Sierra 6.2 vs Corvette 6.2

[TJay74]

Just pour some 118 in it. 93 is childs play.

 

Other than spending a lot of money on that tank of gas, you would actually make less power on high octane fuel.

[Chris]

 

Just pour some 118 in it. 93 is childs play.

 

 

 

Other than spending a lot of money on that tank of gas, you would actually make less power on high octane fuel.

 

And it was a damn joke. 118 Wont make more power without forced induction and a tuner who knows what they are doing. Last thing I ran 118 in was the 383 in my 76 Firebird.

[bdbake01]

I think you have to light 118 on fire before it is injected into the cylinder.

 

True story.

[Chris]

Very easy to burn 118 with a very high compression engine. And my 383 was carb'd. Anyways making light of this thread. There are some differences. Manifolds, cam profiles, possibly combustion chamber size, and tuning

[typhoon186]

I'm the guinea pig.

2014 Sierra Denali 6.2.

C7 intake manifold going on this weekend.

ARH Long Tube headers installed with full 3.5" straight through mufflers and resonator exhaust. Custom intake tube and air box installed. Diablosport in-tune custom tune installed.

 

This combination should be pretty much exactly equal to a C7 Corvette with headers and tune.

 

It looks like there will be no loss in torque. Peak torque will be about the same and in the same rpm range + some. The torque should remain flat through an increased rpm range . HP will increase in the upper rpms and pull higher in the rpm range. There is some minor custom work required to swap intake manifolds. It's a little more than just remove one and install the other.

 

More details and pictures to follow when it's done.

[racerkvn]

I can't wait to hear the results!

[typhoon186]

Here's a stock C7 with a dyno tune - before and after graphs.

 

Followed by one with intake, long tube headers and dyno tune on the same dyno.

 

I plan to have my tuned at the same place next Tuesday.

 

[bass mechanic]

here's the thing..

the LT1 engine and the 6.2 in the truck are identical except for the intake. but here's the problem. the corvette is tuned for a totally different application.

without the tune, your going to end up with less tq and a little more hp but here's what your really missing..

 

first of all you need to understand how HP is calculated and what it means.

HP is torque x RPM / 5252

 

this means you never see actual HP peaking below 5252 rpm the peak is at 5800 rpm on the LT1 your engine only spins to just about that before the transmission shifts.

HP is a CALCULATED number! think of it as bragging rights, nothing more..

 

TORQUE is the actual twisting force the engine makes, just the same way as if you applied a torque wrench to the input shaft of the transmission that's the amount of power you feel when you accelerate. HP is the resulting figure of the work that's being done with respect to time.

your truck already came with 460 ft lbs of torque! putting a shorter intake runner on it and not having the tune to go with it will yield LESS TQ than you have now! even the LT1 peak torque is less in stock form.

also if you look at that graph the only place it made any significant gains in torque was between 4k and 5k rpm with the most significant gain between 4500 and 5k

but if you look where the 2 lines cross this is at 5252 rpm (because of the calculation earlier) the headers made 25 hp and 25 tq (big deal) but it lost 25 ft lbs of tq at 2k rpm.

the only reason the HP is that much higher is because the torque band shifted to the right. the closer you get to 5252 rpm with the peak torque the more HP will be calculated.

HP is great for the drag strip because your always at WOT and that's where you want your max power.

with a street driven vehicle especially a truck you need to be looking at your torque curve.

 

the camshaft timing also plays a large role in where and for how long the engine makes peak torque. so unless you used the Stingray tune, your defeating the purpose anyway.

 

 

then consider the fact that the truck configuration is made to TOW and be run hard for extended periods of time. when you do this you build a lot of heat in the motor. as such GM would have programmed the tune from the factory to use a little more fuel and a little less timing for safety reasons. so the fact is the tunes are totally different and if you put a stingray tune on the truck, it's likely you'll have issues long term with excessive knock and other problems.

 

if you ask me your spending a lot of time without having some some simple research and the outcome will be a total waste of time and money and end up with just the opposite of what you were expecting to accomplish.

 

if you want more power get a blower like I did, there is no mistaking the additional 113 hp to the wheels and I can tell you after you do that, the only thing you need to buy are tires.

