The Official Hot Rod Thread - Part 4: Burnouts for Distance

[ChristianPatriot]

That's part of it I believe as well. But another thing is more HP requires more fuel. If the injectors and fuel pump aren't up to the task, you wont see the gains you're hoping for

Another thing is, it takes horsepower to spin turbos or superchargers. So that blown motor making 450hp may actually be making closer to 500hp but it’s getting eaten up by parasitic losses caused by spinning the blower, turbo, etc.

 

[Brad69]

The 2.4L IHI supercharger runs 14,600RPM at just over 11PSI. The engine flows 30,000 liters of air per minute. It takes 80 horsepower just to drive the supercharger.

Just Saying!

 

[maxwelhse]

The 2.4L IHI supercharger runs 14,600RPM at just over 11PSI. The engine flows 30,000 liters of air per minute. It takes 80 horsepower just to drive the supercharger.

Just Saying!

A top fuel blower consumes over 1,000hp at full send... Just freaking crazy.

 

[Bigtanker]

So how much power does a turbo eat? Seems like it would be very little. Almost like running one size down on the header.

Seems easy enough to test. Make a dyno pull with open headers. Then add a full turbo kit and just don't hook it up to the intake.

 

[maxwelhse]

So how much power does a turbo eat? Seems like it would be very little. Almost like running one size down on the header.

Most turbo guys say they eat basically none. From a real world prospective, hundreds of blown 5.0 Ford pushrod blocks have split down the lifter valley around 500hp. A turbo version of the same engine can usually bang out over 600 in comfort. Just taking the stress off of the crank can do wonders for the whole system.

I'm basing that "knowledge" on ancient Mustang forum musings so things could have changed in either direction at this point, but that's how things were back in the day. That's actually why there's a SloppyMechanic's doing LS stuff today. He got tired of splitting 5.0s in half like he was cording firewood.

 

[jeffsqartan]

Most turbo guys say they eat basically none. From a real world prospective, hundreds of blown 5.0 Ford pushrod blocks have split down the lifter valley around 500hp. A turbo version of the same engine can usually bang out over 600 in comfort. Just taking the stress off of the crank can do wonders for the whole system.

I'm basing that "knowledge" on ancient Mustang forum musings so things could have changed in either direction at this point, but that's how things were back in the day. That's actually why there's a SloppyMechanic's doing LS stuff today. He got tired of splitting 5.0s in half like he was cording firewood.

I've always been told that the ceiling for a pushrod 5.0 was 500hp and then it's going to split down the middle - not if, but when.

But just a few months ago, Richard Holdener did a video about how 5.0's DON'T split down the middle like the internet tells us. How he's had over 15 different engine combinations (supercharged, nitrous, turbo, NA) that all lived well above 500 for a long time. There's only one engine that he's actually had blow apart on him, and he discusses his theory on that engine.

Regardless, I don't think turbos take up that much power. It's a slight exhaust restriction, but if you size the turbo correctly it's not going to be a massive restriction. I'd like to see Engine Masters test it some day.
I think we can probably take some of the information that EM has given us in their exhaust videos and get an idea of how much restriction a turbo setup might give us. The huge variables are going to be in whether it's a single or a twin setup, and what size exhaust flange is it flowing into, along with how large the turbo exhaust housing is.
There's a ton of variables to look at.
At the end of the day, I think that does somewhat explain why a particular sized injector can support more NA HP than it can boosted HP. It's likely a combination of parasitic loss and overcoming the pressure within the intake (since injectors require a specific pressure to flow a specific amount of fuel).

https://www.youtube.com/watch?v=P9O05u0JriY&ab_channel=RichardHoldener
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And this is a link to LMR that shows what they suggest you should use for injectors at certain HP levels. It also has some science in it that I'm now going to read, to see if I can figure out why larger injectors are required on boosted setups:
https://lmr.com/page/Mustang-Fuel-Injector-Size-Guide
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[/COLOR]So they are saying that boosted engines are less efficient and also require more fuel to have lower EGT's. Interesting.
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Found it:
The following guide is a general rule of thumb for sizing fuel injectors on an 8-cylinder engine using a BSFC of 0.50. Forced-induction engines typically range from a BSFC of 0.55 to 0.65, with the latter value arising from the fuel enrichment necessary to keep exhaust temperatures below 1650 deg F and catalyst temperatures below 1750 deg F.
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So they are saying that boosted engines are less efficient and also require more fuel to have lower EGT's. Interesting.

 

[churchmouse]

Meh... In this regard I think your risks are pretty low. Worst thing that I'm thinking is you could choke to death on a small turbo and make less power than you hoped. The fix for that is more turbo, so, you'd win no matter what.

Or 2 small Turbos 1 per bank........But I am a bit nutty that way.

Yes, it might be a choke point but for what he wants from it this might turn out to be a solid package.

 

[Bigtanker]

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[/COLOR]So they are saying that boosted engines are less efficient and also require more fuel to have lower EGT's. Interesting.

