Just getting our Stealth grey LM1 RS to the Nurburgring was a challenge this year. The car has had a lot of work completed on it over the last few months, but with a busy workshop looking after customer cars it often slipped to the back of the queue which meant we needed to complete three weeks work in less than a week! Our August Nurburgring trip made for a good target date to aim for, but with days to go we were still having new parts fabricated and it definitely needed its engine going back in! We had a brand new billet engine block ready for our engine builder Steve to assemble while the rest of the team did an amazing job getting the car ready just in time with it firing into life on the Tuesday, before being loaded onto the trailer on Wednesday night.
Whilst we all thought the performance of our GT-R Track Edition was more than any normal person should require around the Nurburgring, it was exciting to have this confirmed by our LM1 RS Track car.
Where you could attack this famous circuit with our Silver Track Edition, our LM1 RS was a completely different animal; a roller coaster that you’re both pleased you’ve experienced but relieved you can take a break from.
It’s not that it’s difficult to drive, in fact it’s the opposite. The power delivery and handling setup is so accessible you can’t help but start to push…..but then it regularly reminds you that it is trying to deploy 900+ bhp even in the lowest power modes! It’s brilliant and scary in equal measures and we absolutely love it!
Amongst the thrills there was a serious reason for the inclusion our LM1 RS in our group. The car was serving as a test bed for many prototype products, which will hopefully be put into production before long.
The car was now running our brand new billet aluminium engine block with power ranging from 900-1,200 bhp, thanks to our LM1200 turbo kit. We had also reverted the car back to a ‘wet sump’ to replicate most customer setups. Testing the new billet engine block on our dyno and on the road had shown that temperatures and pressures remained the same as the cast factory production block. Pushing this car at the ‘Ring would allow us to test all aspects of this new engine in the harshest environment.
We were delighted to see that the engine coolant and oil temperatures remained low and there was no discernible difference using the billet block compared to our popular original 4.6 litre conversions on a standard block. Our billet block is so much stronger than the stock design, by virtue of the fact we have redesigned the internal backbone structure and increased the distance between the bottom of the head studs and water jacket to prevent the cracking issues we see on the OE block. Given that this block has been in development for the last couple of years this was a great final test and we can now begin work on machining the production items.
The LM1 also featured the final pre-production versions of our gearbox and rear differential coolers, which mount up inside the rear bumper, and a new prototype turbo and gearbox water cooler mounted behind the front bumper. Cooling of all the fluids in the car was not an issue, with coolant never exceeding 88 degrees and transmission oil not exceeding 110 degrees even with hard use around the track.
The main radiator has been re-manufactured and tilted forwards, which together with custom made ducting and a GT3 vented bonnet, allows all of the hot air from the radiator to exit upwards through the vents in the bonnet. Following our wind tunnel testing and last years Nurburgring trip, it was shown that there were improvements to be made to the airflow through the coolers and a reduction of under the bonnet air pressure, which will help the aerodynamic balance. Again we are looking at marginal improvements, but it appears to be working well. We’ll continue to refine this setup and it might be an option in the future for the more extreme GT-Rs as it requires a number of other modifications including the relocation of the power steering reservoir and header tank.
Fuelling for this high powered engine is taken care of by our boot mounted swirl pot and pump setup. This sits in a sealed box and is able to still use the stock fuel tank and sit unobtrusively in the boot, surrounded by your shopping if you so wish! This has been successfully fitted on a few customer cars previously so this really was just confirming what we already knew, that it is capable on both road and track with no real downsides. We also got to see the reduction in fuel temperature that our new, larger metal fuel lines provide. These lines offer greater internal bore size for improved flow, but also re-route the fuel lines away from their original location next to the (red hot) turbo manifolds.
In addition we had also programmed the engine and gearbox ECU using our latest Version 7 maps, which uses Ecutek’s new beta software. This is able to seamlessly control the 12 injector setup along with ability to provide the much needed traction control additions, which we can create with their unique custom map options.
The 4.6 litre engine is so smooth and torquey it only takes a few bends to realise you can be a gear up on every bend compared to the Track Edition and yet its instant power can still work the traction control hard!
Overall we were delighted with the changes we had made to our LM1 RS, from its new colour using our Paint Protection Spray to the Billet engine, everything worked as we hoped, and the car is brilliant fun to drive.