Any ideas?

Newbie Joined: 13 Dec 2004 Posts: 2

Hi there, I'm new to all this and have been told that this is the best place to get some help and advice (thank you Neal!)...
I'm currently in the process of doing up my 19 16V and have come to the engine work stage, i'd planned to go with the uprated cams, ignition leads, plugs and the usual but now different people have given me their opinions on what they think i should do for the major power gain, seein as thou half the words and terms they use are foreign to me I thought I'd ask to see if anyone could explain to me the options and what they basically mean/achieve...
Right, by far the most popular option I've heard about is putting throttle bodies on, now for a novice like me when the mechanic says this it means nothing, any help on what they are and what they will achieve or the risks/problems involved would be great.
The second option i've been given is to uprate the pistons with power pistons, i'm told that with various other items and tweeking it COULD result in similar bhp's as with the throttle bodies but for some reason this seems to be a less favoured option (again, any thoughts on why would be happily received).
The last (and i'm told mosst radical option) i've got is to go for the full-out turbo conversion kit that k-tec are working on at the minute, I'm told this wouldnt be worth it as it'd likely as not destroy the engine and wouldnt result in much more power than the other options anyway so a bit pointless.
If anyone knows anything or could explain the pros and cons of any/all of the options I'd be forever in your debt. Thankyou!!!
Ollie. Smile

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

Throttle bodies. As the car currently stands it has 2 throttle plates (assume 1 though, it has a wee tiny one to only open at low throttle angles to keep gas speed up and the big un for full throttle) and a pllenum chamber which feeds all 4 cylinders.

Throttle bodies gets rid of these and each individual cylinder has its own throttle plate and short port runner.

Basically this increase the VE (volumetric efficiency) thus increasing power. For example the current set up may only be working at 80% efficiency, a swap to throttle bodies may increase this to 92% VE, thats 12% more air in the cyls which means more fuel which means more power.

Cons, expensive, they need setting up, insurance issues maybe, the noise they make

Pros, when set up right smooth power right through the rev range, more power, better MPG (only when set up right though), the gains are there all the time, no waitign for boost or running out of gas, if you further mod the engine you can re-map it to suit the new modificatiosn to get the most from them and the noise.

Power pistons. Hmm

I am a bit unsure as what to say here.

Power pistons is a pretty stupid couple of words really. I am assuming you are reffering to pistons that the likes of K-Tec sell?

These are pistons that are domed slightly to increase the compresion ratio. The standard pistons are flat topped. To increase the compresion ratio you make the combustion chamber smaller, you can do this by adding lumps ontop of the piston or by skimming the head/adding metal to the heads chamber.

Raising the CR does improve performance at all points. Again its all about efficiency, so you do get more power. Also higher CR's improve low angle throttle response and cruise efficiency.

Con's, expensive, you need to dismantle the engine to fit them well you could do it by removing the head and sump and doing it in situ but you'd be daft really, not much gain for outlay, nothign liek as much gain as TB's.

Pro's, slightly more power

Turbocharging is the way to get big number sout of any engine, again its a case of increasing VE. A 2litre engine running 1 BAR of boost over atmospheric pressure should in theory be the same as a 4 litre engine. If the engines made properly and designed for it then you pick a figure and a turbo can achieve it, 1.5 litre engines in F1 used to make 1500bhp!!!

Anyway turboing the 16V will get you gains, it will make it quicker but the thing thats not been done is development.

Plenty of turbocharged engines started off as NA units. The YB cosworth the VX C20LET and so on. However these engines had big names behind them thus plenty of development. The cams are different, pistons are different and so on because turbocharged engines need different things to NA lumps.

If you look at the current turbo conversions they all have a very crap exhaust manifoild, that means less power, more lag and it will cause engine problems. There will be reversion into the middle cylinders, what does that means? Well exhaust gas will be struggling to escape these cyls which makes em run lean eventually that means bang.

They also run high boost, big boost means feck all, you need to keep that in mind. Engines respond to flow not pressure. Get a straw blow through it, hard ain't it, well thats boost pressure. get a hosepipe and blow through that, easier to blow through but less pressure - less boost but more flow.

The fact that the engine runs stock cams isn't to good either, stock NA cams have overlap thats massive in comparison to many turbo engines. What does that mean? That means the boost and fuel go stright into the cyl and out the exhuast during overlap, not to clever, you get flames at the exhuast, but you also get a shortened turbo lifespan and crap MPG.

Some will tell you to fit 2 headgaskets or run a lower CR with dished pistons, thats not to clever either. if you drop the CR throttle response suffers, driveability off boost becomes very, very poor and fuel economy suffers as well.

Cons, expensive, poorly developed, engine lifespan reduced unless its done properly, try phoning KTEC/BB and see what they say about how the engine will be in another 50k miles with the kit fitted!

Pro's you get the power

The other problem is theres a lot of idiots in this industry, saying do this and do that you also get an alarming amount of stupid people on forums who think they know better because MAx Power or somehtign said this happens when you do that. Magazines are full of crap, they are journalists not engine designers etc!

