172 Rally Car
So dth's with 90mm trumpets give a longer inlet length than sf's with 120's so what's the problem?
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Difference between itb trumpet sizes
- Thread starter Andycollins
- Start date
So dth's with 90mm trumpets give a longer inlet length than sf's with 120's so what's the problem?
A shed
Phil still thinks the sf's with 120's is a better option for length.........
Does he or does he just think that sf+120 is a better option for length than the dth on 60s and it fits with better clearance for the filter than the dth with 90?
Its the angle on the dth that seems to be the biggest issue when going in a Clio bay.
p@blo
ClioSport Club Member
Clio/A3
If this is the case hasn't anybody machined the face plate? Presumably theres enough material to realign the mounting holes?
I doubt there is enough material, it doesnt look like a very thick flange, and then you would need to mess around making angle washers so the bolts clamped up straight, why would you bother when you can just buy the proper SF setup in the first place?
A shed
Has anyone ACTUALLY tried the DTH with 90's and found it to not fit? As im told they fit without cutting, and if with cutting 120's fit on DTH's im inclined to believe the 90's fit fine.
bearing in mind Phil felt he needed to cut the bonnet for sf with 120's to fit properly (which is shorter than DTH on 90's by 10mm) i still dont understand why you guys think the sf on 120's is a better option?
All you keep saying is the angle prevents decent length when in fact the truth of the matter is that it doesnt. theres no arguing with the numbers.
And with DTH's on mine, some angled spacers and 120's im looking to have the filter in front of the grill and a huge length (teehee) that the sf's would need 170mm trumpets to match. reckon that would work/fit?
Im not at any point saying the sf's arent any good or are crap or anything like that. I just think youre being a bit narrow minded instantly dismissing the DTH's because the angle looks like it might be prohibitive, when the numbers say otherwise.
also:
from Jenveys website
Direct-to-head-bodies represent the simplest and neatest solution. They are harder to match to the inlet ports if this is required for the engine in question but have the advantage of being angled for best results, unlike a carburettor manifold.
so maybe it was jenvey that wanted the angle not Ktec (though there may have been some compromise to allow ease of fitting in the bay, i dunno)
bearing in mind Phil felt he needed to cut the bonnet for sf with 120's to fit properly (which is shorter than DTH on 90's by 10mm) i still dont understand why you guys think the sf on 120's is a better option?
All you keep saying is the angle prevents decent length when in fact the truth of the matter is that it doesnt. theres no arguing with the numbers.
And with DTH's on mine, some angled spacers and 120's im looking to have the filter in front of the grill and a huge length (teehee) that the sf's would need 170mm trumpets to match. reckon that would work/fit?
Im not at any point saying the sf's arent any good or are crap or anything like that. I just think youre being a bit narrow minded instantly dismissing the DTH's because the angle looks like it might be prohibitive, when the numbers say otherwise.
also:
from Jenveys website
Direct-to-head-bodies represent the simplest and neatest solution. They are harder to match to the inlet ports if this is required for the engine in question but have the advantage of being angled for best results, unlike a carburettor manifold.
so maybe it was jenvey that wanted the angle not Ktec (though there may have been some compromise to allow ease of fitting in the bay, i dunno)
p@blo
ClioSport Club Member
Clio/A3
Was thinking more along the lines of machining the bolt seats on the front of the flange to correspond with the revised angle on back rather than using shims. Presumably just elongate the bolt holes to account for the revised seating angle?
Can totally see where you're coming from Si and was by no means being facetious. Just struck me as odd that consensus would appear to suggest the dth approach angle to be compromised, yet nobody has actually looked to correct/optimise it.
NorthloopCup
ClioSport Moderator
Where are you getting the angled spacers from? The ones Jenvey sell are are SF bolt pattern, unless there's some others on their site? Or are you having them custom made?
A shed
Jenvey do/sell a lot more than is listed on their site - but tbh will probably get them custom made to save money
I have Mark (Icemanuk)'s old bodies BTW so if you want me to measure anything let me know.
I am still mid various upgrade fitting so I don't have it running or any figures yet.
I am still mid various upgrade fitting so I don't have it running or any figures yet.
I'm point blankly refusing to reply in threads you're in these days. You're utter lack of logic or understanding of basic math is insane.
The DTH with 90's is longer than SF with 120's. They also angle upwards a fair bit more than SF's.
I cut my bonnet because it pressed on the filter and I thought that would restrict air flow - plus it's a track car so I don't give a feck.
Why are you so sure DTH with 90's will fit when A) they are longer than the SF setup I have and B) they sit higher than the SF setup I have.
The angle looks prohibitive but the numbers say otherwise? What the f**k are you on? They angle around 10degrees up over SF's - that's both by looks and numbers LOL
They're both good setups, the DTH's are slightly longer so come with 60mm trumpets, the SF's are shorter so come with 90mm's. If you want length without f**king about with angled spacers then SF's with 120mm's fit absolutely fine with no mods.
End of.
Someone please close the thread before my "lack of common sense and logic" meter explodes.
I love you.
FINALLY that is what I was trying to say
They don't match the port angle in the head - they angle upwards presumably for clearance over air-con and other standard gubbins.
Then if you add an angled spacer down you're effectively creating two sharp angles in the inlet path.
If you open the butterflies on my setup and look down it - it's a perfectly straight path from trumpet to valve.
I am by no means an expert in air flow - but I'd say that's more optimum than two bends.
