LBO 16 SS goes 11.0@123
12-22-2016, 01:26 PM
#782
TECH Enthusiast
Stock the heads don't seem so great. We will just have to see how they do on the bench. In the past it really hasn't been that the GM exhaust ports them selves were all that bad. The valve jobs and valve guides were huge hindrances. I am hoping it is the same with theses heads. I think it is the small cam with VVT and the big old head runner that is actually working here. But for a 305 runner the stock flow sucks.
I wouldn't say the IM's are all that bad once they are ported. I currently have both the pump gas bolt on C7 record (I built, ported, tuned, and drove the car. It belonged to a friend though) and the bolt on Camaro records with my ported IM. Maybe they haven't updated the CF C7 list but I had it last I checked. I am going to try to max effort my stock IM as soon as I get a breather to see if there is anything left there.
BTW, I love your Z. That is the exact color scheme I would go with.
I wouldn't say the IM's are all that bad once they are ported. I currently have both the pump gas bolt on C7 record (I built, ported, tuned, and drove the car. It belonged to a friend though) and the bolt on Camaro records with my ported IM. Maybe they haven't updated the CF C7 list but I had it last I checked. I am going to try to max effort my stock IM as soon as I get a breather to see if there is anything left there.
BTW, I love your Z. That is the exact color scheme I would go with.
I didnt realize the LT head was measuring 305cc... I knew it was big but didnt know it was THAT big. I'm curious as what the CSA measures out to. As you mentioned, I wouldnt touch the intake port...all the power will be in the short turn/bowls/VJ..... I would do some serious work in the exhaust ports/throats though... 170 cfm @ .600" advertised is TERRIBLE... Thats worse then a 99' 241 head...LOL
I'm sub'd for your progress. I do follow your stuff on the 6G forum....(I have a 6G as well...), I can't wait to see what you come up with for a head program and stock cam or very mild cam.
To me it seems on paper, that the LT is a step back or two from an LS3 (and the LT4 a HUGE step back from the LS9), however you can not argue with reality and what the 6Gs and C7s are doing on the strip.... Hell we have bone stock C7 Z51 cars here locally running 11.60s@120 in good air.
All comes down to dont believe everything you read...
12-22-2016, 05:52 PM
#783
TECH Enthusiast
12-23-2016, 12:29 PM
#785
Thanks for the comments and the info.
I didnt realize the LT head was measuring 305cc... I knew it was big but didnt know it was THAT big. I'm curious as what the CSA measures out to. As you mentioned, I wouldnt touch the intake port...all the power will be in the short turn/bowls/VJ..... I would do some serious work in the exhaust ports/throats though... 170 cfm @ .600" advertised is TERRIBLE... Thats worse then a 99' 241 head...LOL
I'm sub'd for your progress. I do follow your stuff on the 6G forum....(I have a 6G as well...), I can't wait to see what you come up with for a head program and stock cam or very mild cam.
To me it seems on paper, that the LT is a step back or two from an LS3 (and the LT4 a HUGE step back from the LS9), however you can not argue with reality and what the 6Gs and C7s are doing on the strip.... Hell we have bone stock C7 Z51 cars here locally running 11.60s@120 in good air.
All comes down to dont believe everything you read...
I didnt realize the LT head was measuring 305cc... I knew it was big but didnt know it was THAT big. I'm curious as what the CSA measures out to. As you mentioned, I wouldnt touch the intake port...all the power will be in the short turn/bowls/VJ..... I would do some serious work in the exhaust ports/throats though... 170 cfm @ .600" advertised is TERRIBLE... Thats worse then a 99' 241 head...LOL
I'm sub'd for your progress. I do follow your stuff on the 6G forum....(I have a 6G as well...), I can't wait to see what you come up with for a head program and stock cam or very mild cam.
To me it seems on paper, that the LT is a step back or two from an LS3 (and the LT4 a HUGE step back from the LS9), however you can not argue with reality and what the 6Gs and C7s are doing on the strip.... Hell we have bone stock C7 Z51 cars here locally running 11.60s@120 in good air.
All comes down to dont believe everything you read...
