The Plan - November 19, 2002

Ah, the plan.....   Like so many other plans, there have been numerous starts, restarts, changes and even more changes, but I think I really have a rather concrete plan at this point.  So rather than go through all the changes in detail, let me tell you where I am today and briefly how I got here.  So let me digress for a moment to explain how all this got in motion.  

Way back in the April 2002 timeframe, when the first Sport Compact Car Silvia conversion article came out, I was busting my behind getting my 91 300ZX Twin Turbo prepared for the 2002 Open Track Challenge.  It was so refreshing to see how simple of a conversion it would be to make a 240SX into a SR20DET Silvia.  The low weight of the car and the ease of working on it contrasted so much to what I was doing with the Z.  Also, after having owned the Z since 1995 and having steadily modified it since then, I was getting to the point where there was not much more that I really wanted to do to it.  This was further reinforced after OTC, when I had to rebuild the Z's engine after blowing it up during the race.  If you're interested in details of that preparation and the blowup, read about it in my article in Nissan Performance Magazine.  There are also articles in the summer 2002 and fall 2002 editions of Sport Z Magazine.  So after rebuilding the Z and adding a bunch of cosmetic modifications to it, I decided I needed another project car.  I wanted something on the opposite end of the spectrum of the Z.  Something lightweight, with good handling, rear wheel drive, easy to work on and with the potential for some serious power.  

The Silvia seem to fit the bill perfectly and  the SR20DET seemed also intriguing as a great little turbo four, with HP potential to boot.  Also, it seems that turbo cars seem to be a weakness of mine because when the Silvia is completed, there will be three turbo cars in my garage - the Z, an Audi S4 and the Silvia.

Initially, I was just going to buy a clean and straight 240SX and do the conversion with some additional modifications and use this as a street driven project car and that I would also do a couple of open track events per year.  At the same time, I decided to retire the Z from track duty, as I could not bear to bring her back to the track after all the work to bring her back to her current level.

Well like I said plans change.  When I had trouble finding a clean 240SX and instead received my 240SX for free, plans really changed a lot due to the condition of the car.  Now, since the car is going to require some body work and a change to a different paint color, I am planning to do a total tear down and repaint before it is reassembled.  So as I write this the car is nearly fifty percent disassembled.

Now let's go to the plan.  Overall, the plan is to build a well engineered and sorted car.  If possible, I am planning to use off-the-shelf components that any other enthusiast has access to.  I plan to do most of the mechanical work myself, but want the entire car to looked coordinated and professional detailed.  As I mentioned, the Silvia will be a street car that sees occasional track use so performance and durability is going to be stressed.  In addition, I plan to attend as many of the Nissan and Datsun meets as possible.  As will be evident in the details of the plan, this Silvia is not being built to compete on the import car show circuit, but the knowledgeable enthusiast will recognize its merits.

Exterior

For exteriors,  I personally like the sleeper look and will be using that for the overall exterior theme of the car.  I think the stock look combined with the potential of the SR20DET, does in fact define the ultimate sleeper, as most people would probably figure that the stock KA motor is still under the hood.   I am planning to use the full JDM Silvia body work.  A whole front end clip has been procured as well as a rear deck lid with a Silvia factory spoiler and even a nice Silvia logo key lock on the rear deck.  Also, I am not into wild paint jobs or graphics, so I am planning a brilliant silver paint color similar if the not the same as my S4 or maybe the same as the new M3's.

Suspension

Being that this car is going to be seeing the track and also since it is not going to be a daily driver, I am planning to go moderately extreme on the suspension.  Coilovers and other components that will allow adjustment of the suspension will be the order of the day.  Also, with having all those types of components, it just doesn't seem right to keep the worn stock bushings in the suspension.  So the plan is to replace all those with upgraded components.    

Also part of the suspension are the wheels and tires.  However, in order to open a wider selection of wheels and tires, I am planning to convert to a five lug configuration.  So new 5 lug front spindles and hubs from an S14 are being procured.  In the rear, I have already procured Z32 rear aluminum spindles.

As for wheels, in keeping with the lightweight them, I am looking for forged rims that can take the abuse of the track and are pleasing to the eye.  This might be a tall order, but let's see what I can find out there.  I am doing the research now to see what size wheels and tires I can fit into the fender wells.

