NineMeister

The whole kit including linkages, billet manifolds, throttle bodies, air horns, filters, etc. comes out at £2490+VAT.

kos11-12

just a thought, a road/track car would have a standard gearbox (for eco reasons, parking & motorway) compare to a race car that would have a close ratio G, and keep the engine on the boil and RPM as high as possible in the power band...
how much the torque curve could be move to lower RPM without any lost in maximum power torque,
regardless any lost in top end...!?

NineMeister

If you want low end torque from your 964, fit a Varioram system with Motec and tune the engine to have peak power below 7000rpm. The car will drive like it has a supercharger fitted....

NineMeister

From memory:

964:
Intake port entrance diameter 41.5mm
Intake Valve diameter 49.0mm
Exhaust valve diameter 42.5mm
Valve stem diameter = 9.0mm

993
Intake port entrance diameter 43.0mm
Intake Valve diameter 49.0mm (50mm Varioram)
Exhaust valve diameter 42.5mm (43mm Varioram)
Valve stem diameter = 8.0mm

993RS
Intake port entrance diameter 46.0mm
Intake Valve diameter 51.5mm
Exhaust valve diameter 43.0mm
Valve stem diameter = 8.0mm

9m Billet Head
Intake port entrance diameter 41.5mm
Intake Valve diameter 50.0mm
Exhaust valve diameter 42.5mm
Valve stem diameter = 8.0mm

On tuned engines exhaust valves can run very hot, hence material choice becomes much more important as you increase the diameter.

kos11-12

Thanks Colin !
I thought maybe very long horns or longuer headers/ merging pipe ....

fuch

From memory.....I wish I had a memory like that.

That's why your ninemeister....

Porsche964FP

In the end we've settled on Nick's flat slide ITBs. Forgive me for saying but IMO that spec is too expensive in comparison to what is available in the same ball park.

Thanks you for all the head specs - brilliant stuff.

Rocker specs below.



UPDATE 7

* We've settled on Nick's sealed flat slide ITBs - due to cost effectiveness and throttle response. Which are currently being machined up since the castings are now ready. They'll have a two part trumpets.

* The rockers have been shot peened/ stress relieved. Which we believe will hold up to a rev limit of around 7,500 RPM. RSR rockers would hold better at higher revs but are around £ 250 per rocker x12 and IIRC affect drivability.

* Pictures coming soon.

Notes: At this stage we believe that our head specs will not affect midrange torque. I'll take this op to say that modifying heads is a lot cheaper than buying new ones... As ever any questions I'll do my best to answer with my limited knowledge. I'm finding it very hard not to speculate HP/ Torque figures - anyone have any thoughts?

* REDTEK Modified 964 heads.
Intake port entrance = 45mm 1mm less than 993rs Spec. These seem rather large to me?
Intake valve diameter = 51.5mm 993rs Spec.
Exhaust valve diameter = 43.5mm 0.5mm more than 993rs Spec.
Valve stem diameter = 8mm 993rs Spec.

964:
Intake port entrance diameter = 41.5mm
Intake Valve diameter = 49.0mm
Exhaust valve diameter = 42.5mm
Valve stem diameter = 9.0mm

993
Intake port entrance diameter = 43.0mm
Intake Valve diameter = 49.0mm (50mm Varioram)
Exhaust valve diameter = 42.5mm (43mm Varioram)
Valve stem diameter = 8.0mm

993RS
Intake port entrance diameter = 46.0mm
Intake Valve diameter = 51.5mm
Exhaust valve diameter = 43.0mm
Valve stem diameter = 8.0mm

9m Billet Head
Intake port entrance diameter = 41.5mm
Intake Valve diameter = 50.0mm
Exhaust valve diameter = 42.5mm
Valve stem diameter = 8.0mm

On a separate note here are some old videos made by Peter Morgan ('independent Porsche consultant') documenting his whole rebuild procedure by Nick before he moved his outfit to near Silverstone.

You Tube

You Tube

You Tube

You Tube

You Tube

You Tube

You Tube

You Tube

You Tube

You Tube

http://www.youtube.com/user/petermor...ure=CBwQwRs%3D

You Tube

You Tube

You Tube

You Tube

KaiB

True dat. Here is a real world example of the bottom end of the torque curve working as it should. We often get caught up in high hp on the dyno, and loose touch with the fact that most of our work is done elsewhere.

I can throttle out of most corners, most of the time with 6Cups and leave nothing on the table.

NineMeister

No, sorry, can't forgive you for saying it without the benefit of comparing like with like. The 9m kit includes absolutely everything from the cylinder head to the air filter including fuel rails and fuel pressure regulator. When you take into account the plug-and-play connection to the 964 throttle cable, I think if you add to the comparison the labour required to engineer other systems onto an engine I think you will find that the 9m kit is very cost effective.

