[18.2SS.1LE]

Originally Posted by RobZL1

I'm surprised you had issues with the tune. It seems like Andrew knows what he's doing from all I've seen. Maybe the other guy in the shop tuned yours?

It was the other guy, but at my power level the car should've never left on stock injectors. Couldn't figure out why the car would lay over, upgraded to the stage 2 intercooler which was supposed to already be on the car and had Jannetty retune. High IAT's and running out of fuel is a bad situation for any engine, this was before I started adding Boostane to the tank as well.

[KingLT1]

Originally Posted by Eldi Z

Yes, real world situations are different to Dyno pulls clearly. On the other hand, so many tuners stand with their custromers, after installing / tuning supercharged spplications on their LT1s.
They walk them through and usually customers come back for addtioonal upgrades from time-to-time, so they can follow up in time.
Lets hear these Real-World scenarios from professionals who tuned and tune these LT1s daily on all fuels and boost combinations possible, like Ted J @ JRE, Andy M @ ADM, Mike C @ Elite (Vengeance), Howard T @ Redline, Jeremy @ PPC, Pat G@ Guerra, Ricky Clarke, Justin White, Jeremy F @Fasterproms, Doug @ ECS and so many others....
Ask yourself, would all of them + all the aftermarket kit makers: Edelbrock, Magnuson, Whipple, ATI, Vortec not go out of business if so many of their LT1 engine'd custmers would break them on 93 pump gas?... I did not even mention the Californian crowd who use 91 pump on these platforms.

They are living because they don't make the power real world that they made on the dyno. All of those cars that made 550-570whp on 93 are cold pull perfect conditions and 480-520whp real world out on the road. You referenced stock ZL1 power, again the SS with 7-8psi makes ZL1 power under very limited conditions on pump gas. GM lowered the compression on the LT4 for a reason. And even the LT4's are octane limited on 93 with any increase in boost. I am not saying it can be done; I am saying that the claimed power numbers you can make are reliably exaggerated.

Here is an example. My friend bought a SS from a member(Jfmoore) that had a P1x LT4 fuel system remote tune by shop name mentioned here. I checked the tune after he bought it and had 2-3 degrees of KR and wouldn't make the 4-5 shift clean. On 9psi peak it would only tolerate 10-11 degrees without KR mid summer 90 degrees out. The knock took its toll, It now has a forged bottom end. I see big name shop stuff all the time. A lot of cars get sold off not long after modding and you don't hear about the problems that may have developed. I could keep going but I am not out here to ruin names. The shops mentioned do good work, the problem with remote tuning is that you do not have control over the environment. The data is only as good as what the end user gives you. Hence why I don't tune SBE 93 octane boosted stuff remotely. The tuning window is razor thin.


Side note: far as ring gaps. The LT1 can range anywhere from .008 to .012. The LT4's are around .022-.024.

[Eldi Z]

OK King. That makes sense too, but you analyzed 1 car out of many. Does not mean that the concept is not clear, but I guess there are a few successful examples here and there where KR has not been an issue - not even on 93 (not even talking about 91) and possibly other measures were taken in order to mitigate these adverse effects. Boosting lower than 9 PSI peak and using enough fuel supply might make a successful (Real-World 560-570 WHP) tune possible. Again, I am far from being an expert. I continue learning every day - Including on my new setup. If I will have to "live with" 520 WHP to drive safely in 90+ Ambient, then so be it.

[Eldi Z]

...As to the top ring gaps of LT4s, my understanding is, that the ranges are more like 0.015 - 0.017 on average. 0.021 in the extreme higher range, not more. This is from big data collected since the Z06 began rolling to the streets back in 2015

[RobZL1]

So what's the end game here? Genuinely curious.

[Megahurtz]

Originally Posted by Eldi Z

OK King. That makes sense too, but you analyzed 1 car out of many. Does not mean that the concept is not clear, but I guess there are a few successful examples here and there where KR has not been an issue - not even on 93 (not even talking about 91) and possibly other measures were taken in order to mitigate these adverse effects. Boosting lower than 9 PSI peak and using enough fuel supply might make a successful (Real-World 560-570 WHP) tune possible. Again, I am far from being an expert. I continue learning every day - Including on my new setup. If I will have to "live with" 520 WHP to drive safely in 90+ Ambient, then so be it.

