Intake air temps

I have asked on many forums at what IAT does performance fall off without any real replies. With my combo it starts falling off at 170*.Threw more fuel & boost at it with no performace gain.140 MPH was like a wall that day at atco.
Been looking at W/M for intercooling but I'm now thinking nitrous for the race mode. I wouldn't doubt that a 50 shot could give me over 100 HP due to the lower IAT. What do you think??

I would go with straight methanol injection to start with and tune it as needed Water doesn't burn and alcohol evaporates and absorbs heat a lot faster than water and it burns also

Should help.. just fog it into the front.. should cool everything

Too high IAT can lead to pre-ignition, not sure what the point is as it will change with cylinder pressure.

What’s the IAT on something like a Hellcat with a pulley and a tune?

What are running as fuel? VP 16 will help you make the power and avoid any detonation.

Q16 will make it even better as long as you fatten it up enough and can stand the smell

That is a great question,they use an a/c evap to intercool. I am leaning towards the NO2........

Cab,if the meth has all the cooling properties required,why do they even use water??

I have no idea, you know the deal about some guys can't drink straight whiskey without water in it, correct Maybe it is the same deal on their cars
AKA aside adding water to the mix has never made sense to me
I stated thinking about putting room temperature water on your skin versus putting alcohol on your skin and which one cool down the quickest Same thing in the motor, correct : up:

Fixed it for ya...carry on.

OOOPS

The Hellcat doesn’t have the extra IAT cooling provided by the A/C unit like the Demon does...... but it does untilize s a pair of intercoolers.

Doing a little digging.......

Supposedly they can run flat out for 20 minutes before the ECU dials things back due to heat. Probably pretty close to out of gas at that point also lol

Me thinks that N2O will cool better and have a little more "kick"

Sounds like you’re going to find out.

Take the roots off and go with a Whipple twin screw.

Out of my budget but a nice upgrade

Path of least $$$$ At the present.Just need a few weeks of "busy"!!!

That would be more octane that I need.I have not gone over an effective CR of 15: and will stay there untill I get it very happy.I'm getting very close with the carbs and sill experimenting with timing.Last 2 times out the top end charge is not there When the cooler air comes in the fall I will check plugs after every run instead of just reading the racepak. I will also try different heat ranges.
I have the start and cruise lookin good,now need to work on WOT.
Question........will the plugs read the same at the top of 2nd just into high gear as they will at the stripe? I go over the stripe at 64/6500 rpm

The load is not the same in 2nd as in 3rd at 6500 to check plugs.did you take off the air filters?This may help at top end and the tune you are looking for.

I have tested in the street with & without filters and saw no change in the AFRs. From what I have experienced,the performance starts to fall off at 159* and by 170* I hit the wall. I would think which ever way I go to lower the IAT that I could well without losing a few tenthes to ambient temps. Watergrains is a whole other subject!
I will NOT go to the top of high gear in the street,top of 2nd must be over 100 MPH

Safety

What would be peculiar to your combo where more boost than say, 6-8lbs or so, doesn’t show up as more power...... compared to other builds, also running non-intercooled roots blowers carbureted on gas, where they still show improvements with higher boost levels than you’re running?

In the pic above........ how is the drive shaft rpm higher than the engine rpm?

Cooling the IAT is hard with the blower having so much mass and heat soaking even more so on the street.Look into the NOS nylon lines and run to each intake runner from the side of the manifold if you can.[just an idea]

The BDS manifold is too low,putting it through the blower should help keep it cooler as well.

I used a Snow kit with 1250 ml/min for a short time but have no results to post only an opinion and the fact that I went to an a/w intercooler and got good results.

I have been where you are with this matter 20 yrs ago

Mike,were able to see intake air temps on a gauge or data logger?

I got very little info with an ARC dual probe 1 EGT 1 IAT.I got a small drop with w/m activated driving in the pits and I ran all water ,50/50 w/meth,all meth on several runs and quickly decided to get the air to water intercooler that took out 100 degrees no ice as used on the dyno with and without water.

Al, is E85 not an option for you? I know availability is an issue in some areas, especially on the street as not many stations have it at the pump.
From what I've seen, I personally wouldn't attempt to run a big blower w/o either running E85 or straight alcohol.
Just seems like a fuel change would be easier...but if it isn't readily available, then I completely understand. That's why mine is still on gas. E85 was easy to get here for a lil while about 8 years ago or so, but not now.

There are some stations that sell E,,, if I go to something 23/30 miles away availability becomes unknown. Them I would have carry 2 ,, 5 gallon jugs
I prefer to stay on gasoline for all the street driving I do on pump premium and then add octane with a pulley change. I slowly went smaller on the top pulley and take baby steps so I don't hurt it,but I have found the IAT wall for my combo and now need some chemical intercooling and nitrous is the path of least resistance.

Are there any boost related forums you frequent?

Is the wall you’ve run into fairly common at that boost level with a roots style blower?

It just seems like that’s really not much boost at all.

One of my friends ran a 515bbc with an 8-71 and 2x4500 carbs in a 79 Malibu.
11-12 lbs boost, race gas.

10.5 tires, 3.73 gears, had to walk it out just a bit....... then push the gas to the floor......went 8.90’s at 155-156 on a good pass.
Still had the factory interior, power windows, and tilt wheel.

c
Dwane,I have asked about thus on several different forums without a solid reply.My results are from personal experience. They every combo is different and I had to find the wall myself.The ambient temp and DA must have an effect as well.

Some states can take your car if you run NOS and race on the street and get busted and a sticker must be posted on the car on case of fire.

Have all the nitrous parts lined up for pickup next week. I've been told a 50 shot under each carb will lower the temp by 100 to 120*.That's WINTER air
*

Sounds like a Sneaky Pete kit[small bottle]I don't think you will reduce the boost but I would take 2 degrees out of timing.

Looking forward to testing !! Making my own winter air will put a smile on my face.In another 1/2 a second or so I will be at my legal limit and have NO desire to go any faster. I'm just looking to hit my goal and still drive the streets on pump junk as I have for 45 years.

https://www.youtube.com/watch?v=BlKAnhYCvYY

https://www.youtube.com/watch?v=CH1GhZBVznQ