LT! at SEMA
11-02-2012, 09:45 AM
#41
Burning Brakes
The lifters in the AFM equipped engines will likely have a higher mass than the regular lifters. All else remaining equal, lighter lifters will mean a more agressive camshaft profile can be used without the risk of valve float, potentially offering up extra power/torque in the process.
Another thing to consider is CAFE and the number of automatics sold vs. manuals. Since autos outsell manuals by a LARGE margin, the auto equipped cars have far more of an impact on the CAFE numbers. Also, the manual is rumored to have seven speeds which will surely include a very tall overdrive and resulting improved fuel efficiency. This could contribute to a non AFM manual car getting comparable or even better mileage than the AFM auto car.
This is 100% speculation on my part, but keep in mind that this is generally the same approach they took with the Camaro.
Another thing to consider is CAFE and the number of automatics sold vs. manuals. Since autos outsell manuals by a LARGE margin, the auto equipped cars have far more of an impact on the CAFE numbers. Also, the manual is rumored to have seven speeds which will surely include a very tall overdrive and resulting improved fuel efficiency. This could contribute to a non AFM manual car getting comparable or even better mileage than the AFM auto car.
This is 100% speculation on my part, but keep in mind that this is generally the same approach they took with the Camaro.
11-02-2012, 09:56 AM
#42
Burning Brakes
I hope you are right, but the Camaro approach resulted in a completely different engine for the automatic SS, the L99 vs LS3. So far we have only heard about the LT1 for the C7.
11-02-2012, 11:52 AM
#44
Team Owner
The lifters in the AFM equipped engines will likely have a higher mass than the regular lifters. All else remaining equal, lighter lifters will mean a more agressive camshaft profile can be used without the risk of valve float, potentially offering up extra power/torque in the process.
Another thing to consider is CAFE and the number of automatics sold vs. manuals. Since autos outsell manuals by a LARGE margin, the auto equipped cars have far more of an impact on the CAFE numbers. Also, the manual is rumored to have seven speeds which will surely include a very tall overdrive and resulting improved fuel efficiency. This could contribute to a non AFM manual car getting comparable or even better mileage than the AFM auto car.
This is 100% speculation on my part, but keep in mind that this is generally the same approach they took with the Camaro.
Another thing to consider is CAFE and the number of automatics sold vs. manuals. Since autos outsell manuals by a LARGE margin, the auto equipped cars have far more of an impact on the CAFE numbers. Also, the manual is rumored to have seven speeds which will surely include a very tall overdrive and resulting improved fuel efficiency. This could contribute to a non AFM manual car getting comparable or even better mileage than the AFM auto car.
This is 100% speculation on my part, but keep in mind that this is generally the same approach they took with the Camaro.
The LT1 revs to 6600 RPM(with no valve float) vs the LS3's 6500 RPM.
Last edited by JoesC5; 11-02-2012 at 11:54 AM.
11-02-2012, 06:57 PM
#45
Racer
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Lt1
Well, I spoke to the man who was supposed to be the most knowledgeable person at the show today for a good half hour. He is in the aftermarket/e-rod engineering group. He candidly stated that we probably have received as much information as he has concerning LT1. That being said he still believes that AFM will be on both auto and manual transmissions. He said there is only one RPO and that a non AFM motor would have a different RPO.
He said at this time there was no plan for a crate version of LT1 but he would expect it down the road. It looks like the reason for the accessory drive being like it is was to make all platforms use the same setup to reduce inventory and of course save money.
Also, the bolt pattern on the back of the block has been changed. It looks like four bolt holes may work but the uppers sure won't-seems like an easy adapter to build though.
C7 will use electric steering so there is no provision for a pump-I wonder if the trucks will have it also?
The lock down on information on the C7 has everyone very wary of what they say. I really don't think anyone there knows much if anything more than has been released to us. The show people had been briefed two weeks before the official release to have a heads up for SEMA.
He had no information on the new transmissions either.
So I guess we don't really know much more now than before although my bet would be that AFM will be there on all engines. Maybe January will bring out some more information with the official roll out.
Hal
He said at this time there was no plan for a crate version of LT1 but he would expect it down the road. It looks like the reason for the accessory drive being like it is was to make all platforms use the same setup to reduce inventory and of course save money.
Also, the bolt pattern on the back of the block has been changed. It looks like four bolt holes may work but the uppers sure won't-seems like an easy adapter to build though.