King is absolutely right. Boosted LT1's live on pump gas when the boost pressure is lower than 9psi and a bunch of timing is pulled to be safe. The number one danger on a boosted LT1 is detonation. It will break the weak LT1 pistons real fast. Second is the heat the top rings are exposed to. Too hot and you break a ring quickly. To mitigate this, boosted stock piston LT1's are usually run rich and low on timing. They make good torque but lay over up top. Pushing past this on pump gas, and your risks greatly increase.

As the blower heats up, the ECU pulls more timing, keeping things safe but also lowering the power. So a dyno pull might show 570 rwhp, but then on the street the car gets slower when things are heat soaked or the blower is hot. You can mitigate this with meth or flex fuel and make more consistent power. But on pump gas, you're stuck with this timing logic.

You can push an LT1 harder if you're spraying meth or using Flex Fuel extract more heat from the combustion chamber, reducing detonation chances and keeping the rings cooler. What King has been saying is not "1 car example". It's be proven time and time again on the LT platform.

[arpad_m]

Originally Posted by Megahurtz

King is absolutely right. Boosted LT1's live on pump gas when the boost pressure is lower than 9psi and a bunch of timing is pulled to be safe. The number one danger on a boosted LT1 is detonation. It will break the weak LT1 pistons real fast. Second is the heat the top rings are exposed to. Too hot and you break a ring quickly. To mitigate this, boosted stock piston LT1's are usually run rich and low on timing. They make good torque but lay over up top. Pushing past this on pump gas, and your risks greatly increase.

As the blower heats up, the ECU pulls more timing, keeping things safe but also lowering the power. So a dyno pull might show 570 rwhp, but then on the street the car gets slower when things are heat soaked or the blower is hot. You can mitigate this with meth or flex fuel and make more consistent power. But on pump gas, you're stuck with this timing logic.

You can push an LT1 harder if you're spraying meth or using Flex Fuel extract more heat from the combustion chamber, reducing detonation chances and keeping the rings cooler. What King has been saying is not "1 car example". It's be proven time and time again on the LT platform.

I can attest to this based on my car as well. Initially I had only a blower with a single low side fueling enhancement (JMS), it made 560 rwhp on the dyno at 7.5 psi of boost, but at the drag strip it started "dying off" past 110-112 mph, I could literally feel the "oomph" go away once I hit 5th gear (the big rpm drop in the 8L90 doesn't exactly help there either). Nothing wrong with the setup or the tune, it was a compromise I understood.

Then, once we moved to the current setup with headers and a forged bottom end (leaving nothing but the LT1 block as stock), full LT4 fueling, flex fuel capability and a smaller pulley for 10-11 psi of boost with the appropriate tune, the car is now pulling like a banshee even at 140 mph, with no knock retard or any audible knock whatsoever even on 93 pump gas. Needless to say, it runs even better on E50-60, it's close to scary, which is exactly how I want it.

[Eldi Z]

Originally Posted by Megahurtz

King is absolutely right. Boosted LT1's live on pump gas when the boost pressure is lower than 9psi and a bunch of timing is pulled to be safe. The number one danger on a boosted LT1 is detonation. It will break the weak LT1 pistons real fast. Second is the heat the top rings are exposed to. Too hot and you break a ring quickly. To mitigate this, boosted stock piston LT1's are usually run rich and low on timing. They make good torque but lay over up top. Pushing past this on pump gas, and your risks greatly increase.

As the blower heats up, the ECU pulls more timing, keeping things safe but also lowering the power. So a dyno pull might show 570 rwhp, but then on the street the car gets slower when things are heat soaked or the blower is hot. You can mitigate this with meth or flex fuel and make more consistent power. But on pump gas, you're stuck with this timing logic.

You can push an LT1 harder if you're spraying meth or using Flex Fuel extract more heat from the combustion chamber, reducing detonation chances and keeping the rings cooler. What King has been saying is not "1 car example". It's be proven time and time again on the LT platform.

Thanks again for the heads-up and guidance. I salute you and Joe for the knowledge and caring for me so well. My issue with E is having limited storage place + having to transport 5 Gallons E Jerrycans ~30% E (to get to E40 on a full tank - E10 is already included in the 93 at the pump) to the gas station every time I fill up - is out of the question. Best I could do, is add maybe another 10% E ~ 2 Gallons, just to be a little safer - It would become E20 overall. What is your take on this?

