Supercharged K20a2 Vtec - Race Spec by cptkirk

7 minute(s) of a 377 minute read

So, the post above would have been true had there not have been a mix up with the labels on the packages sent from the US, so I found myself with less than a week to go to the track day and no frickin silencers.

I needed to hatch a plan to try and drop some decibels with what I currently have, plus a few cheap extras. I ended up using some 1.5" perforated tube and some 2.5" perforated discs welded into the tube and approx 45degs and at differing positions around the 360degs of the tube along the length. I have also had a bespoke end can made of which the top is enclosed and all gases are to pass through some 2.5" perforated tube onto the ground to help dissipate the sound (unfortunately I don't have a photo of the end can, will get one once its in place).

Here's a couple of snaps of the work, thanks to my mate Stevie G for doing the welding at short notice.....:

it defo sounds quieter, the only problem is you can feel its getting choked at high revs........bummer.......

Fingers crossed for good weather on Monday at Goodwood, maybe see some of you there???

9-4-2014

LSMOC @ Goodwood 11th Aug 2014 - 98db static, 96db drive by.

Car feeling very choked due to extra silencer work as shown in my build diary, I was two's up with my good buddy Jim in the car and still managed only 0.7 slower than my fastest lap in May. Difference this time was that I took the time to sort my tyre pressures properly, hot = 22psi....first lap is a bit interesting as the nearside rear comes up to temperature but by the second lap you can get on it more.....

I only got black flagged once for noise and was hoofing most of the day, well, when it was dry anyway, there were some interesting moments in the wet morning sessions, coming round St Mary's, up the rise towards Lavant Corner to see a literal wall of water and the rain bouncing a good foot off the tarmac.....Oh Bejesus....

These videos are of the two fastest laps of the day, Lap 22 (video 031) was a 1:38:58, Lap 23 (video 032) was 1:38:67 (0.09 difference)

The Harry's Laptimer App on the phone seems to go awry at St. Mary's, going invest in a stand alone GPS for next time (Dual SkyPro XGPS160)

9-10-2014

Some more footage from Goodwood 11 Aug 2014, this is from the GoPro, the session with the fastest laps. As you can see by the lack of sawing at the steering wheel the cars got a lot more to give in the corners. I think its more the fact that I put so much into it, not just financially but emotionally that is holding me back from driving it like I stole it......

The hand actions as I go round Fordwater were me saying how windy it was that I could feel the wind holding the car from pushing out on the corner at 100+ mph....

I just tried playing this back and for some reason it starts at the end, feck knows why......

A few slower laps - damned rain:

getting drier:

2-4-2015

It can be done cheaper, frankly I was financially raped along the way by people who took advantage of me being a newbie to the whole car building scene.

My advice is to put together a budget and then get someone that's been through it to have a look for you as they might spot things that are missing that you hadn't considered.

I have attached my budget sheet from 2008, you can see how it all starts to add up. Consider the total on the budget doesnt include the rapings, travel/transport, all of my labour hours, the later upgrade to intercooled and then re-dyno'd.

Andy kirk - Mini budget - 02-Apr-2008.pdf

2-4-2015

I am up to my normal winter tinkering now.....

Got a couple of things on the go, one of them being fitting my 2x Flowmaster DBX silencers. I am undecided as to go with a similar in series setup as I had with the two absorption cans or to split the gasses and go parallel with the new cans?? and then that led me to thinking if I have split the flow of gasses and effectively slowed them down this means there is less back pressure as the gasses flow through the two cans, now do I send the gases back together or do I keep them separate and have two exits pipes???

Here's what I've come up with so far:

Into one exit pipe

or into two exit pipes...

And for those looking at the Y conenction thinking it'd just flow past into the bottom can here's how I will over come that:

I received a new part from Clockwise Motion today - however you'll have to wait for more info on that as I am waiting on other parts - lets just say its a replacement for a cheap piece of sh!!t I bought earlier in the project.

2-6-2015

OK, so did a bit more design work tonight and decided that splitting the flow and keeping it split makes sense but rather than try to get both out one side I decided to build on the success of the series setup and use one of the series bits of exhaust.

Remember this???:

So the bit on the left hand side that runs forward before coming aft, is the bit I am on about re-using.

So the aim is to get twin exit pipes either side of the diffuser. I had a fair amount of success with a cheeky down turned tip (with peforated pipe on the underside) to get my db's down last year so if this is still too loud I can get another one made and fit two - that'll fix it but it'll feel choked

So here are this evenings renders of the latest design:

For those that missed what cans I am using here is a link to the bumpf:

http://www.carid.com...technology.html