Extra Power On A 8 Valve On Standard Injection System ?

[m_pugz_1986 0]

i have a 1.9 8v pre cat engine run on motronic management , i have a performance filter and a full scorpion system on it at the moment .

 

I was wondering what else i could do ? was thinking on sending the head of to longmans what about the fueling can i increase the fueling by having bigger injectors ? i have the standard orange injectors in there now , also would it make much difference if i had the inlet manifold ported ? as i understand the inlets prefer to be rough on the inside compared to smooth . cams wise i have herd there is no point changing the cam unless go to carbs or tb's but some people have told me to go to a slightly more aggressive cam than the standard one . So what cam is best to use ?

 

thanks matt

[James_R 3]

for the money you'd spend unless you really want to keep the 8v, 16v is the way to go. not to mention better fuel ecomoney to boot.

[richsmells 2]

I'm guessing you have Jetronic rather than motronic if its the standard pre cat injection system. No point using bigger injectors unless you're going for big power. Mi16 engines use the exact same injectors. You would see small gains with a ported manifiold/head, with 3 angle seats, the standard 205 gti head has quite large valves. Some people have fitted a 2.0 8v Xsi XU10 head from a 306 which has bigger inlet valves but the exhaust valves are still normal size.

 

Some people do fit a cam, but the standard cam is actually fairly lumpy. As you've said anything much larger and you'll need carbs to get the best from it. You'll never get the fueling spot on with standard management. Idle will suffer with anything too lumpy as it makes the AFM flap pulse.

 

You can fit mapped management from a 1.9 zx volcane or 405 sri (using the zx ecu). The zx has the same engine as a pre cat 205 gti, but runs mapped management. This would improve torque, idle and can be remapped if you fit a cam. It's a lot of effort though as it requires manifold, loom, toothed flywheel from donor cars etc. The cost of all this plus remapping for any modifications would add up to that of fitting a 16v lump.

 

Short answer. Fit carbs, go 16v or spend money on suspension componets.

Edited March 19, 2008 by richsmells

[welshpug 1,680]

its a late Motronic equipped 205 that used to have a cat, till the engine died and Matt fitted a pre-cat engine.

[TEKNOPUG 3]

Turbo/Supercharge or fit another engine. Really is no economic sense on spending any money on an 8v

[m_pugz_1986 0]

but i do like the low end power and torque a 8 has

[TEKNOPUG 3]

It has no more low end power or torque than an Mi16/Gti6 - it just feels that way because the 16v's have a rush of power when they come on cam.

Seriously, spending money on an 8v is futile unless you employ forced induction - then they are fantastic

[Alastairh 47]

Well said that man!

 

You need to experience 16 valves/boost to appreciate how s*it them na 8 valves are...

Edited March 19, 2008 by Alastairh

[Ormy 0]

Well said that man!

 

You need to experience 16 valves/boost to appreciate how s*it them na 8 valves are...

 

Now now! Nothing wrong with 8 valvers at all!

[Baz 421]

Yes there is when you want more power than they can offer...

 

Otherwise, a good one in fine fettle, they're great!

 

All the info you need would be uncovered doing a search!

[mad_dome 1]

8v is great my xu9 head was pushing good horsepower not shure what but it used to beat mi16's.

It has now been off the road a number of weeks beacause i am trying out the xu10 head off the 406 as this has bigger valves.

 

I have also gone for a slightly bigger cam (piper 270) witch is a slight increase from the 268 that comes standard.

i am also useing the so called group a injecters witch turned out to be a load of old bollocks(ebay s*it).

 

however useing this head involves a lot of work to thee inlet manifold and head its self as you have to ajust the inletports etc. but a very cheapway of doing things. but i have just purchest a gti6 engine so if youcan get one of them then do that he he.

[Peetypug 5]

up until last week i was going to cam and carb my 8v as well as getting some head work done

for the money i have spent on parts for the 8v i could have bought a accident damaged GTI6

so tommorrow i am picking up said GTI6

 

all my bits are going on ebay, but the best thing is, i will actually save money by doing the conversion (by selling the GTI6 bits)

 

so i'd say DUMP THE 8V as i was told on a number of occasions "you will not be dissapointed"

 

why not do a poll on it 8v versus 16v?

[Alastairh 47]

Pete, you'll love it

 

Matt, i thought you were buying Baz's S16 engine?

[Peetypug 5]

Pete, you'll love it

 

i'm so excited, i cant wait, i pick it up tomorrow morning

 

just got to trawl through all the bickering/topics on which is the best way to do the conversion

[m_pugz_1986 0]

meh i still like 8 valves i dont know why i just like to stick to them or perhaps it because i cant be arsed doing a engine swap , when i use this car everyday , i can afford it to come off the road for a weekend , but not in the week as i have to get myself into swindon center by 7 am

 

call me a lazy bastard i don't care its different when not ur main mode of transport

 

but u never know someone could talk me into changing it , but 16 valves are getting too common conversion for my likening , want to be different me thinks

 

ITB's on a 8valve dont see that much ! hmmmm

Edited March 21, 2008 by m_pugz_1986

[TEKNOPUG 3]

That's fair enough. The power delivery is excellent, just a bit lacking in errr....power.

