Brought this to the top for a number of reasons

JJ

 

Which are ?????

You ain't killed it have you ?

Enjoyed our drive out James, best cossie i have been in, so rounded

Looks crap though

Steve.

 

just noticed this thread, i know its a few pages late, but

Mine done 505 bhp on a engine dyno @ 8.6:1. with gt30 and 25psi boost on pump fuel.

 

Thats pretty Awsome, Dan! Must be quite a handful by now matey!


cossie4i - Thanks for the kind words matey!! And she looks just fine ROFL!

Brought to top following a conversation with Stu. There is quite a lot of pretty good content in this link about how cossie engines can be tuned etc, and explains some basic principals. Hoping it will be moved to the Technical Essay Archive for all to benefit from now that the line is dead!

JJ

 

And how is the lag ? Were you looking for high-end power or mid-range torque ?

 

spool wont be change by comp ratio.

i spec it like that, to get better power/lbft to boost.

But EGT's are alot hotter due to this compared to a similar spec but low comp.

 

just read this , and wanted to say thanks too all you guys that have posted in this thread , i rlly is a great thread

 

yes, i agree , very good thread

but i don't know what i will do

 

the "safeness" of low comp far out weighs the power you lose IMO..

 

Wow - I havent read this thread in ages! Good to see that she still lives in Technical Essay archives

Generally I agree with Rapid Cossie for big power builds, Low comp does make a lot of sense.

The thing is that the further you look into it the harder it gets to get a really good definitive answer!

That I guess is all the fun!

JJ

 

in your opinon is that spec nice and responsive low down?. genuinely intrested as ive never experienced that spec first hand. sorry to go off topic slightly.

 

....... (just so I can find this thread easy later on)

 

Seeing that most of this thread was done over 3 years ago it would be good to see the doubters and believers opinions now on low cr and a better cr...
Iv said now for years that the closer the cr to std the better the engine and the better the response,back then i was told my engine wouldnt last 5 mins!!!
I had an rs 500 running 8.0.1 back in 96 with t4 8 greys etc etc doing 520 hp and that was awesome compared to any low cr set up iv had /driven and since 2006 have been running 8.6 cr in my race car and its still on the same pistons....low cr is not needed anymore full stop...


cheers danny

 

No.
Proof below.
Never had surge on any of my MAD engines because Mark knows what he is doing cam wise. Mines also way over standard compression.

 

Blimey,

What a thread

The answer is yes you could have 500bhp. I am at 480 bhp with standard sized ports on in the head. Ok my c/r is lower than standard at 7.6:1 but my engine is proof that it can be done (well almost anyway) IF i get one of Spec R's intercoolers i think 500 bhp may be cracked. Cam choice is obviously a big winner

 

good read, standard or above standard CR seem to be the way to go

 

rich what would you gain by the bigger intercooler to warrent 20hp gains /

your charge temps high now, or ???

 

Not so much high, but higher than they would be with the spec r cooler i think. Going by the test on Ade's car where they saw very low charge temps even at 2.6 bar. Plus some added ignition as well.

 

ok cool

 

Mine is bang on 8:1 and I'll do everything possible to hit the 500hp with a 3071

 

Yeah and ill be watching

 

what boost you planning on running?

 

Around 2.5bar .

Mark

 

why so much boost mate my engine made 570bhp at 24psi of boost ?

 

But not on a GT3071 and a relatively stock engine,
Rods makes way more than 570hp on 24psi so its also relative to turbo size and engine spec.

Mark

 

ya fair enough mate it was on a t4oz, i speak to you soon ref that viper ecu mate

 

ta,

i guess 2.5 bar is OK then? i assume that is peak

from my understanding of GT's you need to run a recirc or dump valve

 

2.5 bar is fine. Yes you need a dump valve

 

awesome thread this

 

Now don't you go trying to chase numbers and going for a 3076 will you?!

Going to be a cracking engine this, still have the occasional weep over selling it tbh

 

But, will a 205 block last @ 500bhp ??

Sorry, i just felt like dragging this back up....BORED

 

just read the first page, im gonna run 1.5 bar on a t70/gt35 on a stock 205! fuck yea why not

 

just silly IMO, they are huge turbo's and need to be run at near full whack to get the power out of them

lag lag lag lag, boost, rev limiter

 

What do you mean run at full whack to get power out of them ?

 

like 2.4 bar! why put a turbo that size on a yb and run it at 1.5 bar, especially as its a road car

 

because i could say ive got a turbo the size of my head

plus would sound immense with external wg.... im gonna ring mark shead to get more info bout it tomoro, Iv read of a few people that have gt35's come on full boost at around 4-4.5k

 

I personally can't see Mark recommending that tbh, i may be wrong of course..GT3071 will/would be far more drivable....

 

I am with ya but just because a turbo is not making huge boost it still makes the power, that's what it looked like you were getting at ?

 

https://passionford.com/forum/ford-s...15-20-psi.html

 

nope; i fully understand that