Investigation into the correlation between engine bay heat vs performance/economy would be extremely educational. I personally observed a three point five mile per gallon reduction in gas mileage effeciency on a trip from Albuquerque New Mexico to Flagstaff Arizona recently. On the leg we got the worst mileage, we vapor locked twice, with the fuel evaporation occuring inside the under-hood section of the fuel line, and/or the carburetor.

Those items are generally used to protect other items in your engine bay not to gain power. Great products and I also use them, but only to increase longevity of wiring harnesses and other items that could be compromised from long term heat 👍

@@salesteam274 That's not 100% true if you can maintain the heat inside your headers instead of the heat escaping it'll actually go down the headers you do gain a little bit of horsepower.

@@Entertainment_Enterprise the general effect will be the same as doing a pull on cold vs hot headers, the more insulated your piping up to the turbo is the better the response will be but horsepower increase is negligible

@@joshuagriego1562 I certainly think a heavier exhaust tube wall thickness and thermal wrapping would conserve a good amount of thermal energy. 👍

IT WAS A SERIOUS MESS

OG means original gangster or old gangster right I disagree I think he is a good guy

@@james10739 it can mean many things in this case i just think its a way of saying richard is a fucking legand

Like how bad means good and ill means cool and men can be women and babies are not born with a gender and riots are called peaceful protest or mostly peaceful and unarmed means he had a weapon man I remember when words had meaning that mattered

@@james10739 I remember when words (a verbal promise) actually ment something too. And im not even 40 years old yet! My how times have changed quickly..... Crazy to think people used to actually do what they said they would do.... WOW Anyways, Richard is taking all the mystery out of building an awesome power plant. And most of the time he is doing it on my kinda budget!

You’d think the smaller the exhaust pipe the faster the volume fills to spin up the turbo

my thoughts exactly, sure back pressure might be a concern application depending but would definitely help spool time

I think it’s more about energy than volume or speed. Long exhaust means the gasses will cool and loose energy compared to short exhaust.

This is totally anecdotal but on my rear mount gt45 5.3 setup going from dual 2.5 inch to a single 2.5 inch heat wrapped increased my spool by 700-800ish rpm. It definitely affects spool and it's especially noticeable in transient driving when rolling into it but it's hard to say how much of that is heat retention vs size and velocity.

From some old nascar testing done on primary header tube diameters there was a direct relationship between cylinder volume and exhaust pulse speed in specific diameter correlation, the problem mostly seemed to be too small a diameter primary would create a detrimental subsonic pulse speed and HP would drop off, too large a primary diameter had minimal effect in comparison, assuming from that, pipe diameter used for turbos will have negligible effect other than greater surface area for heat loss, just an observation maybe !

As I was watching I was thinking about the heat loss on hot side. Part of it due to a video of his where he compared turbos he displayed evidence of lower power output/boost on cold startup vs building heat in the system before the pulls.

Thank you kindly

Amen to that! Richard Holdener, the Saint of Boost.

that's exactly my plan for my reg cab shortbox mud truck. if the engine let's go I don't want metal going through my turbo. or vice versa

THNX

Agree

so wrap an it improve response

This was settled in the 1980s by the engineering decisions for F1 cars and the better factory turbo motorcycles in the 1980s. 40 years ago. But then people still argue about how airplanes fly, when the math was sorted out in about 1920, or before. 100 years ago.

that seems excessive

@@richardholdener1727 How tight the bend matters a lot. www.thermopedia.com/content/577/ . I know 15 feet seems like a lot but 15 feet of straight pipe really does not have that much restriction. Your first 90 will be the same restriction as 9 feet of pipe.

Yeah K factors and equivalent head losses for different geometries/fittings. This is interesting however, I believe what you are talking about is in steady state analysis

In a car I have no doubt that there would be a many tighter twist and turns to make it fit remotely.

That's only because you're waiting on the 3500 RPM stall to spool on the street.

@@gofastwclass exactly my point. So the lag to the turbos is imperceptible

@@Shadow0fd3ath24 You're missing his point. Few people are running a converter that loose on the street. Off the line the turbo lag would be immense on a streetable converter.

I try

Fancy seeing you here.

@@pissedoffpistongarage Well hello kind sir! Nice boosted S-10 Corvair you've got there!

@@802Garage shhhhh. No body knows about that yet!😂

start at lower boost then work your way up

Oh for sure, but for the truck to trap what I want it to at the weight it's at, my math says 25psi or more. Haven't done as many as you, but this isn't my first turbo rig. Have an 81 c10 with a 416, billet wheel s488 and a csu blowthrough as well. Good advice though, but I'm throwing the kitchen sink and the dirty dishes at it! Lol

You're welcome!

