Small Twin Turbos vs Supercharger - School me Please

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Dockmaster

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I have an LS7 built for my new sand car that I intended to put a Whipple 4.5 on. Problem is, you can't Whipples now due to a foundry casting issue. I already have a thread searching for a 4.5 with no luck thus far (at reasonable price with what I need). So I'm looking to go to small twin turbos instead and this may be my only option. My engine builder is recommending this. He just built a somewhat similar setup on an LS3 and said it runs great. Little to no noticeable difference in bottom end and acceleration compared to supercharged. I originally planned for the 4.5 as I'm more interested in bottom end, acceleration and easy, predictable driving. I don't want to have to worry about keeping RPM's up to avoid turbo lag or other related characteristics with turbos. I'm not at all interested in sand drags or worried about losing a bit on the top end that I'll likely never use anyway.

Does anyone out there have a small twin turbo setup? What can you tell me? Anyone with real-world comparison to supercharged? If it matters, my motor is an RHS block, 427 with Monster Frankenstein heads (too late to switch to the F710 heads unfortunately) and I plan to run 91 pump gas.

Thanks in advance for input and suggestions.
 
Trying to get a whipple has been an extrememly hard task lately. I may have a new in the box whipple gen 6 3.0L available next week if you want.

427 with whipple 3.0 made 1450 HP


Edit: just realized it wont fit your heads, never mind
 
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Josh121 said:
Trying to get a whipple has been an extrememly hard task lately. I may have a new in the box whipple gen 5 3.0L available next week if you want.

427 with whipple 3.0 made 1450 HP


Edit: just realized it wont fit your heads, never mind
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Thanks. I'll talk to my builder. My understanding is the accessory drives for LS on these new gen Whipples are difficult to come by or really expensive. But I may be confusing that with the new 3.8 supposedly coming out that is to replace the 4.0
 
Dockmaster said:
Thanks. I'll talk to my builder. My understanding is the accessory drives for LS on these new gen Whipples are difficult to come by or really expensive. But I may be confusing that with the new 3.8 supposedly coming out that is to replace the 4.0
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There is one "official" front drive kit being the Wegner front drive kit, and it costed me 4 grand. You can find other kits from guys like LSX concepts for a little bit cheaper. The Gen 6 are much more effecient and push much more air then the older units. Supposedly the 3.0L is comparable to the older 4.5 and the 3.8L that hasnt come out yet is a large step above the older 4.5L (from conversations ive had with some builders). But the one i have is a LS3 head, not LS7
 
Josh121 said:
There is one "official" front drive kit being the Wegner front drive kit, and it costed me 4 grand. You can find other kits from guys like LSX concepts for a little bit cheaper. The Gen 6 are much more effecient and push much more air then the older units. Supposedly the 3.0L is comparable to the older 4.5 and the 3.8L that hasnt come out yet is a large step above the older 4.5L (from conversations ive had with some builders). But the one i have is a LS3 head, not LS7
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Yep, Wegner is what I heard too. Don't think LS3 will work for me though unfortunately. Kind of ironic that I went with the 4.5 because they were supposed to be readily available :rolleyes::rolleyes:
 
Has anyone put a Pro Charger on a sand car yet?

I installed one on a Ford Raptor and the power was Insane. Drivability was flawless as well.

They also work well in the boating world. I don't have any personal experience, but I've read a number of stories.

I would think they would work well, if the room was available?
 
I have built one or two motor, hell think i built two this week, 91 octane on any boost is playing with fire, unless you by race 91 out of a barrel, I really recomend a little race fuel mixture, or two make sure you have a stable octane mix race gas with 87, because you mostly get 87 from the pump, even when you hit that little 91 button you are getting a little of the 87,

For bottom end there is not a turbo setup out there that will feel like a supercharger, just not going to happen, and supercharger lays over early, so turbos pull a lot longer, but take some time to get there,

Nothing out there will look like a 4.5, but Max power with that combo will be around 1000 hp, at the crank, the 4.5 does not like RPM on the rotors, so it gives a lot at the bottom,

Making big power can be done with a Magi, Magi on that setup can make up to 1500 hp, but installing a magi - you need experience there is a steeper learning curve on that blower, and the parts to pick.
 
Based on my experience in the drag racing world I don't see a centrifugal doing well in the sand/offroad application. Keeping the drive alive (regardless of type) would be the hurdle to overcome. They also take a little longer to build boost, but not like a turbo. Kind of depends on HP target and blower size too...
 
Dockmaster said:
I have an LS7 built for my new sand car that I intended to put a Whipple 4.5 on. Problem is, you can't Whipples now due to a foundry casting issue. I already have a thread searching for a 4.5 with no luck thus far (at reasonable price with what I need). So I'm looking to go to small twin turbos instead and this may be my only option. My engine builder is recommending this. He just built a somewhat similar setup on an LS3 and said it runs great. Little to no noticeable difference in bottom end and acceleration compared to supercharged. I originally planned for the 4.5 as I'm more interested in bottom end, acceleration and easy, predictable driving. I don't want to have to worry about keeping RPM's up to avoid turbo lag or other related characteristics with turbos. I'm not at all interested in sand drags or worried about losing a bit on the top end that I'll likely never use anyway.

Does anyone out there have a small twin turbo setup? What can you tell me? Anyone with real-world comparison to supercharged? If it matters, my motor is an RHS block, 427 with Monster Frankenstein heads (too late to switch to the F710 heads unfortunately) and I plan to run 91 pump gas.

