[ZR1] Eaton TVS R2300 compressor map
02-23-2009, 01:17 PM
#1
Premium Supporting Vendor
Thread Starter
Eaton TVS R2300 compressor map
Behold...
I could not find this so our friends at Magnuson hooked us up. I was curious to see if the speculation that the LS9's supercharger was out of it's efficiency range at 18psi. By our calculations, this is not the case. At 7000rpm, the supercharger loses 6% efficiency going from 10.5psi to 18psi. In my opinion, 6% is not a huge drop.
The debate came up due to a ZR1 that made 700rwhp and these numbers seemed low. I think another contributing factor is that on the chassis dyno, these cars must be seeing tremendous heat soak in the intercoolers. I would be curious to see what the intake charge temperatures are in these conditions.
I could not find this so our friends at Magnuson hooked us up. I was curious to see if the speculation that the LS9's supercharger was out of it's efficiency range at 18psi. By our calculations, this is not the case. At 7000rpm, the supercharger loses 6% efficiency going from 10.5psi to 18psi. In my opinion, 6% is not a huge drop.
The debate came up due to a ZR1 that made 700rwhp and these numbers seemed low. I think another contributing factor is that on the chassis dyno, these cars must be seeing tremendous heat soak in the intercoolers. I would be curious to see what the intake charge temperatures are in these conditions.
02-23-2009, 01:30 PM
#2
Premium Supporting Vendor
Thread Starter
Speaking of intercooling, the delta temperature going from 13,000rpm (10.5psi relative pressure) to 16,000rpm (18psi relative pressure) takes you from 90 degrees F, to 220 degrees F. If you're adding 130 degrees to the intake charge without increasing intercooling capacity there is your power loss.
02-23-2009, 02:00 PM
#3
Supporting Vendor
Member Since: Nov 2005
Location: Supporting the Corvette Community at Abel Chevrolet in Rio Vista, CA 707-374-6317 Ext.123
Posts: 14,498
Received 1,425 Likes
on
597 Posts
St. Jude Donor '08
Behold...
I could not find this so our friends at Magnuson hooked us up. I was curious to see if the speculation that the LS9's supercharger was out of it's efficiency range at 18psi. By our calculations, this is not the case. At 7000rpm, the supercharger loses 6% efficiency going from 10.5psi to 18psi. In my opinion, 6% is not a huge drop.
The debate came up due to a ZR1 that made 700rwhp and these numbers seemed low. I think another contributing factor is that on the chassis dyno, these cars must be seeing tremendous heat soak in the intercoolers. I would be curious to see what the intake charge temperatures are in these conditions.
I could not find this so our friends at Magnuson hooked us up. I was curious to see if the speculation that the LS9's supercharger was out of it's efficiency range at 18psi. By our calculations, this is not the case. At 7000rpm, the supercharger loses 6% efficiency going from 10.5psi to 18psi. In my opinion, 6% is not a huge drop.
The debate came up due to a ZR1 that made 700rwhp and these numbers seemed low. I think another contributing factor is that on the chassis dyno, these cars must be seeing tremendous heat soak in the intercoolers. I would be curious to see what the intake charge temperatures are in these conditions.
Speaking of intercooling, the delta temperature going from 13,000rpm (10.5psi relative pressure) to 16,000rpm (18psi relative pressure) takes you from 90 degrees F, to 220 degrees F. If you're adding 130 degrees to the intake charge without increasing intercooling capacity there is your power loss.
I guess the guys will have to find another reason to beat the owner of that car up, now that 18PSI is not considered a drastic reduction in efficiency.... 
02-23-2009, 02:44 PM
#5
Full size member
You are very correct about the heat soak. We would lose 50hp after heat soak on my ZR1.
02-23-2009, 03:31 PM
#6
Burning Brakes
Jason, can you repost that picture with a line drawn over it to represent the stock operating conditions and a line to represent the modified operating conditions? This will make it much more obvious to those not used to reading compressor maps.
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
02-23-2009, 03:43 PM
#7
Burning Brakes
10.5 psi = 1.7 PR
18 psi = 2.2 PR
If you follow the immaginary 13,000 RPM line up to an intersection with the immaginary 1.7 PR line you get about 65% efficiency, and if you follow the 16,000 RPM line up to the immaginary 2.2 PR line you get about 61% efficiency. This tells me the drop is more like 4%.
Did I do this wrong?
02-23-2009, 04:57 PM
#8
Premium Supporting Vendor
Thread Starter
Jason, can you repost that picture with a line drawn over it to represent the stock operating conditions and a line to represent the modified operating conditions? This will make it much more obvious to those not used to reading compressor maps.
