extraction hood

[rmcelwee]

Originally Posted by Splitime

I know there has been much talk of the secondary vents, above turbo and/or IM. The ebay vents are such a good price... and so easy to get.... I really wonder if they would melt or not.

I have a few thoughts on how to test it.... how about some people toss ideas out though. I'm to tired right now to write mine out

These vents btw...

Any more pics or info on those vents?

[Splitime]

Originally Posted by rmcelwee

Any more pics or info on those vents?

They are just ebay vents. Not functional until you cut open each vent area... oh the high quality ebay goods.
This format.
http://cgi.ebay.com/ebaymotors/Jeep-...spagenameZWDVW

[m2cupcar]

Originally Posted by Ben

...Trip home got me caught in rush hour stop n go. Laptop battery died, so could not datalog. But the coolant temp gauge held fast at 11:45 right where it's supposed to be.

I think that demonstrates that the hood hole is venting the heat when the car is not (or barely) moving. That's where my fan is continuously cycling. And a good sign that it managed the temps AFTER boosting at speed and then sitting in the traffic. I've yet to have the car overheat in those circumstances, I'm more concerned about what that heat will do to everything under the hood over time.

I think those ebay vents look pretty good the way david has them line up. And for the price, there's not much to lose. Curious to see how the work/hold up.

[Ben]

both my fans (stock) were constantly on. the cooling fan comes on at 175 (basically always on) plus I had the a/c on.

[m2cupcar]

I'm assuming that the on temp of 175 is set in MS? If so, does that mean it's trying to bring the temp back down to below 175?

I originally had my on temp set at 200f, that meant the fan stayed on until the temp cooled to 194f. The fan was on at every stop in traffic- and would remain on for the majority of the time stopped. I raised the on temp to 207f (stock for the 1.6) and they hardly came on at all. When they did, they had reached the off temp of 200f in far less time.

[Splitime]

I can say that with the vmount so far.. I haven't had my fan turn on once yet. Crusing down the highway and side roads, temps do not budge from 83c.

Mind you, I'm not boosting yet. I'll be fixing small stuff next week and hopefully finally have time to tune boost.

[m2cupcar]

As you can see the Zx vent is massive. The pros - easy to install, just cut a hole that the bottom section will drop into, then use the threaded posts to pull the top fascia (flange) tight to the hood. And it can be cut to shorten it by removing some of the grill rows at the rear. You'd just have to resolve the radius edge and trim some of the plastic under the naca vent as it drops down deep (will hit stuff in my engine bay).

The trans am vent would be my first choice for its size and looks, but because it has a contoured edge to follow the fender shape, it's just going to require too much work to install - time I don't have. The easiest route would be to cut a hole so that the vent would install from the bottom and then use filler to blend in the edge.

Turbo Zx hood vent

Zx vent modded/shortened





Trans Am fender vent

[Ben]

I'm surprised how good the T/A vent looks. Would be a lot of work though.

I'm thinking about these as a good compromise between cost/aesthtetics/ease of installation. But I don't know how restrictive the louvers will be. $75/set in black isn't terrible though

[Ben]

Good stuff here. Screen capture below is 3-4-5. I did not go instant WOT in 3rd. It was more of a gentle progression to WOT. 4th and 5th were completely WOT. I got out of it in 5th at 6056 RPM. I was going for 7k, but w/o the undertray the front end felt like it was lifting. When I saw a van coming from the other direction, I lifted.

Temp data:
Datalog shows 86F when I started the car in the garage. It sat for a couple of minutes before I backed it into the driveway, where IAT increases to 103F with the car out in the sun. It remained 105-106F as I drove in vac for a couple of minutes.
WOT starts in 3rd, AIT 106F at first positive pressure, 114F at beginning of WOT, 122F at end of 3rd
4th gear starting IAT 121F, finishing 135F
5th gear starting IAT 134F, finishing 137F

What I found interesting was the minimal increase in temp in 5th. You can see how the slope of the IAT line (bottom graph, white) levels out to nearly horizontal. Presumably due to high velocity of air speeding through the intercooler. Assuming 22mph per 1k rpm, final speed in 5th was 133mph.

[m2cupcar]

I think the TA vent is the ticket. I'll shelf it and do it to the next hood... maybe.

Originally Posted by Ben

...Presumably due to high velocity of air speeding through the intercooler.

I agree. I saw a similar pattern in the IAT curve thru the gears. The slower speeds definitely kill the cooling when reaching those peak boost numbers BUT you'd think that the length of time spent at that boost level in fifth would have a greater impact on the temps. But apparently it doesn't given the speed.

Assuming 22mph per 1k rpm, final speed in 5th was 133mph.

btdt :gay: you're running a 4.10?

[pipe]

Any pics of the zx vent installed?

m2cupcar:
What tools did you use to shorten the vent, any close up pictures of the shortened end? Also, since the rear threaded posts are on the two vents that are cut how are you planning on securing that end?

[trackfiend]

Thought I would put up a pic of my little project so far.






Made a slightly less aggressive lip for the front of it today. Looks a lot cleaner, now all I have to do is do all of my finish work and dress everything out. Plan on just shooting the hood flat black when it's done.

[wildfire0310]

Originally Posted by trackfiend

Thought I would put up a pic of my little project so far.






Made a slightly less aggressive lip for the front of it today. Looks a lot cleaner, now all I have to do is do all of my finish work and dress everything out. Plan on just shooting the hood flat black when it's done.

hey there you are I fixed your links.. you had two http://

[gwilo]

On Club Roadster I guy is looking at producing this one

http://clubroadster.net/forum/viewtopic.php?t=11406

[Ben]

it's just a drop in scoop rivited on

[Splitime]

Originally Posted by Ben

it's just a drop in scoop rivited on

He's going to be making full hoods in that format Ben.

I really wonder where he got that drop in piece though.

Ah well... I'm already started hacking my hood... buying stuff for it is a waste at this point :P

[Ben]

yeah I read it and looked at his pic. All he did was cut in a drop in vent and rivet it on. I'd rather spend $100 or whatever on a drop in scoop and rivet or bond it on myself than have to deal with (1) shipping and (2) having to fit an ill-made fiberglass hood. And you know for $300 it's going to be ill-made. Also, with a proper drop-in vent, you could get away without any paint work.

[Splitime]

Originally Posted by Ben

yeah I read it and looked at his pic. All he did was cut in a drop in vent and rivet it on. I'd rather spend $100 or whatever on a drop in scoop and rivet or bond it on myself than have to deal with (1) shipping and (2) having to fit an ill-made fiberglass hood. And you know for $300 it's going to be ill-made. Also, with a proper drop-in vent, you could get away without any paint work.

Agreed, 100%. I've never seen a vent like it anywhere though.

[m2cupcar]

I haven't done anything since that last post. I'm still contemplating which vent to use at this point too. The trans am vent really is much more appropriate for the Miata given it's size.

If you search ebay you can find some cheap (tho not in "our" case) extractor hoods, which look like you could just cut the extractor out and add it to the Miata hood.

[y8s]

someone already makes a hood that looks just like that. and it doesnt' clear the valve cover.

where's rappadan and his pics of his car? braineack probably took some on sat.