peteh

iTrader: (3)

Just a general question i need answering please

cheers.

Graceland

If you are thinking in terms of lag, then compression ratio has no effect on turbo-lag

peteh

iTrader: (3)

Im thinking the amount of air produced by the engine would be to great/little (not sure which) for the turbo?

I haven't a clue to be honest

Anonymous

On what engine?

If its a YB, then yes i would say thats too low unless you reguarly take a piss in your petrol tank.

peteh

iTrader: (3)

Yeah cossy, just thinking what my options are with my engine (for sale) if the main engine doesn't sell.

Anonymous

It will work fine, its not that it wont run or anything like that, compared to standard CR it will just feel flat off boost and make a little less power at the top end.

no big deal.

Ryan

got a nice new t38 for sale if he's interested

peteh

iTrader: (3)

would a T4 suit it better? but then there's lag isn't there?

peteh

iTrader: (3)

could well be

Anonymous

Suit it better for what?

peteh

iTrader: (3)

for the engine spec.

Anonymous

The engine spec would better suit a T4 turbo than a standard engine would suit a T4, but that doesnt mean bolting a T4 onto it will give you something pleasant to drive, it all depends on what you are after, and unless its 500bhp or so, i cant see why you would want to fit a big laggy T4



I would worry most about ending up with an engine and turbo that suits your driving.

peteh

iTrader: (3)

I don't want 500bhp far from it , wana fast street /quater mile car

punchy and responsive most of all, not into top speeds and that.

Anonymous

...that comp and turbo is FINE Pete

Its the old school way of doin things..where a T4 engine could only be 7.2-1 or less

Nowadays 7.4-1 is GT35 territory

Anonymous

Then IMHO its not a suitable compression ratio and i would wager the ports in the head are too big as well.

You would be better off for what you want just swapping it for a standard engine!

Anonymous

You think 7.4:1 comrpession is going to be "punchy and responsive" on a T34 compraed to standard compression?

peteh

iTrader: (3)

can't find one of them though well nobody that wants mine anyway.

Anonymous

...oh and before anyone spouts more "in theorys" i have had most comp ratio and turbos ..and the current one just so happens to be the spec your after Pete....feels a lovely combo to me bizarrely

Anonymous

Chip i talk from experience not books

..plus i never said it would be as good as std comp as that never arose in the conversation..he was asking if it would be ok...and IMO yes it will as i have experience..

peteh

iTrader: (3)

sorry phil , explain abit mate, your new car is running a similar spec ti mine with a T34.63?

Anonymous

He doesnt want "ok" he wants "responsive and punchy"

Anonymous

Hi Pete yes....the engine was made for 600bhp so basically its a case of just putting bigger injectors and turbo on it and remap of course.

Its a solid 400bhp with the T34.63 and is setup to perfection and very nice....you wouldnt be dissapointed,you could go bigger turbo but it depends what you want...in my EXPERIANCE it feels nice

peteh

iTrader: (3)

Thank you phil, the wise man has spoken

Ryan

let me know about the t38 pete if your interested

Rick

I'd say it would be fine. I've got a t34 on a 1600 with similar ish compression ratio, and it drives fine off boost. You could have a nice 2.5 bar spike in the mid range for some serious acceleration

peteh

iTrader: (3)

here sounds like a man with experiance

Mike Rainbird

iTrader: (3)

You want a 0.48 A/R T34 then if you want punch AND response.

peteh

iTrader: (3)

NEXT QUESTION

what cams? got BD16's at the mo

Mike Rainbird

iTrader: (3)

STANDARD for punch AND response .

Anonymous

yours feels nice because you have a good map on it and probably havent had on a standard compression engine with a t34 on it.

If you had EXPERIENCE of both back to back you would realise that


It will work, but its far from ideal.

Anonymous

...or MAD secret cams seem to work quite well

..becareful if you choose .48 as from MY experience i didnt like the way the power drops off before the limiter... .63 to the limiter baby no worries...about a 500rpm difference.

Mike Rainbird

iTrader: (3)

That is correct .

But a 0.48 housing on a 2wd car, gives more consistant drag times as you can get the launch right more easily...

I used to able to REGULARLY punt out 12s quarters with my 0.48 A/R equipped car (over ten in one day before), whereas with the 0.63 A/R, it would only be possible if the launch was perfect, as it was much more all or nothing (bog or wheelspin city).

CossieRich

iTrader: (1)

Persoanly, i would use the .55 housing as it can hold on to the boost that much longer up the rev range over the .48.

BD14 inlet and 2.5 bar spike of boost in the mid-range. you wont be disappointed

Anonymous

Excuse me??? This MAD engine is running an off the shelf Ahmed map Same as my std comped t34 .48 map ...i have no experience of a LIVE mapped car except my M3 ....and nor do the majority of users here...so a very poor attempt at a dig

peteh

iTrader: (3)

this ok with double valve springs?

Anonymous

I cant see why not

Mike Rainbird

iTrader: (3)

You don't need them with standard springs...

peteh

iTrader: (3)

Thanks phil, your being surprisingly helpful

Anonymous

Pete i actually KNOW about YB engines contary to popular beleif I have built a couple and specced them too with a little help from my friends I dont however profess to know everything to earn internet brownie points,i know what i need to know ONLY..anything more is a waste

peteh

iTrader: (3)

just i don't wana take the head off