C7 will use electric steering so there is no provision for a pump-I wonder if the trucks will have it also?
The lock down on information on the C7 has everyone very wary of what they say. I really don't think anyone there knows much if anything more than has been released to us. The show people had been briefed two weeks before the official release to have a heads up for SEMA.
He had no information on the new transmissions either.
So I guess we don't really know much more now than before although my bet would be that AFM will be there on all engines. Maybe January will bring out some more information with the official roll out.
Hal
Last edited by eaglebusman; 11-02-2012 at 07:59 PM.
11-02-2012, 08:58 PM
#46
So I spoke to another guy and he said the same thing as the previous poster, that as far as he knew they were using AFM on both trannies. However, he was far less confident with his answer than the first guy who stated otherwise. I guess that leaves us back where we started. Sorry fellas, back to arguing.
11-03-2012, 12:21 AM
#47
Le Mans Master
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Thank you both for making an effort.
11-03-2012, 03:40 AM
#48
Le Mans Master
They acted as though the new platform will only have the LT1, no LS7 or LS9. I also asked for the flow numbers in comparison to the LS3 heads but he didn't know any direct numbers for the two. Neither of them were real GEEKS so I hope to find someone there that really is a gearhead and work on him.
BTW, they called the new C7 a 'tighter package' whatever they meant.
BTW, they called the new C7 a 'tighter package' whatever they meant.
Ports remind me of a Diesel motor, accessory packaging of H2O pump and A/C compressor make me think WTF? they are further Starboard than the LS series componenets. This motor will never be a swap candidate like the LS series of motors is.
I am too familiar with the problems of DI motors building up deposits onto the backsides of their intake valves and having those depositis turn into a massive glob of tar. My B7 Audi RS4 lost 35HP in 8000 miles of use because of reduced airflow caused by intake valve depositis. Yes DI will make more power with less fuel but, there are still some unanswered questions on this system. My wife's current ride (besides a C6 Z06) is a Lexus IS250 again there are problems with build-up in the intake system on this DI motor. Same for many VAG DI motors and the GM DI V6.
Time will tell of this platform excells but, unlike the Gen3/4 motors, I don't expect the Hot Rod community to adopt this motor for use in their projects. GM fumbled the ball in that court.
11-03-2012, 06:07 AM
#49
Le Mans Master
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The lifters in the AFM equipped engines will likely have a higher mass than the regular lifters. All else remaining equal, lighter lifters will mean a more agressive camshaft profile can be used without the risk of valve float, potentially offering up extra power/torque in the process.
Another thing to consider is CAFE and the number of automatics sold vs. manuals. Since autos outsell manuals by a LARGE margin, the auto equipped cars have far more of an impact on the CAFE numbers. Also, the manual is rumored to have seven speeds which will surely include a very tall overdrive and resulting improved fuel efficiency. This could contribute to a non AFM manual car getting comparable or even better mileage than the AFM auto car.
This is 100% speculation on my part, but keep in mind that this is generally the same approach they took with the Camaro.
Another thing to consider is CAFE and the number of automatics sold vs. manuals. Since autos outsell manuals by a LARGE margin, the auto equipped cars have far more of an impact on the CAFE numbers. Also, the manual is rumored to have seven speeds which will surely include a very tall overdrive and resulting improved fuel efficiency. This could contribute to a non AFM manual car getting comparable or even better mileage than the AFM auto car.
This is 100% speculation on my part, but keep in mind that this is generally the same approach they took with the Camaro.
See, I don't like driving autos. They're boring to me. But I also don't like using fuel I don't have to use. Often times in my Z06 when I'm in 6th gear at 1700-1800 RPM, I wish I had another gear. I highly doubt GM's putting a 7 speed in so we could have 3 over drives. LOL I'm pretty sure that would be an epic fail.
I know a lot of people on here don't like AFM for one reason or another, but I have no plans to mod and therefore I'm not worried about the sound AFM would make, and based on what I've seen of other cars with AFM (and an older generation of it), there's no noticeable delay that would have me waiting for power. So I see no negative side to AFM.
Well, I spoke to the man who was supposed to be the most knowledgeable person at the show today for a good half hour. He is in the aftermarket/e-rod engineering group. He candidly stated that we probably have received as much information as he has concerning LT1. That being said he still believes that AFM will be on both auto and manual transmissions. He said there is only one RPO and that a non AFM motor would have a different RPO.