Edited September 4, 2014 by bass mechanic

[Jon A]

Good luck. Let us know all you have to do to get it on. I've had a C7 manifold sitting here for a couple months, just waiting to find the time to get it on.

 

I plan to do a before/after dyno as well with the intake being the only change to see exactly what it does. According to the dyno comparisons I've done, it looks like we might lose a tiny bit of torque below 2800 RPM or so but gain everywhere after that (a little in some areas, a lot in others). It's pretty clear to me it's the better manifold for any time you actually have your foot in the throttle more than 1/2 way (including towing), but the stock manifold might have the edge in light throttle cruising (admittedly, where 90% of owners spend 90% of their time). It'll be interesting....

[Jon A]

this means you never see actual HP peaking below 5252 rpm the peak is at 5800 rpm on the LT1 your engine only spins to just about that before the transmission shifts.

HP is a CALCULATED number! think of it as bragging rights, nothing more..

 

TORQUE is the actual twisting force the engine makes, just the same way as if you applied a torque wrench to the input shaft of the transmission that's the amount of power you feel when you accelerate. HP is the resulting figure of the work that's being done with respect to time.

your truck already came with 460 ft lbs of torque! putting a shorter intake runner on it and not having the tune to go with it will yield LESS TQ than you have now! even the LT1 peak torque is less in stock form.

the camshaft timing also plays a large role in where and for how long the engine makes peak torque. so unless you used the Stingray tune, your defeating the purpose anyway.

 

then consider the fact that the truck configuration is made to TOW and be run hard for extended periods of time. when you do this you build a lot of heat in the motor. as such GM would have programmed the tune from the factory to use a little more fuel and a little less timing for safety reasons. so the fact is the tunes are totally different and if you put a stingray tune on the truck, it's likely you'll have issues long term with excessive knock and other problems.

 

A lot of that just isn't going to be the case. No, a $200 manifold isn't going to be a blower. And yes, you'll want to adopt the Stingray tune as a baseline for ignition and cam timing. But you'll tune it to minimize KR the same way you do with a truck so there will be no heat or durability issues if the tune is done correctly. These trucks often have lots of KR stock, so a good tune with either manifold is the best thing you can do for longevity.

 

As for the gains, my engine shifts at 6200 so power above 5200 does make a big difference if you're trying to accelerate quickly. And it should be a pretty large gain on the top end. And my prediction shows while the torque peaks will be very close in value, the stingray manifold will have a lot more area under the torque curve, starting at just 3000 RPM--which means it may be a very beneficial mod for towing as well.

 

And FYI: Chassis dynos don't measure torque. They calculate torque from the HP they measure. Disconnect the RPM pickup and a chassis dyno can still measure your HP but it has no idea how much torque you're making.

[Cliff14Denali]

I downloaded a stock C7 tune from HP Tuners website and will be doing some comparison to both tunes. Should be interesting.

[typhoon186]

I got the C7 intake manifold installed.

 

I'll get some pics up soon.

 

Using an iphone app call Gtach, I checked my 1/4 mile times and trap speed.

 

before was 14.76 @ 107 mph after was 14.18 @ 109 mph. granted it's a phone app and not a drag strip time slip but I can feel the extra pull on top.

 

Still running the previous Diablosport custom tune but will get the C7 tune installed with HPTuners tomorrow and retest the 1/4 mile.

[typhoon186]

Here's the two intakes side by side. L86 on left LT1 on right. I added the silver radiant heat insulation top and bottom.

 

And the final installed pictures. I painted the top cover to match the truck.

[bass mechanic]

I think your app is way off because on another thread bombastic ran 13.1 @ 103 with an SC don't see how it's possible to have that trap speed running NA

 

 

Sent from my iPhone using Tapatalk

[typhoon186]

I was going to comment that I thought bombastic's trap speed seems very low for a 13.1 time unless maybe he was running a 3.73 gear ratio and ran 4x4 the entire way. maybe he can elaborate on that. I can't put a lot of faith in a phone app but the trap speeds seem to be fairly close to true speed from what I can tell.