12-23-2016, 07:04 PM
#789
Pray you need to tell Tim something is up with the website. I tried to order hp tuners with remote tune combo today from the efi tuning website and it won't let me. Don't want to miss out on the Christmas special. He could also be losing out on other sales.
It keeps telling me the order can't be shipped and I need to change my address. I've tried a couple times and double checked my info with no luck. Also sent him a PM with no reply.
Thanks
It keeps telling me the order can't be shipped and I need to change my address. I've tried a couple times and double checked my info with no luck. Also sent him a PM with no reply.
Thanks
12-23-2016, 07:08 PM
#790
Pray you need to tell Tim something is up with the website. I tried to order hp tuners with remote tune combo today from the efi tuning website and it won't let me. Don't want to miss out on the Christmas special. He could also be losing out on other sales.
It keeps telling me the order can't be shipped and I need to change my address. I've tried a couple times and double checked my info with no luck. Also sent him a PM with no reply.
Thanks
It keeps telling me the order can't be shipped and I need to change my address. I've tried a couple times and double checked my info with no luck. Also sent him a PM with no reply.
Thanks
12-23-2016, 09:01 PM
#793
TECH Enthusiast
A first order Helmholtz runner for a 370" motor with a torque peak of 4k is 37.95" from the valve head.
BUT. that is a rough number. I need the exact intake lobe duration @.001". I need the intake port dimensions,. When there is more info like you are providing a more accurate runner can be calculated.
That is longer than I expected. It is simply NOT unrealistic. If a person has a motor with what I consider to be a perfect design, he can easily fab an intake to take advantage of torque.
BUT. that is a rough number. I need the exact intake lobe duration @.001". I need the intake port dimensions,. When there is more info like you are providing a more accurate runner can be calculated.
That is longer than I expected. It is simply NOT unrealistic. If a person has a motor with what I consider to be a perfect design, he can easily fab an intake to take advantage of torque.
12-23-2016, 09:04 PM
#794
TECH Enthusiast
If I had a lt1 I would ignore aesthetics and give it what it wants. I would build plenum volume between one half and one engine displacement in size. Two throttle bodies. The closer to one engine displacement in size, the more refractory the plenum will be.
Less responsive. Less reflective of the waves
Less responsive. Less reflective of the waves
12-23-2016, 09:16 PM
#795
TECH Enthusiast
I want to also mention that taper starting at the port entrance will add a rpm component for upper rpm power. For example the perfect runner for a 5.4 4v cobra R engine is 14" long with a 7 degree taper. Long for torque, tapered for high rpm power
12-24-2016, 07:03 AM
#799
A first order Helmholtz runner for a 370" motor with a torque peak of 4k is 37.95" from the valve head.
BUT. that is a rough number. I need the exact intake lobe duration @.001". I need the intake port dimensions,. When there is more info like you are providing a more accurate runner can be calculated.
That is longer than I expected. It is simply NOT unrealistic. If a person has a motor with what I consider to be a perfect design, he can easily fab an intake to take advantage of torque.
BUT. that is a rough number. I need the exact intake lobe duration @.001". I need the intake port dimensions,. When there is more info like you are providing a more accurate runner can be calculated.
That is longer than I expected. It is simply NOT unrealistic. If a person has a motor with what I consider to be a perfect design, he can easily fab an intake to take advantage of torque.
12-24-2016, 07:13 AM
#800
Here are my total gains so far. Run 1 is bone stock. Run 47 is right after my last fuel adjustment and no fuel trimming was added but we lost tach signal in a couple spots. AFR was pretty much perfect. Run 48 was the back up run but the trims kicked in and added fuel. Run 48 was about .4 richer on average IIRC. But I think this tells the story of why the car did a 1.577 60ft on the stock converter. Almost 450rwtq at 2,700 where the converter flashes.
Mods to date:
Pray ported IM/TB, Rotofab CAI, EFI Tuning E85 flex fuel kit, Pray/EFI Tuning Tune.
Next mods will be 3" dual cut outs pre AFM valves and 2" headers with cats.
Mods to date:
Pray ported IM/TB, Rotofab CAI, EFI Tuning E85 flex fuel kit, Pray/EFI Tuning Tune.
Next mods will be 3" dual cut outs pre AFM valves and 2" headers with cats.