Tuning 2lt 8valves

[hardleydangerous]

Is it possible to get more power out of a 2lt 8valve engine, if so,how?

[dean]

Hi Hardlydangerous.

Is this the n/a 8v?, if so i have given mine a slight tweak, but nothing major. firstly i removed the cat and replaced it with a down pipe off of a carb engine, then polished the inlet manifold, inlet and exhaust ports, piston crowns and combustion chambers, so they are like a mirror (it dont half take some doing too), then new valve springs and re seat the valves. This made quite a difference to the power output and was certainly noticeable without being silly and looking like a 10yr old with a fart in a can exhaust .
Alternatively, you can just have the ecu remapped, dont be fooled by the quick to install 'chip' which are about £20 because all they do is make the ecu think the engine is cold all the time and makes it run rich as a b*tch, a proper remap job will be a couple of hundred but then the bhp gain will reflect money spent. I always steer well clear of induction kits and straight through exhaust systems because of the noise and minimal if any increase in power.
And finally you could do all the above, but for that extra bang go for uprated valve springs, high lift camshaft, increased displacement and the all important uprated oil pump??????? no i didn't think so

Dean

This post has been edited by dean on May 20, 2008 05:46 pm

[bigjohnh]

Or, buy a turbo one.

If it is a turbo you can get about 25 more horsepower with a boost controller....apparently.

John

[wirdy]

2.0 CT + boost controller gives 190-200 horses before detonation sets in.

Haven't tuned my CT, just going on previous experience of Activa (same engine) and other activa forum members

[Ciaran]

Dean do you know of anyone who does remaps on that engine, and, perhaps more importantly, know anyone thats done it?

I wouldn't mind a bit of extra kick, but don't wanna push it toooo much, it is an elderly engine

Ciarán

[aengus-xmv6]

there's a guy from Greece on fleabay selling superchips for £30, who may be able to do one for you... assuming you can get the old chip out to swap it over it'd be a lot cheaper than getting it done officially over in the uk.

I found my old 2.0sei manual was much livlier after the head was skimmed and fully rebuilt at 115K miles - felt like a much newer car

regards
Dave

[dean]

Hi all

It depends how attached to that particular car you are i suppose, but your right John, just going out and buying a turbo would be far less hassle.

Ciaran
On the island we have a big performance car following and as a result have many small tuning shops with rolling roads, ecu remap facilities etc etc. I had my cavalier sri remapped and it made one hell of a difference but as we all know cars are built with a trade off between economy, performance and longevity, unfortunately the later two mix like oil and water , the sri was 10 at the time and with 187k on the clock the remap, and my heavy right foot, it all proved too much for the old girl and one day the already tired engine fell asleep .
This time with the xm i concentrated on getting the existing engine back to as close to 'new' performance as possible by making sure the injectors and compression where good and that there was no carbon build up anywhere on the engine, as Dave has testified, and by helping it breath a little better by porting the head and removing the cat it gained that little extra high rev (motorway) performance without putting any undue strain on the car.

This post has been edited by dean on May 21, 2008 05:44 pm

[Ciaran]

Thanks Dean.

Goes to show, there's just no substitute for getting down and dirty and doing work on the engine. Bet its quite satisfying to have a practically new head and the inlet polished up too

Ciarán

[dean]

Yeah, its one less thing to worry about packing up , also she uses no oil, or water......at all, it doesn't turn over when you turn the key , it just starts, and idle is nice and smooth again too. The main thing i think is decarbonising and re seating the valves, cars of old would of had such things done at regular intervals as a necessity, I'm not saying that it should be done every year, unless your clinically insane, but there comes a time when it will need doing and after 15 years that time is now. Lets face it maintaining an old car was a monthly if not weekly thing at one time, the quality and refinement of modern engines has improved a thousand fold since then but modern cars still have to be serviced, just not so often, and the same goes for re seating the valves etc. The main problem comes really from their complexity, a 1930's engine is so easy and cheap to work on its untrue but you cant reuse or make a modern head gasket when you take the head off, indeed just getting the head off a modern car can be a nightmare in its self, and if the car in question is 10-15 years old its not economically viable to do such work just because you want that little extra power and smoothness back.............i suppose i must be mad

D

[citroenxm]

RE: The Turbo CT Engine.

I had a thought, it didn't hurt though, how about an electro solinoid valve fitted into the Wastegate control vaccum pipe..

Where the standard valve is located, the vac control pipe that goes to the waste gate down the back of the engine, if you remove that pipe from the valve and go for a drive you find a significant increase in power.. so rather then have the pipe removed all the time, why not put in a solinoid valve with a button on the dash - Yes JUST like the lastest Astra VXR and - what the BMW M5 - press it to open the solinoid and blocking the vac pipe to the waste gate, and then when your done, press again to open the vac pipe restoring normal peformance!

Then you can p@@@ the new astra drivers with the line "You only just got that now? Huh, my car has it 15 years ago! Time to catch up in the times!"

Rgds

C

[DoubleChevron]

I'd suggest a huge car like an XM with a 2litre N/A motor is just hopeless if you want fast.... Leave her alone and save your $$$$ for a nice XM 24valve v6 5spd, or prefably a nice CX 2500 GTi Turbo is you want a true "Big Cit" with serious grunt

seeya,
Shane L.

[Ciaran]

You're right Shane, something the size of an XM with the 2l N/A in it is never going to be scary fast, however I'd say its reasonably quick, and there's no harm in tweaking it a bit if you have the time and inclination.
See with 'quick and easy' things like a remap I'd probably be inclined to try it, but with the obvious concerns Dean mentioned about doing it to older engines.

If I had the money, time, and space I would of course transplant / buy a V6, as would many forum members if they could I suspect, but with ever spiralling fuel costs and all the rest of it I guess some thought has to be given to what you can achieve with existing components and resources.

Now if money was no object I'd love to stick a dirty big V8 in there.....

Ciarán

[citroenxm]

Shane,

I have a v6 24v 5 speed, 1991 vintage! 200bhp, and your right! It bloody flies!!


Rgds

C

[dean]

Hi gents

Point taken about the n/a's but as Ciaran has said there's economy to think about, and before any derv owners jump in, yes i know i could do much better mpg with a diesel, but im just not a diesel fan .
Personally i would love to go back to a 200bhp + car, but i am unnaturally attached to my prestige, there is no rust, anywhere, of any kind, and it is in near perfect condition, mechanically and cosmetically. But if i was rear ended tomoz?? i would be after a mk1 12v 3l Xm to replace it, no doubt. I just couldn't bring myself to sell the old girl.............This ain't normal is it?

D

[robert_e_smart]

The 2l non turbo is grand, it has plenty of poke to move you around at more than stately speeds. Same with the 2l douvrin CXs, plenty of performance. More power would be nice, but the way our motoring world is heading you'd never get the opportunity to enjoy it. The other thing to consider is the amount of room there is in the engine bay of these 2.0l cars, they are a dream to work on. All those turbo models, diesel and petrol look like nightmares to work on!

This post has been edited by robert_e_smart on May 22, 2008 09:34 pm