Poping exhaust sound on rally cars.

[Mike Zamikhovsky <MikeZ755@sprintmail.com>]

Brett Corneliusen wrote:
> 
> Just thought I would ask who had the 20V at Maine.  Sprongl's car is a
> 10V Turbo...
> 
> Also if Orisek's car idles like this-
> 
> Blaaaat, pop,pop,pop,pop,pop
> Blaaaat, pop,pop,pop,pop,pop
> Blaaaat, pop,pop,pop,pop,pop
> Blaaaat, pop,pop,pop,pop,pop
> 
> it's gotta have a pretty radical cam in it
> 
> Both of the Hyundai's and the Lancer Evo II sound that way too.
> 
> --
> Brett Corneliusen               mailto:afmoa@skypoint.com
> VW/Audi owner                   accountible for my own actions
> Cendiv ProRally Page----->      http://www.skypoint.com/~afmoa


It is great to see interest in rally technology from Q list subscribers I 
hope that it will make our sport grow. The reason for poping noise is 
that in order to keep turbo spinning when shifting using clutch (no crash 
gear box) it is possible to retard ignition timing at idle speed so that 
not all fule is burned and some of it goes to exhaust manifold where it 
exploads and propels the turbo.One needs to redevelope exhaust manifold
so that it can survive this punishment. Carl Merel's Ford has this beefed
up manifold, but he still destroys it. 
This began to appear when it was possible to have several programs for 
ECU so that they could be switched at a push of one button. Untill 
recently only works rally teams could get this developed. However now 
Autotronoics, which in this country is destributed by Murry Thomas of 
TAD( the guy who maintains Henry Joy's Mitsubishi Lancer)has option of 
multiple programs. If Ivin still uses his Halltech
his car will keep popping in transit because Halltech allows only one 
program at this time. Factory rally efforts however go further and relate 
programming of their active differentials to programs of engine ECU.
Alsow water injection is connected to all that. Toyota Motorsport allows
5 different programs to be selected by the driver and switched at speed 
when road conditions change.This technology is allready available for 
sale to Toyota Motorsport customers ( those ten fortunate ones in line to 
purchase new Corolla World Rally Cars for next year). Who wants to mess 
with vintage Audi S1 after that? It could not keep up with even moderate 
GrA cars of mid 90's.Dialynx has Hannu Micola's car. They consider it 
strictly as collectors item.
By the way Dialynx purchased Autotronocs system capable of multiple 
programs from TAD and plans to develop a bolt on EFI kit for 10V Turbo 
engines and sell it with all the modifyed sensors and a program (don't 
know for what state of tune) for about US$2300. They promise to use Dyno 
for development.
All this is a small portion of world rally technology that is finding its 
way into our ProRally seene. I like to visit UK in the fall and learn all
about it.You get to see application of technology to the highest 
levels and much of it in Mom and Pop racing shops.

Mike Z