He said at this time there was no plan for a crate version of LT1 but he would expect it down the road. It looks like the reason for the accessory drive being like it is was to make all platforms use the same setup to reduce inventory and of course save money.
Also, the bolt pattern on the back of the block has been changed. It looks like four bolt holes may work but the uppers sure won't-seems like an easy adapter to build though.
C7 will use electric steering so there is no provision for a pump-I wonder if the trucks will have it also?
The lock down on information on the C7 has everyone very wary of what they say. I really don't think anyone there knows much if anything more than has been released to us. The show people had been briefed two weeks before the official release to have a heads up for SEMA.
He had no information on the new transmissions either.
So I guess we don't really know much more now than before although my bet would be that AFM will be there on all engines. Maybe January will bring out some more information with the official roll out.
Hal
He said at this time there was no plan for a crate version of LT1 but he would expect it down the road. It looks like the reason for the accessory drive being like it is was to make all platforms use the same setup to reduce inventory and of course save money.
Also, the bolt pattern on the back of the block has been changed. It looks like four bolt holes may work but the uppers sure won't-seems like an easy adapter to build though.
C7 will use electric steering so there is no provision for a pump-I wonder if the trucks will have it also?
The lock down on information on the C7 has everyone very wary of what they say. I really don't think anyone there knows much if anything more than has been released to us. The show people had been briefed two weeks before the official release to have a heads up for SEMA.
He had no information on the new transmissions either.
So I guess we don't really know much more now than before although my bet would be that AFM will be there on all engines. Maybe January will bring out some more information with the official roll out.
Hal
11-03-2012, 08:23 AM
#50
Le Mans Master
While I'm not an expert head porter, I have spent numerous hours holding a die grinder in my hand. I too attened SEMA and don't think much of what I saw on the Gen5 LT1 display. There are numerous intrusions into the intake port, it has a bunch of "twist" built into it to induce "swirl" of the dry air entering the combustion chambers of the DI motor. There is no way this port outflows a LS7 port. The exhaust side is even worse! it is long and dosent have a perpendicular exit out of the head, I am wondering if GM did this to transfer heat into the cooling system for quicker temprature rise during a cold start emission test.
Ports remind me of a Diesel motor, accessory packaging of H2O pump and A/C compressor make me think WTF? they are further Starboard than the LS series componenets. This motor will never be a swap candidate like the LS series of motors is.
I am too familiar with the problems of DI motors building up deposits onto the backsides of their intake valves and having those depositis turn into a massive glob of tar. My B7 Audi RS4 lost 35HP in 8000 miles of use because of reduced airflow caused by intake valve depositis. Yes DI will make more power with less fuel but, there are still some unanswered questions on this system. My wife's current ride (besides a C6 Z06) is a Lexus IS250 again there are problems with build-up in the intake system on this DI motor. Same for many VAG DI motors and the GM DI V6.
Time will tell of this platform excells but, unlike the Gen3/4 motors, I don't expect the Hot Rod community to adopt this motor for use in their projects. GM fumbled the ball in that court.
Ports remind me of a Diesel motor, accessory packaging of H2O pump and A/C compressor make me think WTF? they are further Starboard than the LS series componenets. This motor will never be a swap candidate like the LS series of motors is.
I am too familiar with the problems of DI motors building up deposits onto the backsides of their intake valves and having those depositis turn into a massive glob of tar. My B7 Audi RS4 lost 35HP in 8000 miles of use because of reduced airflow caused by intake valve depositis. Yes DI will make more power with less fuel but, there are still some unanswered questions on this system. My wife's current ride (besides a C6 Z06) is a Lexus IS250 again there are problems with build-up in the intake system on this DI motor. Same for many VAG DI motors and the GM DI V6.
Time will tell of this platform excells but, unlike the Gen3/4 motors, I don't expect the Hot Rod community to adopt this motor for use in their projects. GM fumbled the ball in that court.
Reading your post and all the information you have supplied about the unanswered problems associated with DI motors, seems to answer my question as to why companies like Lamborghini or even SRT with the new Viper did not move to DI fuel distribution for their motors. (besides making a motor more top heavy)
Understandably, I hope your predictions about the LT 1 are wrong. Unfortunately, because of your experience I worry that you are spot on.
Thanks for sharing your thoughts.
Last edited by Shurshot; 11-03-2012 at 08:25 AM.
