry in the corner...
cosbySweater is offline   Reply With Quote
Old 10-27-2017, 12:24 AM   #24
55superbeetle
Board Member
 
Join Date: Jun 2009
Location: Modesto, Ca
Default

Quote:
Originally Posted by cosbySweater View Post
I used 2.25 inch, on my Fairmont I'm doing 2 inch. Cheaper and easier to work with.
That datsun I work on has a 2" hotside into a cast china 78, its a runner for some junk.
55superbeetle is offline   Reply With Quote
Old 10-27-2017, 01:12 PM   #25
cosbySweater
Board Member
 
cosbySweater's Avatar
 
Join Date: Jul 2009
Location: Monterey/Falun
Default

Yea the 2 inch seems to be the way to go.
cosbySweater is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 06:24 PM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.