86 m325i port and polished head questions

[savvi 0]

my car has done 290 thou ks, motor runs good as gold never misses a beat, but i think its time to get some more performance out of her,

only mod at mo is a custom cold air box with pod filter,

i want to know what my best bang 4 my buck would be, im trhinking getting the head pp after market springs and valves a shrick cam or just get the original cam reground to suit, and if this is the right way of goin about it would i need the intake manifold modified for better flow .

what sort of price should i bee looking at paying 4 a pp.

any suggestions would be great thanks

[hybrid 1044]

sorry im not sure if your already running this or not. But I would look into the exaust side of things first. Equal length extractors, shrick cam and a nice flowing exaust, lightened flywheel .. fairly inexpensive mods. Then moving into springs and valves would be the next thing. From here you can start lightening / treating your engine internals etc etc.. but this sort of thing wont leave you much change from 10k +

A big thing overlooked by most people is the weight in the car. Can be the best performance gains from saving weight here and there. Also your rotating mass, such as wheels, drive shafts ... again .. its more on the hardcore side of modding.

[savvi 0]

sorry im not sure if your already running this or not. But I would look into the exaust side of things first. Equal length extractors, shrick cam and a nice flowing exaust, lightened flywheel .. fairly inexpensive mods. Then moving into springs and valves would be the next thing. From here you can start lightening / treating your engine internals etc etc.. but this sort of thing wont leave you much change from 10k +

A big thing overlooked by most people is the weight in the car. Can be the best performance gains from saving weight here and there. Also your rotating mass, such as wheels, drive shafts ... again .. its more on the hardcore side of modding.

havent done exaust yet or fly wheel i will consider doin that first, would extractors connected to original exaust still make a differance as i cant afford full system yet ,

ive been told by a few people that when you put in a shrick cam u also need to upgrade the springs to accomadate the cam

do you know were to get a lightened fly wheel in nz for bmws

cheers

[Guest Spargo]

Bob Mead in Akl has done a few E30 flywheels, everyone satisfied with his work (esp me)

The major restriction on an M20 is the head. A 2 valve design is never going to be the best, and the combustion chamber is not optimally designed (incomplete burn), so if you're going to touch it, do it properly, ie: ditch the AFM, run a bigger cam with uprated valve springs (shrick do a nice double valve spring), bigger exhaust valves (ala alpina / schnitzer), and a really good port and polish that is flow tested.

A tuned length exhuast did nothing for Andrew's racecar, iirc.

[drifty325i 0]

havent done exaust yet or fly wheel i will consider doin that first, would extractors connected to original exaust still make a differance as i cant afford full system yet ,

ive been told by a few people that when you put in a shrick cam u also need to upgrade the springs to accomadate the cam

do you know were to get a lightened fly wheel in nz for bmws

cheers

Not much to be gained from exhaust work on the m20, they were fairly well designed from factory. Extractors will help a little, but not alot maby 5/8hp.Yes its a good idear to use uprated springs with cam work, you wont make much more power and may even lose down low. You can get your flywheel lightend at lots of local places here in chch, but i would not machine to much off as it will leave you with not much touque if you go to far. All and all not many mildly modifyed m20 325i engines worldwide make over 200hp and are still good in a road car, without major work i.e 2.7,turbos,afm delete etc. Its a hard road to go down and many people have done it before with average results. I know you are a e30 purist Shane but you could spend your money elsewhere and save alot of time and money. cheers

[savvi 0]

Bob Mead in Akl has done a few E30 flywheels, everyone satisfied with his work (esp me)

The major restriction on an M20 is the head. A 2 valve design is never going to be the best, and the combustion chamber is not optimally designed (incomplete burn), so if you're going to touch it, do it properly, ie: ditch the AFM, run a bigger cam with uprated valve springs (shrick do a nice double valve spring), bigger exhaust valves (ala alpina / schnitzer), and a really good port and polish that is flow tested.

A tuned length exhuast did nothing for Andrew's racecar, iirc.

im in the south so that aint gonna work, when you say ditch the afm do you mean get a map sensor thing.

full custom exaust must make some differance.

who would i have to go thru in nz to get shrick components

cheers

[savvi 0]

Not much to be gained from exhaust work on the m20, they were fairly well designed from factory. Extractors will help a little, but not alot maby 5/8hp.Yes its a good idear to use uprated springs with cam work, you wont make much more power and may even lose down low. You can get your flywheel lightend at lots of local places here in chch, but i would not machine to much off as it will leave you with not much touque if you go to far. All and all not many mildly modifyed m20 325i engines worldwide make over 200hp and are still good in a road car, without major work i.e 2.7,turbos,afm delete etc. Its a hard road to go down and many people have done it before with average results. I know you are a e30 purist Shane but you could spend your money elsewhere and save alot of time and money. cheers

cheers for your input drifty ill do sum more research on the net , want to keep the original motor and do it up and if i get 200hp

ill be pretty happy love the sound of a worked na straight six

[drifty325i 0]

im in the south so that aint gonna work, when you say ditch the afm do you mean get a map sensor thing.

full custom exaust must make some differance.

who would i have to go thru in nz to get shrick components

cheers

Full aftermarket computer ie, link etc. You will notice some gains with full custom exhaust but it will cost you sh*t loads to do it right.

not worth it imo. Shrick are very very good and also very expensive here, i would talk to the guys at kelford camtech in chch on one of there grinds.

[savvi 0]

Full aftermarket computer ie, link etc. You will notice some gains with full custom exhaust but it will cost you sh*t loads to do it right.

not worth it imo. Shrick are very very good and also very expensive here, i would talk to the guys at kelford camtech in chch on one of there grinds.

thats not a silly idea actually might give them a call 2morrow, geting a link system might be the way to go then depending on pricing

[Gus 5]

its a pre FL?

light flywheel works well. i like my cam, if for nothing else but the idle. to get good gains you need $$ to have decent headers..apparently BTB ones in the UK make a decent amount of power (dyno proven, +10hp if i remember).

the pre fl has slightly higher compression, so go a little better.

after market link is good, $$ but it allows you to take advantage of any mods you do. loses the AFM (big metal flap in airstream)

also allows tuning of fuel. i have read (true or not diff story) that m20s run slightly lean with any mods..marginally bigger injectors might/might not be a bad idea, esp with a cam.

IMHO keep it simple and cheap..enjoy it for what it is without spending $$$$$ on marginal engine improvements (20-30hp)

[DCEIVN 0]

When considering a link you need to take some thought into actually what kind of modifications you plan to make. If you dont plan to go into the full on N/A side of things, running a piggy back like unichip may actually give you better advantages

[savvi 0]

its a pre FL?

light flywheel works well. i like my cam, if for nothing else but the idle. to get good gains you need $$ to have decent headers..apparently BTB ones in the UK make a decent amount of power (dyno proven, +10hp if i remember).

the pre fl has slightly higher compression, so go a little better.

after market link is good, $$ but it allows you to take advantage of any mods you do. loses the AFM (big metal flap in airstream)

also allows tuning of fuel. i have read (true or not diff story) that m20s run slightly lean with any mods..marginally bigger injectors might/might not be a bad idea, esp with a cam.

IMHO keep it simple and cheap..enjoy it for what it is without spending $$$$$ on marginal engine improvements (20-30hp)

can you buy aftermarket lightened flywheels or am i better off getting factory 1 lightened, whats the diff between a full link and a piggy back system as that is what decievn reckons i should do, and i take it that your talking about your factory cam , 1 more thing do you know what cc factory injectors are pre fl

[Gus 5]

not sure of stock injectors..search on e30tech.com im sure it was up there

my factory one was taken down to 12lbs or so and works well..makes the gearbox rattle though

was referring to a lumpyish cam, 288 or similar

[savvi 0]

not sure of stock injectors..search on e30tech.com im sure it was up there

my factory one was taken down to 12lbs or so and works well..makes the gearbox rattle though

was referring to a lumpyish cam, 288 or similar

did you upgrade your springs or rings or anything internally

does it rattle on idle or when driving chur

were did you get your cam from

Edited October 16, 2006 by savini

[Gus 5]

at idle

it wasn't done by me so i am unsure...may need to upgrade springs but def not rings. diff part of engine.

