Supercharged K20a2 Vtec - Race Spec by cptkirk

8 minute(s) of a 377 minute read

BOOT LID HEAT PROTECTION

Pretty much what it says on the tin really:

So I got to drive the car around abit over the weekend.

1st thing to note is the standard single baffle exhaust on this supercharged setup is 106db's, not a problem if your not going near a track, big problem if you are. Now I need to sort out a second baffle, I have an idea of what I want to do with this, I'll keep you'all posted

2nd thing, I advise all Zcar owners to check that the hats on the top of the coil-overs are properly tightened to its locking nut as mine wasnt and the whole suspension unit came apart doing about 60mph. I say this as it must have come from Protech loose. Its not the kind of thing you can normally check as the nut is hidden up in the cap of the suspension unit, I was really very fortunate that the damage was minimal, I did have a serious sense of humour failure over it though. Big thanks go out so a guy called Simon that lives just over Portsdown hill, near Portsmouth as he stopped, took me to his house, loaded me with tools and within 45mins I had it fixed and back on the road. The only tell tale sign is the dent in the under-slope of the expansion tank where the coil came to rest, thank god for the anti roll bar as this helped no end, also helped when trying to put it back together at the side of the road, threads on the piston shaft were flattened, which needed some attention, however now the threads are tight when tightening so it should not happen again. Also testament to the exp tank as it took a real battering.

The steering wheel is not straight when running in a straight line, so that needs sorting, it does run fairly true in a straight line, the large scrub radius is evident as it wants to pull on uneven roads, also under braking with a small amount of either lock on.

I can confirm that the car is fast as foook, stops on a dime and IMO looks awesome to boot.

I will show one picture of the car 98% complete for now, its not the best photo of it, but rest assured there will be more I just need to find the time to take some good photos.

Maybe I didnt exlain myself very well, the dyno used connects straight to the wheel hubs (see the dyno chart post in the thread and you will see what I mean) so it measured 288HP at the hubs, which when you consider 10% loss through transmission gives a reading at the crank (where BHP is measured) of approx 315BHP. WHP is something different and is pretty much what is being read at the hubs, minus the weight of the wheels.

I am not wanting to teach you how to suck eggs so please dont take offence if you've read all this before, it might help others to understand. Here are a few examples of the differences between the various types of horsepower:

Brake horsepower (bhp) is the measure of an engine's horsepower without the loss in power caused by the gearbox, alternator, differential, water pump, and other auxiliary components such as power steering pump, muffled exhaust system, etc. Brake refers to a device which was used to load an engine and hold it at a desired RPM. During testing, the output torque and rotational speed were measured to determine the brake horsepower

Horsepower Measurements

The power of an engine may be measured or estimated at several points in the transmission of the power from its generation to its application. A number of names are used for the power developed at various stages in this process, but none is a clear indicator of either the measurement system or definition used.

In the case of an engine dynamometer, power is measured at the engine's flywheel (i.e., at the crankshaft output). With a chassis dynamometer or rolling road, power output is measured at the driving wheels. This accounts for the significant power loss through the drive train.

In general:

Nominal is derived from the size of the engine and the piston speed and is only accurate at a pressure of 48 kPa (7 psi).[11]

Indicated or gross horsepower (theoretical capability of the engine)

Minus frictional losses within the engine (bearing drag, rod and crankshaft windage losses, oil film drag, etc.), equals Brake / net / crankshaft horsepower (power delivered directly to and measured at the engine's crankshaft)

Minus frictional losses in the transmission (bearings, gears, oil drag, windage, etc.), equals Shaft horsepower (power delivered to and measured at the output shaft of the transmission, when present in the system)

Minus frictional losses in the universal joint/s, differential, wheel bearings, tire and chain, (if present), equals Effective, True (thp) or commonly referred to as wheel horsepower (whp)

Got a few more photo's tonight, some turned out OK but the sun was still abit to strong in some of the photo's - must try harder:

Anyhoo, here are a few from tonight, no prizes for guessing where they were taken.

You can start to see why it has taken me so long to get to the finished article, there are many, many subtle bits that needed doing, in a couple of days I will have the interior complete and will post some photos of it for you'all.......

This is the first showing of the badge on the boot, anyone recognise the style of writing?

6-7-2010

In the week that I have been driving it the front suspension has 'settled', leaving the front wheels toeing out like a barsteward and has worn the inside of the front tires to the limit in a week. So this weeks mission is to find someone local that can do me a 4 wheel align as it just doesnt feel right. The front wheels are now so far up in the arches that they rub so it needs some ride height putting back into it.

In answer to your question the ass is a bit wobbly, mostly due to the size of tyre wall, it tends to roll over on the tyre abit. It skips all over the place down a bumpy back lane which is a bit disconcerting and due to the toe out it nows pulls like a fecker under braking. I now have to pay for a second 4 wheel alignment, which combined with some new tyres should hopefully cure all the niggles of the handling.

6-8-2010

I have just booked in to get my car 4 wheel aligned and corner weights done, so come friday 25th June when I pick it up it should be well and truly sorted on the handling front.

Rene, your quite right my friend, thats why I will let someone else have the headache, although I would love to have the equipment and the know how for this task as it is a black art from what I can see.

FRONT TOWING POINT, UNDERTRAY AND OTHER RANDOM STUFF

When I had the wheels off checking all the suspension was still tight after the hoohaa with rear suspension unit I took the tiem to take a couple of photos of how I overcame the lack of front towing point. I like to use this to tow the car into the trailer as it then acts as a stop for the front of the car.

In the photos you can see the fuel tank protector I put in place and you also get a glimpse of how the undertray sits at the front of the car.