11-03-2012, 09:30 AM
#51
Race Director
While I'm not an expert head porter, I have spent numerous hours holding a die grinder in my hand. I too attened SEMA and don't think much of what I saw on the Gen5 LT1 display. There are numerous intrusions into the intake port, it has a bunch of "twist" built into it to induce "swirl" of the dry air entering the combustion chambers of the DI motor. There is no way this port outflows a LS7 port. The exhaust side is even worse! it is long and dosent have a perpendicular exit out of the head, I am wondering if GM did this to transfer heat into the cooling system for quicker temprature rise during a cold start emission test.
Ports remind me of a Diesel motor, accessory packaging of H2O pump and A/C compressor make me think WTF? they are further Starboard than the LS series componenets. This motor will never be a swap candidate like the LS series of motors is.
I am too familiar with the problems of DI motors building up deposits onto the backsides of their intake valves and having those depositis turn into a massive glob of tar. My B7 Audi RS4 lost 35HP in 8000 miles of use because of reduced airflow caused by intake valve depositis. Yes DI will make more power with less fuel but, there are still some unanswered questions on this system. My wife's current ride (besides a C6 Z06) is a Lexus IS250 again there are problems with build-up in the intake system on this DI motor. Same for many VAG DI motors and the GM DI V6.
Time will tell of this platform excells but, unlike the Gen3/4 motors, I don't expect the Hot Rod community to adopt this motor for use in their projects. GM fumbled the ball in that court.
Ports remind me of a Diesel motor, accessory packaging of H2O pump and A/C compressor make me think WTF? they are further Starboard than the LS series componenets. This motor will never be a swap candidate like the LS series of motors is.
I am too familiar with the problems of DI motors building up deposits onto the backsides of their intake valves and having those depositis turn into a massive glob of tar. My B7 Audi RS4 lost 35HP in 8000 miles of use because of reduced airflow caused by intake valve depositis. Yes DI will make more power with less fuel but, there are still some unanswered questions on this system. My wife's current ride (besides a C6 Z06) is a Lexus IS250 again there are problems with build-up in the intake system on this DI motor. Same for many VAG DI motors and the GM DI V6.
Time will tell of this platform excells but, unlike the Gen3/4 motors, I don't expect the Hot Rod community to adopt this motor for use in their projects. GM fumbled the ball in that court.
What about resale. Sounds like wait and see problems. Extended
warranties are a must. Could be like the 08 250 diesel had. No
resale since motor was so problems prone. New body, new
motor and all the other stuff = gm stay away for first models
11-03-2012, 02:12 PM
#52
Melting Slicks
While I'm not an expert head porter, I have spent numerous hours holding a die grinder in my hand. I too attened SEMA and don't think much of what I saw on the Gen5 LT1 display. There are numerous intrusions into the intake port, it has a bunch of "twist" built into it to induce "swirl" of the dry air entering the combustion chambers of the DI motor. There is no way this port outflows a LS7 port. The exhaust side is even worse! it is long and dosent have a perpendicular exit out of the head, I am wondering if GM did this to transfer heat into the cooling system for quicker temprature rise during a cold start emission test.
Ports remind me of a Diesel motor, accessory packaging of H2O pump and A/C compressor make me think WTF? they are further Starboard than the LS series componenets. This motor will never be a swap candidate like the LS series of motors is.
I am too familiar with the problems of DI motors building up deposits onto the backsides of their intake valves and having those depositis turn into a massive glob of tar. My B7 Audi RS4 lost 35HP in 8000 miles of use because of reduced airflow caused by intake valve depositis. Yes DI will make more power with less fuel but, there are still some unanswered questions on this system. My wife's current ride (besides a C6 Z06) is a Lexus IS250 again there are problems with build-up in the intake system on this DI motor. Same for many VAG DI motors and the GM DI V6.
Time will tell of this platform excells but, unlike the Gen3/4 motors, I don't expect the Hot Rod community to adopt this motor for use in their projects. GM fumbled the ball in that court.
Ports remind me of a Diesel motor, accessory packaging of H2O pump and A/C compressor make me think WTF? they are further Starboard than the LS series componenets. This motor will never be a swap candidate like the LS series of motors is.
I am too familiar with the problems of DI motors building up deposits onto the backsides of their intake valves and having those depositis turn into a massive glob of tar. My B7 Audi RS4 lost 35HP in 8000 miles of use because of reduced airflow caused by intake valve depositis. Yes DI will make more power with less fuel but, there are still some unanswered questions on this system. My wife's current ride (besides a C6 Z06) is a Lexus IS250 again there are problems with build-up in the intake system on this DI motor. Same for many VAG DI motors and the GM DI V6.
