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Prima Racing I think do a conversion for £3000 to £4000 fitted. You can buy the parts for about £1500 but I havent found anyone yet who makes the inlet manifold required. Prima will obviously have this and might sell as a separate item. You would be looking at about 225 BHP @ the flywheel.
The biggest problems with all these power mods. is that it will be very difficult to find a standard insurer to cover the risk. It would mean using someone like Adrian Flux and gut feeling is it aint going to be cheap. But then if money aint an issue then thats cool.
For me personally id love either turbo, supercharger, throttle bodies and could splash out on it. What will put me off for time being is Insurance hike and being able to resell the car. So far I can change my car back to std. as Ive got the original parts and it would probably take 3 ot 4 hours to do so. Ill just have to be content with the decat, chip, steel hoses and dot 5.1 for now. Bloody house is taking all my money up :-(
Simon I think of all those things the Turbo would be the most expensive considering the need for lower compression pistons. I would say the supercharger would be very nice Throttle bodies are 4000k fitted from Hillpower I think. He didnt say exact horsepower figures but did say over 200Bhp. Another thing is the throttle bodies would be a lot easier on the gearbox + clutch.
im not too fond of turbos as the power delivery on big boost items can get sketchy mid corner......so its not so much fun to drive at the limit.
charger is good, but the amountof work doenst warrent it i think.
its gotta be TBs for me. Easy to tune, easy to make/fix/modify. the head is the limiting factor. a good 240bhp should be attainable if you work hard enough at the head. the S1600 are restricted to a single 40mm inlet (just bigger than 1 inlet valve on the 172!!!) and make 220bhp on a single TB.....its all down to how good you are.
3000quid wouldnt get you a drive in drive out turbo or charger conversion though, you would need to do alot of the plumbing in.
Yup, I agree with you totally. Ive always admired throttle bodies and also the sound is amazing! just think what it would sound like on a 172!! "rrrrrroooooooaaaaaaap!!!" (sorry, got carried away there! )
ok... Supercharging and turbocharing is effectively one and the same !.. the source of power is different only.
you still need lower comp - preferably forged pistons...
Now for bodies...
You need, as do the above.. an independent engine management computer at at least 500 quid plus vat..
then another 500 to get it mapped...
the turbocharging is the most expensive at about 3500 in parts and mapping. (and that is presuming a grand for the mechanical parts of the exhaust / induction syste) Reno prices would be about 2500 more.. so.. to do it properly with genuine parts - about 6k
Supercharging... no exhaust mods... charger is about 1500.. brackets and mounting about 200... pipework and intercooler about 225 - so.. about 1925 - call it 2k.. plus a grand for the ecu and mapping.. so.. 3k - then, ya still need the low comp forged uppy downy thingies... say.. a grand again.. so.. cost 4k
Throttle bodies.. Jenvey make them in the uk.. cost about a 1400 for the full kit... with sensors and fuel rail mods..
Laser cut adapters to fit the bodies to your head - your own VERY simple design... including aluminium - about 75 !!!!!
ECU and mapping..a grand.. so 2400
these prices are for parts only - but labour is included for mapping time on the rollers at a total cost of 500.. could be as high as 800...
Turbo.. too many people are not aware that a turbo can be tamed.. old tech cars like the 5gtt, porcheT - any damn turbo was given the reputation of being a handful due to agressive power delivery.. that is stoneage now though.. a mapped boost control monitoring rpm and throttle position can make the turbo the car of your dreams... it shouldnt be abrupt.. shouldnt spool the power up suddenly whilst accelerating hard... all it should feel like is having a far bigger, more torque delivering lump at the sharp end...
but.. there may be times.. 25 degrees (C) lol... clear roads... ya know... you want to get a kick in the back from a bootfull on the limit of traction (cos thats when you have exceded the design limits of the chassis ... easy.. press a button and select map 2 for the boost... look at mammy Im dancin type stuff lol..
the supercharger.. bloody excellent all round... what the turbo has to be programmed to feel like.. no option for brute force silliness and fun ......
tbs... the noise would drive you insane unless the car was a toy for occasional blasts... I know.. !
