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twin plenum triumph stag.

Posted: Sun Oct 21, 2007 1:47 pm
by sax player
Hi all newbie to this site. I am looking to get more power from my sd1 vitesse with a twin plenum in a stag. At present i have 220bhp. http://www.youtube.com/watch?v=4xuLGI-ltX4 from standard engine.
Do i go for a bigger engine or look to replace my cylinder heads? what extra bhp can i expect from replacement heads?

Posted: Sun Oct 21, 2007 2:54 pm
by katanaman
This is one of those there isnt a right answer type of things.
Heads on their own will give you more power but without doing more stuff its limited. Bigger on its own is the same, you will get a lot more torque but your peak BHP will be limited. Add a big engine and heads together with other components and you start to make power.
It all comes down to money at the end of the day so how much do you want to spend? What kind of figures are you looking for? If your still on standard efi then thats going to start limiting you soon as well.

Posted: Sun Oct 21, 2007 7:05 pm
by sax player
ok the exhaust can cope. 3" into two expansion boxes exiting into 2 x2". twinplenum system is good , 75mm air metering unit, ( yes flapper type ) rising fuel regulator, mild road cam, Mallory dis (but i am not convinced with it). I feel better heads may help? My ultimate would 300bhp.
On the heads i am willing to say good bye to £500. am i realistic?

Posted: Sun Oct 21, 2007 7:49 pm
by katanaman
300bhp on £500 no your way off base there. 300 is big power on a rover and needs thousands. You need a new big engine and big heads to get that power not to mention loads of other parts just to get the engine to hold together. The best you could hope for on that money is maybe 250bhp if your lucky. Actually you will have to be really lucky as personaly I would say you need a new ecu to hit that figure and possibly new injectors but I dont know what ones you have fitted.

Posted: Mon Oct 22, 2007 3:10 am
by sax player
the ecu is a rovotec with a mixture adjustment and the injectors are standard twin plenum that have been overhaulled (new pintle valves etc)
i am convincing myself to look at changing the heads 250 bhp is still respectable

Posted: Mon Oct 22, 2007 8:40 am
by katanaman
If you go that route then remember and make what you have safe as in ARP main bolts and all that. Your going to have to rev a 3.5 a bit harder to get up there so you will need the extra strength to keep it all together. Something like stage 2-3 heads and a typhoon or 285 cam should get you there. Obviously easier said than done but have a good read round here and you will get a good idea whats involved