Rob H
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Off the top of my head, a 1.6 16v with a mantzel or similar would make 120 brake, and the same engine with Throttle bodies would make 140 ish both after a mapping session.
There's probably loads of reasons why you can't do it, but where do you think a system would come in that used two standard throttle bodies and inlet tracts.
i.e two tb's, two airflow meters, and two filters? Think 4-2 inlet manifold, not 4-1.
Obviously provided you have the space to do it, but do you think it would work?  .
[Edited on 15-04-2007 by Rob H]
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AK
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Location: Aberdeen City
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what? what? what?
Like a TB and inlet for 2 cly, then the same for the other half?
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jr
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no
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Rob H
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quote:
Originally posted by AK
what? what? what?
Like a TB and inlet for 2 cly, then the same for the other half?
Yeah 
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Robin
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Registered: 7th Jan 04
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There would be no significant gain over the standard setup, and it would cost as much as TBs, as you'd need management to cope with the extra sensors.
[Edited on 15-04-2007 by Robin]
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Rob H
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quote:
Originally posted by jr
no
I'm thinking aloud, so need reasons why it wouldn't work.
There would be gain as your still doing away with the 4 foot inlet system. A TB set up works as you have an indiviual feed to each cylinder with a butterfly for each. Surely this is just going half the way towards it, only really needing a special manifold made up?
Not sure how the sensors work, always presumed it's just a voltage, and can't see why you can't just use one sensor, as the other one will be telling you the same thing.
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AK
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but WHY on earth would you go to the trouble when TB's are an off the shelf solution.
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Rob H
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Cost - if you can get gains better than a mantzel (which i'd expect), but only marginally less than a TB set up for the price it costs you to knock a manifold together (next to nothing if you can get the pipe and welding done for beer tokens), then why not?
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AK
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Location: Aberdeen City
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x2 AFM
x2 TB's
x2 induction
2 complicated manifolds
you sure its a cheap thought
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Robin
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Registered: 7th Jan 04
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quote:
Originally posted by Rob H
if you can get gains better than a mantzel (which i'd expect), but only marginally less than a TB set up
Not a chance.
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Rob H
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quote:
Originally posted by AK
x2 AFM
x2 TB's
x2 induction
2 complicated manifolds
you sure its a cheap thought
AFM, induction & TB should be fairly cheap to pick up if somoenones gone the Throttle body route
Manifold is nothing more than a standard lower one cut down, and a Y piece welded on with a flange to fit the original TB to.
If you find the right parts cheap, can't see why you couldn't try it for under £100 .
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Rob H
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quote:
Originally posted by Robin
quote:
Originally posted by Rob H
if you can get gains better than a mantzel (which i'd expect), but only marginally less than a TB set up
Not a chance.
Why not? your doubling the area through which the air has to pass through the throttle body, and if done right you can get rid of the nasty 0 degree radius 90 degree turn the air has to do in the mantzel box to get into the lower inlet  .
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AK
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quote:
Originally posted by Rob H
quote:
Originally posted by AK
x2 AFM
x2 TB's
x2 induction
2 complicated manifolds
you sure its a cheap thought
AFM, induction & TB should be fairly cheap to pick up if somoenones gone the Throttle body route
Manifold is nothing more than a standard lower one cut down, and a Y piece welded on with a flange to fit the original TB to.
If you find the right parts cheap, can't see why you couldn't try it for under £100 .
try it then and let me know when the 100 is gone
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Rob H
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Small problem of needing a car first .
In theory though, if you can get it to work there's no reason why you shouldn't see good gains .
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Robin
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Registered: 7th Jan 04
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quote:
Originally posted by Rob H
Why not? your doubling the area through which the air has to pass through the throttle body, and if done right you can get rid of the nasty 0 degree radius 90 degree turn the air has to do in the mantzel box to get into the lower inlet .
You'll make more than a Mantzel, yes, but it will DEFNITELY cost you mroe than £100 to do it right, and you won't see anywhere near the power you do with 4 TBs, a basic 4 throttle kit will see 160bhp on a STANDARD engine.
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Rob H
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quote:
Originally posted by Robin
You'll make more than a Mantzel, yes, but it will DEFNITELY cost you mroe than £100 to do it right, and you won't see anywhere near the power you do with 4 TBs, a basic 4 throttle kit will see 160bhp on a STANDARD engine.
Like i said, it depends what can be bought on the cheap/at mates rates.
TB output was more than i thought it would be, so no don't think you'd get particularly close. It should flow much better than the mantzel does though, and also - something i've just realised, you should keep your equal length manifold, which you loose with the mantzel.
Judging by how much time and effort vauxhall spend on the standard engine to keep it equal lengths (i/e the cast manifold on top of the engine - unsure how far along this goes though?), i'm presuming it's quite an important factor .
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ShEp
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seen it done on an s1 rs turbo,
was in performance ford years back,
i wouldnt even know where to go looking for pics 
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Dave A
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Registered: 10th Dec 03
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£100?
what about the £1000+ for management, loom and mapping
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Rob H
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Why would you need aftermarket management?
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Dave A
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because the standard ecu wouldnt cope with 2 afm signals and go into limp home mode, also the fuelling and ignition timing would need mapping to suit the new mods. and then theres the fact a standard loom wouldnt run 2 seperate tps, icv's and afm's
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Rob H
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Registered: 28th Oct 00
Location: Staffordshire Drives: Astra SRi
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How do the AFM signals work though? Are they a pulse, or a constant voltage that varies with the amount of air flow?
i.e can you bodge the wires together off two AFM's to the ecu, and it'll think it's getting one signal .
Like i say i'm only saying in theory it should work better than a mantzel - getting it to work is where it's make or break .
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AK
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Location: Aberdeen City
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i'd think they'd be a varing voltage acording to air flow.
Bodging two AFM's togther is defeating the point of having two.
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Dave A
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I would imagine you would see better gains on a well set up engine with a mantzel.
the other problem is the Icv wont give the correct amount of air for 2 cylinders so it will idle high as you have each one running half of its equivalent on a standard inlet.
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Rob H
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quote:
Originally posted by AK
i'd think they'd be a varing voltage acording to air flow.
Bodging two AFM's togther is defeating the point of having two.
Suppose it depends on the frequency of the readings, i.e if it takes 10 readings every second and creates an average, bodging the two shouldnt make too much difference, compared to if it takes a couple of thousand every second to get the exact air flow going into a cylinder - if that makes sense?
TBH I didnt give the ICV's much thought  .
Think the concept is good, but the problems associated with doing it properly are more hassle than their worth .
Only thing i don't like about the mantzel is the way the air has to travel through a "square" 90 degree turn to get into the lower inlet. Just think there's got to be a better way of doing it, cause that's surely not doing any good for the airflow at all. Ideally you want something similar to the inlet on the Redtop, where it's much shorter than on the small block XE's, but still has nice flowing lines without sharp bends .
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ainsley_brader
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Location: Tattershall, Lincolnshire
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this is something i had thought of in the past.
I don't see why you would need two air flow meters tbh, could do it off 1 regal tb style.
I also think you could get away with 1 tps.
And just split the icv wire to both icvs so they work together to balance the cylinders.
In fact having read this thread i think i have got enough parts lying around the workshop to try it for less than £100.
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