Did a search and surprisingly didn't come back with anything on front breathers.

Just finished up mine tonight. I know there are still a few nickle size holes here and there and was wondering how critical it was to seal those up.

TIA.





My fab skills are waaaay behind some of the others around here. Pop rivits FTW!

 

I think the small holes here and thare are going to be ok, if you can get them filled, go for it, but I would test it and see. The key is to get a pressure drop behind the radiator, and a high pressure zone in front of it. You might consider adding a smallish air-dam under the radiator anyway, even though you are a front breather, the airdam may help to get a good lower pressure zone behind the radiator.

Aero stuff is so hard do visualy though, the best thing to do is go test it. Get to a OT or practice day, and run a few laps watching the temps, and see how she does.

BTW, what class are you running your car in?

 

I've removed the rubber strip at the back of the hood and jacked the stops up at the rear as high as they will go already. This upcoming weekend I'll be racing at Hallet, OK, and we'll see how well it works. I'm running in NASAs Camaro Mustang Challenge series.

*edit* https://www.thirdgen.org/forums/orga...tml?highlight= */edit*

So you're saying to add an small air dam basically where the stock one used to be? I can see how that would work in creating low pressure right behind the radiator, but what about adding a small air dam coming down at the very front of the nose? Would that have the same effect? That would give me a bit more front downforce too.

Thanks

 

for cooling, i would be inclined to put it as far back as possible basicly right at the end of where your undertray is. That should make sure that their is a good low pressure void right behind the radiator.

Doing the airdam at the front for downforce you could do, it may not have that much effect on cooling, or it might. Its hard to say, it would come down to how good of a job it did, at keeping the air out, and how well you are able to extract the underhood air to keep a pressure drop behind the radiator.

I haven't really read up too much on the CMC rules, are you allowed to modify the hood? Puttting some vents/louvers in the hood, right behind the radiator should help a lot also, as this will get that hot air moving out of there, and give you a even bigger pressure drop across the radiator, and should also give you less high pressure area underhood, so it should also help with the anti-lift on the front end.

--John
(waiting for NASA to really get going in the PNW, i would really like to run CMC)

 

Hey Gary, how did the conversion work out? I am pretty interested, and would love to hear how it went, and also if you have some more pictures of what you did. (front breather has always been on wish list of things to get to and do)

 

CMC doesn't allow you to modify the hood. I had made my louvers functional before I considered going into CMC and had to cover up the holes to be legal. You're also only allowed to remove so many sqaure inches from the bumper.

pics here...
http://www.fototime.com/inv/A8493E1502C7294

The past weekend at Hallet, OK, it was hot!

The car was running quite hot as well, til I realized that the timing had shifted. I corrected that, temps came down a bit but still high for my liking ~240. I ended up taking off the grill cover. I had previously modified it by cutting the slots all the way along thinking this would be enough. Once I removed it completely and took some racers tape to fill in the gaps at the top/around the airfilters, temps never got over 220. I *think* I still have a 195 thermostat. The radiator is a stock b4c radiator using water and water wetter and I still have one fan.

I'm still pretty new at this racing thing, so I'll admit I didn't keep as close an eye on the gauges as I should have. Next event is TWS in August and I'll keep a better eye on the temps.

 

A 160 thermostat and a dual fan setup would cure the rest of your problems.

How is your first season going so far? I really want to get into this series one day.

 

160 is too low for a sbc, I may put in a 180 later on. I already had the duel fan setup and pulled one of the fans... it's just more weight and it's not really doing anything once you get up to speed. Most guys don't run any fans, but I like the safegaurd of having one if it's a long wait on grid or red flag etc...

So far my season has been a blast. I'm still trying to get up to speed, and this last event I was actually able to keep up and pass some of the guys at the tail of the field. Baby steps.

 

If you are running at 220*, then changing the t-stat isn't going to do a thing, the t-stat had been open for 30* already.

I would agree, the single fan is all that is needed as a safeguard, the computers won't turn the fans on about 40mph anyway.

If you saw a 20* temp swing with the front grill off, you may still need to try to get better airflow through there, or get a better pressure drop. Although, running full out like that, I don't know that you will do that much better than 220*. Have you talked with any of the other racers from that weekend, to see what kind of temps they were running? If it was really hot out, it could be that everyone was running in the 220-240 range, in which case your conversion is doing its job.

 

Yeah, a few of them were commenting that this was the hottest their cars have ever ran. I'm going to see how TWS is like, then may put on a lower air dam like you suggested.

 

I need to pull up the CMC rules. Could you add a wicker-bill to the rear end of the hood, to help it pull underhood air out? That along with extending the undertray, may give you some better cooling, and also some anti-lift on the front end.

--John

 

Been debating on building my car to CMC specs..but I think I'm going to go with AIX, get a lot more leeway, and freedom to do what you want with your car, and by golly I want 400 at the rear wheels, and ya just can't do that in CMC.

8.5.2.

 

heh, doesn't the front air dam on a sock f-body hang down lower than 4"?

 

Definetly when you lower the car

There's a rules change coming to fix that, something to the effect that unmodified stock stuff is acceptable.

Yup, that's pretty much the rules in a nutshell, but they're talking of some big changes for 2010.

As far as AIX (why not AI?) over CMC... your wallet must be a LOT bigger than mine.