The second hand jenveys I have bought came with 19mm stubby trumpets. Is there much to be gained from increasing the length of these?
Cheers
Adrian
bottom end power so it seems me old fruit
they have a handy if long winded explanation on their website, in the FAQ section, worth a read.
but in the real world of driving your car can you even tell lol
quote:
Originally posted by imp paul
but in the real world of driving your car can you even tell lol
I have had some calculations done for my engine build, it takes in a lot of factors, cam duration, lift, etc, etc... If you have done or are
considering doing a serious engine build then intake length and exhaust primary lengths + the rest of the exhaust all come into play.
Find out what length of intake you need for your set up and use it but in the main it's all the factors together that make a real difference.
If you want some longer trumpets I have some to swap? assuming 45mm TB's of course. I have some at about 50mm, 65 and 90mm from memory
(don't ask, I keep getting things wrong
)
quote:
Originally posted by r1_pete
quote:
Originally posted by imp paul
but in the real world of driving your car can you even tell lol
Anything less than WOT I'd doubt it, just my opinion of course.....
If I recall correctly, it is as said ^^^^, more than just trumpet length, and on the jenvey site they talk about the position of the injectors too,
either close to the head, or further out, for locost, I guess it will be a compromise unless you are able to have adjustable inlet lengths and
injection positions,...
I am going to fit TB's to my zetec, and it will be what fits in the engine bay, combined with anything I can read, and learn here.
Here's an idea.
If you put on 2 short trumpets and 2 long trumpets, would this not give you some more low down power from a couple of cyclinders, more top end from
the other couple, so it wouldgive you a net effect of increase power all up the power band.
Go on, try and disprove that logic!
quote:
Originally posted by balidey
Here's an idea.
If you put on 2 short trumpets and 2 long trumpets, would this not give you some more low down power from a couple of cylinders, more top end from the other couple, so it would give you a net effect of increase power all up the power band.
Go on, try and disprove that logic!
quote:
Originally posted by HowardB
If I recall correctly, it is as said ^^^^, more than just trumpet length, and on the jenvey site they talk about the position of the injectors too, either close to the head, or further out, for locost, I guess it will be a compromise unless you are able to have adjustable inlet lengths and injection positions,...
quote:
Originally posted by matt_gsxr
quote:
Originally posted by r1_pete
quote:
Originally posted by imp paul
but in the real world of driving your car can you even tell lol
Anything less than WOT I'd doubt it, just my opinion of course.....
Anything less than WOT, then why bother starting her up??
I like the idea of two sets of injectors, especially as I have two sets, so here is the question,....
could that be done with a Megasquirt ECU?
hmmmm, this ITB thing is growing more complicated by the minute.
thanks
quote:
Originally posted by imp paul
but in the real world of driving your car can you even tell lol
I've seen the effect trumpet length has on mine on the RR at Dave Walkers place.
I have 20mm trumpets on mine. Dave set the car up and when he'd finished hje fitted sliding trumpets and then experiemented by adjusting them and
doing power runs.
Result is at 90mm I got the best gain. 10lb/ft of torque increase in the mid-range and a 6 BHP loss off the top end. It is all a compromise and on the
road that would be the best option for my car. On the track and at high revs the horses would probably be best.
HTH's................. Neil
2 long and 2 short trumpets unless properly set up with a plenum like some bikes would unbalance the engine.