fiestaturbo.com

[sunnyFRST]

Firstly before you read this thread please note we are not having a laugh and the information below is accurate! - trust me (just the same way as we all trust other people's power claims on the internet)

Just before FezzyTurbo got his new exhaust fitted we laughed about which type he should go for.
Me and FezzyTurbo were in deep discussion regarding the diffierence in Outward Rolled Exhaust Backbox tail pipes and Inward Rolled Exhaust tail pipes.
We wanted proof therefore we took a certain FRST to a rolling road along with 2 exhaust back boxes...... the results were amazing (We were both shocked!)

Inward Rolled Exhaust produced 184bhp on standard injectors and a T3.

Outward rolled Exhaust produced 230bhp on the same engine!

Wow - what a diffierence!
Everyone get your exhausts sorted to 'outward rolled back boxes'.
Me and Fezzie are gonna!

Sunny

[Fezzy Turbo]

Yes in deed folks....the truth is there.....

Myself and Sunny were absolutley gobsmacked when we saw the differences, i think it has something to do with the exhaust gases getting a smoother exit with the outward rolled tailpipe.....this means the turbo has less strain and can produce more power.

get them rolled out!!!

[sunnyFRST]

even PaulR was with us and can confirm that this is accurate!!!

Sunny.

[Jon ERST S2]

Was that with or without the Max Power stickers?

[Doc]

I can confirm also, but i thought you would have picked up on this earlier Sunny/ Fezzy??
I came across this a few months back when i read Max Power they stated i should be getting +16 BHP with a S/S exaust, i was only getting around 4 BHP increase!!!
After looking at this further i came to the conclusion that the inward rolled exhaust was causing fluctuating turbulance on immisions, thus i simply rolled the lip outwards to improve immision flow, hey presto the next trip to the rollers + 25BHP!!!
WOW.
I`m now looking into the inlet side of induction and after removing the Turbo lettering on the cross-over pipe i`ve noticed gains also, i will let you know the full outcome.
Doc

[packers]

cool thats wicked.....who would have thought summat so small could make such a difference!!

[Project]

Think Doc's havin' a bubble here ...

[sunnyFRST]

It's True...It's True! - I knew no-one would take us seriously! The facts speak for themselves!!!

Sunny Outward is the way to go.

[Project]

Not you Sunny you numpty! I meant Doc - how does the "Turbo" lettering affect the airflow? Is it embossed inside the pipe? Or is he just pulling our chains????

[Doc]

The Turbo lettering IS embossed inside the pipe thus causing an induction "rippling" effect, not good! I`m investigating this at the mo, "clean" air = smoother induction = increased power.

[Project]

Well fffuuuuck me you guys really *are* nutters!

[elm_us]

so the outwards rolled is just on the backbox or the whole system

(does it have to be a s/s system)

(whats backbox?)

[TrekkieFRST]

It's true that having smooth exaust ports can increase power but with inlet ports if the air and fuel moving in are turbulent it will allow for a better mix of fuel and air thus providing better burn in the engine so I don't know whether it's better smooth and rough for inlet

[Doc]

Trek, thats what I`m investigating!

so the outwards rolled is just on the backbox or the whole system

(does it have to be a s/s system)

(whats backbox?)

Just the backbox, the whole system should be clear of any obstruction.
S/S has a smoother surface and is treated different from frous metals this gives even more airflow so expect bigger gains from S/S
A backbox is the final part of the exhaust system that pertrudes out of the rear of the vehicle. ie. mine is a 4" OUTWARD rolled backbox tailpipe.
Hope this helps:wink:
Doc

[elm_us]

ok thats kewl i thought u or people have to roll em them self

[EvilFranky]

STOP TALKING ABSOLUTE B-O-L-L-O-C-K-S!!!!!!!!!!!!!!!!!!!!!!!!

[Robin]

i don't belive that, how does having a different desgin tailpipe give such a increase in BHP.

[Project]

Anything that helps you to breathe more efficiently and more smoothly will allow a more effiecient combustion - compare it to human breathing if you like. How much easier is it to breathe out hard with your lips curled inwards over your teeth, and outwards??

And inlet tract airflow needs to be turbulent only after the TB usually - up to that point the smoother the surfaces of the inlet tract, the more fficient and faster the airflow.

As far as tuning goes, these things are really only the icing on a well-tuned cake in the first place. Putting an s/s exhaust and an airfilter on a 1.1 doesn't mean worrying about the above becomes necessary in general terms at least.

[sunnyFRST]

On 2001-12-19 07:11, EvilFranky wrote:
STOP TALKING ABSOLUTE B-O-L-L-O-C-K-S!!!!!!!!!!!!!!!!!!!!!!!!

We didn't believe it also but It's true..It's ture!!

Sunny.

[chumkila]

Thank you Sunny. good timing as im gona bet changing me exhaust real soon!

[Doc]

AH HA, Theres another trick to squeeze that extra BHP out, polishing the inside of your backbox, no sooty deposits in my backbox distrupting my airflow
I cant believe these secrets are coming out
I suppose people would find out in the end

[Paul R]

It does sound like crap.. but the evidence was there right in front of us!
You learn something new everyday

[EvilFranky]

This has gone on long enough...i'm calling the men in white coats for u boys...

I mean 230bhp on standard injectors! LOL

_________________
Later

EvilFranky...



<font size=-1>[ This Message was edited by: EvilFranky on 2001-12-19 09:03 ]</font>

[Paul R]

Fezzie has got a Focus RS fuel pump and FSE power boost valve, so i guess he's able to get the fuel through somehow

[EvilFranky]

Paul...stop it, u know thats got nowt to do with it...

[Mike Gurney]

This sounds like it should be reproduced on a dyno for everyone to see the results.

anyone want to do this ??

I wonder what the bhp would do if there was no back box at all.

Over here in Auz they already know about inward rolled exausts and most manifolds and pipes have special outward welded seams to improve hp !!

Mike.


p.s - I would like to say tho that 230 bhp from std injectors just sound very suspicious !!! - who's rollers were they ??



<font size=-1>[ This Message was edited by: Mike Gurney on 2001-12-19 09:29 ]</font>

[Jon ERST S2]

The rolling road operator was a guy called Max on Power rollers in Peterborough.

[Jon ERST S2]

the injectors were taken out and outwardly rolled to increase their flow - that is how they managed to get 230bhp

[~Lexy~]

If u think about it makes sense really
just take a moment to think about it.

[Project]

I'm still mulling this over, since the maximum bore of the tailpipe on an inward rolled box can still be larger than the overall bore, and yet it can cause these probs, kinda like shockwaves.

Port-matching the zorst ports is done for the same reasons too I guess, but the massive change in power between back boxes could well be attributed to the internal design of the box as much as anything

[sunnyFRST]

Why the hell some of you lot not taking me serious!? - this is soo true!
If you wanna joke about it...it's your loss!
Knowledge is power!!!
Everyone else - remember, outward folded exhaust tail pipes are the dogs!

Sunny.

[Mike Gurney]

Sunny - who's rollers were they ?

Mike.

[Doc]

Will your flamer kit not interupt the flow? Try removing it you "may" get over 300bhp

[sunnyFRST]

Mike the company that carried out the experiment do not wish to disclose their name.
Doc - It wasn't my car that was the test vehicle

Sunny.

[Doc]

Was it Fezzy`s??? Cause that cheeky scamp has took his side stripes off to improve aurodynamics, then sold em to me so i am slower!