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lewis_willy2
15-08-2005, 17:43
wen i get my car back safe and well (i hope) from renault i want to do some thing to the engine, its got filter, stainless steel exhaust with decat and i was thinkin about twin 40's?

wot is the difference between twin 40's and throttle bodies?

how much for it to be done? is it a difficult job and how much power increase is there?

Fred
15-08-2005, 19:28
"twin 40's" are carbs, no EFI needed, cheap and simple

throttle bodies = not cheap

BenR
15-08-2005, 20:24
Twin 40's are carbs as Fred pointed out. To fit them that will involve you dropping your baseline fuel pressure, a DCOE flange manifold which arent great for flow. You will also be limited to a short inlet tract length with the std radiator in place AND a filter, high induction temps. Add to that the fact that 40 DCOE's are a tad on the small side if you want to be pushin over 150bhp, the whole thing will run a bit iffy and take a good long day on the RR to have the carbs setup.

Bodies cost substantially more, but running wise are superior no end.

Zollo
15-08-2005, 20:58
Carbs are good if you're on a budget. You need someone who knows what they're doing, but they can can be set up to run very sweetly. And they still give good power gains. Plus they sounds the nuts.

How about some 45's?

lewis_willy2
15-08-2005, 21:16
ok 45's sound like an option, will i hav to replace my radiator? hs anyone got any contact numbers of people who carry out such a job?

also been looking at bike throttle bodies? if i were to purchase some of these instead which ones will i be able to use on my 1.8 16v? and what other parts are needed? i read that they are cheaper?

which if u had the chance would you get? 40/45's or bike throttle bodies?

Zollo
15-08-2005, 21:48
Hmm, didn't realise you have a valver. I think 45s may be a little big for a 1.8. You'll get more top end with 45s, but 40s would drive better and give better low-end/midrange.

Mark_Ritchspeed was thinking about bike throttle bodies. Might be worth asking him?

VIPERONE
15-08-2005, 22:47
45s have been done. red valver at york..running mid 14s

kj16v
15-08-2005, 22:48
Twin 40's are good for upto 150bhp. From their you need 45s. So for it to be worth the trouble you need 45s. I've looked into this before and no one seems to do manifolds for valvers. You'd probably have to have one made whhether it was for TBs of carbs.
I haven't made any measurements but I think it would be seriously cramped on space without moving the radiator somehow.

kj16v
15-08-2005, 22:50
Ah didn't read the bit about the valver at York. So it has been done then.

Craig
15-08-2005, 22:58
it has, i was talking to the lad for ages. best he ran that day was 15.0 i think!

he claimed it was 230bhp as wll but i doubt that very much!

Martin
15-08-2005, 22:58
45s have been done. red valver at york..running mid 14s

Think he was running 15s was'nt he...anyway it was'nt as quick as the spec suggested...

kj16v
15-08-2005, 23:09
Yeah wishful thinking I reckon. 200bhp would be impressive[/i]

Fred
15-08-2005, 23:57
a certain 2.0l hybrid on throttle bodies was running 13.4's IIRC

Craig
16-08-2005, 00:02
wonder who owns that :twisted:

VIPERONE
16-08-2005, 00:28
lol.

i'll warn you now.. the mantle will be taken within the next month.... a good friend of mine has a mark 1 clio.. and im pretty sure it will oust the white throttle bodied beast of its title. ;-) non turbo also.

lool :-)

BenR
16-08-2005, 00:35
Hmm, didn't realise you have a valver. I think 45s may be a little big for a 1.8. You'll get more top end with 45s, but 40s would drive better and give better low-end/midrange.

Mark_Ritchspeed was thinking about bike throttle bodies. Might be worth asking him?

45's are fine, you can run a smaller choke and the corrent aux venturi sizing to keep booster signal really high and retain torque if your engine isnt upto much BHP wise.

BenR
16-08-2005, 00:42
ok 45's sound like an option, will i hav to replace my radiator? hs anyone got any contact numbers of people who carry out such a job?

also been looking at bike throttle bodies? if i were to purchase some of these instead which ones will i be able to use on my 1.8 16v? and what other parts are needed? i read that they are cheaper?

which if u had the chance would you get? 40/45's or bike throttle bodies?

