Wednesday, 20 April 2011

R33 Brake Stopper

Due to the high forces exerted against the bulkhead under braking, the Brake Stopper bolts onto the suspension turret and is adjusted upto the end of the master cylinder. Thereby reducing bulkhead flex for a sharper more direct feeling that can be felt from the brake pedal.

Originally I was a bit unconvinced by fitting one of these and many of them usually come in a pressed metal bracket. However I have gone for a machined item (see pic). This was supplied from SuperForma and although they were slow on delivery (no stock) they generously refunded my postage. I strongly reccomend you try them if your interested in high quality items. The part is not particullarly cheap, although quality components will usually set you back more (you get what you pay for) with postage it would have set me back near enough £70 (79 Euro or $114 USD).

The component comes is a matt shot blast finish. I can tell you that from my days working in the casting industry that this is usually to hide machining marks! I took the 400 grade sand paper to it and it actually did polish up quite nicely! So all in all it is a good quality item.

Supa Forma Brake stopper for GTST

After a quick buff and polish
 As the car is currently waiting at the tuners (Abbey Motorsport) for it's all important mapping session, I will have to keep you all in suspense as to fitting and if it actually feels like it makes a difference!





Tuesday, 19 April 2011

Thursday, 14 April 2011

R33 Anti Roll Bar Upgrade

No, these aren't the things that are bolted inside the car in case you turn it over - those are rollover cages. Anti-roll bars do precisely what their name implies - they combat the roll of a car on it's suspension as it corners.
They're also known as sway-bars or anti-sway-bars.
Almost all cars have them fitted as standard, all have scope for improvement. From the factory they are biased towards ride comfort. Stiffer aftermarket items will increase the road holding but you'll get reduced comfort because of it. The anti-roll bar is usually connected to the front, lower edge of the bottom suspension joint. It passes through two pivot points under the chassis, usually on the sub frame and is attached to the same point on the opposite suspension setup.
Effectively, it joins the bottom of the suspension parts together. When you head into a corner, the car begins to roll out of the corner. For example, if you're cornering to the left, the car body rolls to the right. In doing this, it's compressing the suspension on the right hand side. With a good anti-roll bar, as the lower part of the suspension moves upward relative to the car chassis, it transfers some of that movement to the same component on the other side. In effect, it tries to lift the left suspension component by the same amount. In doing this, it's actually compressing the suspension on that side which basically counters some of the roll in the chassis by lowering that side of the car.
Typical anti-roll bar (sway bar) kits include the up rated bar, a set of new mounting clamps with polyurethane bushes, rose joints for the ends which connect to the suspension components, and all the bolts etc that will be needed.

The standard Anti Roll Bar fitted to a GTS-25T Spec 2 is 17mm this upgrade supplied from Serious Performance Autos is 26mm. So you don't have to be a rocket scientist to see that it's going to be somwhat stiffer!
Naturally this will be fitted with Polybushes manufactured from a high grade polyurethane compound which as similar elastic properties to rubber, but with inherently superior shear strength and resistance to wear.
Kit consists of the following items.

26mm rear Anti Roll Bar
SuperFlex Drop link poly bushes
SuperFlex ARB poly bushes
New drop links



Thursday, 7 April 2011

delays ahead

The modifications have been continuing at a fast pace now. All that is left to do is fit the adjustable rear camber arms for wheel alignment. However unfortunately Ms Skyline has run into a snag, whereby I can't get any dyno time at the tuners (Abbey Motorsport) until May 6th.
Abbey run a drag car and are preparing it for the Easter weekend (22nd April).

I could run the car at a steady pace with upto 0.5 bar boost and 4k RPM but really that would be a major step in the backwards direction.
My options are that I could go with another tuners, but Andy at Serious Performance Auto's has advised against that.

So am a bit stuck and will just have to wait it out. Slightly frustrating as it means my forthcoming touring holiday is now all off and I will be sitting around. Still can't be helped! Naturally the thought sticks in the head that four hours of tuning should be do'able, although if a slot comes up they will fit the car in. So there is the outside chance, although I won't hold my breath!

I must admit I did have my suspicions that Abbey would let me down, no big reason for this, other than having spoken to them once and having seen a few people complain about them not coming back to them. The main reason I am sticking to them is personal reccomendation. After all I got off to a shakey start with the car, when I had it tuned at Rising Sun. They managed to practically keep the actual performance of the car the same, build in a terrible misfuelling judder on mild acceleration, scratch the wing and charge me a load of cash up front for the privilege. So now I'm actually back at the stage of 'everything sorted', I am hesitant to trust the car to anyone else that 'say' they know what they are doing.

I suppose I did call the blog 'adventures in motoring' Although not quite the adventure I had hoped for!

Wednesday, 6 April 2011

Intercooler - what does it do?

One of the first modifications I made was to fit an intercooler. At the time I wasn't actually sure why I wanted one and it was just an item on my list. In many respects intercoolers seem to be a vital fashion accessory and you will see all manner of heater matrix poking out the front of cars.

Air molecules when banged together, heat up. Pump up a bycycle tire with a hand held pump and you can feel this in action!
The same thing applies to a turbo blowing air into an engine and since hot air contains less gas molecules than cool air, the engine isnt getting as much oxygen as it should do.

An intercooler sits between the turbo and the air intake. Hot air from the turbo passes through the intercooler, which acts like a big radiator and cools the air. The air then becomes denser giving more oxygen to any given volume, this in turn burns in the engine, making the power.
One bar or 14.7 PSI of boost increases the air temperature by around 60 degrees Celcius, while every 37.8 degrees Celcius reduction in air temperature increases air density 12 - 13 percent.

