Sputnik Racing

[sputnikracing]

waiting for pitstop

[sputnikracing]

Rear: poly bushings, extended studs. Front: new calipers, axles, ball joints and lower control arms. poly bushings. 

[sputnikracing]

949racing 6UL 15x8 +36et 225/50r15 Yokohama Advan A048 r-compound tires (temporary..)

[sputnikracing]

The hybrid transmission is ready for assembly. It has internals from an Altima, with the bellhousing from the Stanza. Apparently, it all fits together.

[sputnikracing]

The Sentra diet

Preparation on the Sentra is in full swing. Mainly, we're removing everything and anything that we don't absolutely need. So far, that includes

A million coolant hoses that circulate coolant through the lower part of the intake manifold and throttle body

Powersteering

A/C

Secondary radiator fan

EGR

Secondary idle control valve

Cruise control

Windshield washer parts

Misc splash shields

The biggest difficulty was the powersteering. You see, on a GA16DE motor that we have, powersteering pump was on the same belt as water pump. So  to remove it, the alternator had to be relocated to where powersteering used to be. So, many hours later with the angle grinder, I trimmed the massive alternator/compressor bracket to fit where powersteering used to be. It worked out fantastically well. The bracket fits well, alternator pulley is in same plane as crank/water pump and even the stock tensioner is reused (although it had to be extended about 1").

Looking at the alternator from the above

View from below

Idle control system was greatly simplified. In stock form there are 2 idle valves - one for warm-up and another one for idle-up. We removed the idle-up valve and about 5 air hoses. The warm-up solenoid was relocated to the front reusing 2 of the stock hoses. Looks almost factory, doesn't it?

The EGR system was very easy to remove. The stock cross-over pipe was cut and then crimped in a vise. This is temporary until the bung can be properly welded.

And finally, overall view of the engine as it sits

[sputnikracing]

Wheel and Tire: Lightweight vs Wide

When it came to choosing wheels and tires for the new Sentra, Alex and I couldn't agree on a single choice. At all. Not even close. We have completely different opinions on what would be best.

You see, the Sentra is a going to be a light, underpowered, simple car. Weight reduction, at this point, is way more important than any other modification on the car. To fulfill the lightness requirement, Alex said we should get the lightest 14" wheels - Kosei K1 TS @ 9.3lbs (mindblowing!) and  195 or 185 wide 14" tires. These wheels are insanely light, but, in my opinion, are too narrow. I'm of the opinion that a wider tire on a wider wheel will be faster and easier to drive, despite the extra weight. I was suggesting we get 15x8 949racing 6UL and 205/50r15 tires - a combination that's very common in the Miata world.

Since we couldn't come to an agreement, we decided to each get our choice of wheel and tire, and do a head-to-head comparison at the race. We will also both be using the same tire - the new Dunlop Direzza Z2, in 185/60R14 and 205/50R15 sizes. The smaller tire has a big advantage being smaller and hence, lighter.

The specs on each combination are:

Alex's 14" lightweight special - $1075, 26.3lbs weight (9.3 wheel, 17 tire). Tires are currently at $129 each, which is way more than it should be. Once the prices settle, I figure the smaller tire will be cheaper - less than $100.

Leonid's 15" wide and fat - $1100, including used 15x8 wheels. 31.9lbs weight (12.9 wheel, 19 tire). As you can see the combination is a whole 5.6lbs heavier, or, a whooping 21%!

In my opinion, the wider tire, despite being 20% heavier, will feel much better, in particularly in transitions. The tire will be stretched a tiny bit over the wheel, instead of bulging. This will improve feel and sidewall stiffness  Better feel -> easier to drive -> more confident drivers -> faster laps. That's my logic

Alex's logic is that the car is so underpowered, that almost 6lbs will make a huge difference in acceleration. 

We'll find out!

[sputnikracing]

We have wheels! 15x8 +36 949racing 6ul in their famous super-easy-to-chip nickel finish. Perfect! The mounted tires are 225/50r15 Yokohama ADVAN A048 r-comp that we can't use. Instead, we will have 205/50r15 Dunlop Direzza Z2

[sputnikracing]

We race cars.