Increased power - M20 320i(?)

[Careanla]

Whats the best and cheapest way to increase the power of my 88 320i?

I don't want to do anything extreme but just a bit more overtaking power would be great.

It's really flat low down in the revs as well, get over 3k rpm and it does pick up but just not enough especially when your overtaking.

Any ideas?

Cheers
Craig

[toby]

Keeping it standard eh?!
You're already thinking of modifying!
Some alternatives for making it go faster (other than replacing it for a 2.5 engine).

1) Fit the engine block and pistons from a 525e and a new profile camshaft to have a budget 2.7 engine with lots of torque.

2) If that's too extreme, wait til your camshaft wear out and fit something with higher lift - cat cam camshaft for example.

3) If yours has the later management system you can simply fit an Atech engine chip - I've got one in my 325i and it made a flatter torque curve through the rev range rather than the later pickup after 3K that the standard chips seem to be set to. Combine this with a bigger throttle body and you will notice a bit more power. This is probably your best bet.

[Careanla]

Yup... keeping it standard... but just want a little more pull when overtaking!!

No harm done as I see it as still being standard... it's more the lowering and huge alloys and body kits that I see as modifying...

But giving it that extra little more help on pulling is a bonus!

I thought about the 2.5lump but I know my cars a good'un and changing things like that doesn't seem right.

Will give some thought and speak to my mate about what you've suggested...

Cheers mate

[maxel]

get a turbo from the td, manifold should fit with slight mods, just use the old turbo

[maxfield]

325i TB and inlet manifold.
Chip.

Maybe cam depending on how much you want to spend. But if you were spending that much, you could just drop a 2.5 engine in with a much bigger gain.

[daimlerman]

Best option is the budget 2.7,I did this and it works a treat!!

[Careanla]

so what sort of cost is this?








Sits in corner and waits for shocking £Â£Ã‚£Ã‚£ figures....

[daimlerman]

How long is your piece of string?My costs,£100 for eta short motor.£35 for sound 325 block.Rregrind crank,new rings,new shells,£300.Assorted gaskets,oil seals,etc£200.Head rebuild(valve guides,skim,new valves)£350.Think thats about it.Try not to think about it too much.Oh yes,new standard 325 cam,£85.

[goosiegander]

pay £70 and get a fse valve to boot the fuel pressure, it can be set however you like it and there was a marked improvement in acceleration without harming the mpg below 3000rpm i'm in the process of setting up my 2.5 engine replacement but before that i had an fse valve and it did the job nicely on my 320

[Jhonno]

fse is a load of wank that is likely to set fire to your car as it has done to several members cars on here

best budget 2.7 is a 2.7 (525e) bottom end, 2.5 top end with a skim and new head gasket and bob's your uncles sister

[maxfield]

pay £70 and get a fse valve to boot the fuel pressure, it can be set however you like it and there was a marked improvement in acceleration without harming the mpg below 3000rpm i'm in the process of setting up my 2.5 engine replacement but before that i had an fse valve and it did the job nicely on my 320

It just makes the engine over fuel.

As Jhonno said can set your engine on fire...

[goosiegander]

well it worked for me but i guess im the exception -not the rule lol

[Jhonno]

placebo imo unless you have cold hard back to back figures

[goosiegander]

fse valve was recomended, fitted and set up by peter bradly at spot on tuning, i think he knows what he is on about, but like you say if its set up wrong its gonna be trouble...

[Jhonno]

and he was being paid for the work? hmm thinking about it i can understand why bmw wouldnt have developed the fuel system properly with an optimum pressure..

[goosiegander]

lol! it seems we are disagreeing again Jhonno,

I can only go by my actual experience, it worked for me it was set up to cut in above 3000rpm and gave a nice lift...

Regarding the bbq'd engines thats not good, go for the 2.5 conversion instead, i've almost got mine sorted

[kadettc]

fse is a load of **** that is likely to set fire to your car as it has done to several members cars on here

best budget 2.7 is a 2.7 (525e) bottom end, 2.5 top end with a skim and new head gasket and bob's your uncles sister

I had a 320i with a Superchip, Full Stainless Scorpion, Pipercross induction Kit a few years back. Made 149bhp on Rollers at RGS Motorsport in 2001. No problems with FSE in two years of ownership.

On the TD Turbo route............has anyone done this? I always thought TD Turbo units boosted too low pressure for petrol applications.

[Jhonno]

lol! it seems we are disagreeing again Jhonno,

I can only go by my actual experience, it worked for me it was set up to cut in above 3000rpm and gave a nice lift...

Regarding the bbq'd engines thats not good, go for the 2.5 conversion instead, i've almost got mine sorted

Erm.. how exactly would a mechanical device which has no form of electrical connection or ability to read the rpm of the car be able to know when its 3k and kick in?!

[goosiegander]

well, you get an extra bit of hose and a pressure gage between the fuel line and the standard regulator
-Measure the fuel pressure at 1500rpm with the standard fuel regulator -you then fit the fse valve with the gage still attached and adjust the valve so its almost the same pressure reading at 1500 rpm (or slightly more) its actually quite easy to do -i helped set it up on my 320. the valve increases the pressure as its designed to do, but, given the setting we made on my car it makes a noticeable difference at 3000 rpm at that specific fuel pressure, so the mechanical valve needs no electronic imput. I assume you haven't actually played with one of these valves...

does that answer your question kind sir?

Ps if anyone wants to fit a valve thats how i would recommend doing it, just winding it all the way in will only torch the engine

[maxfield]

All these valves do is chuck more fuel in the engine...

Expect bore wash...