A shed
Lack of logic or understanding basic maths? Where am I missing basic maths?
All you're saying is 'it doesn't look like it will fit so I don't believe you ner ner'.
Let's apply some of that common sense you're fond of. 120s on DTH fits if you cut the bonnets inner skin, yet you think 90s won't fit? Need me to draw a diagram so you can play join the dots? Here I'll help.......wait for it......90s fit
And no one would describe a 22.5deg bend as sharp.
All you're saying is 'it doesn't look like it will fit so I don't believe you ner ner'.
Let's apply some of that common sense you're fond of. 120s on DTH fits if you cut the bonnets inner skin, yet you think 90s won't fit? Need me to draw a diagram so you can play join the dots? Here I'll help.......wait for it......90s fit
And no one would describe a 22.5deg bend as sharp.
182cup & 172 racecar
I think 2.5 deg camber should do it.
RB 182
Yup, this is exactly what I did on my home made induction setup and it fit's snugly over the alternator and smaller rad, I could have squeezed an extra 25mm out of the overall length. The angle was done on the pipes so the plate was sitting flush with the Jenvey casting.
RB 182
If you wanted extra length regardless of running 90mm or 120mm you can buy the spacers, I'm sure Jenvey will be more than accommodating to machine them with angle on 
http://www.jenvey.co.uk/home/accessories/adaptors-and-spacers
http://www.jenvey.co.uk/home/accessories/adaptors-and-spacers
Here is a picture showing the clerance issues if using 90mm trumpets:
(on the ktec kit, they fit fine as do 120s on the proper kit)
From this thread:
http://www.cliosport.net/forum/showthread.php?724562-ITB-airbox-design/page2
(on the ktec kit, they fit fine as do 120s on the proper kit)
From this thread:
http://www.cliosport.net/forum/showthread.php?724562-ITB-airbox-design/page2
A shed
Here is a picture showing the clerance issues if using 90mm trumpets:
(on the ktec kit, they fit fine as do 120s on the proper kit)
From this thread:
http://www.cliosport.net/forum/showthread.php?724562-ITB-airbox-design/page2
cheers
172
Im assuming when you say proper kit you mean the one direct from Jenvey?
Yes mate.
Bumping this back up as I have just refitted my engine and have fitted some 120mm trumpets , along with jenvey 20mm spacers between the bodies and airbox backing plate giving 140mm inlet.
I can get the bonnet shut but the filter is just touching so going to cut the inner skin out and may drill 4 holes in the bonnet to force more air to the filter aswell.
Photobucket is being a .... but will try and get pics up soon.
I can get the bonnet shut but the filter is just touching so going to cut the inner skin out and may drill 4 holes in the bonnet to force more air to the filter aswell.
Photobucket is being a .... but will try and get pics up soon.
Twingo Gordini RS133
Is this why the At-Power bodies can be shorter? Smaller diameters (or equivalent oval area) can be used due to being shaftless butterflies.
With oval port sized bodies, the gas speed will be kept up, hence allowing a shorter overall package (body, extensions, trumpets)...
Too short, or a good compromise?
Theres not only the trumpet size to think of with the at power kit but also the injector position (being right next to the valve mouth) that affects things.
Im pissed out my dick currently and will let Chipapedia explain the intricacies.
182cup & 172 racecar
Mine work ok.
Twingo Gordini RS133
Mine haven't been tried yet (new AT design for RS133) so I'm not sure how well they will compare if another company were to make a set. I know the injectors are close to the head, but that's exactly the same distance from the head as the original inlet manifold, with the injectors firing at the back of the valves.
Hopefully Paul will get it up and running early in the new year.
I know both of yours are fine but they don't lend themselves to big power engines. Nothing wrong with them though.
Twingo Gordini RS133
Seems a bit of a contradiction :S
Not really, they do the job fine (i.e having ITB's) but they are not the best on a high power build (circa 220 up)
They would need staged injectors to have a half decent torque figure as they struggle to make torque from all the graphs I have seen.
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You got any of the graphs for me to look at Morgan as it’s an area i’m looking at atm?
AT do staged injector setups
AT do staged injector setups
Twingo Gordini RS133
So a second set of injectors before the butterfly, for higher revs and throttle openings.
Nothing to hand James although the AT setup is known for lower torque figures on most cars just by their design. Yours and Tonys would be good ones to compare against a Jenvey graph.
The AT stuff is the best to look at definitely, I really like the look of that pictured setup, saves having to do custom bracketry for the 2nd rail etc and having the wiring loom inside the airbox. It does look REALLY long though.
Injector being so close causes issues with high rpm usage as the fuel doesnt have long enough to mix with the air properly before it enters the chamber.
100 lbft per liter is the holy grail of N/A tuning Tom, so if that really is still a 2.0 then that is a fantastic result.
Wonder what it would have held onto higher in the rev range if it had decent bodies with the injectors a sensible distance from the head, as without a doubt that setup looks compromised.
Wonder what it would have held onto higher in the rev range if it had decent bodies with the injectors a sensible distance from the head, as without a doubt that setup looks compromised.
I'm sure it's 2045cc so not the 1988cc it used to be. But still a 2.0.
It made 317bhp higher up but the torque dropped off so it has been left as you see above. Not sure what the peak rpm was for 317, although the way the graph is going I'd guess about 9500.
I can't remember if the bodies are 48 or 50mm, I'll have to ask him sometime.
For what a F4R revs too it seems the AT bodies (if you have the larger 45mm diameter) won't hold you back.
