[KingLT1]

Originally Posted by BunnyBoy

Road coursing with ported blower and E... Is it even worth considering?





How much gain with X port, E, headers, CAI, TB?

Considering that the IAT vs Spark retard table can be raised 40 degrees in the tune on E vs Pump gas, I think so.

+125whp or so.

[ZLRob]

Originally Posted by KingLT1

Considering that the IAT vs Spark retard table can be raised 40 degrees in the tune on E vs Pump gas, I think so.

+125whp or so.

Are you saying you can raise those values up to 40 degrees higher than the stock values if you run E? Am I understanding that right, or is that only the case if you have a ported blower and run E?

[KingLT1]

Originally Posted by ZLRob

Are you saying you can raise those values up to 40 degrees higher than the stock values if you run E? Am I understanding that right, or is that only the case if you have a ported blower and run E?

Blower doesn't have to be ported.

If you plan on only running the car hard on Ethanol then you can modify the IAT spark table to not pull any timing until 170 degree IAT's. That is probably still conservative on mild setups. If you plan on running the car hard on pump gas then I wouldn't modify that table as aggressively. Instead use meth/water injection. Most tuners don't modify this table that aggressively in the event the customer wants to be able to do WOT runs on pump gas.

Ethanol actually likes more heat to burn more efficiently, Hence why gas stations lower the E content in the Winter.

[ZLRob]

Originally Posted by KingLT1

Blower doesn't have to be ported.

If you plan on only running the car hard on Ethanol then you don't need to pull any timing until 170 degree IAT's and that is probably still conservative. If you plan on running the car hard on pump gas then I wouldn't modify that table as aggressively. Instead use meth/water injection. Most tuners don't modify this table that aggressively in the event the customer wants to be able to do WOT runs on pump gas.

Ethanol actually likes more heat to burn more efficiently, pump gas does not. Hence why gas stations lower the E content in the Winter.

Interesting info! Thanks for the insight brother. I actually have had mine left stock from the time I started getting this thing tuned up until now and recently revisited this table thinking to myself it seemed to be a little bit on the low scale, but didn't ever touch it thinking it was probably better to leave it. Turns out I was wrong there.

[KingLT1]

Originally Posted by ZLRob

Interesting info! Thanks for the insight brother. I actually have had mine left stock from the time I started getting this thing tuned up until now and recently revisited this table thinking to myself it seemed to be a little bit on the low scale, but didn't ever touch it thinking it was probably better to leave it. Turns out I was wrong there.

Yeah I am currently helping a friend sort out a SS that has rod/pistons/btr stage 2/P1x making 12 psi and I recently bumped that table up to start pulling 2 degrees around 172 degrees. That P1x will start at 105 degrees pre pull and be 164 degrees by 130mph. So it was constantly pulling timing until I adjusted that table. It doesn't show any KR at all by doing so on E50.

Even on my SBE LT1 I don't pull any timing until 154 degrees. So yeah no need to be pulling timing at 132 degrees with a stock compression LT4. That is ULTRA conservative and just killing performance for no good reason at all. This table is the biggest reason why stock blower LT4 cars drop a bunch of power after 1 or 2 pulls. It's nothing for a stock blower to hit 150 degrees after a pull and be pulling 4-6 degrees of timing there after without a bunch of cool down time.

As I have mentioned before Ethanol isn't just about peak gains, it provides consistent gains. Put E50 in the same setup, raise the IAT spark to not pull any timing until 170, now you have a car that is consistently getting another 4-6 degrees of timing after multiple pulls vs a car with a stock IAT spark table.

But again as I previously noted, you don't want to do this if you plan on running the car hard on Pump gas. You could still daily drive and make light pulls on pump gas but not flog it.

[ZLRob]

Originally Posted by KingLT1

Yeah I am currently helping a friend sort out a SS that has rod/pistons/btr stage 2/P1x making 12 psi and I recently bumped that table up to start pulling 2 degrees around 172 degrees. That P1x will start at 105 degrees pre pull and be 164 degrees by 130mph. So it was constantly pulling timing until I adjusted that table. It doesn't show any KR at all by doing so on E50.

