Throttle Body Setups - Trumpets

[rushy_23]

After much more reading into TB Setups and that, Ive realised that even down
to the trumpets you use makes a bit of difference!
The ideal spec Ive always been looking at is roughly as follows:

supersprint 421
pugsport
ITBs - no sure of characteristics yet
most likely omex management
piper 285s or catcams 708s
gas flowed head/port polish
forged pistons
l+b flywheel

Its not a really ambitious setup as thats not what Im after, but with regards
to that sort of spec, what kind of trumpets would I be looking for?
Seems theres different length and radius ones, what benifits do that have in
general and also for my own spec.

[leeroybrown]

If it was me i would

supersprint 421 - change to the GMC 4-1 the new one which is 2 1/4 bore
pugsport - Am sure these where only good to 150, so again i would go for BTB
ITBs - no sure of characteristics yet- Check Ryans and JP's mate i think they are the bestmost likely omex management
piper 285s or catcams 708s defo 708's or even the newmans PH3's
gas flowed head/port polish, go for a big valve head maybeforged pistons defo
l+b flywheel defo

[rushy_23]

Cant really justify the BTBs mate. Seen a lot of setups now running 2inch
bore systems and pushing out 165bhp+. Doubt I will be running a huge spec.
Just want a nice simple setup that will keep me happy.
Wouldnt mind a big valve head but that means more monies

Hoping Ryan and Josh will put some input in when they have time. Im going to
have a chat with my Pug guys on Tuesday you see about the setup. See how
much of my hard earned they are wanting.
Might have to do it in 2 stages but thats not an issue. Monies still a bit tight
like but just want to know what Im looking at.

[Toad]

With regard to the actually TBs, I read a very interesting thread on SSC yesterday. I believe the chap with a fair bit of knowledge is called 106rich or something close to that? Anyway, he was talking about a 45mm TBs, tapering them to 42mm which would allow the use of a longer airhorn. I'm not exactly sure how this works in practice, but it was interesting nonetheless...

[rushy_23]

Sounds a bit extreme lol!

I was looking at the 42mm but tbh I dont really know whats out there and also
what the different types are like. Will keep reading up.

[williamsvts]

if your using forged pistons why not go for a wilder cam?
my mate is using 110mm length trumpets on his corsa, the longer inlet tract helps make more torque.

[KamRacing]

simple rule of thumb, for torque in the mid range, go for long trumpets, for top end power run them short.

pulse tuning seems to be very important with the saxo engine so cut the bulkhead to run longer trumpets and give them space...

[jeeves_101]

i'm looking into bodies, but at bike ones.

i know people don't seem to keen on them, but it's to a budget and i'd love bodies.

also, the GSXR1000 has tapered bodies, 42mm on the head side and 44mm on the filter side, and i believe its for the use of bigger/better trumpets.

[jeeves_101]

Originally Posted by KamRacing

simple rule of thumb, for torque in the mid range, go for long trumpets, for top end power run them short.

pulse tuning seems to be very important with the saxo engine so cut the bulkhead to run longer trumpets and give them space...

instead of cutting the bulkhead, could you not lengthen them by curving them?

have seen some thing like this on gmc's website iirc.

[rushy_23]

Problem I have then Williams is then I will need to look into larger bore exhausts
and Im sure you need to uprate other bits and bobs to run wilder cams.
Its not stupid power Im after as tbh. Just a good setup for fair money.

Longer trumpets sounds interesting, but does your power/torque higher up
the rev range suffer? Is there a fair compromise.

[williamsvts]

the thing is though, you going to spend a few thousand for 170hpis at the most. is it really worth it? i would think about boosting it.

[jeeves_101]

sorry for the jack, but while on this topic, what sort of cams could be run with bodies?

i'm considering newman ph4's, could i run them with tb's and standalone ok?

[rushy_23]

Originally Posted by williamsvts

the thing is though, you going to spend a few thousand for 170hpis at the most. is it really worth it? i would think about boosting it.

Im a fan of NA over Turbo'ing. And being honest if I went for a Turbo I would
go the whole hog and make sure its reliable - which is my main concern.

I want a reliable setup. Dont mind paying 3k+ for 170bhp on TBs. Being honest
on the track to get the full potential out of the 120bhp is more difficult than
you think. So trying to use the full 170bhp and the wider power band to its
max potential on track will take time and experience.

[Toad]

Williams has a fair point, but so do you Rush. Your decision at the end of the day...

My next step will be keeping the 708s in for now. If I feel like I want to spend the extra couple of grand to run high lift / duraiton cams, then I'll cross that bridge when I come to it so to speak. But you have to draw the line somewhere don't you?

I'm still edging towards the KMS setup, which includes their own DTH bodies and ECU. Unless someone can prove to me that there's a better / cheaper option that is...

[KamRacing]

Originally Posted by jeeves_101

instead of cutting the bulkhead, could you not lengthen them by curving them?

have seen some thing like this on gmc's website iirc.

no they will restrict the engines performance. Induction angle is very important in getting the best state of tune. Extra bends screw up the pulse tuning and i dont think GMC got great results compared to a more traditional setup. To be honest its so easy to cut a box section out the scuttle panel that i wouldnt consider any other route..

[KamRacing]

throttle bodies may not have the ultimate power but they make up for that with instant throttle responce - And quite frankly a sound that makes you grin like your insane. My girlfriend used to be scared of the noise of my 205 lol

[Toad]

Kam, can the increased length actually lose you power towards the top end where you might actually want the power? Or are there only benifits by increasing the overall length?

[leeroybrown]

i wouldnt go with bike bodies tbh

never seem to make good power

[KamRacing]

Originally Posted by Toad

Kam, can the increased length actually lose you power towards the top end where you might actually want the power? Or are there only benifits by increasing the overall length?

its a bit hard to generalise these as when building individual engines they react differently to fine tuning. As a rule of thumb longer trumpets will move the peak power down the rev range, whereas shorter will move it up.
For a road engine ou want a big spread of torque across the whole rev range rather than creating a peaky engine that needs to be thrashed to get any performance.

Originally Posted by leeroybrown

i wouldnt go with bike bodies tbh

never seem to make good power

I havent seen any make good power compared to a kit made for the car. Usually because there are so many compromises in the inlet manifold design.

[jeeves_101]

will you see any gains if using bike bodies?