Ok since cold air is denser... More air can be consumed by an engine.

Now would a NA engine have more to benefit from cold air than a turbo engine?

Since the turbo already compresses the air to X pounds. So why would it matter how dense the air is?

Where as a NA motor can fit more air inside...

 

an N/A engine does not heat up the intake charge the way a turbo does, so the n/a benefits less from the extra cooling.
the less heat a turbo motor has in the intake air, the less likely it is to detonate, and the better it runs.


theres much more to it than that, but one of the turbo experts will explain it in better way.

 

Sure cooler is better in either case. The supercharger (turbo or otherwise) adds a lot of heat to the charge, maybe much more than the difference between ambient air (say 77* F) and the inlet air temp (say 100* F for NA angine). 'Charger could have a "delta T" (or change in temp) of 100*F+.

As I see it NA or blown, you are moving a given volume of air, do if it's colder (denser) there are more molecules and more O2, which is what we're after. Yep, higher inlet air temps increase chances of detonation, as well as reduce the total O2 and therefore power.

Would an intercooler help an NA engine? You betcha it would. Remember the 200 mph S-15 NA pickup GM ran at Bonneville about 12-13 years ago? NA but with an pickup bed full of intercooler. Anyone remember the "cooling medium"? It wasn't water-to-air or air-to-air.

 

You mean the LSR Syclone? No I don’t know the medium, though I'm sure interested now. I do know the successor the Sidewinder used a air/water in the bed.

 

Boost and air density are two different animals. Comparing 15#s of boost at 75*s and 15# at 150*s. The boost is the same but the 15#s at 75*s is more denser and will make more power. A forced inducted motor will benefit more from colder air than N/A.

 

Set world land speed record for the two-way flying mile:

210.069 top speed
204.145 mph average for flying mile
204.076 mph average for flying kilometer
Normally aspirated 5.0L engine, Max rpm 8000, 549HP @ 7200 RPM, 412 lbs/ft torque @ 6000 RPM, curb weight 3585lbs.


That's about all I could find out about it. 550hp from a 5.0L isn't too much power these days...

I'm gonna guess dry ice? or maybe mercury to add weight (Bonneville folks like to add weight instead of remove weight like drag racers)

 

FWIW, I normally see 10psi of boost in about ~75* weather at 5900rpms. Last week it dropped down to ~27* over here and I hit 12 psi at 5900rpms. My car was pulling much harder, it felt like it picked up another ~35-40HP. I belive the extra boost plus the colder air cooling off the intercooler is what made such a difference in how strong the car felt. So Colder densor air does effect a Supercharged combo a lot.

Thx,
Claude

 

Good info, AdioSS. Thanks.

It was a 5 L V6, up from 4.3 L stock. That's equivalent to a 625 hp 350. As far as 92 hp per cylinder, that equates to 730 or so from a 406 V8. Not all that bad for 10+ years ago. 550 was all the needed to get into the 200 mph club.

Extended cab AWD pickup for aero. Didn't need much weight for traction!

They used lots of nitrous, but not into the engine. Rather, they released it across the outside of the air-air intercooler and I believe it cooled the inlet charge to about 60*F from probably over 100*F ambient. If you plumbed it correctly, the driver was one happy dude.

 

That's one expensive intercooler. You'd think expanding something like CO2 might be a little more cost effective. Or is there less liquid CO2 in a high pressure vessel?

 

I don't believe cost was a major obstacle in that program.

 

Well, ambient air temp won't affect compressor efficiency, so say the colder air has a 5% density increase over the warmer air, and assume a turbo that increases density by 50% (say, xx lbs of boost at whatever efficiency it would take). On a warm day, it is compressing 100% dense air by 50% (1.5 times original density) for a final density of 150%; on the cold day, it's compressing 105% dense air by 50% (1.5 times original density) for a final density of 157.5% That's a 5% increase in air-just like the NA motor would see.

HOWEVER-the intercooler (if used) will cool more, so the increase in intercooler effectiveness will go up-the temperature increase through the turbo will be the same, but the temperature drop through the intercooler will increase, resulting in additional increase in density.

So, I would think that a supercharged engine with air-to-air intercooler would see more benefit than a NA motor or supercharged engine without intercooler. The NA motor and supercharged engine without intercooler should see the same %increase in HP.

Of course, there will be changes to radiator performance, etc.- probably a small difference from engine to engine. Maby a turbo'd engine would loose out if cooler ambient air sucked heat from the exaust header faster?

 

Yeah, Ive had both big cube and turbo motors and the turbos benefit more from cooler air. i have slips to back up the seat of pants test. My turbo car got slower and slower as it got hot.

 

Exactly. With the same ambient air temps (any) I think the power gain/loss would be linear on either set-up. I beleive any supercharger is simply a multiplier for the intake charge and the supercharged air did start out N/A (pulling a vacuum) with the same ambient air. So, the engine that consumes the greatest volume/cfm of air would benefit the most from cooler air.