Time will tell of this platform excells but, unlike the Gen3/4 motors, I don't expect the Hot Rod community to adopt this motor for use in their projects. GM fumbled the ball in that court.
11-03-2012, 05:38 PM
#53
Le Mans Master
I also saw the LT1 and spoke to a few GM reps/engineers who also stated that the new C7 platform will need to compete with the GTRs,Vipers and Mustang Shelbys. Good to know they are looking at all the competition as I see the new GTR has yet again upgraded. they do seem to move forward each and every year since inception which is way cool that they stay ahead of the game hopefully the new C7 will also be very pro active and continue to push the envelope.I will be ready for a new performance ride in the next 12 to 18 months,I want some real power and 450 is not enough. if GM wants my money they better have something with 550 or more hp.I spoke to several Vette guys at the Show and the majority also seemed disappointed with the hp#s of the new C7? just saying???
11-03-2012, 07:58 PM
#54
Team Owner
I also saw the LT1 and spoke to a few GM reps/engineers who also stated that the new C7 platform will need to compete with the GTRs,Vipers and Mustang Shelbys. Good to know they are looking at all the competition as I see the new GTR has yet again upgraded. they do seem to move forward each and every year since inception which is way cool that they stay ahead of the game hopefully the new C7 will also be very pro active and continue to push the envelope.I will be ready for a new performance ride in the next 12 to 18 months,I want some real power and 450 is not enough. if GM wants my money they better have something with 550 or more hp.I spoke to several Vette guys at the Show and the majority also seemed disappointed with the hp#s of the new C7? just saying???
11-04-2012, 06:36 PM
#55
Le Mans Master
The DI build up question is answered by Tadge Juechter here: http://wot.motortrend.com/qa-with-co...280789.html/0/
On the other hand most high performance gasoline racing motors have high duration overlap events. The Gen5 motor will be a tough nut to crack for the cam companies. I wouldn't plan on modding my C7 Vette. Lousy motor for a retrofit too due to the accessories and their mounting points on the Gen5.
Last edited by Solid LT1; 11-05-2012 at 01:10 PM.
11-04-2012, 07:22 PM
#56
Melting Slicks
Tadge is DEAD WRONG in the statement that intake valve deposits are caused by oil deposits only. The deposits happen on motors with high valve overlap timing events like the Audi R8/RS4 motor because of fuel mixture entering the intake tract from reversion events and because the head of the intake valve is running much hotter than a port fuel injected motor, components of the gasoline mixture remain on the head when the fuel boils off the metal valve face. Now that being said, the GM Gen4 motors had very little valve overlap timing in them and I expect the Gen5 will again have no overlap timing.
On the otherhand most high performance gasoline racing motors have high duration overlap events. The Gen5 motor will be a tough nut to crack for the came companies. I wouldn't plan on modding my C7 Vette. Lousy motor for a retrofit too due to the accessories and their mounting points on the Gen5.
On the otherhand most high performance gasoline racing motors have high duration overlap events. The Gen5 motor will be a tough nut to crack for the came companies. I wouldn't plan on modding my C7 Vette. Lousy motor for a retrofit too due to the accessories and their mounting points on the Gen5.
Read more: http://wot.motortrend.com/qa-with-co...#ixzz2BIpDbb7V
11-04-2012, 07:41 PM
#57
Race Director
I also saw the LT1 and spoke to a few GM reps/engineers who also stated that the new C7 platform will need to compete with the GTRs,Vipers and Mustang Shelbys. Good to know they are looking at all the competition as I see the new GTR has yet again upgraded. they do seem to move forward each and every year since inception which is way cool that they stay ahead of the game hopefully the new C7 will also be very pro active and continue to push the envelope.I will be ready for a new performance ride in the next 12 to 18 months,I want some real power and 450 is not enough. if GM wants my money they better have something with 550 or more hp.I spoke to several Vette guys at the Show and the majority also seemed disappointed with the hp#s of the new C7? just saying???
11-05-2012, 10:56 AM
#58
Regardless of what they tell you at the show we have seen renderings that are obviously from a GM computer of an LT1 with a supercharger installed on it.
Greatly appreciate the information you are posting, envious of your time at the show.
Greatly appreciate the information you are posting, envious of your time at the show.