Also this country is very poor in the tuning stakes, Germany have TUV approval that means if something says it will do this then by law it has to. America, if something doesn't work the company gets sued goes bust or the customer comes back and shoots the guy that sold him it, they also have a lot of competition so they cant not develop things. Over here if we get done over we accept it and move on and thats the downfall.

When things are developed properly then you don't tend to get problems. You could easily turbo the engine to make 400bhp reliably if you spend the time on it and develop it to remove any problems within.

Anyway hope this is of some use and remember there are other routes to more power as well that you haven't mentioned.

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

The main aim of any modification that increases power/torque is to simply get more air into the engine. This means more fuel can be burned, and therefore more emergy can be released.

Throttle bodies do this as they simplify the intake system, and 1 throttle per cylinder makes for less of a restriction than one for all four cylinders. If you have never seen then before, go on google and type in Jenvey and you'll get the picture. It will cost you around Â£1500 for a complete set-up, and then you will need to get it set-up on a rolling road..Â£200-300. They give nice gains and sound awsome!

"Power" Pistons?!! never heard of them! Maybe forged pistons? these are manufactured differently to "standard" and so are a lot stronger. They can therefore take more force that comes with greater power figures. They can increase compression ratio by a fair bit, but this wouldnt be the same sort of levels as throttle bodies like you have been told.

As for the turbo-conversion, reliability is only an issue if its not done correctly. plenty of people say to lower compression ratio, but its not necessary. remember the engine is naturally aspirated when off boost, so performance can be reduced untill the turbo kicks in. Proper charge cooling and ignition/fuelling is the way forward. AER developed a nissan Le Man 24hr engine....2.6 bar of boost and a compression ratio of 11.6:1!! and that runs vertually flat out for 24hrs. I bett BBT's clio cant do that!!

Cams are a good starting point, and they compliment cylinder head work nicely. By increasing lift and flow performance of the head, more air can flow into the cylinders...more fuel...more power blah blah blah! Can be costly, but nice gains can be seen.

so...it all depends how much you've got to spend really! If you can do some of the work your self, it will be FAR chaeper to get good performance

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

nah Craigy poo (Stan to everyone else, but I be mod and thus do what I like pretty much) power pistons pure mad mental man! lol

look http://www.k-tecracing.com/show_product.asp?id=326 bargain I think not (do NOT bad mouth any company on the public forum, feel free however to make use of pm's etc)

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

Damn you, you always post before i finnish!!

hmm, not aimed at the "Lax Power" market then!!

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

I am the all seeing and all knowing Supermod, I sense every key stroke before its typed so I am always one step ahead, muwhahahahamwuhahahahahahaha hahahahahaha, hahaha, ha, ok I'm bored.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

also I'd say Ktec is very lax power, in a very good way though, be nice Chris, just be nice...

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

Hi Tom/Ollie/forsaken. Good to see you on here Smile

I used to openly plug Retro-Renault on that other messageboard, but kept getting flamed for it by cocks, so now i just email a select few who i think are worthy Smile

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

which board are you refering to?

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

Paul's old one.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

Ahh that board, I used to be on there years back then everyone turned into arseholes so I left as did Paul!

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

its full of trolls, also you try to explain to people the benefits of having logins so noone can pose as you and post bollocks, categorised forums and a search function so you can find what youre looking for without reading through hundreds of pages of random crap, and they slag you off.

n00bs.

Site Subscriber Joined: 15 Oct 2004 Posts: 1139

Stan, did u receive that letter from BBT?

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

HUH??! Sorry mate, u've lost me...completely!!

Newbie Joined: 13 Dec 2004 Posts: 2

Hey all, thanks for your help on this. Its great to finally meet some people with the same love for the cars. Been speaking to the mechanic and i think the way i'm gonna go is with the Throttle Bodies. From what I can gather these seem to be the best balance between results and reliability/problems, i've been given a list of other things that would apparently compliment them nicely, things, as you suggested, from the cams, ranging to unknowns to me (words such as 'Chipping' it, ECU re-mapping and the likes!?!) The money issue you talked about isnt really that much of a problem, got around 15k allocated for the whole thing so not too limited there, just looking for something that'll give me a nice amount of reliable power ( arent we all!?! Wink

).

Hey Neal, of the options you mentioned my real name's Ollie, Tom, who posted the original is my brother who found the site and asked the questions on my behalf and forsaken is just a word that I think is kinda cool... Smile

thanks again for leading me here, I've learned more about the ins and outs of those the options in a few posts here than the mechanic has been able to drill into me after 5 weeks of trying his best to ''dumb it all down to my level''.

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

well you'll need the throtlle bodies themselves + all the accessories throttle linkage, fuel rail, injectors, inlet manifold etc, then management (ECU) to run the set-up, then you will need to get it mapped on a rolling road (this is where the engine experiences all speed and load events, and the fuelling/ignition is set for each event).
If you've got 15k to play with you shouldnt have a problem.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

tbh with 15K i'd geta decent motor to start with.

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

well, i was going to say that, but some people like renaults.....maybe a bit too much!!

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

I refrained from doing it earlier but I can just say you told me to say it.

Gay Rights Activist Joined: 07 Apr 2004 Posts: 1268

lol, why not, just blame me!!

Forum Moderator Joined: 16 Feb 2004 Posts: 1356

RS200