Pleasure, only too happy to clarify.


We've even had shot peened rockers break at these RPMs, hence why we made the 9m Billet rocker. Not only is this part a direct fit into a 964 or 993 cam carrier, the geometry is vastly more accurate than a standard part, the pads are super-finished and the whole rocker is DLC (Diamond Like Carbon) coated to practically eliminate wear and reduce friction on the cam. I've tested the 9m rocker to 8300rpm in my own engine. We've recently made the decision to make two versions of the 964 (oil spray lubed) and 993 (shaft lubed) 9m rocker to the same high standards: the maximum effort, ultra lightweight race follower at £225 each and a slightly heavier Clubsport version at £145 each, both from the same material and strength. The difference in price reflects the additional detail CNC machining required to produce the ultimate version. It is recommended that you use matching 9m DLC coated rocker shafts (964 & 993) and elephant's feet adjuster screws to get the best from this installation.


In my experience a fully re-machined & ported cylinder head with new valve guides & seats will cost around 50% of the cost of a new part. Suitability of a standard 964 head for this work should be decided on inspection of the ceramic exhaust port liners cast into the head which often crack & fall out in extreme use.

I think the specification of your heads should achieve your target of 340-350hp. Obviously Nick will have to chose his camshaft specification carefully to optimise the valve timing events for his ITB design to maintain the low to midrange torque (which would ordinarily be boosted by the large port varioram intake on a 993RS engine with similar valve & port sizes).

Porsche964FP

Rothsport as one example to do a complete in house low butterfly system with all of the parts necessary to bolt and go for around $5,500 = £ 3,400. Which for a complete custom system is around £500 more.

At the same time RedTek's flat slide system all in costs less...

Now of course from my understanding each system is different and works in different ways so putting cost comparisons may be irrelevant - my mistake.

At the end of the day I'm just learning - using this opportunity to try and educate myself/ take an in depth interest in a service that I'm a client in.

Great info on your rockers - impressive stuff

Since there are so many more variables associated with rocker efficiency - we're feeling confident they will fit the bill for years to come. From my research billet rockers are a massive over kill for this application. Nick and others have standard rockers running all over the place at high, high rpm without failure. At the same time I would rather have a rocker failure than have billet ones muck up other vitals.... If I was running even more aggressive cams then billet items would be appropriate in my mind.

We'll see...

Yup Nick gave the exhaust ceramic coating the all clear before proceeding. Cam specs are 993 RSR cams.

evoderby

Great engine project you have there Frank.

Gas flowing is the process of re-shaping the cilinder head ports to increase performance. Flow testing on a flow bench is a means of measuring the results of actions taken.

Mind you flow is only one part of the equation that leads to performance. Port velocity is a very important factor as well, as overly large ports have the potential to flow well but loose the ram effect of the intake charge through low intake velocity.

At lower revs, with big overlap sports cams they are especially suspect to intake reversion causing an even further decline of the engine's potential torque.

Quadrant Scientific used to do very sophisticated flowbenches that were able to not only measure CFM, but also wet flow, port velocity in multiple locations, turbulence, boundary layer flow etc. F1 stuff....;-)

The above means that often times a combination of building up material and taking it away in others gives superior results to old school porting as it provides the best suitable shape and volume to provide ample flow with highest velocity.

Hope this helps;-)

Porsche964FP

Thanks for the feedback and clarification re. gas flowing, flow testing definition.
My logic/ understanding that may be unfounded - the head specs that I have are basically 993RS head specs. 993RSs with those head specs run an intake plenum that have a lower intake velocity than flat slide ITBs so in theory I should be good to go...

Depends on the ITB port sizes I presume?
What are the port sizes on 993RS Varioram intake?

mf_rsr

Doh-This is the topic of one of the vids you posted frank - btw, i love those, just wish i understood it...

bigunit_271078

I wonder if Nick will give a group discount once we all fall in love with this engine and half the UK based 964 owners want a similar package LOL

sounds like its going to be great overall package with circa 350BHP tied into the other mods/enhancements already done to the car.

evoderby

If only it were that simple;-)

Runner size, shape, length, plenum size, MAF/throttle flow, pressure harmonics, inter cilinder interference all play a role here to name but few.

An ITB systems short length means its harmonics are 'tuned' to give maximum torque at high RPM's. At lower RPM's torque is lost.

The RS varioram manifold intends to create a best of both worlds by increasing length at low RPM's for optimal torque, and providing a shorter path at higher RPM. Your combination of 993RS type large ports with ITB's will noticeably hurt torque in the lower RPM region I'm afraid.

Colin's testing has shown the Varioram works to about 6500RPM, above that RS plastic manifolds perform better, above 7000RPM ITB's are king. Of course the cams used dictate at which point the engine gives max power, therefore which inlet system is best suited for max performance.