[savvi 0]

at idle

it wasn't done by me so i am unsure...may need to upgrade springs but def not rings. diff part of engine.

do you still run a stock fuel pump

[DCEIVN 0]

Someone correct me if I am wrong as I am no expert:

A Link replaces your current ECU and requries complete programming yet you can cater for all modifications you make to your engine. A piggy back system such as Unichip is installed between your ECU and your engine and alters the variables the ECU sends to the Engine in order to maximise performance - it can be thought of as a tuneable chip I suppose.

Unichip is the only piggy back system I know of that allows you to tune timing and mixture. Basically every time you add a new modification you rock up to your installer and they tune the car with the unichip on the dyno. I was reading somewhere that the advantage over a link is that you can tune in much smaller incremements. However as its a piggyback, you cannot ditch AFM for MAP.

If anyone can shed any further light on this I would be interested.

[Guest Andrew]

The best way is to not spend any money on it.

M20 is not a cheap motor to get power out of.

[hybrid 1044]

The best way is to not spend any money on it.

M20 is not a cheap motor to get power out of.

werd

[savvi 0]

The best way is to not spend any money on it.

M20 is not a cheap motor to get power out of.

ive made my mind up want to keep the car original and numbers matching im just looking at getting a reliable 200hp out of the old girl so im going pursue this option no matter what it takes

[Guest Andrew]

ive made my mind up want to keep the car original and numbers matching im just looking at getting a reliable 200hp out of the old girl so im going pursue this option no matter what it takes

200 rwhp?

Easy

Read this

http://www.metricmechanic.com/pdfs/M20_Engines_Brochure.pdf

You'll probably come to realise that a normal e30 isn't special at all - (it's not an M3) - and that you should just chuck an m50 motor in it.

[drifty325i 0]

ive made my mind up want to keep the car original and numbers matching im just looking at getting a reliable 200hp out of the old girl so im going pursue this option no matter what it takes

If your dead set on an m20 ,See if you can get a deal on that race prep one trademe, its brand new. Hook it up with a link and you will be set for good revvy times. prob work out cheaper in the long run and it will be alot of fun

[savvi 0]

200 rwhp?

Easy

Read this

http://www.metricmechanic.com/pdfs/M20_Engines_Brochure.pdf

You'll probably come to realise that a normal e30 isn't special at all - (it's not an M3) - and that you should just chuck an m50 motor in it.

i realise that im quite happy with the m20 not really a fan of engine swaps unless im going hard out drag racing

cheers 4 the site

If your dead set on an m20 ,See if you can get a deal on that race prep one trademe, its brand new. Hook it up with a link and you will be set for good revvy times. prob work out cheaper in the long run and it will be alot of fun

its going 4 about 7-8 thou thou isnt it

[m325i 711]

200 rwhp?

Easy

Read this

http://www.metricmechanic.com/pdfs/M20_Engines_Brochure.pdf

You'll probably come to realise that a normal e30 isn't special at all - (it's not an M3) - and that you should just chuck an m50 motor in it.

The main reason I turned to the dark side. Any amount of power is never enough. But there is i sweet spot i reckon. Where, yes you could do more, but it will always catch you with, 'yeaaah, this pulls.' IMO the m20 falls JUST below this level. (In stock -> mild tune).

It sux bc I reckon it is just, by the tiniest amount, not quick enough. What is an m20? 170hp? 210-220hp would be mean. 280hp in an FR e30 would would be so mental.

Its a real shame a 250hp e30 isn't very affordable.

Edited October 17, 2006 by m325i

[Gus 5]

agreed..it doesnt need a lot more power and torque to be a whole lot better...im semi seriously thinking of an m52. aim for 210ish Hp with the eventual plan to build more...and more torque and better driveability than my m20.