Page:
Home > Technical Chat > straight thru exhausts

Lone Wolf

User Avatar

146 Posts
Member #: 1092
Advanced Member

Yours from the Funny Farm

will a turbo engine benefit from having a straight thru exhaust?
i wouldnt think so due to the backpressure needed beeing created by the turbo

i know about the legalities BTW

ta

tom

Warning:Stig in Training


The Turbocharger:God's Finest Minute


Bat

User Avatar

4559 Posts
Member #: 786
Post Whore

Bermingum

Hi,
The less backpressure in the ehuast the better for a turbo engine.
With no back pressure in the exhaust the gases exit the turbo easier meaning less backpressure at the turbo.
It also lowers turbo temperture too.
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary


Lone Wolf

User Avatar

146 Posts
Member #: 1092
Advanced Member

Yours from the Funny Farm

so in a word yes. right bat?

Warning:Stig in Training


The Turbocharger:God's Finest Minute


Badger

User Avatar

197 Posts
Member #: 1488
Advanced Member

Bristol

Basically any exhaust with a minimum of back pressure. So yes.

There is no sense crying over every mistake- you just keep on trying til you run out of cake.


JT

User Avatar

2742 Posts
Member #: 637
Post Whore

Hertfordshire

im going to try and make a exhust so its 2.5" from the turbo outlet to the tail pipe with a single back box on it.

not sure if theres a system for a mini already that size? i might just get maniflow or somwere similar to make me up a back box and just make the rest up myself.

the only thing that will be a proplem that i can see is getting it past the subframe, might have to oval the pipe in that area or somthing.

cheers
josh

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985


Bat

User Avatar

4559 Posts
Member #: 786
Post Whore

Bermingum

Hi,
The problem will be getting it in the tunnel past the remote *wink*
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary


Joe C

User Avatar

12307 Posts
Member #: 565
Carlos Fandango

Burnham-on-Crouch, Essex

I have been looking at doing a 2.5" system, with a rod change box it shouldn't be to much of an issue as you can always move the gearchange inside to give more room, and move the engine forward a tad, but with my remote box and full length works style sumpguard its just not practical...

The problem you will have is getting it past the pot joint, you will need to oval the pipe to get it to clear (there is about 2.25" beteen my spicer joint and the subby), and its possible the boot might not like heat that close to it so a change to spicers might be a good idea.

for 2.5" bits 16v minis are worth a look, they do a 2.5" stainless rear box (not cheap tho!) and 2.5" bends and stuff.

On 28th Aug, 2011 Kean said:
At the risk of being sigged...

Joe, do you have a photo of your tool?



http://www.turbominis.co.uk/forums/index.p...9064&lastpost=1

https://joe1977.imgbb.com/



JT

User Avatar

2742 Posts
Member #: 637
Post Whore

Hertfordshire

cheers for that mini13

i may just put the gear selector in the car, havent looked into it proply yet but i know theres a long thread on here about it!
do you think it will be worth the work to cange it from 2" maniflow to custom 2.5"? i supose it would make it breathe better and spool up sooner?

cheers
josh

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985


Bat

User Avatar

4559 Posts
Member #: 786
Post Whore

Bermingum

Hi,
What size it the outlet on the turbo?
I can't see any advantage to having an exhaust bigger than that.
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary


Lone Wolf

User Avatar

146 Posts
Member #: 1092
Advanced Member

Yours from the Funny Farm

thanks
so to elaborate how do you bend exhaust pipe without a pipe bender?
i heard something about filling it with sand once but not sure how that works

Warning:Stig in Training


The Turbocharger:God's Finest Minute


Rob H

4314 Posts
Member #: 700
Formerly British Open Classic

The West Country

I was under the impression that if you made the exhaust too big it would cause turbulence slowing the gasses down & increasing back pressure.

Don't want to sound negative but I'd suggest you consider whether you need a 2.5 exhaust.

Someone please correct me if I'm wrong.

Isambard Kingdom Brunel said:
Nothing is impossible if you are an Engineer


Bat

User Avatar

4559 Posts
Member #: 786
Post Whore

Bermingum

Hi,
I don't know if that's applicable to turbos Rob, but I'm no expert!
Either way, bigger than the turbo outlet isn't going to give any advantage.
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary


JT

User Avatar

2742 Posts
Member #: 637
Post Whore

Hertfordshire

so basicly the ideal size exhust for a turbo moter is whatever the turbo out let is?

My build thread..

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=542985


wil_h

User Avatar

9258 Posts
Member #: 123
Post Whore

Betwix Harrogate and York

It is recommended that there is still some backpressure in a turbo exhaust system. This is because of the way the oilseals work in the turbine. Too little back pressure and you risk the seals leaking.