When it works though.. it works baaaddddddd .. the sound is heaven.. but.. like a babies first cry that seems like an angel crying.... .. it soon becomes a pain in the ass when you are tired !
you can modify the standard TB as its not very good interms of outright flow. But, you would need to do flow tests to be accurate.
well done mate.
i used ot go into pages and pages of detail, you might be able to find some (i rant on about overlap and back pressure, how standard exhausts are the only ones that are actually tunned by the manufacturers, and other theory mumble jumble) but i stopped now, never got any interested response, the thread tended to fade away.......now i have somebody to talk to!!!!! yay!!
As far as forced indution goes, comming form a racing background, its not my favourate (since race items tend to forget tractability and go for outright power, which can be scary! especially having to decide weather a long curve need a shift in the middle of a short shift before) but super charges are AOK with me.....its just the plumbing in in small bay that puts me off, especially when you have to weaken the shell by cuttin and shutting, thts why my MK1 XR2 remains a 4 speed and not got a MK2 5 speed in, i dun wanna cut across the support rail!!!
And im really into N/A tunning, pulse tunning theory (especially the use of trumpets/tunned lengths and pulse plates) heads are fun to work on, and exhaust systems are good fun too, easpecially working on primary and secondary lengths. I dont have too good a head for numbers, but i can visualise flow patters (if that means anything to you) in my head and i usually get them right, same goes for most theory, i viasualise it with diagrams in my head....cant put things down on paper...never works.
Simon, the throttle body size on the single unit is often connsidered a weak point or restriction.
Early golf gti tuners (VW Rabbit in US) had a craze for increasing the tb size..
when actually tested it didnt do anything apart from move the torque curve up slightly, hence reducing low end pulling power.
There is a maze of theory regarding pusle tuning, inlet tract length etc..
a lot depends on the design of the plenum chamber (the box with inlet pipes going to your cylinder head)
the bottom line is that bigger is not always better, and as Ben rightly says, it needs to be dynoed to see the results.
imagine HOW the intake charge air is induced into the cylinder, the cylinder goes down due to the expansion of the ignited mixture, as the piston passes C (bottom dead centre) the exhaust valve opens and the whole lot exits at high speed into the exhaust manifold.
now the inlet valve opens as the piston starts its downward cycle 1 rev later.
We now have a dual effect, vaccum created by the downward travellinmg piston and also a little factor called overlap of the valve timing meaning that at a certain point the exhaust valve and inlet are still effectively open.. the high pressure exhaust pulse exiting the engine causes an even greater vacuum or pressure differential in the cylinder as compare to manifold air... the inlet charge is drawn in. yep ?
now, if the inlet system consists of an air holder device.. ie - inlet tract tube / plenum or throttle body unit that is sized correctly for the volume of air, then not only do we have a charge ready to inhale, but the SIZE of the orafice that leads to outside air becomes critical for power delivery.. why ??.
Well, wouldnt it be nice to NOT have a huge opening to atmospheric air.. have a slight restrictor, the reason for this is to allow still another pressure differential to happen between the intake valve when sh*t and the intake from the air outside... this causes a high gas velocity / flow rate and the charge holder or inlet tract / pipe is filled ready for the next intake.
air is a fluid to all intents, can you picture the turbulence at the intakes if no pre charge length was used ??.. ) it would be chaos with each induction interfering with the next.. as air is induced rapidly, and stops being induced rapidly, a layer of distured air exists at the intake that will reduce power by making the gas flow uneven. Providing the length and volume of the pipes is designed correctly, then you can have enough charge in the intake pipe ready for the next cycle, and keep the disturbed boundry layer out of the system. The pipe will be effectively recharched ready for the next induction.
AND this is only effective a t one point in the rpm / load range. so all other areas have to be a compromise.
bottom line.. it aint that simple lol...
we could start discussing why a free flow exhaust is more often than not BAD for power in another thread.
agree, but were you explaining that to me? kinda knew that.
gas velocity is an all importent part of tunning.....agreed!!!!
Man, i should marry you!!!!
but im talking that if you make the TB larger....than you would have to modify the enf\gine to make use of the reduced restriction....so basically, i was just meaning very high rpm power geains, especially if you could get it to rev ot 9000rpm or so.