I’m contemplating ways of reducing underbonnet temperatures, especially the supercharger. I’ve got an oil cooler, alloy rad & intercooler which are all fed through the standard mouth with a GV style chin spoiler.
So, anyone have any advice? I’ve looked at the flyin Miata vent kit but looks expensive for what you get, also the under bonnet clearance is very tight above the SC manifold (about 3mm).
Are you more concerned about the blower getting hot on track or on the road?
On the road my personal preference is a single pre-blower throttle and a bypass to reduce the pumping effort of the supercharger while cruising, but that's not really ideal with an air/air intercooler rather than a chargecooler. On track I guess the greater concern is time spent at WOT in which case I suspect the biggest gain would be feeding the blower cold air, maybe from a Randall style cowl intake, although I think Mk.2s offer more options to route cold air from the front than Mk.1s.
with an undertray fitted the enginebay is fed air through the bumper/rad then around the engine and out around the gearbox. with a bonnet vent the airflow will change and maybe not give the results you hope for maybe worth ducting some air from the front?
look into aero & high/low pressure areas / venturi's & ducting
I have too a single TB pre charger and take the intake air from behind the nearside headlamp, made a heat shielding around the filter as used by many people with NB’s. I have a double layer of aluminised fibreglass mat heat shielding between the standard heat shield and the s/charger. Works for me so far, but I only use the car thrashing around in the roads, not on track.
Making a decent undertray should make a big difference. For normal motorway usage on a warm day there's ~10C difference in both oil and water temps on mine depending on if the undertray is fitted.
I have a sheet of dibond aluminium sheet in the garage ready to make a 'mushroom' shaped undertray that follows the shape of the front bumper and then the narrow part back to the standard mounting points. I'm also going to duct the inside of the nosecone so that all of the air is forced into the engine bay rather than escaping out of the sides of the void between the bumper and rad (I can't use the standard ducting due to pipework and the intercooler)...
If you have a look on miataturbo there's a fair bit of information / plans on how best to reduce temperatures..
nielex claims this.. .... • Reduces engine temperature by average of ~5 degrees
I think a small stop at B&Q would give you everything you need to replicate this, well, it's basically a gurney flap attached to a cut-back undertray
Thanks for that! I have exactly the same thing on the Griffith & was wondering if something similar might show up. Conveniently, I already have some left overs in the garage too- a free upgrade!! (Proper man-maths)😁
Shout, shout. Let it all out. MX5's is what we're all about.
wannabe: I've had both front bearings replaced on the missus' car over the past few months and it's STILL making a droning noise... lol. Need to check if the mechanic actually replaced the correct one the second time I took it in!!
Jan 15, 2020 11:10:07 GMT
FFS Corders: Are the wheels straight? Buckles can cause a drone
Jan 15, 2020 11:41:07 GMT
wannabe: Hmmm... That's an interesting idea... no wheel wobble on the missus' car, which I would have thought was a strong indicator of being out-of-round, but I guess they could be bent side-to-side..??
Jan 15, 2020 14:34:13 GMT
wannabe: Ooooh, interesting - thanks, Howard. I'll have to get the tyres swapped round to see if it makes a difference! I will be most annoyed if it is tyres, seeing as they are only a few months old...
Jan 17, 2020 1:08:22 GMT
howardb66: If it is the tyres, don’t chuck them away, try getting them shaved.
Jan 17, 2020 12:04:28 GMT
wannabe: That sounds pervy haha.
Jan 18, 2020 18:27:11 GMT
fizbne: More build thread updating wow.
Jan 22, 2020 14:24:03 GMT
V6: I had an education in dampers today. I like expensive ones. Floaty, not bouncy for the win.
Feb 1, 2020 22:03:45 GMT
Zed.: that all depends on what you call 'expensive'
Feb 2, 2020 19:42:58 GMT