Look at Benross'ssss exhaust. It seems a reasonable compromise, 2" til past the selector then amassive after that (2.5" or 3", not sure).

I have a 2" all the way, it fell off at the elbow once when racing, and there was no noticable differance in power (or noise as it happens).

Fastest 998 mini in the world? 13.05 1/4 mile 106mph



On 2nd Jan, 2013 fastcarl said:

the design shows a distinct lack of imagination,
talk about starting off with a clean sheet of paper, then not bothering to fucking draw on it,lol

On 20th Apr, 2012 Paul S said:
I'm mainly concerned about swirl in the runners caused by the tangential entry.


Scruffy

User Avatar

1451 Posts
Member #: 328
Post Whore

Seaford Rise, South Australia

You will need some form of silencer if you ever want to take it to Combe!

On 5th Sep, 2011 Vegard said:
I stand corrected. You should know *wink*



johnK

1425 Posts
Member #: 690
Post Whore

Norfolk

This is the one on my gold car - the main tube is 2 inch inside dia from manifold back to the silencer - the silencer is circa 60mm bore. The silencer is Ti and weighs 1kg - the rest of the system is thin wall T304 and weighs 2.5kg - so all in 3.5kg - not surprisingly it sounds like a big superbike!lol! - but not excessive or chav like by any means.



JK

If Carling made Mini engines
it would probably be like this one!


Bat

User Avatar

4559 Posts
Member #: 786
Post Whore

Bermingum

Hi,
You've got 1/2 a bike engine, so why not a bike exhaust *wink*
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary


wil_h

User Avatar

9258 Posts
Member #: 123
Post Whore

Betwix Harrogate and York

Nice undertray John, mine is a bit more extreem as the exhaust is on the boot side of it. Made a massive differance to speed and stability at speed.

As for the scilencer, looks a similar size to mine, but mine is steel and DOES NOT weight 1kg, it weighs a shit load more.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph



On 2nd Jan, 2013 fastcarl said:

the design shows a distinct lack of imagination,
talk about starting off with a clean sheet of paper, then not bothering to fucking draw on it,lol

On 20th Apr, 2012 Paul S said:
I'm mainly concerned about swirl in the runners caused by the tangential entry.


MikeRace

User Avatar

6549 Posts
Member #: 1149
#1 Basshunter Fan

Force Racing ICT Dept Manager Miglia Turbo Am frum Yokshyer tha noes!

This pic was taken a while ago but heres my pipe! Its a straight Stainless all way to front down pipe. Im going to have to see wether its gunna be too loud yet!



Edited by MikeRace on 3rd Jul, 2007.

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/


johnK

1425 Posts
Member #: 690
Post Whore

Norfolk

yip - that one may burble just a little!

Will - thanks it is quite important to the dynamics of the cars to flush the rear floor area off - especially running beam style axles. When I first built the car in 96 it ran for a year without the tray but was very oversteery/ unstable at high speeds, lift off situations - 97 saw the tray go on and it really does keep the rear on the floor at high speeds

JK

If Carling made Mini engines
it would probably be like this one!


dn89mini

User Avatar

143 Posts
Member #: 1506
Advanced Member

Cheshire

Does anyone sell an undertray like that?

Check out the (slow) progress at.......
http://www.turbominis.co.uk/dn89mini


Badger

User Avatar

197 Posts
Member #: 1488
Advanced Member

Bristol

Aye, also interested in the rear tray... heard about them but never really seen one before. Looks easy enough to make, but I'm sure I'm wrong lol *happy*

There is no sense crying over every mistake- you just keep on trying til you run out of cake.


wil_h

User Avatar

9258 Posts
Member #: 123
Post Whore

Betwix Harrogate and York

You'll have to make your own I'm afraid boys. Big sheet of alloy, bent to shape thwn rivited to the subframe.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph



On 2nd Jan, 2013 fastcarl said:

the design shows a distinct lack of imagination,
talk about starting off with a clean sheet of paper, then not bothering to fucking draw on it,lol

On 20th Apr, 2012 Paul S said:
I'm mainly concerned about swirl in the runners caused by the tangential entry.


mikemph

450 Posts
Member #: 449
Senior Member

Oxford

Don't spose you have some more pictures? so I could knock up one at work.


Turbo Shed

1303 Posts
Member #: 30
Post Whore

Epsom, Surrey

i think i will make one as well.



where did i leave the cardboard and sticky backed plastic?

Home > Technical Chat > straight thru exhausts
Users viewing this thread: none. (+ 1 Guests)   Next ->
To post messages you must be logged in!
Username: Password:
Page: