A Day with a ZL1 in the eyes of Torq!

[c4maroboy]

[lakersftbl69]

I still don't understand why there is a 100 hp loss from motor to tires I thought on average stuff like that was suppose to be about a 17% loss only

[tooslow]

Originally Posted by Russell James

The engines are not broken in at the factory.

They have minimal run time from a couple of tests, then some time moving the cars around. The actual break in occurs over the first couple thousand miles of driving.

As proven by the gain in hp after a couple thousand miles. If they were already broken in, they would have max power at delivery. Not the case, when a car is new many things are quite tight... such as piston to bore clearance. After some miles the clearances will be better and also better ring sealing = more power.

I can see that. So that would be the case with any engine then, right, not just the LS series? Not sure why this even matters.

Originally Posted by ddavis

Spraying before the intercooler would be a bad idea. Seems like it would eat the intercooler alive more so then just not getting the full benefits. I would bet theres some good benefits for spraying it after the intercooler. I havent pulled apart a zl1 yet ,so not sure how possible it is and if theres a good outlet to tap into, but meth has plenty of benefits especially for a heat soak happy engine (more consistent pulls, added fuel, lower temps...).

Definitely it has it's benefits. Even if you're now lowering IAT's, you still get the ability to run more advanced timing on pump gas tunes. I was simply commenting on its effect on reducing intake temps.

[radz28]

Originally Posted by tooslow

Not unless you place the nozzles to spray after the air charge has passed through the intercooler, otherwise the incoming meth-cooled air would actually be heated up by passing through the factory setup. If there were any cooling benefits, they would be minimal, at best.



You do know that all the LSA engines are broken in at the factory before they are ever placed in the chassis, right? Little chance of any engine bearing failure due to not following the recommended break-in procedure. And last I checked, Scott is not a mechanical engineer.

I don't believe Scott is either, however, there are reasons for the break-in proceedures GM outlines. While you can argue both sides, which side do you think GM will take if they can prove there was a failure as a result of incorrect break-in?

I also don't believe these engines are broken in, let alone fired. I know LS9s and LS7s are run on natural gas to check for correct sealing and pressures (after other previous oil and coolant pressure checks - and these, unlike LSA, are hand-assembled in Wixom, MI; not Mexico - last I checked...). I'm almost positive these aren't broken-in any more than other 6.2s, outside of LS9. However - I am on the fence as to correctly break a motor-in; I've heard and engine dyno' is best, since in a new car, you have other powertrain and chassis considerations to worry about.

Scott is only making sure the customers are aware of how GM recommends the proceedure to be. Everyone is on their own otherwise.

[actireman]

Originally Posted by lakersftbl69

I still don't understand why there is a 100 hp loss from motor to tires I thought on average stuff like that was suppose to be about a 17% loss only

Isn't 17% of 580 HP 98.6?

[lakersftbl69]

Stock zl1 here said 476rwhp multiply that 476 x .17=80.92 we will say 81 so add the 81 to the 476 and you get 557 which to me seems more like these are the same as the ctsv

[Mr. Wyndham]

Great read, Torq!!

Lots of great modification threads coming out, now. I'm enjoying them all!

Originally Posted by radz28

I don't believe Scott is either, however, there are reasons for the break-in proceedures GM outlines. While you can argue both sides, which side do you think GM will take if they can prove there was a failure as a result of incorrect break-in?

I also don't believe these engines are broken in, let alone fired. I know LS9s and LS7s are run on natural gas to check for correct sealing and pressures (after other previous oil and coolant pressure checks - and these, unlike LSA, are hand-assembled in Wixom, MI; not Mexico - last I checked...). I'm almost positive these aren't broken-in any more than other 6.2s, outside of LS9. However - I am on the fence as to correctly break a motor-in; I've heard and engine dyno' is best, since in a new car, you have other powertrain and chassis considerations to worry about.

Scott is only making sure the customers are aware of how GM recommends the proceedure to be. Everyone is on their own otherwise.

He's not making this stuff up - so the "mechanical engineer" comment was quite off-base. Call him the messenger, if you will...

You certainly don't have to obey the recommendations....but I am.

[rmyers]

Originally Posted by lakersftbl69

Stock zl1 here said 476rwhp multiply that 476 x .17=80.92 we will say 81 so add the 81 to the 476 and you get 557 which to me seems more like these are the same as the ctsv

Since you are trying to measure a "loss" consumed by the drivetrain, you would multiply the crank horsepower x .83 which would be the equivalent of subtracting 17% from the total. That gives you 481.4.

[lakersftbl69]

Originally Posted by rmyers

Since you are trying to measure a "loss" consumed by the drivetrain, you would multiply the crank horsepower x .83 which would be the equivalent of subtracting 17% from the total. That gives you 481.4.

still though i feel its still a big hp loss compared to the amount we lost on our ss

[showstopper]

Originally Posted by fbodfather

a word of caution - please note 'break-in' period as described in your owner's manual.

They were serious about that?

[PQ]

Wow. Homepage sponsor thread?

[Bad@ssCamaro]

Originally Posted by lakersftbl69

Stock zl1 here said 476rwhp multiply that 476 x .17=80.92 we will say 81 so add the 81 to the 476 and you get 557 which to me seems more like these are the same as the ctsv

580 SAE hp at crank
-476 rwhp
= 104 hp drive train loss

104/580= 17.93%

[doc7000]

Originally Posted by lakersftbl69

still though i feel its still a big hp loss compared to the amount we lost on our ss

Different dyno, differeny car, different day....

you really can't compare your dyno run to any other dyno runs out there, I have seen ZL1 Dynos report around 510RWHP on youtube somewhere.

Where dynos are useful is seeing what your gains are (where you started and where you ended up at). Though in this day and age a car with 20% loss is a bit on the heavy side, I would expect this car to really be in the 10-15% range.

Though from the first post it sounds like they were seeing a good drop from the heat. So really a 580BHP engine could have been running at around 560BHP on that day in that condition.

So many variables and not enough info to real make such a judgement call that you are making.

[KILLER74Z28]

mmmmm popcorn...