Where is the weak link in Making a yb rev? With stronger rods, pistons etc, what stops one being revved to say 9k? Would solid lifters be good enough, or would you need to go one piece valves as well?

 

I am no expert on the mechanical side but I would guess solid lifters are the first thing and a blue printed balance of the whole bottom.

The YB Piston dimensions were designed for high revving IIRC !!


However, as far as engine managment goes, I wouldnt run the L8 or P8 above 8500 rpm as they are not fast processing and could miss crank pulses.

You may need bigger injectors to reduce the duty/rpm ratio as there will be less time for them to pulse open between cylinder firing events.

Coil pack ignition or a high energy coil may be needed as again, the coil charge times will be reduced at high rpm and could reduce spark strength.

 

Karlos should be able to help you with this one as his 3 dr revved somewhere up past the 8500rpm mark.

 

Why is the question, the natural max power on a cossie is between 6.5k to 7.5k to make it rev any more will ruin the low end TQ.

Mark

 

std YB rods are VERY strong as I understand it. They are just heavy... and at 9k its alot of weight to be slinging around!

but as Mark said.... why you wanna rev that high mate?


P.S 3.6 is a much better engine size to start with

 

Also Will, if you want to go for silly high revs, you are also going to need to address other areas such as oil pumps (you might want to consider dry sumping for those sort of revs), cambelt tensioners, cambelt idlers, alternators etc.

T4/GT30 stuff with a rev limit of 8k is plenty fun enough

 

just to throw one in the mix

the engine i just dropped out the old mans car

rev limit of 9200 rpm, this was only due being needed for the gearing top end due to the ffd ratios

peak at 8k,

7.5k 608bhp
8k 613bhp
8.5k 604bhp

and didnt take a reccording at 9k but iirc it had dropped a little but still rather good for a yb

the torque max figure was 456lbft on a straight 2.0, so not bad considering theyre very top endy cams

that engine was std/std crank, high pressure oil pump no dry sump , standard tensioners, idlers, grp a alternator, and no problem for 2years of track abuse,

 

Was looking at it simply to extend the powerband.

Porkie, It might still be an option, but putting 35k into a car at the moment is a massive decision as I might need the cash in a year or so, as I might be leaving the RAF..

 

where was the peak torque mate and how long was it there for???
when did you see full boost???


cheers danny

 

Fair play Jimbo, i guess it's all part of the R&D work for your dad

 

full boost 4k, torque was good spread to be fair, i will check out the graph tomorrow as i dont wanna say and be wrong as cant remember !

 

got to try these things aint ya, and its seen 9k+ a few times too

 

nice one..would be nice to see the graph mate???


cheers danny

 

will see what i can do !

 

We used to have Evo engines with 9400rpm rev limits - on T88 turbos and relatively close gearing they sounded more like big bikes at full pelt through the gears

Bet the Escos sounded awesome up there

 

surely its alot quicker and easier to sell one 911 Turbo.... than a truck load of cossie bits, than may or may not be working at the time!

 

Why not just buy an Evo 8 or 9 instead at a fraction of the price of a good 911 turbo and still have mega reliability and same amount of thrills?

 

Good shout actually

 

Not a massive Evo fan, and you are still on a 2.0 highly strung turbo engine.

I think for the time being I have to sort the Cossies, then see what's happening in a year or so!

 

Mine makes 500+bhp from 6000rpm to 8500rpm and 400+lbft from 4000rpm to 7000rpm . Shonky old T4s . Harvey's solid lifter cams rock !

 

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