Supercharged K20a2 Vtec - Race Spec by cptkirk

8 minute(s) of a 377 minute read

70mm Throttle Body

I made some progress with the new TB over the weekend, I had to spend some time lapping in the throttle plate to body to ensure zero leakage of air at closed throttle, it purrs like a kitten at idle now.

I had to made a spacer for the intake air control valve (IACV) so that the loom would reach it. I used some acetal as it's easy to work with and can stand the heat of the bay.

I got the whole lot back together again and this is how it looks currently (note the throttle cable is not connected):

4-8-2015

AUTOMATIC THROTTLE BLIPPER

Not a great deal to report on this right now, other than I got a new timer unit through so now I only need a single timer unit as this has a delay built in and its tunable to 0.1 of a second, you can see in the photo that it reads 00.2, meaning the initial delay is 0.2 of a second and I have the on period set at 0.6 of a second, although I think that might be too long.....

I am using two relays to ensure that, should I catch both pedals accidentally, for a split second, that it will not send power to the solenoid, even though the timer will go through its cycle. The timer now has permanent power to it and uses a signal wire from one of the relays, again both pedals need to be depressed for this to happen.

I've got a nice little enclosure for it, that will initially sit within easy reach of the seat (probably next to the seat) so I can do any fine tuning really easily.

My only problem now is that when I fitted the 70mm TB over the weekend I noticed that I can get to 6-7k rpm with about 1/3 opening of the throttle so my initial plans with the solenoid setup might have to be changed slightly.....

4-9-2015

I am running:

Front - 7x13 rim with 185/60 R13 R888

Rear - 8x13 rim with 225/45 R13 R888

You could easily get the 225/45 to fit a 9" rim. and if you want wider than 185 on the front you could go 205/60 (R888) but be aware the sidewalls are massive...I was glad to get rid of mine as the tyre roll on the rear was considerable. Conversely the tyre roll on the front 185/60 is virtually none existent, I think this is due to there being very little weight on the front of the car...

I get on fine with them and recently I have been playing with pressures and made good gains.....That said I haven't had any other make of tyre on the car.

Here is the difference between 205/60 (on the car) and 225/45:

4-16-2015

Flowmaster DBX Silencer Setup

I have been busy working on the car, trying to get it all back together for a track day at Goodwood on May 25th (Bank holiday Monday).

Among many other things I test fitted the exhaust last night, not much more to say than that really at this point.

I don't think the photo's do it justice but here they are:

4-17-2015

No Jim, I didnt, to be fair on tickover its pretty bl00dy quiet and didnt want to be revving it without tail pipes directing possible fuel over-run flames away from the car. Considering I've only ever had absorption cans on it before these should make a massive difference and by putting them in parallel I am reducing the back pressure they will inevitably create due to their design.

I am making a housing for the air filter to sit in that is going to be fed by 3" piping to the two scoops on either side of the car, this will reduce the intake noise/whine of the SC and by sucking in from both sides should half the amount of intake noise seen by trackside decibel meters (there's never one on both sides of the track at any one point).

To be fair there are a lot of tracks that you wouldn't need to go this level of noise reduction for, however Goodwood is really strict and there db meters are linked to the local council offices so anyone going over the limit get black flagged and registration number reported. Its more so that they can be seen to be "doing something about it". And as Goodwood is less than 10 miles from my house it seems a good idea to get in their good books as so far every time I get black flagged. Annoyingly though the last two times I've been pulled it was when there was another vehicle involved but as mine has always been the noisy one I get the naughty noise sticker on my car......

4-23-2015

Flowmaster DBX Silencer Setup

Final welding session last night for the silencer setup, I now have a sweet looking double silencer/ exhaust that should be one hell of a lot more effective (even if a little more restrictive) than the original setup. Don't get me wrong though, when it's not on track I am going back to a single absorption can because its sounds fricking awesome and I've had it reported to em that you hear me coming from behind (finaar finaar)......

I am waiting on a couple of parts before I can final fit it but here's a couple of snaps from last night, was double chuffed when I realized it would stand on its own.....

It's a shame the old part that I am re-using isn't as shiny as the rest of it but hey ho, you cant have everything.

Big thanks to Stevie G for giving up yet another evening for me and the car....

turns out it does look like the design:

A few more shots:

4-24-2015

Flowmaster DBX Silencer Setup

Well, I fitted them last night and run it up to temp, then gave it a few blips and I am undecided as to whether its quieter than before?!?!? Before making judgement I am going to wait until I have it out on the road under load. I would have got some video of the blips but it was getting late and I didn't want to p!ss the neighbours off, it has more of a raspy sound to it now. I did get a couple of photo's, not the best but they show how it fits in there.....