extractors --(simmo)

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

can anyone tell me what the best extractors for my basically stock TE gem are( on a budget of course )
i have single 32/36 weber stage 2 cam and 2 1/4" exhaust
Thanks.

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

Pacemaker tuned length four into one extractors would have to be my suggestion based on dyno testing by mark on his gemini 1600 rally car. 13hp at the wheels gain on a regulation stock motor, $240 or so...

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

i was under the inpression that 4 : 2 : 1 extractors were the best is this so??? ta

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

In overly simple terms 4-2-1 extractors are designed to make torque and power at low-mid RPM and 4-1 extractors are designed for outright HP at high RPM.

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

so for my gem which is quite mild and is a daily driver, 4:2:1 would be best ??? thanks for the info adam

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

Yep, I would stick with 4-2-1s, that said, we have done just about every possible modification to destroy the bottom end torque of my engine (in return for top-end power). So if I had the dosh I'd just say fuck it and fit the 4-1s

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

Adam, when you say regulation stock, as you probably know, its not really stock. Standard bore and ports, but balanced to the finest degree with a 35/75 control cam, and modified carburettor off a 2 litre rodeo. They go a lot better than stock thats for sure. Standard motor wouldnt get anywhere near that sort of hp gain, and 4 into 1s only really benefit a finely balanced high revving motor.

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

i think i will go with the 4:2:1 It is my understanding that these extractors increase low to mid range torque and power. This, in my understanding should translate to increased acceleration and power at low revs ( good for street driving ). Is there much difference between the various brands of off the shelf extractors eg genie outlaw etc and if so which would you recommend please feel free to correct me if im wrong ta Simmo

old forum · hod rodder Joined: 04 Oct 2001 Posts: 15499

I couldn't agree more, however I would argue that a fairly good proportion of the geminis owned by readers of the hotgemini.com forum are in fact modified to a greater degree than is allowed under the CAMS regulations for either the QLD gemini rally series or the QLD gemini circuit racing series and may/should/could make a greater power gain at the wheels.

I have the greatest respect for any engine builder who specialises in making motors which extract the most power from a control engine, IMHO it shows attention to detail and a willingness to spend hours on R&D as to which component can make the most power (I was amazed to watch numerous different spark plugs tested on a gemini circuit motor on an engine dyno). As proof of my convictions, every company which was involved in the building of gertie's engine has wide-ranging experience in gemini 'control' motors