[goosiegander]

Not trying to be arguementative both a bmw specialist (who did exactly the same thing to his e30 320i) says its faster and improves acceleration when properly set up.
I have done this to my e30 and it does do exactly that.
I have never experienced any problems as a result...

It is a credable solution to Careanla's question at £70 plus fitting.

[maxfield]

They probably just wanted your money...

I'm sure the 'specialists' on here will agree it is a waste of money

If you felt again then that's fine

[goosiegander]

I'll have you know That Peter Bradley is a former RAF Flight Lieutenant and an honerable man as well as being one of my friends. He is over 70 and is still a full time mechanic doing the job for the enjoyment not the money. He has done his absolute best for me frequently improving the rates at which he works.
So please, Don't assume he is dishonest...

Again not trying to be arguementative but i'm telling the truth about my experience with the fse valve and all i seem to be getting is a counter arguement and subtle p*ss-taking from people who have based their standpoint on hear-say...

Its a little frustrating being made out like i don't know what i know.

Or am i wrong? surely this isn't what the zone is about...

[maxfield]

If you feel you've got a gain and you're happy then that's all that matters.

All I'm saying is it justs chucks more fuel in. Not good in the long run...

It will be a big advantage with a modified car.

Anyway, here come the mods to tell us we're going off topic...

[goosiegander]

ok fair play man...

[StuBeeDoo]

I've gone the 325i TB + wild chip route.
I'm happy with it. Never had it on rollers, but a couple of people who have similar spec talk of 145+bhp. Not a bad increase for under £100.
At the end of the day, it's all about drivability. Mine pulls well from below 3k rpm now. Something to do with getting more air into the ports (which are far too big for a 2ltr).
Have a word with Andyboy.
Stuart.

[jkarran]

If there's power gains to be made by changing the fueling via a new chip (which people seem happy to accept) then equally there's gains to be made changing the fueling by altering fuel pressure.

The difference is changing the rail pressure is as likely to lead to power/economy/longevity losses elswhere in the rev range where as a well set up chip shouldn't compromise on light load/cruise economy or high load torque anywhere in the rev range. Considering the similar costs I know which I'd be more likely to go for.

jk

[toby]

so what sort of cost is this?








Sits in corner and waits for shocking £Â£Ã‚£Ã‚£ figures....

That depends if you can do some work yourself. This would only be a cheap option if you didn't have to pay someone else to do it. You'd be looking at £500- to do it yourself and up to £1000 or more for someone else to do it. You can do it in stages though. Start with just a camshaft upgrade as this is a weak link in the M20 engine with a low profile and not good for power output.

Forget all this though. Just to get a chip and throttle body would set you back £55 for chip and £150 for bigger throttle body. Spending anymore and you may as well buy a 325i instead.

[chu346]

What you on about £150 for bigger throttle body???

Use a 325i TB for £15

[StuBeeDoo]

Use a 325i TB for £15

Seconded!

[dannyboy759]

Whats the best and cheapest way to increase the power of my 88 320i?

I don't want to do anything extreme but just a bit more overtaking power would be great.

It's really flat low down in the revs as well, get over 3k rpm and it does pick up but just not enough especially when your overtaking.

Any ideas?

Cheers
Craig

Buy a 325!!!!

[reggid]

There is a difference between altering the MAP using a chip and simply changing fuel pressure because the fuel pressure changes are always there…. where as remapping the WOT map via a chip the fuel changes at idle and part throttle are not affected (unless these are also remapped). On cars with an O2 sensor this can be important because of the closed loop mode where the ECU adapts the fuel mixture at part throttle. Also with a remap the fuel and timing are remapped and both these are important and produce gains if you only do fuel then you can only do so much.

[toby]

What you on about £150 for bigger throttle body???

Use a 325i TB for £15

Sorry that was an expensive typo.

[johnna]

Now then, some basics needed...
...please don't be offended if
I have built many a Ford Pinto engine (like fuzzy hasin his touring...) and the efi ones are at a similar stage of development to the M20 just with two fewer cylinders). Can I recommend you spend £16 on Dave Vizard's book on power tuning the SOHC engine?

Tuning an engine is like making a cake, all the constituents have to go in at the correct ratio to one another. Too much egg and you get a sweet tasting omlette and so-on.

By just adding extra fuel (as we used to with carbed engines) gives results upto a point until the engine overfuels and leaks petrol to the sump via the piston bores or stops as there is too much fuel to burn.

Petrol engines need compression, air, fuel and spark. Look up the word stoichometric to get it bang on...

My advice is:
Get the book.
Buy a spare intake manifold.
Buy a 325i tb.
port the manifold to suit the tb.
Buy a 325i cam (or is this the same as the 320i item???) must check etk...
Buy a Zone wild chip.

Fit them all together, you will love it! I was doing this until I got offered a superb low mileage 325i engine for cheap.

Oh and the 325i engine is not more economical than a 320i when it is fitted to a 320i box and diff IME.

Following on to the ultimate 320i build without altering the capacity...
The above is interim, move to fully mapped ignition to cut out the distributor. Dizzies are only ever a compromise and a weak spark in the right spot of duration is better than a strong spark in the wrong spot of duration.

Engine management systems include weber alpha, emerald and Megajolt.
In the 80's BMW got it close, within one thousandth of a second, but as Paddy said to Murphy in response to the American tycoon, "that's no good, me n him have to be spot-on..." Modern technology allows the ignition to be set at different places in the combustion cycle according to any given rev speed.

That would also allow individual tb's, but that will cost more than the car.
HTH!

[cheecho]

hey im kinda in the same situation as what to do wit my 320 6cyl but was thinkin more along the turbo route.know a guy wit a full turbo kit ready to go who lookin a G for it ,is it worth goin for or are there better ways to go?
cheers!