Improving my 320i

[Peg83]

Morning All,

I'm keen to make some perfomance improvements to the engine on my 320i. The low end torque is pretty poor.

I don't really want to get too involved with modding up the engine too much as it seems a pretty strong engine at the moment and I don't want to mess it up. Plus I'm not sure I have the money to get that involved with it.

I'm keen on the 3 part scorpion exhaust. Which I would like to put with a performance manifold. What websites are going to be best for me to start looking for these parts? Are second hand manifolds worth looking at!? I see on wiki that I could get an Alpina. Are they hard to find?

Prob going to get a k&N panel filter. I heard the forced inductions kits don't do anything for our cars.

Another thing I have in my head at the moment is I'm not sure if there is a bit of a tapping coming from the engine? If it is it is minor. But how much am I going to be looking at to get them sorted??

Any advice would be great.

Thanks

[Jim320i]

For the cost of a exhaust and manifold you could buy a good 325i engine and put that in which will be best pound for pound improvement you can do.

Then once you want to upgrade that you can look at the exhaust and manifold etc

[Sanchez]

Morning All,

I'm keen to make some perfomance improvements to the engine on my 320i.

Any advice would be great.

Thanks

Ill be the 1st of many to say stick a B25 in there.

If you dont want to do that then the B25 inlet manifold allows a bit more air flow.

A Scorpion exhaust can be had of ebay and other places.

[daimlerman]

2 litre M20 is a short stroke engine,so it will rev freely to allow the use of it's top end power.Low gearing also helps with this;
In manual form 3000rpm=65mph,right at the bottom of the power band.

Nothing,really,is available to boost bottom end power,the only real solution is a longer stroke to increase capacity.The existing cylinder head will work very well with an ex E28 525e short motor,combine this with an ex 325i inlet manifold/injectors and you will see a power hike from about 130bhp to around the 175bhp area...with an almost 'flat' torque curve...

Your tapping is most likely the tappets,re-set them with a slightly generous gap as we find this helps the idle.It could also be the injectors ticking away,they all do that!

[Peg83]

I think the thing is I am worried about putting a B25 engine in there is that my engine certainly seems in pretty good condition and has 90k on the clock which was low compared to other cars I was looking at when I bought it.

Daimlerman: How much would I be looking at to convert to a 525e short motor and 325i inlet? I would prob have to get a garage to do this for me!!

I think the tapping is prob just the injectors. it is hardly noticeable when the engine is warm.

[daimlerman]

Your initial problem is finding a decent donor engine!
E28 525e was imported from '82 to '86.I think.

I built mine myself about 7 or 8 years ago,I started to hide reciepts after about £1500 had been spent.BUT,the engine is now in it's second E30 and still makes me giggle when I overtake.

So not really cost-effective to pay labour,but a good way to get to know how an engine works yourself.M20 is a lovely engine to work on,pulls apart in a logical way and goes back together easily.

These days,those keen on keeping a 'stock' look to their engine room and who want more grunt are building 2.8's,there should be plenty of information in the wiki or in the 'Engine Mods' section of the forum.a user by the name of 'hairyscreech' has done a lot of research on this conversion,but be warned,M20 is not a cheap engine to either tune or re-build!

[Peg83]

I would LOVE to be able to strip the engine down and do various mods myself. BUT Im not sure I have all the tools and the space to do it. And I have a Wife and two young Children. Finding a couple of hours to do anything is hard enough.

I think for now I'm going to have to settle with carrying out basic maintenance on the car and maybe get the 3 part stainless.

Arches will need to be done sooner rather than later so I will try to get some cash together to do that.

Shame the K&N induction kit doesn't work well on the M20 engine. I used to love the sound on cars I have had in the past.

Anyone know of a chip I could get. I did have one from Speedtouch but it made my engine over rev on idle??

[jimbom30cab]

Finding a couple of hours to do anything is hard enough.

Join the club mate, that is the "all work done on the car is between 8 and 10 at night whilst the kids are in bed" club

loads of us on here are the same

[Peg83]

Yeah I should really give up rugby and then I caould dedicate more time to the car.

There are loads of simple things that I want to get sorted. Such as the car was overheating so I got a local garage to sort it out (Friend of my Dad). He ended up replacing the radiator. But now the engine runs very cool. So I think he has removed the thermostat.

I can't prove this though until I drain the system down and have a look myself. But if he has removed it then I wonder if there was any need for the new radiator!!

[Peg83]

Would putting a 325 inlet manifold with a 325 Throttle Body be any good for my 320?

There is something about doing this on Wiki. I can get a cheap manifold which has been powedercoated red. So all I would need to get is the TB.

[daimlerman]

Would putting a 325 inlet manifold with a 325 Throttle Body be any good for my 320?

There is something about doing this on Wiki. I can get a cheap manifold which has been powedercoated red. So all I would need to get is the TB.

Not really.
The port shapes are different,so the incoming air/fuel will hit a ridge,and this will upset the airflow.
A better mod would be the 325 t/b onto the 320 inlet manifold.

Use the 325 t/b gasket as a template to scribe onto the manifold to show the material that needs to be removed.
Use a rotary file in a power drill to modify the manifold.Do remove the manifold first,and clean out all of the swarf afterwards!

[tha881]

320i owner here and the best advice i can give is to get a speedtouch mild chip for £35. A standard 325i exhaust is apparently a worthwhile mod aswell as it allows the exhaust gasses to escape quicker. Unless you need to replace the exhaust anyway then i wouldnt bother.

I have fitted a 325i throttle body on a modified b20 manifold and although the gains are quite noticable, it is a lot of work and probably not worth the effort.

The best thing you can do is concentrate on the handling/suspension of the car. A 320i can still be a very fun car to drive on the right roads. Its not going to win any drag races but get it setup well and you will enjoy it a lot more.

Ive got used m-tech springs on mine with new bilstein b4's and a range of new bushes. I also fitted a 14mm rear anti roll bar. Its great fun to drive, quite agressive but relaxing too when you just want to cruise about. The final pieces to the puzzle will be an lsd and then one day a b25 engine.

[Laith]

I too fitted the mild chip, and its worth its weight in gold on my 320i cab.

One day, if I still have the bugger, a b25 will go in there. But 'till then I quite like the smoothness of the 320. Even if it drinks like a v8.

[Brianmoooore]

Would putting a 325 inlet manifold with a 325 Throttle Body be any good for my 320?
.

It will be, as long as you leave it attached to the rest of the 2.5 engine!
The best advice for 320 owners is to get it running as it was when it left the factory, then just enjoy the sound track.

[Peg83]

Thanks for all the advice lads.

I think I have decided that I'm going to keep the engine fairly standard and concetrate on repairing the arches and improving the handling. Fitted a strut brace the other day and just that has made quite a difference. So I think I am going to replace all the suspension for standard parts and replace many of the probably degrading bushes. Plus maybe fit a rear strut brace and maybe ARB.

Going to try and do a service on the car thins weekend so a change to some high quality oil and plugs should get her singing nicely. Plus I'm sure that the last garage I took it to removed the thermostat as it runs really cold. So I'm prob going to have to put one of them in.

tha881: I did get a chip from speedtouch. But I have had to send it back as it caused my engine to over-rev on idle.

Cheers

[Peg83]

Another question.
I'm now thinking about replacing shocks and springs. But not bothered about lowering. What make would be good to go for!?
Blisteins for shocks?

[Rtaylor2208]

Blistein B4 or Boge turbos for the shocks. GSF do the boges for approx £57 a piece. I can't comment on the springs as I changed mine to lowering ones.

[Peg83]

So £57 for the Blistein B4's a piece is a pretty good price?