 

Seriously though, modding an 8v other than forced induction is a complete false economy. You'd be far better off getting the engine running properly as standard and investing your hard earned on suspension and brakes - then you can always attend to the engine at a later date.

[m_pugz_1986 0]

That's fair enough. The power delivery is excellent, just a bit lacking in errr....power.

 

Seriously though, modding an 8v other than forced induction is a complete false economy. You'd be far better off getting the engine running properly as standard and investing your hard earned on suspension and brakes - then you can always attend to the engine at a later date.

 

 

that bit is nearlly done brakes are 266 mm just need some better pads for it now :S as i have bendix crappy things and just need some uprated shocks and some strut braces 309 setup on the front too but a 205 arb , and a 24mm arb on the back im thinking

[Peetypug 5]

if you get all the parts together you should be able to do an engine swap in a weekend

or am i being a bit adventurous? (and no mine wont be done over a weekend as its in a severe state of malnourishment right now)

 

if its extra power your after then its cheaper to do the swap, unless somebody on here is selling a ready modded engine

 

standard 1.9 130 bhp

standard gti6 167bhp

 

you would have to spend quite a bit on the 8v to get it up to the gti6 power, then you have a car that isnt very good for driving round town, which aint good for an everyday car surely?

[m_pugz_1986 0]

if you get all the parts together you should be able to do an engine swap in a weekend

or am i being a bit adventurous? (and no mine wont be done over a weekend as its in a severe state of malnourishment right now)

 

if its extra power your after then its cheaper to do the swap, unless somebody on here is selling a ready modded engine

 

standard 1.9 130 bhp

standard gti6 167bhp

 

you would have to spend quite a bit on the 8v to get it up to the gti6 power, then you have a car that isnt very good for driving round town, which aint good for an everyday car surely?

 

 

well my old minis was like that had a v lumpy cam in but i have been thinking gti6 but its not the conversion part its the actual wireing that will have me stumped if someone has a digram i might get persuaded

[Peetypug 5]

well my old minis was like that had a v lumpy cam in but i have been thinking gti6 but its not the conversion part its the actual wireing that will have me stumped if someone has a digram i might get persuaded

 

i'm not 100% sure myself

but i'm just gona jump right in but take my time with it

there is no complete list of parts needed so i'm gona make one as i go along, just to help people if i can

knowing me i'll be asking loads of numpty newbie questions that will just get laughed at until somebody takes pity on me and buys everything off me

 

but i do still like the old 8v

check the video in this post

clicky

[m_pugz_1986 0]

i'm not 100% sure myself

but i'm just gona jump right in but take my time with it

there is no complete list of parts needed so i'm gona make one as i go along, just to help people if i can

knowing me i'll be asking loads of numpty newbie questions that will just get laughed at until somebody takes pity on me and buys everything off me

 

but i do still like the old 8v

check the video in this post

clicky

 

 

see you know u love 8valves on carbs lol sounds live heaven , well i always fancied a mi on twin 45's

[taffycrook 2]

On comp. cars that have to run 8v's I have had fair results with the std inj system.

1.6 rally cars have shown 140 bhp with not too much spent.

All the talk of 160 bhp 1.9's is possible but not on a budget.

Engine swops make sense, as does turbo charging however, in real world terms my 205 8v track day car is as quick as a mi16 around the circuit with around a 20 bhp diss-advantage.

The new engine build is going to hopefully put me on par with a std mi16, but this will cost around another 500 quid.

On top of carbs, mapped ign and the rebuild.

[Alastairh 47]

if you get all the parts together you should be able to do an engine swap in a weekend

or am i being a bit adventurous? (and no mine wont be done over a weekend as its in a severe state of malnourishment right now)

 

if its extra power your after then its cheaper to do the swap, unless somebody on here is selling a ready modded engine

 

standard 1.9 130 bhp

standard gti6 167bhp

 

you would have to spend quite a bit on the 8v to get it up to the gti6 power, then you have a car that isnt very good for driving round town, which aint good for an everyday car surely?

 

Yup. Thats why after doing most engine conversions on 205s now id go back to a GTI6 if i had to. For the money to power to fuel economy for a daily drive id like to see someone better it...

[Baz 421]

Matt, i thought you were buying Baz's S16 engine?

 

Pffft, that was old news, tbh i didnt really expect that to come to fruition, i think you know why...

[Matt Holley 11]

see you know u love 8valves on carbs lol sounds live heaven , well i always fancied a mi on twin 45's

 

You can come out in my gti6 on carbs if you need some convincing on 16v power