Brakes

Being that the car is going to be driven hard at the track and have some serious power, upgraded brakes are going to be required.  Since any brake kit for the Z32 will fit on the Silvia, I was at first thinking of the newer systems that have recently come out on the market.  However, when I looked in my garage and saw all the spare pads, rotors, and hats that I had for my Z, the answer became very obvious.  AP 6 pot calipers with 13.5" rotors.  Might be a little overkill for my lightweight Silvia, but like I said, most of the parts are already sitting in my garage.  Also, to balance things out, stock rear Z32 brakes are going to be used as they came with the rear aluminum spindles that were already procured. 

Drive train

Well I am sticking with the stock five speed transmission that came with the front clip.  A lightweight flywheel will be used as well as an upgraded clutch to handle the expected power.  Also, a NISMO VLSD has already been procured for the rear end.  

Engine 

Ah the SR20DET.  What has not already been said of this wonderful motor.  My plan is to modify in stages.  The access to the engine will easily allow this, which is quite the opposite on my Z, where it seemed that any major modifications required the pulling of the engine to gain access.  

The first stage is mostly the usual bolt-ons with a target of mid to high 300 RWHP.  On the intake side, I am looking at the one of the aftermarket intake plenums as well as a low restriction air cleaner.  Larger injectors are also going to be needed.  On the exhaust side, I am trying to find a tubular stainless steel, equal length header.  This may be a custom part due to the turbo that I will be using.  Further down the exhaust, a down pipe and low restriction catback exhaust system will be utilized.  For cooling the intake charge, a FMIC will be sourced, and a larger aluminum racing radiator will be used to keep the water temperatures down.

Rather than upgrading the turbo at each stage, I have consulted with Mike Kojima and also done some net research for a turbo that will be good for all possible stages that I foresee.  For this, the recommendation is the HKS GT3037 ball bearing turbo.  So everything in the engine bay is going to be built around this turbo which should be arriving any day now.

As an added safety precaution, ARP studs are going to be replacing the stock head bolts, a metal head gasket will be used and upgraded valve springs will also be utilized.  Rocker arm stoppers will also be used since the head will be off and accessible.

Engine management will be handled via a modified JWT (Jim Wolf Technologies) ECU.  

Finally, I plan on running an Aquamist water injection system.  I have had great success with this system in my Z, and see the need for it in the Silvia, especially with the crappy premium gas that we have here in California.

Depending on the how the Silvia performs with the first stage of motor modifications, it might not be necessary to go to the second stage.  However, if more power is necessary, cams will be the next stage.  At this point, I think there would be more than enough power to have a hell of a ride.  

However, if we go off the deep end and decide that we really need more power, then it will be time to dig into the internals and do a fully built motor with all those trick internal goodies.  At this point, let's wait and see how things go before planning for this stage.

Interior

Being a mostly street driven car, I am planning to keep a full interior.  I am also considering addressing the interior in stages.  

For the first stage a lot of freshening up is going to be required.  Carpets, headliners and door panels are being repaired/updated or replaced.  Also as the tiny rear seat is not really going to be used, I am pulling it out and going to panel the that area with aluminum panels.  At this point in time, the front seats are going to remain stock, but also get reupholstered.  At this stage a few aftermarket gauges are going to be installed, such as a boost, EGT and water temperature gauges, but space will start to become an issue after that.  

It makes sense in the first stage to make accommodations for other things, as well as thinking of what might come in future stages. At this time provisions will be made for a racing harness and possibly a roll bar and aftermarket seats.

Stay tuned for my next update which will show the disassembly process of the car and some of the goodies that are starting to arrive in the mail.

Late Breaking News:  Carl Merritt and myself have been inquiring with the OTC organizers where my converted Silvia would be classed if I were to enter again.  It was unclear because if it were classed as a 240SX with an engine change and turbo upgrade, it would be classified as Class II car going against the same cars that I competed against with my Z.  However, if it were classified as a Silvia with 2.0L turbo engine, it would be a Class IV car where it would be competing against other 2.0L turbo and NA cars where it would be very competitive.  So the word came back that it is a Class IV car.  Although it would be too late to compete in 2003, I will have to take a close look at maybe making a run for it in 2004.