Birth of a rally car

[Darren65]

Congratulations on your Tour Britannia result Phil, magnificent achievement….It prompted me to re-read this thread, this really is a special car.

Love all the weight saving, where did you end up with final weight?

A general update on the car would be most welcome.

Cheers,

[pht9]

The weight of the car without fuel is 980kg in Rally trim, we can reduce that down to around 965kg if it was in 'circuit spec'

I guess the biggest update for the car is the upgrade to the 3.0 MFI engine, that I have been developing for around 18 months. It is pretty unique specification, as it uses our own design pistons, camshaft profile and exhaust system. I am very pleased with the results, we have just under 300bhp and I have been working on the tractability of the engine throughout its range, which is so important for a rally motor. The MFI pump has been on and off so many times with adjustments to the fuelling . I use a lambda sensor in the exhaust, and datalog the runs, so that I can fine tune the mixture

The latest upgrade was switching the ignition to the 8-pin HKZ units as the RSR ran in period, along with a spare, plus the rpm limiter that is adjustable

[pht9]

for anyone attending Castle Hedingham next Sunday, we will have the SCR on display, along with a VERY special friend that makes its first public UK debut

Look forward to seeing you all !

[yoda]

Great result Phil and a super car - must be a hoot to drive.

Now tell us about the special friend ...........

[stretch]

Do i know this "Special friend" Phil ? Or is she not special yet.

[Bootsy]

How special is she? Will have to come and see next Sunday

[pht9]

its special, you guys won't be disappointed

[Darren65]

its special, you guys won't be disappointed

Understatement

I will document the engine build a little later

Well?

I just love this car Phil….another thread I keep drifting back to, just awesome!

[pht9]

I have decided to market the SCR. Hopefully this thread will become useful in documenting the build process, its a wonderful car and I am sure its future owner will enjoy it as much as I have.

http://www.tech9.ms/car-sales/porsche-9 ... rallye-lhd

[yoda]

Hmmmmm ..... just thinking what body parts I could sell to buy that! Lovely car, best of luck with the sale.

[Bootsy]

Amazing car, good fortune with the sale

[dragonfly]

Great car, someone's in for a treat

[pht9]

Its been a while since I posted on the build thread of my SCR, I had a few requests to share the details of the engine. Having successfully completed numerous events, trouble free over the past few years in my car, we have now started to market this engine and have just finished our first client build, I enclose some of the build details. This engine differs from my engine, in that its twin-plugged, my car being built to FIA 3062 homologation where only single plug allowed - I hope you enjoy the content

Engine is based on a 911SC - retains 3.0 Capacity

Layout of components, prior to build



Tech 9 Custom pistons and conrods



Mahle Cylinders, machined for accuracy (bore perpendicular to mounting faces) then plated with ceramic composite



Cylinder heads twin plugged and new sodium filled Intake and Exhaust valves installed



Ports machined for flow and accuracy of mounting to intake manifolds, Injector ports added for MFI injectors



Heart of the beast ! – here you can see the large capacity GT3 Oil pump, one piece steel Intermediate gear, Crank and con-rod assembly, cases with shuffle-pins installed on the main webs. To ensure this lot don’t burst out, secured with ARP Porsche specific engine fasteners throughout




Build completed



Details, Details……. Magnesium High Butterfly 50mm Intake system, MFI Red Top RSR Fuel Pump





Tech 9 Custom exhaust system with equal length stepped headers, with merge collectors



Pre-Dyno – Installed on our engine test bed to bed in camshafts and set ignition timing, set throttle butterflies etc



Dyno testing – Final results 308bhp @ 7600rpm with 233 ft/lbs torque @ 5300rpm with silencing requirements met to allow for MSA event testing
Built as a rally specification engine with good low-mid range torque characteristics, the torque curve is very flat. In race/circuit specification the power output would be closer to 340bhp (any takers ! ??? )

[911hillclimber]

Quite a thing of technical beauty Phil, fabulous.

What 'class' will the car with this engine run in?
What cams did you use (if that is the major influence on mid range torque?)

[alanchester]

A thing of beauty!

One detail missing was the spendy part. Ball park how much would the engine above cost from a starting point of say a known good SC engine?