So if that's the case, seems like a good idea to run methanol or E85

 

[churchmouse]

I think you can probably find a good balance with a single if you want. Doubles are just so much more stuff... it's like there's twice as much of it!

I'm curious to learn more about what you're talking about with injectors as I've never seen any testing like that. I suppose the rising pressure in the intake could pretty seriously **** off a setup that wasn't built with boost in mind. If the regulator can't flow enough fuel pressure to counteract against the boost, you'd get less fuel through them.

You have to put a bigger carb on a bigger engine.
Boost equates to "MORE"............More air/more fuel.
There is a calculation for this (baseline) but it eludes me.

 

[churchmouse]

So if that's the case, seems like a good idea to run methanol or E85

Methanol requires a lot of work. It eats things.

 

[RustyHornet]

All hail the mighty 292.

Sent from my iPhone using Tapatalk

 

[Bigtanker]

All hail the mighty 292.

Sent from my iPhone using Tapatalk

Plenty of room for some turbos!!!

 

[maxwelhse]

So if that's the case, seems like a good idea to run methanol or E85

It is, but you have to run twice as much of it because the energy density of alcohol is basically half that of gas. So you need monster pumps, lines, and injectors.

I have thought more than once about putting a very, very, simple non-intercooled turbo setup on my 5.0 and running it on E for exactly that reason. No cold side plumbing would make it basically no more invasive to the car then a set of aftermarket wheels. At 6 or 8lbs it would easily make as much power as I care for in that car and I think the alcohol would give me acceptable IATs for light-to-light romps around town. With an ethanol content sensor I could dial it off to basically no boost on 93 just to tool down the highway with twice the range if I wanted.

Not saying I'm going to do it, but it's on my mind. I should probably hang the other speed parts I already have for it on it first.

You have to put a bigger carb on a bigger engine.
Boost equates to "MORE"............More air/more fuel.
There is a calculation for this (baseline) but it eludes me.

I get that. What I read him saying is that the same injectors on an NA motor, when placed in a boosted motor, make less power in the boosted application. When the O2s are controlling fueling, I would think that duty cycle would be duty cycle and the ECM would command 100% of the injector at a certain point in both engines and that would be your hard limit on power, regardless of boost, as long as you were hitting the same stoichiometric efficiency. You'd think X much fuel at 14.7 (or whatever you pick) AFR would yield Y horsepower if everything else were held the same.

It's an odd study that I've not seen anyone conduct, which isn't to say no one has, so I'd be curious to dig into that more. Usually the limit of power with a turbo motor is how much fuel you can shove into it before it quits making power (or something breaks) so that's how guys tend to size their injectors. Putting wimpy NA injectors on a turbo motor isn't something I've studied.

 

[churchmouse]

It is, but you have to run twice as much of it because the energy density of alcohol is basically half that of gas. So you need monster pumps, lines, and injectors.

I have thought more than once about putting a very, very, simple non-intercooled turbo setup on my 5.0 and running it on E for exactly that reason. No cold side plumbing would make it basically no more invasive to the car then a set of aftermarket wheels. At 6 or 8lbs it would easily make as much power as I care for in that car and I think the alcohol would give me acceptable IATs for light-to-light romps around town. With an ethanol content sensor I could dial it off to basically no boost on 93 just to tool down the highway with twice the range if I wanted.

Not saying I'm going to do it, but it's on my mind. I should probably hang the other speed parts I already have for it on it first.



I get that. What I read him saying is that the same injectors on an NA motor, when placed in a boosted motor, make less power in the boosted application. When the O2s are controlling fueling, I would think that duty cycle would be duty cycle and the ECM would command 100% of the injector at a certain point in both engines and that would be your hard limit on power, regardless of boost, as long as you were hitting the same stoichiometric efficiency. You'd think X much fuel at 14.7 (or whatever you pick) AFR would yield Y horsepower if everything else were held the same.

It's an odd study that I've not seen anyone conduct, which isn't to say no one has, so I'd be curious to dig into that more. Usually the limit of power with a turbo motor is how much fuel you can shove into it before it quits making power (or something breaks) so that's how guys tend to size their injectors. Putting wimpy NA injectors on a turbo motor isn't something I've studied.

They have a flow rate and you always see the injectors get an upgrade.

 

[ghitch75]

you should see the rice burners faces when a 9k work van with ladders on top hands there asses to them.....D-MAX BABY!!!!.....

 

[Jaybird1980]

Plenty of room for some turbos!!!

I think powernation put a turbo on the 292, worked pretty good

 

[ChristianPatriot]

I’ve been waiting for this one

[video=youtube_share;n8_2rWB5vRw]https://youtu.be/n8_2rWB5vRw[/video]

 

[d.kaufman]

Motor was definitely hurting on that last pass

 

[maxwelhse]

I quit following Dahm ages ago... I never expected that car to become operational, so, a win for him no matter what.

...and Rob Dahm things happened.

 

[ChristianPatriot]

Never have understood all the Rob Dahm fanboi’s, but to each his own I guess. There is for sure a massive cult of rotary lovers out there.