Thank you!

Learned that the hard way myself after being told my small turbo large intercooler wouldn’t work on a 2JZ. I datalogged and debunked that! The tubing has volume but the engine and turbo move massive air and fill that pipe.

If anything a bigger IC has less pressure drop and can probably dissipate heat better

it could be a large restriction to air flow though

In the subaru world going from a relatively inefficient top mount setup to a front mount intercooler typically increases boost onset rpm by 400-600 rpm on the same turbo. We are adding 6 ft of piping though and usually a bigger intercooler core. I doubt the piping makes much difference but the bigger core definitely has an impact. You're trading response for the ability to cool the air much better at higher boost levels.

Is not only the lenght of the exhause. The turbo doesn’t rely 100%on exhaust blowing and spinning the turbine. In fact a vast majority of the force driving the turbine is heat, ie hot expanding gases. On a remote mount you lose a lot of this thermal energy. There are ways to regain some of that thermal energy. Back in the day we experimented with adding cats before the remote mout turbo. And there were noticeable gains. But who would chance it with a chunk of cat making it to the turbine. Another way some of that thermal energy can be re gained is by retarding timing. But its harder on the exhaust valves and you lose power by giving up timing. Now the most extreme way i have seen this done was adding an injector and a coil and plug near the turbo(think mexican low rider flame trowers) this method actually produced better results then turbo front mounted. But it was problematic. We teied this on the 90’s, so we didn’t really had a way to control what was going on with the injector by the turbo. It was either on or off. So lets say we had “issues” with the flame traveling back into the exhaust and exploding the pipes, so we aborted that. With todays available controllers, this may be wort a re-visit.

i went from an s480 t6 1.32 at to an s475 t6 1.10 ar. the spool rate was night and day

@@srninjastar me too but I did it on the 80

THEN THE SYSTEM IS WORKING

Excellent question. When testing remote mount turbos on the chassis dyno making several consecutive runs will result in dramatically improved spool up. I can only attribute this to the exhaust system being much hotter therefore pulling less heat out of the exhaust stream before it reaches the turbo. When you think about it from a physics perspective, this makes sense since the velocity of both the intake and exhaust streams at full throttle are quite high (100-200 ft/s easily - pressure pulses in the streams move even faster). This means that covering the extra distance should only take a tenth of a second or less. This would equate to about 50-100 rpm on the dyno depending on sweep rate. But the rpm to reach full boost is much, much later - on the order of 500-800 rpm. That implies thermal factors.

I was thinking the same thing. Header wrap that exhaust pipe. I also wonder if it would improve spool by downsizing the exhaust diameter to keep the gas velocity up. It would probably hurt top end boost, but maybe only when running the highest boost settings. Lastly, I wonder how bad it would be if you put a cat on, e.g. to simulate doing a remote turbo on a late model car. I know the cats pull a lot of temp out, so I know it would be lousy, but the question is "how lousy"?

It depends what you are doing with the engine. For engines under high load for long periods (endurance racing, hauling etc) wrapping the exhaust can create such high exhaust temps that the tube can melt and cave in. This happened to the mod father with his circuit racing holden. Then you have to start looking a either exotic exhaust tube (titainium?) or losing the wrap. For high load for short periods (street/drag etc) its super beneficial to wrap/coat the exhaust as richard mentioned.

Keeping heat in will be better, just like any other exhaust setup, but there is still a large surface area to transmit the heat out. There is probably a break even point where a long exhaust with wrap will preform as well as short and no wrap. But I would think that point is not long enough to be called a remote mount. TLDR wrap/coatings will probably make any situation better, but it can only do so much, shorter is better on the exhaust, as shown in the video.

What about a ceramic coating? Would that not reduce thermal transfer to the pipe itself providing good benefits

HOW DOES IT GO?

Nobody knows!!!!!!

NEEDS SMALLER TUBING, SHORTER AND CHANGE IN AR

If the post turbo pipe work is sized appropriately to not reduce the pressure difference across the turbine then the length of that pipe should have little impact to low end response. I don’t think there is such thing as too big for post turbo pipe diameter. Having said that, it would be challenging to fit the correct size full system behind a big single turbo V8 particularly in a tight engine bay.

@@BoyRacer141 the diameter of the pipe feeding the turbo doesn’t really matter. it’s the diameter of the dow pipe that does. lots of power can be gain from going to a 3” dp to a 4” and so on. the faster the exhaust can be expelled the more power it will make.

Fabbing that up in the dyno room is awkward enough....

dissipation vs inhalation lol ?