R35 GTR - Full Race Report by RC Developments

[LAURENCE]

RC Developments - Race Report on R35 GTR.

Introduction.

On July 5th 2008, RC Developments entered their stock R35 GTR into the Club Challenge of the 2008 UK Time Attack Series Round 4 at Oulton Park, Cheshire, U.K. Clive Seddon (M.D at RC Developments and driver of the Yellow RC Evo 6) drove the car throughout the day. The car was 100% stock JDM model, with exception to the exchange of tyres from original Bridgestone over to Toyo T1R Tyre. Weather conditions were very wet/rain in the first session, and later the sun came out to dry the track completely.

The following points were noticed;

Engine/Powertrain.

The R35 GTR presents immediate power delivery with excellent Throttle Response. The car is reported to drive similar to a Normally Aspirated Large Displacement V8 Engine, with no turbo-lag experienced above 3,000 rpm, with a large powerband, no noticeable tailing off of power at the top of the rpm, making it a very forgiving car to drive. An increased level of overall power would help, and would help to make the car produce quicker lap times, with no real indications that increasing the power would unsettle the balance of the car.

Transmission.

The R35 GTR was run in Race Mode for Transmission, and reported to perform excellently. The driver never felt cheated/over-ridden by the computer, allowing for total control, however one very slight drawback felt, was the restricted ability for the driver to gain extra gear braking when foot braking deteriorated, as the limited range for rpm did not allow the computer to shift down the gears when desired by the driver, to achieve deceleration.

The Clutch performed excellently throughout the session, with immediate response.

Brakes.

The Brakes were the most disappointing part of the car, with them failing completely after 2 hot laps, with the driver experiencing sever brake fade, and spongey pedal feel. This is indicative of the overall weight of the car, and the stock brakes will require immediate attention before any amount of fast road or circuit use.

Chassis & Suspension.

During the session, the track was very wet and also dry, and the driver tested the car with Traction Control on and off with the following points noted.

Traction Control in the Wet helped a great deal and was a real aid to the driver, and highly recommended. Without Traction Control, the car could not be pushed hard as traction was severely insufficient.

During the Dry conditions, Traction Control was preferred to be turned off, as once engaged, the Traction Control Programming offered too slow decay time, with power being reintroduced painstakingly slow which was very frustrating for the driver. The response of the Traction Control was not sufficient in the dry conditions, and as an indication, the car was around 1.5seconds quicker per lap than with the traction control enabled. The car could be driven over the kerbs, but only with the traction control disabled. However, the driver felt that on kerbs, and in corners, rear inside wheelspin was sensed which prevented acceleration out of the corners. This would be resolved by stronger acting rear differential and/or increase of hydraulic pressure to increase diff lock.

General feedback in chassis was good, with positive, heavy steering providing excellent feedback. The R35 turns in very well, however its weight is always apparent, although this will only be noticed once the car is raced on track. The handling of the car displayed oversteer during low speed cornering, which was easily correctable, and should not pose too many problems for intermediate drivers, and at high speed, the handling was reported to be very neutral. Severe understeer was experienced when using incorrect sized front tyres (245/30/18) but stock Bridgestone Tyre responded well.

In terms of suspension, the dampers were set to Race Mode throughout testing, and the car felt compliant to track, with no excessive bodyroll for a car in street trim. To focus the car to track use, improved springing will help to reduce bodyroll, but damping is very good, with the dampers reacting quickly, as kerb riding did not present any problems. Damping control is sufficient for track use, with the only suggestion being a lower ride height and a stiffer spring rating.

In Conclusion.

The R35 GTR as a stock vehicle is extremely impressive, with its compliance to street conditions, and its versatility in competition mode, with a few modifications, the car will make a great trackday car, without losing focus as a formidable tourer. We anticipate owners of the 35 to have a great deal of fun with the car at trackdays, and keep a comfortable car for the drive home. For full competition use, reduction in weight is immediately required, significant upgrading of the brake components, and increased power will transform the car into an ultimate racing machine.

[DRAGON]

How come RC have got one? Are they interested in tuning them?
Great to get one out there, awesome result. Must make perspective owners very pleased.

[LordeRyall]

Thats a great, informative write-up thanks.

Clearly the brakes are an issue for any hard driving scenario. TokyoGTR has also mentioned this.

Is it just a matter of upgrading the pads or do you think the whole system (calipers, fluid, cooling capabilities) needs to be re-done??

[LAURENCE]

Dragon,
Our company director here at RC Developments, Max Waung, runs Car Planet also, so we have access to new cars imported direct from Japan.

We are very interested in offering full tuning and servicing support for 35 Customers, and currently working hard towards establishing this. We should have some official news on this before the end of the year, when we'll become an official trader here on the GTR Register and launch our advertising.
We're very excited about this new car, and are looking to offer 35 Owners the highest possible level of quality in service and offeringour own parts for the car + a whole plethora of high quality aftermarket parts and tuning solutions.

In regards to the brakes, yes absolutely evident that spirited driving really will require improvements within the braking system, and we are currently working with manufacturers to introduce superior braking components to the 35, for Street/Fast Road Setups, and then setups for more track orientated driving. There is improvement to be made in all areas and we will have news shortly.

Thankyou for your interest.

[mindlessoath]

ALot of tuners are finding alot of problems with the R35 for the race track. brakes is such a major issue. they upgrade them right away. plus the car doesnt have enough downforce and suspention has to much body roll.

the good thing is, for brakes there are cost effective solutions. upgrade the brake fluid to higher temp, replace the pads with track pads and the most importaint upgrade is brake cooling, ducting air to the center of the rotor with carbon air ducts, which has already been done in japan.

suspention is so wide assortment, coilovers of many brands are being offered with differnt specs for each tuner, some even use the same hardware, differntly tuned. but in any regard, they come out much better than stock, some tuners even recived better daily driving comfort with differnt setup.

downforce is something major issue for the car too. mines, amuse, cobb, autoselect and a few others have been making aero pieces for the R35, and they seem to be helping (the amuse canards didnt work, but they might be re-designing them). with the right aero you can even impliment brake cooling like the autoselect devil front spoiler.

you will also notice that weight is a major issue too... the new nismo car reduces weight by 270lbs or so (i belive thats with a crappy cage installed), but includes alot of carbon fiber and window replacements.
im not sure what brakes this car will imploy, but the spec-v has the carbon rotors which should increase the wear and track endurance.

[vex]

Originally Posted by LAURENCE

Brakes.

The Brakes were the most disappointing part of the car, with them failing completely after 2 hot laps, with the driver experiencing sever brake fade, and spongey pedal feel. This is indicative of the overall weight of the car, and the stock brakes will require immediate attention before any amount of fast road or circuit use.

agree with most of your points but my experience with the brakes are completely opposite. the stock brakes have _never_ faded despite tonnes of abuse at sepang, six performance laps at a go. and on sustained highway runs (for about 2 hours at above 250kmh interspersed with heavy braking), the stock brakes give a tremendous amount of confidence through their predictability and linearity. currently running on dot 5.1 fluid.

[LordeRyall]

And then there is another point of view!!

Thanks Vex. Out of interest what time were you posting around Sepang in the GT-R?

[vex]

Originally Posted by LordeRyall

And then there is another point of view!!

Thanks Vex. Out of interest what time were you posting around Sepang in the GT-R?

pm'd