Even on my SBE LT1 I don't pull any timing until 154 degrees. So yeah no need to be pulling timing at 132 degrees with a stock compression LT4. That is ULTRA conservative and just killing performance for no good reason at all. This table is the biggest reason why stock blower LT4 cars drop a bunch of power after 1 or 2 pulls. It's nothing for a stock blower to hit 150 degrees after a pull and be pulling 4-6 degrees of timing there after without a bunch of cool down time.

As I have mentioned before Ethanol isn't just about peak gains, it provides consistent gains. Put E50 in the same setup, raise the IAT spark to not pull any timing until 170, now you have a car that is consistently getting another 4-6 degrees of timing after multiple pulls vs a car with a stock IAT spark table.

But again as I previously noted, you don't want to do this if you plan on running the car hard on Pump gas. You could still daily drive and make light pulls on pump gas but not flog it.

The stock tables on LT4 are designed to start pulling at 154 and then it's pulling from there on out. I raised it up to the 198 cell, since the next cell the LT4 version is 176 and that's still a bit low considering you mentioned 40 degrees.

Unfortunately, we only have access to 91 octane here at the majority of our stations and I've witnessed firsthand the amount of knock this engine produces on the garbage quality of fuel that this state gives you access to. As much as 8-9 degrees at times! So as of this time, the only way you can reap the full benefits of what the LT4 is capable out here even in lower stock form, it's best to run E40 and up. I don't see a sense in doing that outside of better fuel economy, so I just run full pump E all the time.

[Katech_Mike]

The OP cannot get ethanol fuels where he's at in Canada.

I'm assuming the cost listed is in CAD which is around $3,700 USD right now.

Reasonable for the work being done. Davenport is a top notch shop.

[CalgaryZL1]

Originally Posted by Katech_Mike

The OP cannot get ethanol fuels where he's at in Canada.

I'm assuming the cost listed is in CAD which is around $3,700 USD right now.

Reasonable for the work being done. Davenport is a top notch shop.

Yes $5,000 Canadian and yes they are a world class shop

[KingLT1]

Originally Posted by ZLRob

The stock tables on LT4 are designed to start pulling at 154 and then it's pulling from there on out. I raised it up to the 198 cell, since the next cell the LT4 version is 176 and that's still a bit low considering you mentioned 40 degrees.

Unfortunately, we only have access to 91 octane here at the majority of our stations and I've witnessed firsthand the amount of knock this engine produces on the garbage quality of fuel that this state gives you access to. As much as 8-9 degrees at times! So as of this time, the only way you can reap the full benefits of what the LT4 is capable out here even in lower stock form, it's best to run E40 and up. I don't see a sense in doing that outside of better fuel economy, so I just run full pump E all the time.

Edit*

ZL1 LT4 cars are set from the factory to pull timing at 133 degrees. I have both a 2019 and 2021 stock tune files pulled up.

[ZLRob]

Originally Posted by KingLT1

Edit*

ZL1 LT4 cars are set from the factory to pull timing at 133 degrees. I have both a 2019 and 2021 stock tune files pulled up.

They must have dialed back the timing pull back a cell since the initial Camaro Z's came out because my 2017/2018 base tune files I have start dialing it back at the 154* threshold. Very interesting.. I wonder why they did that.

[KingLT1]

Originally Posted by ZLRob

They must have dialed back the timing pull back a cell since the initial Camaro Z's came out because my 2017/2018 base tune files I have start dialing it back at the 154* threshold. Very interesting.. I wonder why they did that.

Probably because they are so knock prone on pump gas. Especially 91

[ZLRob]

Originally Posted by KingLT1

Probably because they are so knock prone on pump gas. Especially 91

That would make a lot of sense actually.

[6spdhyperblue]

I think there’s an E multiplier for that table so you can leave it stock for pump and crank it up on E

[ZLRob]

Originally Posted by 6spdhyperblue

I think there’s an E multiplier for that table so you can leave it stock for pump and crank it up on E

I believe you are right. I gotta take a look at that table again because if that is the case it would be helpful in keeping stuff stock and not having to deal with reverting back if I'm going to ever need to run full pump.