[Healeys] Exhaust system advice needed

Bob Spidell bspidell at comcast.net
Thu Sep 10 11:49:41 MDT 2009


FWIW, there's a TV show I watch called "Horsepower TV" where they regularly try mods to engines and test them on an extremely elaborate ($$$) engine dyno. Some mods are very extensive, but sometimes they test little things like aftermarket exhausts and ignitions. Granted they're usually testing big block V8s with lots of HP to begin with, but they usually get a few HP by just bolting on a bigger/better-flowing exhaust. 

>From what I hear the Healey exhaust is particularly restrictive, so I can believe you might get a couple of extra ponies (not necessarily torque) with a better flowing exhaust. 

bs 

-------------------------------- 
Bob Spidell - San Jose, CA 

----- Original Message ----- 
From: "Eric (Rick) Wilkins" <e-wilkins at cox.net> 
Cc: "Healey List" <healeys at autox.team.net> 
Sent: Thursday, September 10, 2009 10:23:15 AM GMT -08:00 US/Canada Pacific 
Subject: Re: [Healeys] Exhaust system advice needed 

I'm pretty sure that in the case of a factory Healey, the added flow 
is going to give an increase in performance as the stock system--BN4- 
BJ7--is smaller than the opening allowed by the carbs. 

Wilko 

On Sep 10, 2009, at 1:06 AM, Oudesluys wrote: 

> What strikes me is that a lot of people have changed their exhaust 
> system for a more free flowing/louder set up and claim they have 
> increased power. True/false? It feels faster because of the noise 
> but in reallity hardly ever is, because neccessary alterations on 
> the carb side are and probably ignition are ignored, not to mention 
> the possibly neccessary changes in camshaft timing. These all need 
> to be reset as the free flowing exhaust only will upset the overall 
> balance in the engine settings. 
> Just try to drive without exhaust system (free flow in extremis) and 
> see what happens. It will seriously affect drivability. 
> The so called improvement is often observed compared with a rotten 
> exhaust in the first place. 


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