As title

 

low comp and LOTS of NOS, thats the way forward

 

high comp - good off boost
but limit to amount of boost it can run
more prone to det
less ign


low comp more boost can be run
less chance of det
more ign possible

 

sort that avatar out mike!

 

as jim said its throing my screen all out

 

fook me how big is that,cue stu

 

See Paul Hills at Engine Advantages...end of topic

Most tuners on here talk crap...ok 1 tuner on here in particular Get proper info and then base a decision..................

 

isnt yours high comp phil?

 

I think high comp is the way to go

 

isnt high comp the more expensive route at the moment ?

 

Why would it be?

 

cos for as long as ive been playin wiv turbo,d motors , its allways been low comp this , low comp that !! now tuners are starting to go the other way
so surely there arent as many high comp options available yet , which makes me think it would be the more expensive option .. ( takes a breath )

 

Personally I am a fan of higher compression.

My current engine build is 8.6:1

Depends what your after I think, I know people like Gareth and Karl prefer low compression. Hihg compression I believe will generate more power, but you have problems of EGT and reliability.

I know Ian@Racetek's old engine was a fooking monster, WRC spec, 9.6:1CR and 2bar of boost, was balistic. Died right off top end though. (De-restricted).

Now Karls is low comp i expect, and that caris awesome, come on boost later, BUT, you have a much wider power band because he revs it up to 9000+ rpm. And that car is the fastest car ive ever been in. Quiet possibly the fastest cossie in the UK.

For my own car, am medium power, torquey, not a high revving engine, I have chosen a higher CR.

 

but low comp gives good low down torque, thats why all the amercan engines, even n/a are low comp, cos they dont like low revving torquey thumpers. so why is a high comp engine better off boost?

 

most NA performance engines run high comp , its allways been the way to go if u havnt got a turbo , but as with everything , technology moves on
i mean imagine building a cossie 10 years ago and saying u were gna use high comp pistons !! u,d get a few funny looks !

 

i use OVER 9:1 for my car and it runs OVER 24 psi of boost

off boost is fookin mint ! like driving a nasty aspirator ! then before you know it full boost at 2200rpm, !

 

Adus..yes mine is hi comp...as i said its the way foward....mentioning Karls car apparently dont hit full boost till 5500rpm??..so 0-5500rpm...lo comp bet thats fun..ROFL......although my T4 doesnt power up till 4300rpm its corking off boost plus add anti-lag and quite possibly the most awesome car there is bar Ian@Raceteks..LOL.

 

why are u talking about when its off boost anyway ??
mine runs 7.2-1 comes on boost @3000, 26psi and released 420 brake .
these cars are racing cars and therefore should be driven like 1 !! keep it in the boost range so u dont even have to worry !!
if u wanna go high comp then do so , personally i will stick with low comp and be as happy as ive ever been .

 

How Funny!!

You high comp engine is so good is does not make proper boost until 4300, my bullshit old LOW COMP T4 engine made proper boost by 3500 and driver fine off boost!! Explain that then Mr know it all!!LOL

 

 

Keep it sensible please guys

 

I aint got secret cams like yours Monte...bd10's....

I had a touring car style engine and because its a road car it needed drivability as with this kinda power you cant use it much unless you are a total wanker...So hi comp cured this..now it drives like a normal 2.0 litre sierra(with anti lag on even better) with the added bonus(once its final mapping session is over) the advantage of 2.1bar T4 power at the 4300rpm onwards mark.

So yes i'd say well worth doin over old tech lo comp.....all or nothing.

That enuff Mr Monte?

 

If low comp is so good why are all these sedish cossie running high comp and some the biggest turbo's?

 

You all talk shit (high compers). do you actually know anything about engines?

 

An NMS groupie has arisen..ROFL

 

...oh whilst your here please enlighten us in to why we talk shit?

 

Keep it as a sensible discussion please mate, if you favour low comp then state your reasons why it is mechanically better

 

This is very true and I completely agree but........

With modern engine managment systems, EGT probes, Wide band lambda,
special piston designs, it is possible to have
HIGH comp with HUGE BOOST provided it is properly managed and set up.

Alot of people in the past have stuck LOW comp chips into ecus fitted to HIGH comp engine and it went bang !
This has led to a general miss belief of HI comp HI boost is bad.
It is far easier to lower the compression ratio than spend the time
to set up/map the engine properly.

The jap boys are seeing 800 hp + from 2.1 litres and over 8.5:1
compression ratio on pump fuel reliably - No bullsh*t !

Having said that, there are quite a few cossie motors doing 700 hp +
at the moment on high compression. Bult using some Jap specs.....

Times and technology are changing faster than the people using it !

 

Have a look at the fuel they run... comp ratio is mainly based on fuel octane.....

 

i gotta be honest , i havnt read that much about the high comp motors exept the guys on the board who are using them , so i couldnt compare the 2 in a scientific personal experience kinda way , all i know is , im happy with 400 horses and low comp . i guess if i won the lottery and wanted the fastest cossi in the world i would pay the money and leave it to the tuner to decide , but as i havnt won the jackpot i,l stick wiv wot i know

 

Nope!! Not at all!!

 

i gotta be honest , i havnt read that much about the high comp motors exept the guys on the board who are using them , so i couldnt compare the 2 in a scientific personal experience kinda way , all i know is , im happy with 400 horses and low comp . i guess if i won the lottery and wanted the fastest cossi in the world i would pay the money and leave it to the tuner to decide , but as i havnt won the jackpot i,l stick wiv wot i know

 

Top post simon, monte if it's down to the fuel how come ian@racetek and markk can run high comp high boost?

PJay

 

my old 7.2 engine wasnt too bad off boost really..

you people just need to learn to drive..

look at Tibs car.. 3.5 secs 0-60 on 7.6:1 ish cant be too bad really can it..

if it was laggy the 0-60 time would show it afterall!!

 

This is also very true !!

 

I could attempt to answer it but I won't, requires Karl's input really!!

Sure if you search back you will see this post already done with Karl explain what the deal is.

 

be interesting to put , similar power cars together on a drag and see which is best . im sure they would all be very similar . horse power for horse power !!

 

my low comp engine has no lag 400+ lb of torque @ 3k.....

WHO gives a feck about bhp

for a road car, high comp seems to last the least amount of time....

Chadley is one of the few who actually work with engines day in day out ima, nothing to do with karl.

Nice dig at him btw you kvnt.

 

be interesting to put , similar power cars together on a drag and see which is best . im sure they would all be very similar . horse power for horse power !!

 

Here we go: