"Hotdog" is a resonator.
Offers very little muffling.
Awful type of exhaust system in my opinion.
Sounds "okay" when going full throttle, but the backing off makes it sound like shi-ite.
Not to dissimilar from the noise that a donkey makes.

IMO this whole back pressure thing is a myth or urban legend..
What IS important is the mixture is correct through the rev range- if you go to a straight through pipe with no muffler, you will probably have to change jets or needles to achieve this .
Most race Minis have bugger all back pressure, and they don't burn valves. Of course their valves are probably (maybe) better material than stock.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

ATC put 36mm (or 38 cant quite remember) venturi in the weber when they rebuilt it, and that was going on what the engine was. He said that should be ok for starters, but yeah we do have a couple of workshops down here with dynos, but none are familiar with Minis I used to run 40mm venturis and it ran a little rich, but that didnt bother me)

There is a local Mini guy who races Minis, he might be able to tune it enough for driving to Perth for proper tuning.

Yay, so hot dogs it is

ummm whats BHP?

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78 van 1300 cam extractors weber, 12" Superlights Metros Konis HiLos MP3 Amp Sub Alpine speakers and lots of fur
www.crazybitchracing.com

Brake Horse Power....

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

aaaaaaaaaaaaaaah yeeees it will

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78 van 1300 cam extractors weber, 12" Superlights Metros Konis HiLos MP3 Amp Sub Alpine speakers and lots of fur
www.crazybitchracing.com

Sounds like a job for Mythbusters!

You could buy the exhaust where ever and take it to Perth and get someone to fit it then drive it around the corner to get it tuned or does the 'hotdog' have to be bought and fitted locally

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Roads need more corners
A Deluxe(CG13DE), 2 Clubbies(998 and 1275) and 2 Morris 1100Ss

what does the (brake) in braking horse power stand for?

me and another kid almost had a punch on over this we were playing GT4 and he reckons they used (british horse power) and i reckon it was (braking horse power)

whats the drifferance in the two?

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67' Matic
73' S

It's properly called brake HP because it is measured by a brake (dyno).
This applies whether it's an engine dyno or a rolling road (chassis dyno).
Obviously the numbers are different though.

The old British RAC HP (eg Morris 1100, 10.4HP) rating used to be used to determine road tax/insurance costs there and here. It was determined by bore(2) x (no of cyls) /2.5 or something. The stroke was not considered. That's one reason why Pommy cars had such long strokes...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Thanks Kev makes sense now

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67' Matic
73' S

No it doesnt have to be fitted locally, thats just a lot easier. I can drop it off, walk home, work, go pick it up when its ready. Perth is basically a day trip and while their working on my car I have no transport There are dyno workshops around town, I'm sure they can tune it so its running ok (not too rich, not too lean). Then I could get it tuned by Mini specialists in Perth next time Im up there.

2 x 9" hot dogs, 1.75" pipe and fitting to my extractors $199.
Im thinking I might pull the existing exhaust off and get them to match it (shape wise) but with hot dogs instead of the muffler Ive got now. I just have to get a new exhaust manifold gasket and I can fit the weber at the same time

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78 van 1300 cam extractors weber, 12" Superlights Metros Konis HiLos MP3 Amp Sub Alpine speakers and lots of fur
www.crazybitchracing.com

This guy sounds like a toss and is geared to jap cars, but the principals are the same on our fours as theirs.

http://www.nsxprime.com/FAQ/Miscellaneous/exhausttheory.htm

And this will give you a better understanding of what he is talking about.

http://auto.howstuffworks.com/muffler.htm

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Ive been using 2x 18" hot dogs on all my mini builds for years,,,they work a treat

not loud at all & allow heaps of flow, no problem what so ever,,,

i`m not a fan of just one hot dog tho,,,way too loud & get louder & LOUDER as it burns away with time/use

With My race minis (in the past) i would have a tuned length 2" system (Tuned to the quietest length) with no mufflers at all, BUT!!!, i would shove a muffler over the top just to please the screw-tin-ears

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Hi Jill - I was talking to Al the other day and he mentioned that Darryl Penley has closed his business. I just checked the ATC website and it says this...


I still recommend you try Mini Central - Al tuned my weber before I took it to Darryl's and they hardly changed anything. I do like the precision of a dyno, but i reckon you'd be much better off with Al than a dyno operator who doesn't know mini's. He can tune it however you like and will get it pretty much spot on just by experience and test driving it... and as a bonus Rockingham's also much closer to you than Welshpool

however if you do happen to find a good local dyno operator in Bunbury i'd be interested in knowing about it for when i move down there... bought a block in Dalyellup...

Thanks Geoff, I also went to their website and found the same Al was going to be the next point of call as Ive been meaning to go see him since I started the rebuild project. I will get there.. one day
Once Ive got the weber and exhaust sorted I'll book my Mini in for a tune.
Theres a couple of dynos down here, but none are Mini familiar to ANY extent as far as Im aware, and I couldnt recommend one as I havent had a lot to do with any of those workshops.
You're moving down here... and Im moving to Perth end of this year

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78 van 1300 cam extractors weber, 12" Superlights Metros Konis HiLos MP3 Amp Sub Alpine speakers and lots of fur
www.crazybitchracing.com