[Eldi Z]

Originally Posted by arpad_m

I can attest to this based on my car as well. Initially I had only a blower with a single low side fueling enhancement (JMS), it made 560 rwhp on the dyno at 7.5 psi of boost, but at the drag strip it started "dying off" past 110-112 mph, I could literally feel the "oomph" go away once I hit 5th gear (the big rpm drop in the 8L90 doesn't exactly help there either). Nothing wrong with the setup or the tune, it was a compromise I understood.

Then, once we moved to the current setup with headers and a forged bottom end (leaving nothing but the LT1 block as stock), full LT4 fueling, flex fuel capability and a smaller pulley for 10-11 psi of boost with the appropriate tune, the car is now pulling like a banshee even at 140 mph, with no knock retard or any audible knock whatsoever even on 93 pump gas. Needless to say, it runs even better on E50-60, it's close to scary, which is exactly how I want it.

Thanks Arpad for this input. When the forged Rods & Pistons went into the motor, did you/ the shop have to take out the motor, or was it done with the motor remaining inside the engine bay? Did you have the RA balanced and blue-printed as well?

[arpad_m]

Originally Posted by Eldi Z

Thanks Arpad for this input. When the forged Rods & Pistons went into the motor, did you/ the shop have to take out the motor, or was it done with the motor remaining inside the engine bay? Did you have the RA balanced and blue-printed as well?

Ted Jannetty's shop rebuilt my engine, and AFAIK it did come out of the car. Yes, the new rotating assembly was balanced, I paid extra for that of course, but now it's perfect, no vibrations, no weird power dips etc.

The dyno sheet is like a curve, I know smoothing was also at play in the good looking graph, but I have the giant table with the raw measured numbers, too, it's proper.

[Megahurtz]

Originally Posted by Eldi Z

Thanks again for the heads-up and guidance. I salute you and Joe for the knowledge and caring for me so well. My issue with E is having limited storage place + having to transport 5 Gallons E Jerrycans ~30% E (to get to E40 on a full tank - E10 is already included in the 93 at the pump) to the gas station every time I fill up - is out of the question. Best I could do, is add maybe another 10% E ~ 2 Gallons, just to be a little safer - It would become E20 overall. What is your take on this?

E20 isn't going to help you run more timing but it would help add a little buffer for detonation resistance. Blending to E 20(if using 92 octane) would increase your octane rating to 94. But keep in mind, you're not getting a significant amount of the chemical cooling effect until E40-E50.

[Eldi Z]

Originally Posted by Megahurtz

E20 isn't going to help you run more timing but it would help add a little buffer for detonation resistance. Blending to E 20(if using 92 octane) would increase your octane rating to 94. But keep in mind, you're not getting a significant amount of the chemical cooling effect until E40-E50.

OK. My goal is actually mitigating detonation - protect the rings/pistons, not adding timing in order to up the WHP.
Why did you write that I use Octane 92? It is actually 93+, the Spec is 98 RON (Euro 6).
There is already ~ 8% of E in the petrol at the pump. I can add another
10-12% to make it 20 in total.

[Joshinator99]

Originally Posted by Eldi Z

OK. My goal is actually mitigating detonation - protect the rings/pistons, not adding timing in order to up the WHP.
Why did you write that I use Octane 92? It is actually 93+, the Spec is 98 RON (Euro 6).
There is already ~ 8% of E in the petrol at the pump. I can add another
10-12% to make it 20 in total.

I’d do E20 if you can along with the 93+. Better than none for sure.

[Eldi Z]

Originally Posted by arpad_m

Ted Jannetty's shop rebuilt my engine, and AFAIK it did come out of the car. Yes, the new rotating assembly was balanced, I paid extra for that of course, but now it's perfect, no vibrations, no weird power dips etc.

The dyno sheet is like a curve, I know smoothing was also at play in the good looking graph, but I have the giant table with the raw measured numbers, too, it's proper.

Very nice indeed! Way to go.
How long did the job take?
Did JRE give the option at all to install a rods & pistons combo without taking out the engine?
If you had gone with a set of matching Bob-Weighted Rods & Pistons (I.E. GPI's Diamond + Callies Combo), would you still have opted for a balancing of the RA?
Question is if balancing in such case is absolutely necessary.