technical thread discussing the ZL1, potential expansion projects, capabilities of...

[adamgl]

Originally Posted by SSmoked

^FYI they didnt do the 24 hour test at the 'ring it was at there proving grounds.

Boost is at a fixed output (+/- 2psi pending airtemp), via the pully. more boost = more heat. thing with blown motors is heat soak so with more boost comes the need for more cooling mods ( heat exhacnger, meth....), especially on the road course where the car is full out for more than 12 seconds. It will be interesting to see, i think 95% of ZL1 owners wont have the car on the road course where its meant to be.

None close to me, but I'll have to take mine to Heartland park in Topeka.

[WheelmanSS]

Originally Posted by brada

..
Its gonna be interesting to see how far these FI motors can be pushed..

Agreed. I think for a lot of people, it's going to be a "what's going to go out first" mentality since it will be easier to get more power out of the LSA with lesser mods.

My buddy with the CTS-V gave me some early ideas, so I researched a bunch of CTS-V "power packages" to get some perspective.

150 RWHP gains - crank and idler pulleys for the boost, headers, meth kit, injectors, heat exchange, plugs/wires, tune.

100 RWHP gains - CAI, pulleys, headers, intercooler, tune.

75 RWHP - pulley and tune.


Sounds like some shops do some porting to the blower as well to squeeze a few extra ponies out of it. Interesting option.

So it appears these guys are able to make 150 RWHP on pure bolt-ons, stock long-block.

Not sure on durability, but i wonder what possibilities a big blower would offer on a short-block (throw stock heads under that assumption)? Thoughts?

[brada]

Originally Posted by WheelmanSS

Agreed. I think for a lot of people, it's going to be a "what's going to go out first" mentality since it will be easier to get more power out of the LSA with lesser mods.

My buddy with the CTS-V gave me some early ideas, so I researched a bunch of CTS-V "power packages" to get some perspective.

150 RWHP gains - crank and idler pulleys for the boost, headers, meth kit, injectors, heat exchange, plugs/wires, tune.

100 RWHP gains - CAI, pulleys, headers, intercooler, tune.

75 RWHP - pulley and tune.


Sounds like some shops do some porting to the blower as well to squeeze a few extra ponies out of it. Interesting option.

So it appears these guys are able to make 150 RWHP on pure bolt-ons, stock long-block.

Not sure on durability, but i wonder what possibilities a big blower would offer on a short-block (throw stock heads under that assumption)? Thoughts?

I think duability wont be an issue for gains of 100-125 hp.. with midium light abuse. after talking with one engineer, it seems they predicted (and engneered for) mods in that range.. (hush hush)
Is the ZL not intercooled?.. that alone would help with charge density!!

[Scarrzz]

.

What about bottled octane boosters and multi-tune setups for when you change the octane level? Run 92-93 at the stock tune and then have another for when you "bottle up" the octane.

[SlingShot]

Originally Posted by brada

I think duability wont be an issue for gains of 100-125 hp.. with midium light abuse. after talking with one engineer, it seems they predicted (and engneered for) mods in that range.. (hush hush)
Is the ZL not intercooled?.. that alone would help with charge density!!

Everything I've read says it is intercooled ...

[brada]

Originally Posted by SlingShot

Everything I've read says it is intercooled ...

Thanks for that.. I wasn't sure

[htron50]

Originally Posted by Scarrzz

.

What about bottled octane boosters and multi-tune setups for when you change the octane level? Run 92-93 at the stock tune and then have another for when you "bottle up" the octane.

Do those Octane Boosters really work? I've always been skeptical. Don't know why of course! LOL.... they never detail the ingredients. And there are no checks and balances on what they say.

[CamaroSpike23]

Originally Posted by brada

yes.. my bad.
from what i've been told, the fisrt few development engines GM ran.. (bench tested) on 100% duty cycle.
-first test , they were run to 6000 rpm for an hour straight..
-second test, from idle to WOT repeatedly for an hour
-third tested , roll on throttle acceleration from 2200 rpm to wide open.

the point being that they assume it very unlikely that an average joe will run the car at 6000 rpm for an hour.. that being thier worst case scenario.
So the mind set was , build engines to worst case scenario and tune down for street reliability.. vs.. build to nornal street use and then tune them to the max limit.
It seem GM has left lots of room for modification and still stay relatively safe and reliable.

GM has done far more longevity tests than just running at 6000 for an hour... (think days at a time) for durability testing

Originally Posted by brada

I think duability wont be an issue for gains of 100-125 hp.. with midium light abuse. after talking with one engineer, it seems they predicted (and engneered for) mods in that range.. (hush hush)
Is the ZL not intercooled?.. that alone would help with charge density!!

it is intercooled.

Originally Posted by Scarrzz

.

What about bottled octane boosters and multi-tune setups for when you change the octane level? Run 92-93 at the stock tune and then have another for when you "bottle up" the octane.

don't waste your time with octane boost bottles. they are a waste of money. they only affect the RON and not the overall octane of the fuel

and for a quick octane lesson for everyone

Octane values of fuel that you see on the pump are whats called the Anti-Knock Index (AKI) which is the average of the Research Octane Number (RON) and the Motor Octane Number (MON)

so if your RON is 95 and your MON is 86

(95+86)/2=90.5 AKI.

why is this important? Octane boosters only affect the RON so if you have a booster that says it adds 2 octane points you get this

[(95+2)+86]/2 = 91.5 AKI


so in reality you are only getting half of what you paid for. if you are lucky. and no, pouring two bottles in wont help, and you'll just waste even more money.

its like putting 87 octane in then adding a $5.00 bottle of octane boost.

average price difference with 87 vs 91 is about $0.20

so with the average 18 gallon fuel tank size

18 gal X $0.20 = $3.6 more for 91 octane over 87 vs spending an extra $5.00 on a bottle of boost

[adamgl]

Originally Posted by CamaroSpike23

GM has done far more longevity tests than just running at 6000 for an hour... (think days at a time) for durability testing


it is intercooled.

don't waste your time with octane boost bottles. they are a waste of money. they only affect the RON and not the overall octane of the fuel

and for a quick octane lesson for everyone

Octane values of fuel that you see on the pump are whats called the Anti-Knock Index (AKI) which is the average of the Research Octane Number (RON) and the Motor Octane Number (MON)

so if your RON is 95 and your MON is 86

(95+86)/2=90.5 AKI.

why is this important? Octane boosters only affect the RON so if you have a booster that says it adds 2 octane points you get this

[(95+2)+86]/2 = 91.5 AKI


so in reality you are only getting half of what you paid for. if you are lucky. and no, pouring two bottles in wont help, and you'll just waste even more money.

its like putting 87 octane in then adding a $5.00 bottle of octane boost.

average price difference with 87 vs 91 is about $0.20

so with the average 18 gallon fuel tank size

18 gal X $0.20 = $3.6 more for 91 octane over 87 vs spending an extra $5.00 on a bottle of boost

So what if I can only get 91 where I live? No good way to get it up around the 93 range?

[CamaroSpike23]

Originally Posted by adamgl

So what if I can only get 91 where I live? No good way to get it up around the 93 range?

you could buy some race fuel and mix your own, but you don't need 93. 91 will do you just fine.

the biggest issue with octane values is that everyone thinks that you can just pour in a higher octane and BOOM! you have more power.

well, with the SS, the opposite is true, if you put in 89/87, and the engine senses knock, it will drop the power and then it will be time for the magical fuse pull.

however, when going up in octane, you wont see any benefits unless you have the vehicle tuned specifically for the higher octane.

and in reality, 87 is more "powerful" than the higher grades, it just doesnt resist detonation as well which is the basis of how engines make more power on higher octane.

with a higher octane (read: higher resistance to detonation/ignition), you can advance the timing further and add more fuel to the mixture to create more power.

[SlingShot]

Thinking about it I don't recall GM ever building a boosted engine without an intercooler.

[Number 3]

Be careful on any claims that adding HP doesn't impact durability and reliabilty (2 different things).

Adding HP adds heat. Heat is bad for everything. You can add countermeasures, better cooling, better oil etc.

Adding HP with boost will simply increase cylinder pressures. So stock you are hitting your piston with a hammer. Adding 100 HP increases that hammer blow. Do you think your pistons, rods, crank and bearings can all take the same number of blows with a bigger hammer? No.

And Spike is correct, the GM dyno testing alone isn't in hours, it's in cycles. It is, I believe the equivalent of on heck of a lot of 1/4 mile runs.

But for all of you that think GM has all this power in reserve, keep in mind they busted butt to get the 30 HP increase over the CTS-V. To get that 30 HP and be reliable and durable enough for a 5 year 100,000 mile warranty as well as maintain emissions compliance is a HUGE amout of work. Yes, there is plenty of power available, just not when you want to offer a 100,000 mile warranty with low emissions.

[adamgl]

Originally Posted by CamaroSpike23

you could buy some race fuel and mix your own, but you don't need 93. 91 will do you just fine.

the biggest issue with octane values is that everyone thinks that you can just pour in a higher octane and BOOM! you have more power.

well, with the SS, the opposite is true, if you put in 89/87, and the engine senses knock, it will drop the power and then it will be time for the magical fuse pull.

however, when going up in octane, you wont see any benefits unless you have the vehicle tuned specifically for the higher octane.

and in reality, 87 is more "powerful" than the higher grades, it just doesnt resist detonation as well which is the basis of how engines make more power on higher octane.

with a higher octane (read: higher resistance to detonation/ignition), you can advance the timing further and add more fuel to the mixture to create more power.

I'm planning on CAI / headers / high flow cats / and turning up the boost by about 4 lbs. or so in the future. Is it worth the race gas mix just for safety or will 91 be ok with a good tune?

[leviticus88]

I'm thinking E85 should result in some large increases in power and lower temperatures.
E85 and Boost play well together and my Zl1 would be running on the corn.