The most common kind of intercooler is air to air, these are light and simple (although you can get fluid intercoolers). The are usually positioned at the front of the car behind the grill, where they can get a good flow of cooling air right through the front bumper. With the skyline there is some modification to do and a large chunk of front bumper has to be sacrificed in order to fit. It is possible to fit a larger R34 side mounted intercooler in the position of the original one. Although this is only good for around 300 BHP. So the size of intercooler is important, too big and the turbo will take a long time to fill the intercooler with air. Delaying throttle response.

I have seen on Subaru's that they use top mount intercoolers on WRX's at least. I would assume that this is not ideal, suffering from heat soak from the engine and degrading the intercoolers function. However they would have the advantage of being located close to the engine, not requiring long connecting pipes that can degrade throttle response.

Air Flow Meter Z32

What is an AFM?
Afm stands for Air flow meter, occasionally known as MAF. Its what the computer uses to measure the quantity of air entering the engine to determine how much petrol to inject and how much ignition timing to apply.

What?s a Z32 afm? Why would I need to upgrade to one?
The z32 is a very common upgrade with Nissan cars. They are generally upgraded on those cars more since they support larger amounts of power compared to the stock afm.
How does at faulty Afm cause the engine to detonate/ping?
If it reads less air than is actually entering the engine, the ECU puts less fuel in, and while it also sees less air it also thinks less load which is bad as the timing generally high in those areas on the map, both bad, the engine pings/knocks.

Z32 AFM

Tuesday, 5 April 2011

Fuelling - Injectors, pressure regulator and pump

At this stage of modification we can't modify one thing without having to modify a whole other section. So  along with a bigger turbo all the fuelling has to be looked at.

Larger 555 Injectors: When factory standard injectors reach their maximum capacity, they can no longer flow any additional fuel for higher boost levels.
So... Any time you force more air into a car engine, you need to compensate with more fuel to correctly meter the air fuel mixture, since a turbo adds more air, you need more fuel to make the correct air fuel mixture.
And that means I will have to feed the fuel to the injectors better
So...Fuel pressure regulator: This pretty much does what it says and regulates the pressure that fuel is delivered at.
Fuel pressure adjustment range: 196-588kPa (28-85psi) + Flow volume 40L/h

So the last link in fuelling is of course, the fuel pump. As fuel pressure increases, fuel pump flow rate decreases, for most pumps it's a linear decrease. The rate depends on the specific pump. The plan is to fit a larger pump from a GTR to help feed the beast. This should slot pretty much straight in without too much trouble.

All clear? Good! Simple isn't it?
 

Hybrid Turbo's



Admittedly I have been quiet on the posting front, this is due to my carrying out large work on the car and the time constraints that this offers. Rather than a big list of non descript modifications I will drill down through them as I go along.




Starting with a Hybrid Turbo. Sounds kind of sexy doesn't it? But what does it actually mean?

The Basics....

Air entering the engine first passes through an exhaust driven compressor. Compressed air results in a larger quantity of air being forced into the engine, creating more power.

The energy used to drive the turbo compressor is extracted from waste exhaust gasses. As exhaust gasses leave the engine they are directed through a wheel placed in the exhaust flow. The gasses drive the turbine wheel around, which is directly connected via a shaft, to the compressor wheel.

Increased exhaust gas drives the turbine wheel faster, this provides the engine more air, producing more power. A limit is met once a pre-determined boost pressure is achieved. At this point the exhaust gas is redirected away from the turbine wheel, thus slowing it down and limiting the maximum boost pressure. This redirection valve is known as the wastegate.

This extraction of energy, from exhaust gas, to improve engine efficiency is the device known as the turbocharger.

Turbochargers are usually seen as power enhancements on performance cars, but today, turbochargers are becoming more regularly used to provide greater torque on small capacity engines. The advantages of using a turbo engine include improved fuel efficiency and reduced exhaust emissions.


The standard Skyline R33 GTS-25T comes with a ceramic turbo as standard and at max strength can deliver .8 bar (14.5 psi = 1 bar) of boost to the engine. Anything over that and it will have trouble.

Hybrid turbos only become necessary when significant performance improvement is required, normally on a modified engine. Most hybrid turbochargers will look identical to standard units from the outside. The changes occur inside, by using steel components, different aerodynamic configurations, both in the compressor and turbine housings.


 
Turbo Charger


Most turbocharged engines respond well to increased boost pressure, but only if the engine is modified to capitalise on the change. The same can be said of turbochargers. A hybrid turbo on a standard engine may offer a small benefit, but will be more effective on a modified engine.

Another way in which a hybrid turbocharger can improve an engine’s performance is by improving response, or reducing turbo lag.

Boost pressure will be able to be increased to 1.2 or 1.3 bar safely, any more than that would require a thicker head gasket to be fitted to handle the pressure build up.



The turbo unit I am fitting comes with a twin port Stainless steel turbo elbow (see picture) which replaces the standard cast iron combined turbo elbow. This should help reduce the affects of negative feedback pressure on the turbo vanes by separating the turbo and wastegate exhaust gasses, improving flow, speeding turbo spooling and reducing turbo lag.

Turbo Elbow


Did you know?

The air entering a turbo's compressor impeller can be travelling at a speed close to mach 1.

A turbo will accelerate from 20,000 revs per minute to over 150,000 revs per minute in less that one second.

At average engine revs, a medium size turbo will swallow 130 cubic feet of air per minute, equivalent to the interior volume of a transit van.

The "hot end" turbine blades in a turbo, are made from a high nickel content alloy, as used in jet aircraft engines. A blade will travel in the region of 820 mph at average engine speed, and the exhaust gas entering it will be supersonic.


For more information on Hybrid's or general turbo enquires visit the
Turbo Technics web site