The Official Vortec 454 Info thread

[Mangonesailor]

I ran a log today. Climbed a pretty good hill with my camper hitched at about 45mph, and at the top of the hill, IATs were pushing 115* with ambients in the 70s. It was enough to kick in the fan clutch, so it got warm.

A few miles down the road, at a steady 50-55mph, here’s where I was sitting.

Mercy

 

[PlayingWithTBI]

A "cold air" intake won't help with low speed IATs though, imo.

at about 45mph, and at the top of the hill, IATs were pushing 115* with ambients in the 70s. It was enough to kick in the fan clutch, so it got warm.

Hmmm - what's causing the high IATs? Probably more hot air coming through the radiator, huh?

I wonder if an aftermarket open air cleaner will get hotter under the same conditions? FWIU pretty much everyone says yes.

It seems the OE CAI is somewhat restrictive in more high performance applications so, the open air cleaner should give you better performance unless, you get hotter air which may defeat the gain in air flow? What if someone logged IAT and MAP with both systems at harder pulls and/or WOT at different speeds? I don't have an IAT sensor - yet, but I've been wondering how much of a difference it would make?

Does this make any sense?

 

[Mangonesailor]

Hmmm - what's causing the high IATs? Probably more hot air coming through the radiator, huh?

From what I can tell, the only good way to avoid some of the heat would be to insulate the air box and tubing as much as possible.

But we have a giant aluminum intake that needs to get cooled off. But anything you can do to keep the inlet charge cool (I mean, the sensor IS in the plastic tubing) then the cooler the charge temperature.

Sometimes I think a ram-air scoop just for blowing air under the upper plenum (where the injectors live) would help some. Or what about a cowl hood? How much could that realisticly help all of this?

 

[PlayingWithTBI]

Or what about a cowl hood? How much could that realisticly help all of this?

FWIU a cowl hood would help when standing still but too much pressure builds up at the windshield when moving preventing heat from escaping. Only a sealed cowl induction hood (like NASCAR) would do the job.

I'm more concerned about air flow vs hot air, I think

 

[Frank Enstein]

A cowl hood if sealed to the air inlet helps at highway speeds and higher with a bit of pressure. At low or no speed it is at least pulling air from outside the engine compartment.

The manifold heating up will help the fuel to atomize and will help drivability when it is really cold outside.

A vacuum operated Thermac controlled air blend door will keep the AIT consistent until heavy throttle when it opens fully regardless of temperature to give maximum performance.

I recommend getting the air from the grille area instead. It has a bit more pressure than the cowl induction and is less likely to get clogged with leaves! A drain built into the inlet for when it rains is a good idea.

Ram air scoops under the bumper while effective will serve to make the air filter dirty very quickly.

They all work to feed the engine cool air and you decide which is best for you.

Frank (my avatar) is currently carbureted and without the warm air in the winter runs very poorly and without cool air in the summer it's bad too. When the inlet temperature is consistent it is much easier to tune. Although EFI has the ability to adjust for different AIT's and you don't strictly need the heat it can help drivability in the winter.

 

[JSlezak83]

I’m thinking a heat shield around the manifold might help here. That’s a big lump of hot iron sitting directly under the air filter and inlet tubing.

One thing that might be hurting my IATs too is my torn up fender pants. My front end guy butchered them when it was in for an alignment. I noted in the past on my L98 S10 Blazer, under hood temps were a little higher at speed without these. There must be some weird low pressure zone keeping the heat in place. It did help when stopped though.

 

[RichardSwinger]

I ran a log today. Climbed a pretty good hill with my camper hitched at about 45mph, and at the top of the hill, IATs were pushing 115* with ambients in the 70s. It was enough to kick in the fan clutch, so it got warm.

A few miles down the road, at a steady 50-55mph, here’s where I was sitting.

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That's really cool! What app are you using for that? I didn't know our old trucks were "smart" enough for something like that to work with them

Sent from my Pixel 3a XL using Tapatalk

 

[JSlezak83]

The app is OBD Fusion and works with a Bluetooth OBDII dongle.

 

[RichardSwinger]

The app is OBD Fusion and works with a Bluetooth OBDII dongle.

I have a cheap OBDII dingus from amazon and I started messing around with the torque pro app yesterday once I realized it might work with the old truck. Unfortunately I wasn't able to get either of the two trans temp PIDs to work, nor could I get the oil pressure or temperature to work (there were options for all of these things but they didn't highlight and show up as having an output). Are you able to see these with your scanner?

I need to try and find what "normal" values are for MAF and the LTFT values... On a short trip the the grocery store my LTFT were reading around 10.0 at cruise speed.

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[Mangonesailor]

my LTFT were reading around 10.0 at cruise speed

Because ethanol probably... and/or low fuel pressure.