Louis19's Build Thread

**louis19** · 12-02-2018, 12:31 PM

Originally Posted by sambb

“Did this guy have a v8 before the polo, or is he bait to my v8?”

.....and while they're trying to get their brains around it the lights have gone green and you're a spec in the distance.

**Sydneykid** · 12-02-2018, 03:25 PM

Too late now of course, but the usual convention is for the vents to be below the surface profile, to avoid creating turbulence.

The bonnet actually creates some down force, particularly the area in front of the windscreen. Turbulence from protruding vents would disrupt that.

Cheers
Gary

**seangti** · 13-02-2018, 10:46 AM

Originally Posted by Sydneykid

Too late now of course, but the usual convention is for the vents to be below the surface profile, to avoid creating turbulence. [img]

Cheers
Gary

Hi Gary, a lot of the timeattack cars run them above the bonnet, e.g. Under Suzuki's S15 and Nick Ashwin's Evo, etc, etc. All the leading cars engage aerodynamacists, seems to work for them. I don't disagree with an effect on turbulence, though perhaps that aids in heat extractions causing a low pressure behind vent lip therefore suck engine heat out.

Am I missing something in that thought process?

**Sydneykid** · 13-02-2018, 12:55 PM

Originally Posted by seangti

Hi Gary, a lot of the timeattack cars run them above the bonnet, e.g. Under Suzuki's S15 and Nick Ashwin's Evo, etc, etc. All the leading cars engage aerodynamacists, seems to work for them. I don't disagree with an effect on turbulence, though perhaps that aids in heat extractions causing a low pressure behind vent lip therefore suck engine heat out.
Am I missing something in that thought process?

Some time attack guys are admittedly pretty good, but I guess I just trust WEC, Indy Car and F1 aerodynamicists a little bit more. Anyway, it (drag, turbulence etc) is probably meaningless at our speed and downforce levels. I do suspect that at any decent speed the rear vent on your bonnet may well be letting air in rather than out as it is possibly still in the high pressure area in front of the windscreen. The front 2 vents would most likely vent outwards as they are possibly far enough forward to be outside the higher pressure area.

This video shows a hood scoop on a Camaro actually letting the high pressure air from in front of the windscreen into the engine bay, not letting the hot air out. Yours is bit further forward so it would be a good test with some wool tufts at a track day to see what's actually going on. Plus it's a fun thing to play with, gets the spectators' interested.

We can see the 2 tufts on the scoop and the 2 on the bottom of the windscreen showing the airflow going into the scoop.

Cheers
Gary

**louis19** · 24-02-2018, 07:20 PM

Small update, replaced the 265LPH to a Walbro 460 fuel pump. It requires some slight modding to the oem basket to get it to fit properly and perform correctly. Ive attached some pics of the pump in place after trimming the bottom of the basket. New fuel sock/strainer in place and wire onto the stock pump plug.

**louis19** · 18-03-2018, 07:10 PM

So, clocked up about 2700kms on the polo now. We are closing in on finalising the tune now and it’s starting to really rip along nicely. This week I needed to buy a 4 bar MAP sensor as I didn’t realise the ECU can’t read above 22.5psi on the stock sensor, so that will go in and be scaled in, followed by upping the boost so we can work on final parameters.

AFR gauge installed, a matching boost gauge and a few other “bling” bits as well.

Watch this space

**sambb** · 18-03-2018, 10:55 PM

you're pushing over 22.5psi with that turbo! bloody hell. Yeah I will watch this space.

p.s your little red coil looks all lonely there by itself.

**louis19** · 19-03-2018, 06:58 AM

Originally Posted by sambb

you're pushing over 22.5psi with that turbo! bloody hell. Yeah I will watch this space.

p.s your little red coil looks all lonely there by itself.

Haha, yeah I didn’t build the engine to only run 22psi. We did one log where my gauge was showing a peak of 24psi, that started to feel mighty quick.

The last coilpack didn’t quite make the cut