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General => General discussion => Topic started by: Dub_Dude_16v on 18 June 2006, 11:27
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My best mate (Blandy on here), has just bought a mk 2 16v on a G plate. Lovely mint car, looks well looked after. It's completely standard no engine mods, standard exhaust, etc.
Now my 16v is on an F plate, gas flowed head, 4 into 1 stainless manifold and complete stainless exhaust system, port & polished, k&n filter, drilled box. He has 15 inch BBS RM's i have 15 inch MiM's.
When it came down to us on a dual carriage way giving it large ( :rolleyes: ), A) he could keep up with me and B) his car was a little bit faster :shocked: How could this be i wondered? Why spend loads of money on the engine when it seems to have made it slower?
You guys and girls got any ideas because i\m sitting here scratching my head looking empty :angry: :grin:
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maybe urs needs a tune?
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somethings not right with yours if thats the case. Get it looked at.
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To be fair you haven't actually done anything that will increase power massively, you have got an engine that will get rid of the gases smoother and breath better, but nothing to actually boost performance massively. Valvers are not slow at the best of times, and his could have been well looked after before hand.
If you are really worried about it, then book it in to a RR and get all the fueling/air ratios worked on and see what you can get out of it.
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Ah i see. Is it possible to get a valver chipped? What could i do to give it more horses? Like changing the cam and that i guess?
Think it does need a tune up because it struggles to start sometimes, runs lumpy when first started up and i polished the tailpipe last weekend and it is blacker than a coal miners face! Pumps out smoke too apparently :undecided: :sad:
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Nope valvers cannot be chipped, as they have nothing to put a chip onto.
Cams, bored out etc are the way for power increases.
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if you can get your hands on a 'star chip' module this will increase standard bhp by about 5-7bhp.... rare as rocking horse shat.. were only out for a few years... but believe.. they work.. i had one on my old 16v.. which was standard.. but i put money on you not being able to be able to find one... they were a very early piggy back style add on, that altered the ignition curve slighty...very similar to that of early rs turbo's etc, they reffer to it as an ecu but on mechanical fuel injections (golf 16v/rs turbo's etc etc) it just sets the ignition curve... which can be adjusted by above means... (or chipping on rs turbos etc)
finding a star chip would be fun....
so i guess its a bit like finding the a-team... you find one... and it can help
:drool:
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What youve got is things to give you a little more BHP, that really doesnt get you up the road any faster than a standard well looked after tight engine.. what you need is torque :wink:... higher compression, big valves, lightened and balanced flywheel, and probably a slightly more restrictive exhaust system!.. you'll weed him every time :smug:
Tom
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Lightened and balanced fly will actually loose you torque rather than gain it.
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there was a k star on ebay a couple of weeks ago went for about 50 quid so they are about!
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Lightened and balanced fly will actually loose you torque rather than gain it.
Dead right, but the torque gained with all the other mods will far outweigh the torque lost by a lightened flywheel, and will give a more useable, real, BHP output..
any rotating mass kills Bhp!
Tom
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Why will a lightened flywheel cause the car to lose torque at the wheels?
I'm not that technical so i need it to be explained :embarassed: :grin:
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Because of the weight of it (or rather lack of) anything that spins in a circle has a certain inertia of force and weight. If you lessen this then the inertia drops aswell.
This means that the torque rating will drop as there is not as much inertia from the flywheel as it spins.
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hey could it not be just down to my slick gear changes :grin:
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theres no such thing as a smooth gear change in a mk2 :laugh:
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Getting a flywheel lightened and balanced (through machining) can give you a more free reving engine, ie improving the engines response to throttle openings, however this will NOT increase power output. In addition, tuning an engine usually results in a shift of power up the rev range, losing torque at low revs, a lightened flywheel will greatly exagerate this loss of torque at low revs decreasing driveability.
Lightened and balanced fly will actually loose you torque rather than gain it.
Exactly what popped into my head!
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I wouldn't of thought that a lightened flywheel would have much of an effect on torque/bhp output.
As said above it would make the engine rev more freely.
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theres no such thing as a smooth gear change in a mk2 :laugh:
yea there is no first to second its first....crunch.....second! :laugh:
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glad I had mine done then :D
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I wouldn't of thought that a lightened flywheel would have much of an effect on torque/bhp output.
As said above it would make the engine rev more freely.
regardless it still looses inertia, that which makes a final say in the final torque rating. NOT BHP.
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and on a mk2 engine, it wont make significant drop in torque....