Thanks in advance for input and suggestions.
Click to expand...
We have had both in funcos over the last 7 years. I will say I have never driven a turbo motor on 91 so I can’t tell you how they perform. A blower motor on pump gas will be slow. Anyone who says something else has never drive something actually fast. A blower motor at 14-15 psi on good fuel is the perfect dune motor. Wheelies 3rd gear all throttle but won’t do it in 4th or 5th without a rise. Out of the hole the blower is a raped ape all the time. They are very easy to drive it’s kinda cheating in my opinion. A turbo motor at 14-15 psi will be borderline un drivable at full throttle. You will struggle to keep the front in down. The car will wheelie all 5 gears on command and you will have to get used to trying to not crack the egg shell on a fast dune ride. It’s really hard to turn when your front end is off the ground. There will be turbo lag even with the new small precision turbos. It is night and day better than it used to be but they still have lag. You will need to shift in and out of turns. A blower motor can be in 4th the entire ride. Hopefully that helps.
 
DZRTRUN said:
We have had both in funcos over the last 7 years. I will say I have never driven a turbo motor on 91 so I can’t tell you how they perform. A blower motor on pump gas will be slow. Anyone who says something else has never drive something actually fast. A blower motor at 14-15 psi on good fuel is the perfect dune motor. Wheelies 3rd gear all throttle but won’t do it in 4th or 5th without a rise. Out of the hole the blower is a raped ape all the time. They are very easy to drive it’s kinda cheating in my opinion. A turbo motor at 14-15 psi will be borderline un drivable at full throttle. You will struggle to keep the front in down. The car will wheelie all 5 gears on command and you will have to get used to trying to not crack the egg shell on a fast dune ride. It’s really hard to turn when your front end is off the ground. There will be turbo lag even with the new small precision turbos. It is night and day better than it used to be but they still have lag. You will need to shift in and out of turns. A blower motor can be in 4th the entire ride. Hopefully that helps.
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Thanks! Appreciate the perspectives and input. Ultimately I may not have a choice if I can’t find a blower.
 
J Alper said:
I have built one or two motor, hell think i built two this week, 91 octane on any boost is playing with fire, unless you by race 91 out of a barrel, I really recomend a little race fuel mixture, or two make sure you have a stable octane mix race gas with 87, because you mostly get 87 from the pump, even when you hit that little 91 button you are getting a little of the 87,

For bottom end there is not a turbo setup out there that will feel like a supercharger, just not going to happen, and supercharger lays over early, so turbos pull a lot longer, but take some time to get there,

Nothing out there will look like a 4.5, but Max power with that combo will be around 1000 hp, at the crank, the 4.5 does not like RPM on the rotors, so it gives a lot at the bottom,

Making big power can be done with a Magi, Magi on that setup can make up to 1500 hp, but installing a magi - you need experience there is a steeper learning curve on that blower, and the parts to pick.
Click to expand...
Not to derail this thread but planning to run pump gas on my tt setup. I'm hesitant to run E85 because of fuel consumption. What are you thoughts on 91 pump with VP additive? Race gas just keeps getting harder and harder to get in CA.

 
DarkSide said:
Not to derail this thread but planning to run pump gas on my tt setup. I'm hesitant to run E85 because of fuel consumption. What are you thoughts on 91 pump with VP additive? Race gas just keeps getting harder and harder to get in CA.

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It's VP, I wouldn't doubt their claims, though I doubt you'll get much better results than 93 octane. Aeromotive tested one of their products:

aeromotiveinc.com

Fueled To Perform: Dyno Testing VP Racing Fuels’ Products

By BRIAN HAVINS JUNE 20, 2020 Website: https://www.lsxmag.com/tech-stories/fueled-to-perform-dyno-testing-vp-racing-fuel-products/ We are excited to share with you that Aeromotive received an editorial or content mention in a Power Automedia media channel: Acommon problem —...
aeromotiveinc.com aeromotiveinc.com

Hard to beat leaded fuel for octane boosts, just keep an eye on your O2 sensor. I've had some luck "refreshing" them with a propane torch (heat to cherry red), but they last maybe 2 seasons doing this with a 1-2:10 race:91 mix.
 
str8uptoytrader.com

Whipple 4.5 Supercharger

Whipple 4.5 Supercharger for LS7. Comes with a 8” lower pulley and an extra 3.5” top pulley. Great condition. $8,500. Contact @bjeskew or BJ (702) 885-3018. Located in Las Vegas, NV.
str8uptoytrader.com str8uptoytrader.com
 
To much money at stake,
I always mix my fuel now, at worst i mix 4 gallons of 87 to 1 gallon of 110, to get 91 octane, most of the time i mix 3 gallons of 87 to 2 gallons of 110,
Even doing that a barrel lasts me all season,

I have built so many Turbo Motors, and i have done some true 90 octane motors, and you have to take so much compression out of the motor that it makes for a 6lbs max with under 9.1 com ratio, at that point just do a big Cube motor, my 468 walks away from a 6lb-8.5com motors,

One issue is air temps, a hot day with a lot of load in lower RPM's is going to detonate if the octane gets low, unless you have a octane tester you are playing with fire, if you get fuel at the same place and run out the 87 in the line and get pure 91 you can check the density, then check the density of the 87, and record that, then if the fuel sits, checking the density over time might save your motor,
 
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