SMIC vs FMIC

[mb3000]

More lag might be a good thing for td04 guys since so many of us are having weird surging problems at low boost levels due to the turbos being too efficient

I know its not helping me.

[mb7050]

i think the sideskirts could be functional afterall.see what they did here

[IPD]

what for? to mount an intercooler in front of the rear wheels?

MAYBE if you did a complicated amount of ducting you could make vented fenders viable for something; it would be an assload of work though. perhaps something like gixxerdrew did to his DSM spyder's widebody front fenders.

skirts wouldn't do a darn thing.

[mb7050]

I already have widebody front fenders and those can be made functional to vent out exhaust air behind sidemounts ..

[mb7050]

skirts wouldn't do a darn thing.

i think sideskirts like those can help to reduce the wheel well pressure.

[DG]

It can be difficult to predict where the pressure zones are and what the air is going to do - thus all the money spent on CFD models and the subsequent verification of these models via tunnel testing. Nobody can tell what the air will do via coup d'oeil.

Tuft testing and manometers can help, but precious few people actually try it - far easier to flex keyboard muscles and make blanket statements unfounded by actual experience.

There *should* be a low pressure area in the wheelwell, so cutting out the louvers and replacing it with wire mesh *should* work - but one never can tell without testing.

Routing a duct through the fender and out a vent behind the wheel is an interesting idea and may have merit. Off the top of my head I'd expect it to be a high (or at least ambiant) pressure zone... but a NACA duct on the back edge (or something similar) just might work. Ideally the fender would be sealed up with sillicone along the top edge, and it might need a sealed bulkhead to create an actual duct and prevent leakage... but the idea is interesting and is worth investigating. Doubly so for a "widebody" fender, which would have more room for ductwork and should provide a larger/stronger low pressure area to exhaust the duct.

Pressure drop is not a very useful metric. I can make an IC that has zero pressure drop by simply replacing all those restrictive tubes/plates with a straight run of 3" tubing. Mind you, it won't be a very effective *cooler*....

The aim is to try and get the outlet air temp down to ambiant. You can never quite get there without a misting system, but that is the aim. In order to do that, the air must spend enough time in the cooler in contact with the exchanger elements to transfer heat away. So you are always trading off flow rate against heat transfer efficiency.

There is a point of maximum flow choke, beyond which you just can't stuff any more air through it. So long as this point is larger than the maximum possible air demand curve of the engine, you're golden. And it doesn't have to be much larger, so that you aren't trading heat transfer efficiency against flow capacity.

If the boost control reference is in the manifold plenum, where it belongs, pressure drop doesn't matter at all - with a caveat. The larger the pressure drop, the more the turbo compresses the air, the more heat is induced into the outlet charge. Plus, the actual pressure ratio influences where the compressor is on the efficiency map, which in turn changes the amount of heat induced in the outlet charge. At some point, the extra heat from the extra compression needed to force the air through the cooler overpowers the extra cooling that comes with longer dwell in the cooler and pressure drop now starts to matter.

So there is a sweet spot of pressure drop vs cooling that has to be determined experimentally.

DG

[mb7050]

For about ten years I measured every intercooler I came across for pressure drop and effectiveness. The data lead me to believe pressure drop was king and effectiveness not quite the king. That was 25 years ago. That info was as summarized in Maxboost1.

With another twelve years of measuring things and a bit of supplier supplied computer work, I have changed my mind regarding the relative value of flow loss versus effectiveness.

In the past four/five years of BellIntercoolers.com, I have built approximately 4000 intercoolers with feed back on some ranging from a Bonneville record setting twin engined motorcyle (record only lasted 1.5 days) to Ford, Cummins, and Harley's test labs to oil field stationary power plants to turbocharged observation UAV's drones for the Isrealis, even tractor pullers. All of which has been fun.

Between my fabulously able partner and myself, we have at least been exposed to the opportunity to learn a bunch about how heat gets through a boundry and into the atmosphere with the least of other bad effects. However, I would not be in a position to judge how well we learned anything.

An intercooler has proven to be a more complex part that I could have imagined 12 years ago. There are probably 25 separate considerations to be sorted in any design. Lost of fun trying to put the consideration in order to come up with something that proves to be five to ten percent better than anything else, and often 50% better than the haphazard intercooler. When finally done, you just haveta know, its a hoot. At present, it IS a hoot.

interesting

[mh3kgt]

Why hasn't anyone tried retrofitting their wife in the engine bay with some palm leaves to aid in cooling?

[mb7050]

i don´t know but cooling in these cars sucks when you drive it hard you will have cooling issues ..

[MR2]

for the record I was not suggesting cutting fenders and routing out behind the wheel...I was suggesting cutting fenters in the side of the bumper in front of the wheel