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Where is good old SK when you need him....

This whole AFR argument is an interesting one, Id sure like to know the answer to all the questions :)

what knock is everyone getting?

also I beleive Jim turned up the sensativity of my knockmeter?

what AFR does say a stock porsche TT have or say a GT2 GT3?

anyone?

SK :O

Your not scared of a few little gtst's running on the dyno aswell are you  :ph34r: ? be easier to get the numbers for a dyno day if you let them in, I'm sure they don't mind it not being fair you being RB26 and all

Ben,

Congrats on your result! Jim @ CRD knows his GTR tuning.

My car is going in early next week for a health check before I run my previous boost (finally ran it in with 1600km)

BTW - I am in for the track day, Nick (blitz) & Ben, keep me in the loop!

Marko

Hey Dave,

yeah I am sure CRD's is a happy dyno! I'm only able to compare like for like.... many other guys on this forum have been to CRD and got with similar setups 285-315 AWKW so Im in there somewhere....

I did the DART dynolog because :-

A) Jim @ DART offered and is a great guy!

B) very accurate NM torque reading

C) unbiased back to back testing with a known base.....

to gain 65 AWKW and 122NM with slightly less boost is great news from a dynolog....

I also know of a GTR with GTRS making 280AWKW on dynolog making 385 AWKW on DynoDynamics....

Hi Ben,

Do i know this guy with the GTRS setup?

Marko

Im not sure marko, its a car that had previously been down to the GONG for a tune on the dynolog... similar setup to you I guess...

Im living in Adelaide now, but will take the car to PI for a track day in Vic for sure! great drive along the great ocean road!!!

Im over there for the weekend with the racing at EC, keep me in the loop also RE your car!!!

I have to ring Jim at some stage... I need to chat to him about a few things :D

Ben

kekekegay.gif

Buy some, they are a worthwhile investment  :O

we're gonna try my 26/gt-ss without any cams at all to begin with and see what we can get out of it with just a cam gear among other things.

Should have a full assesment by Dec... wishing it was sooner but time isnt my friend at the moment.

Good result indeed williams

sounds like a great idea....love to see a heap of cars in action.....then maybe a drag run for the top ten.....ala supercar shootout

can i throw down the gauntlet and say 450 AWKW

using shoot_6 or shoot_8 :O

difference with shoot 6 or 8 ?

IIRC, it refers to the ramp rate used on the dyno: shoot_8 being for an eight cyclinder cars, shoot_6 for 6 cylinder cars. This is all part of a long running saga about whether or not twoogle achieved a certain power rating (I forget the exact number) at a dyno comp. The number achieved was done so with the dyno in shooutout 8 mode (which -- not wanting to step on any toes here -- allegedly produced a higher than normal figure), hence the sly comment :P

but making low 1/4 times can be a whole lot of things other than pure power... and besides we all know the GT-R was meant for corners :)

Ben,

I totally agree that the gtr was purpose built for the circuit

BUT

to crack a high 10 pass i believe u would need at least 350awkw - i remember jim @ crd telling me about one of his customers r34 gtr with 350awkw pulled a 10.8 1/4 mile.

For Paul to get a 10.3 u would need 450awkw minimum :D

Marko.

Top thread , its good to see engine development that goes way beyond big turbos and filthy rich AFR's . I'm sure its a challenge to get good power (torque) over a wide range from limited capacity and forced induction .

The individual I've had most to do with also does not like rich AFR's and I get the feeling that the "bit more fuel through it just to cool the engine" theory may have come from the carburettor/mechanical advance ignition days . An EFI system (production style) usually injects close to the inlet port so I'd imagine the evaporative cooling effect would be little if any before the charge reached the cylinder through and round hot ports and valves . With carburettors the inlet system is what some call a wet system (everything downstream of the carby has fuel and air) so I suppose there was more time to do the charge cooling thing . AJ leads me to believe that rich mixtures are more likely to enhance detonation and not going to help either your hip pocket or ring/bore life . Is there someone here that can explain why this rich thing is ie burn rate or excessive carbon or whatever .

My own very limited experience proved to me that leaner 12.5/13:1 max gave best performance but timing was critical and very much tied to charge temps .

My own theory is minimal exhaust restriction helps reduce reversion with its charge poluting and pre heating effects .

More people are looking at high lift short timed cams to make engines breathe well in the mid range where most engines are much of the time . In David Vizards later books he talks about cams like these in the BMC A Series (dinosarur I know) , where lots of development means the performance of yesterdays race cams can be streetable today . He quotes an example of the old BMC Road rally Cam (648) being 300/300 x 394" lift . It had 300 deg on the seat timing with 244 deg at 50 thou lift . A later type Crane "tight lash" profile has 286 deg on the seat and 252 deg at 50 thou . What this means is the Crane cam has 14 deg less seat timing but 8 degrees longer duration at 50 thou which tells us that the opening rate is much faster . So I reckon more valve lift (the valve is usually the greatest restriction in the port) and shortish duration to help trapping efficiencies . Shorter timed cams set up with a little less valve overlap should help with reversion . Fast opening rates would help cylinder charging and free flowing turbine/housing/exhaust reduce the reversion problems .

It sounds like you're engine is making very efficient use of its air and fuel to make bulk torque over a wide range without towing a fuel tanker around . I'd like to PM you about workshops you've used in southern Sydney as my mechanic is now out of reach .

Cheers A .

Ben,

I totally agree that the gtr was purpose built for the circuit

BUT

to crack a high 10 pass i believe u would need at least 350awkw - i remember jim @ crd telling me about one of his customers r34 gtr with 350awkw pulled a 10.8 1/4 mile.

For Paul to get a 10.3 u would need 450awkw minimum :)

Marko.

Hey Mate,

Nah I think you didn't get what I was meaning... basically I think Paul and Stace have done an Uber job!!! and if they make 400 or 450 or 500 who cares? Im sure that is the last thing they really care about....

What I was getting at with the 10.3 there are a lot more factors that just power figures to getting a good time :D

-driver

-suspension

-gearing

-weight!

-mechanical grip

-aero

-drag

-weather

-track condition

I'm no Drug racer, but those are to name a few... I would say there is more to be gained in suspension, tyres and weight reduction than most consider to do, and having taken a peek at Twoogle with you that day out at the SAU show, it certainly was heading in the right direction in those things :)

I'm going to be at EC on the weekend, you should come and watch a few GT-Rs in action... turning :D:P

how many more km to go mate also? I can't wait to see how well the new engine goes... :(

Ben

The 400m dyno never lies......Whats your car running NISMOID??????

So far ive run 12.1... :)

Bit of a joke, no need to start the jumping...

Didnt know a dyno run in shoot_6 or shoot_8 was so important to the world leader :D

And you know there is a difference as much as i do :D

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