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Supercharger for 6.2

GMCvirgin
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Rob Mugs Enthusiast

Rob Mugs

Posted
Posted

Wonder what people are running for fuel on those.  The N/A 6.2 is 11.5:1 whereas the S/C is 10:1

kodiakdenali Enthusiast

kodiakdenali

Posted
Posted
3 minutes ago, Rob Mugs said:

Wonder what people are running for fuel on those.  The N/A 6.2 is 11.5:1 whereas the S/C is 10:1

Both are good on pump gas, premium of course, 91+, but nothing special. They'd be pretty useless if you had to find race gas just to run them.

Rob Mugs Enthusiast

Rob Mugs

Posted
Posted
Just now, kodiakdenali said:

Both are good on pump gas, premium of course, 91+, but nothing special. They'd be pretty useless if you had to find race gas just to run them.

With 8+ lbs of boost on a 11.5:1... I'd be a bit nervous :)  Sure it's hitting lots of KR 

Rob Mugs Enthusiast

Rob Mugs

Posted
Posted
3 hours ago, redwngr said:

Anybody priced an LT4?

 

https://gmpowertrain.com/products/lt4-engine/

 

https://gmpowertrain.com/products/gm-powertrain-6.2-l-lt4-engine-features-specifications.pdf

Looked it up and you should probably sit down before reading this:

 

 

https://www.hotcars.com/lt4-crate-engine-facts-costs-figures/

According to GMPerformanceMotor, the LT4 wet sump retails for $14,693 whereas the LT4 dry sump goes for $16,164. Apart from this, GM Performance offers its T56 6-speed manual box for $4,948 that can withstand up to 700 pound-feet of torque.

 

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kodiakdenali Enthusiast

kodiakdenali

Posted
Posted
Just now, Rob Mugs said:

With 8+ lbs of boost on a 11.5:1... I'd be a bit nervous :)  Sure it's hitting lots of KR 

I honestly don't know! my tuner has been working with Whipple for a long time, he knows them on a first name basis. he says their tune, which he recommends unless you have other mods that require a custom tune, is very very well done, safe, conservative. he's got a good safety margin built in.

For what its worth if you are making the decision, I spoke to 2 different professional tuners about this, both say without any hesitation, get the Whipple.

They both cite first off the low end power you get with the twin screw design. the procharger is a centrifugal supercharger. I'm not sure if it has to do with the design of the compressor itself, or if it is the distance between the output of the compressor and the cylinders that does it, but they have to build boost before you get the horsepower. the twin screw gives you that power immediately. The procharger is off to the side of the engine, charged air has to exit the compressor, travel through the intercooler, then into the intake manifold. The whipple is quite a different setup. it replaces the intake manifold, the compressor is right there on top of the engine and the intercooler is sandwiched between the compressor and the engine. (please correct me if I'm wrong). I think this is the reason for the differences in the performance. both seem to report pretty similar performance numbers on the dyno, but as anyone knows its not really about what that top number is, its the area under the curve that matters when it comes to how powerful your vehicle feels. If you can get that boost and thus that power down low in the power band, that's more "Streetable" power, that's your acceleration, towing etc. even if both setups give similar hp and tq numbers, it doesn't mean they both perform the same way.

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Rob Mugs Enthusiast

Rob Mugs

Posted
Posted
1 hour ago, kodiakdenali said:

I honestly don't know! my tuner has been working with Whipple for a long time, he knows them on a first name basis. he says their tune, which he recommends unless you have other mods that require a custom tune, is very very well done, safe, conservative. he's got a good safety margin built in.

For what its worth if you are making the decision, I spoke to 2 different professional tuners about this, both say without any hesitation, get the Whipple.

They both cite first off the low end power you get with the twin screw design. the procharger is a centrifugal supercharger. I'm not sure if it has to do with the design of the compressor itself, or if it is the distance between the output of the compressor and the cylinders that does it, but they have to build boost before you get the horsepower. the twin screw gives you that power immediately. The procharger is off to the side of the engine, charged air has to exit the compressor, travel through the intercooler, then into the intake manifold. The whipple is quite a different setup. it replaces the intake manifold, the compressor is right there on top of the engine and the intercooler is sandwiched between the compressor and the engine. (please correct me if I'm wrong). I think this is the reason for the differences in the performance. both seem to report pretty similar performance numbers on the dyno, but as anyone knows its not really about what that top number is, its the area under the curve that matters when it comes to how powerful your vehicle feels. If you can get that boost and thus that power down low in the power band, that's more "Streetable" power, that's your acceleration, towing etc. even if both setups give similar hp and tq numbers, it doesn't mean they both perform the same way.

Agree with all of this.  My one and only concern is high compression ratio with boost.  Even with direct injection, it's going to be pulling loads of timing  to keep from knocking.  That's why the Maro/Vettes that are blown are dropping down to 10:1.  Back before advanced injection systems, you'd be going into the 8/9:1 area.  Running E85 will probably see large gains in this area since the timing can be advanced.

If you can afford it, an LT4 would give most anyone way more than enough and run all day, every day, for 150k miles+. 

If you wanted pure balls out performance in a 'bang for the buck' fashion, I'd personally go with a built bottom end 5.3 and turbo the hell out of it

 

 

kodiakdenali Enthusiast

kodiakdenali

Posted
Posted
3 hours ago, GMCvirgin said:

Im a noob. So do i need any other parts for this whipple? Any things i should worry about?

you will need tuning of course, which at the moment is only available with HP tuners and requires a physically modified ECU, you have to do an exchange to get an unlocked unit, then the tuning on top of that. However if your truck is otherwise stock or nearly stock (like cool air intake + exhaust or similar) Whipple can provide the tune, you don't need a professional dyno tune in that case.

I can let you know in a few weeks if anything else ends up being needed, but as far as I know the kit should include everything you need save for the ECU unlocking. Whipple is about 6 weeks out for orders at the moment.

  • Thanks 1
CamGTP Senior Enthusiast

CamGTP

Posted
Posted

Compression ratio doesn't really scare people anymore. People have been boosting LQ9/L94/L98/LS3 engines for years with port fuel injection on pump gas. Those are all over 10:1 compression.

 

Now that we have direct injection with more compression it's in the same ball park as the port fuel engines.

 

A good tune should let you run 16-20 degrees of timing easy on 6-10psi of boost. We can even run low 12's AFR in boost with DI engines because they are that good. I run 12.9-13.0 AFR on E85 in a NA engine. I don't worry about knock like I do with the port fuel injection vehicles.

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GMCvirgin Enthusiast

GMCvirgin

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On 11/9/2020 at 6:42 AM, kodiakdenali said:

you will need tuning of course, which at the moment is only available with HP tuners and requires a physically modified ECU, you have to do an exchange to get an unlocked unit, then the tuning on top of that. However if your truck is otherwise stock or nearly stock (like cool air intake + exhaust or similar) Whipple can provide the tune, you don't need a professional dyno tune in that case.

I can let you know in a few weeks if anything else ends up being needed, but as far as I know the kit should include everything you need save for the ECU unlocking. Whipple is about 6 weeks out for orders at the moment.

When you say whipple will provide the tune, will they send a chip for me to use or do I have to take it to whipple or what.

lapoolboy Senior Enthusiast

lapoolboy

Posted
Posted
7 hours ago, GMCvirgin said:

When you say whipple will provide the tune, will they send a chip for me to use or do I have to take it to whipple or what.

?. There are no "chips" anymore.....those are so 1995!  

 

Whipple will guide you through it.  They will remote tune it and hope it works on your particular truck.  Good luck.

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