I find bike bodies a pain.
They are cheap, but thats where the benefit stops. Their profile isnt great, you'd have to fab up a manifold, and the method of using silicone hose as part of the manifold isnt great. The throttle linkages are a time consumer if you want to space them out to the cars port spacing, and not use them in the tight bank they originally come in.

I can get hold of a DCOE manifold no problem.
And ideally you'd replace your radiator just to create more space just the like one i used on the white clio on bodies.

Converting to DCOE's isnt hard, and not really that expensive in the grand scheme. However it does get expensive if you buying new parts, as they've only just started re-manufacturing the 45's again.

BenR
16-08-2005, 00:46
lol.

i'll warn you now.. the mantle will be taken within the next month.... a good friend of mine has a mark 1 clio.. and im pretty sure it will oust the white throttle bodied beast of its title. ;-) non turbo also.

lool :-)

Just remember, the engine has another 20-25bhp in there, craig only has to reclaim them when he's feeling upto it.

2 live
16-08-2005, 08:20
lol..........manifolds for the bodies/carbs can be had from prima


45s would def be the best bet......but to get the best out of em .what no1 else seems to have hit on yet......u would be better off using a megane head, for the inlet port shape more than anything else.


carbs would be easier, bodies would be more expensive............but i dont think thered b much between em performance wise if both set up correctly

TwisT
16-08-2005, 09:36
I remember posting a similar question a while back and people said it was generally a bad idea to run 45's.........

That confused me a bit because i was thinking along the lines of the Pug MI16 engine which loves twin 45's for a good 180bhp............

so i was thinking why cant the F7R make the same power on carbs ?

Craig
16-08-2005, 09:41
an F7R can make the same power (180ish bhp) with cams and a remap!

my mate has a Mi16 on bodies and hes just shy of 200bhp.

that clio at york on 45's wasnt anything impressive at all!

Zollo
16-08-2005, 09:55
I had 45's on my old 1.9 205. Got 30bhp from head/cams/carbs. Not bad for Ye Olde engine like that. Mine ran pretty rough because I couldn't find anyone that could set it up properly.

You could happily run 45's on the F7P, and it would give big power high up the rev range, but at the expense of low down power. I was also told that 40's would make it run better and be better for low and mid range power. Surely better for a road car, driven for 95% of the time in the lower rev range? Unless it's a sprint/track car?

It also depends what other mods you have. With a wild set of cams and head work, you'll probably need 45's. If you just have a s/s exhaust, then 45's will be over kill.

Just something to think about!

jill
16-08-2005, 09:58
'Why doesnt someone take a .45 and baaaaang?'

Swervin_Mervin
16-08-2005, 11:37
lol..........manifolds for the bodies/carbs can be had from prima


45s would def be the best bet......but to get the best out of em .what no1 else seems to have hit on yet......u would be better off using a megane head, for the inlet port shape more than anything else.


carbs would be easier, bodies would be more expensive............but i dont think thered b much between em performance wise if both set up correctly

Sounds to me like this might be a plan for my proposed track weapon next year! :twisted:

kj16v
16-08-2005, 13:05
Well wadya know? DCOE manifolds on Prima for £245. I've been looking for those for ages! Shame they're so expensive. Vauxhall ones are £120 including misabs, nuts and everything else. Plus it'd need some sort of ignition management. So none of the options are really cheap. It justs depends on how serious you are about gaining power. I don't think carbs or TBs are worthwhile unless your prepared to spend enough time/money to get over 30bhp

2 live
16-08-2005, 15:12
carbs would be easy to get round the ignition problem


bodies would need standalone ecu

kj16v
16-08-2005, 20:17
how?

2 live
16-08-2005, 20:30
run a perm live to a coil wen ignition on lol.....easy

BenR
16-08-2005, 20:46
or just keep the std ecu fed with inputs so it can run a normal ignition curve.