One thing i have learnt fom my course, is as you increase bhp, you start to lose torque and vice-versa...(that was for electircal motors though, but it is the same thing really :huh: )
Edit: that was for speed and torque, ignore my ramblings the spary paint has gone to me head :laugh:
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On a standard engine it won't no, but a modded one it will, which is what this post was about primarily. :wink:
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I wouldn't of thought that a lightened flywheel would have much of an effect on torque/bhp output.
As said above it would make the engine rev more freely.
regardless it still looses inertia, that which makes a final say in the final torque rating. NOT BHP.
If torque drops, then BHP will drop at any certain point in the rev range.
They are both linked together.
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i just realised it is Corin :laugh:
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Bottom line.. Torque gets you up the road faster, not necessarily BHP. Thats why low BHP turbo diesels haul ass! they ooze torque!
Unfortunately there are lots of modded cars out there, of all types that claim to have extra BHP, stick them on a Dyno.. that soon sorts the men out from the boys!
In my experience, one of the biggest culprits for loss of power on a heavily tuned engine is a poorly designed exhaust system, usually the bore dia is too large! beware of exhaust that claim to increase BHP by 5-8bhp.. that power usually comes at the cost of torque!
Tom
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2.5" is the optimum for a valver.
In regard to torque, if you didn't have any then what is the point of having loads of power? We have had this arguement before, and it went the same way this is going. So i can't be bothered.
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2.5" is the optimum for a valver.
In regard to torque, if you didn't have any then what is the point of having loads of power? We have had this arguement before, and it went the same way this is going. So i can't be bothered.
There is no real point to the BHP figure, but people understand what it means. I've always thought of it as power being the 'weight' it would be able to pull at a given RPM, but torque governs how quickly/easily it spins faster (obviously required for making the car actually accellerate/pull away)
You could have all the power in the world at 2000RPM, but if your engine doesn't have enough torque to accellerate up to 2000RPM, it's of no use to anyone. :nerd:
In essence, IMO, BHP is basically a marketing figure. People know what a horse is, so "150BHP" is something they can cope with. "230Nm" means nothing to most people.
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torque isnt as important in lightish cars like a mk2 i wouldnt have thought, as long as there is 'enough' to get it up to speed, once your on the go your gonna be keeping the revs up high anyway :laugh:
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take away the torque mark and you aint going no-where...might as well use the engine as a generator
torque = Nm (how well the engine is at moving stuff)
BHP = Power/kW how much energy the engine produces....
:nerd:
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but as long as you have enough, which you will with a 2.0l bottom end it will be ok. any more like with a turbo engine its gonna be stupid trying to get the torque down from low speeds. im not saying you dont need torque :grin:
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but as long as you have enough, which you will with a 2.0l bottom end it will be ok. any more like with a turbo engine its gonna be stupid trying to get the torque down from low speeds. im not saying you dont need torque :grin:
true, you dont want it to high or you just wheel spin everywhere...look at some of the mercs that have 700+ lb/ft it can be stopped by 8 rugby players....:laugh:
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Does anyone understand the difference between bhp and torque?
Torque is a moment of force or turning force, bhp is calculated off this at any point in the rpm range.
You can't have lots of power(bhp) without torque unless you have a very high revving engine.
Torque describes how much 'pull' you will have at any point in the rev range, so if you like describes how engine performs through the rev range.
Power is only that, it gives an overall figure for the engine.
However to have a powerful engine, you either produce LOTS of torque at a low rpm(diesel engine), or more commonly a good amount of torque at a higher rpm(petrol engine), the other alternative for a high power output is a very high engine operating speed.
HP = (torque*rpm)/5250
The above equation is the link between power and torque.
As anyone can work out, you can't really have one without the other, unless the engine rpm is excessively high.
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i would consider a 16v a high revving engine, not many cars rev to 7100/7200 as standard :drool:
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Ah i see. Is it possible to get a valver chipped? What could i do to give it more horses? Like changing the cam and that i guess?
Think it does need a tune up because it struggles to start sometimes, runs lumpy when first started up and i polished the tailpipe last weekend and it is blacker than a coal miners face! Pumps out smoke too apparently :undecided: :sad:
Well you just hit the nail on the head.....a high mileage worn out engine wont deliver the goods regardless of how many tune up parts you bolt to it....the smoke will be oil blowing past the worn or broken piston rings which lowers the compression and looses you power, fit a recon bottom end and you'll see the change.
G...