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
Here is the an estimation. I made sure to not that on the image before this gets quoted all over the internet.
Unfortunately the pressure map does not go over a 2.4 pressure ratio so the 18psi dot is off the scale. For those who will ask why 18psi is not 2.2 pressure ratio like it should be, we estimated a pressure drop over the intercoolers since Eaton is measuring the compressor discharge pressure and the car is measuring manifold pressure after the intercoolers (I think).
I think LS9 head ports are the same as LS3. I'll go check.
02-23-2009, 05:01 PM
#9
Premium Supporting Vendor
Thread Starter
One more thing, how are you seeing a 6% drop? I did the following:
10.5 psi = 1.7 PR
18 psi = 2.2 PR
If you follow the immaginary 13,000 RPM line up to an intersection with the immaginary 1.7 PR line you get about 65% efficiency, and if you follow the 16,000 RPM line up to the immaginary 2.2 PR line you get about 61% efficiency. This tells me the drop is more like 4%.
Did I do this wrong?
10.5 psi = 1.7 PR
18 psi = 2.2 PR
If you follow the immaginary 13,000 RPM line up to an intersection with the immaginary 1.7 PR line you get about 65% efficiency, and if you follow the 16,000 RPM line up to the immaginary 2.2 PR line you get about 61% efficiency. This tells me the drop is more like 4%.
Did I do this wrong?
I think my most recent post answers this. In short, we estimated a greater pressure drop over the intercoolers at a higher boost level. When you do it this way you get 65%-59%=6%. These are just estimations. We don't know the actual.
02-23-2009, 05:12 PM
#11
Premium Supporting Vendor
Thread Starter
Jason, can you repost that picture with a line drawn over it to represent the stock operating conditions and a line to represent the modified operating conditions? This will make it much more obvious to those not used to reading compressor maps.
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
02-23-2009, 05:47 PM
#12
So the ZR1 will need a larger heat exchanger if the boost is turned up?
02-23-2009, 06:03 PM
#13
Burning Brakes
Hmm... it would be interesting to flow a set of LS9 heads to see what GM's interpretation really means in practice. A stock LS6 with headers will make similar peak power with only ~7 psi from a centrifugal. Better intercooling might make up part of the centrifugal's advantage, but I'd be suprised if it was all in the intercooling since the LS6 has smaller intake ports and is a smaller motor by a half liter.
02-23-2009, 06:10 PM
#15
Premium Supporting Vendor
Thread Starter
02-23-2009, 07:09 PM
#16
they flow 314 cfm and they will flow more. but they are not the reason for higher iat's when running more boost.
Jason, can you repost that picture with a line drawn over it to represent the stock operating conditions and a line to represent the modified operating conditions? This will make it much more obvious to those not used to reading compressor maps.
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
IMO, the ZR1 heads are likely a restriction. They have a huge swirl producing feature in the intake port that will surely improve emissions through better fuel mixture but will almost surely kill their power production potential as well. Stick a good CNC program through that intake port and I bet that 18 psi of manifold pressure will drop pretty quick.
Likewise with the stock motor at 10.5 psi, I was a little shocked to see "only" 638 hp out of a motor of this size with that much positive manifold pressure...
Has anyone flow-benched the stock ZR1 heads yet? Since the cam in the car in question was changed it leaves only the heads as suspect IMO.
What style of intake port was used on the ZR1 head? Will other GM heads swap in?
02-23-2009, 08:23 PM
#17
Burning Brakes
Member Since: Jul 2006
Location: MD (or Ft Benning GA)
Posts: 1,027
Likes: 0
Received 1 Like
on
1 Post
Speaking of intercooling, the delta temperature going from 13,000rpm (10.5psi relative pressure) to 16,000rpm (18psi relative pressure) takes you from 90 degrees F, to 220 degrees F. If you're adding 130 degrees to the intake charge without increasing intercooling capacity there is your power loss.
check out this link for more info http://www.enginelogics.com/cmaps.html
Last edited by GForceSS; 02-23-2009 at 09:48 PM.
02-23-2009, 10:53 PM
#18
Melting Slicks
Member Since: Feb 2006
Location: LAS VEGAS NV
Posts: 3,007
Likes: 0
Received 111 Likes
on
56 Posts
St. Jude Donor '08
so, you are saying the weak link is the intercoolers?
that could be a possiblity.. i also think the car might make more power on real driving experience as you are getting fresh air...
the only thing the kind of makes me think it might not be the cooling is b.c the guy who made 700.. let the car cool off with a bag of ice and it still did not help...now i do not know how long or how cold the engine got.. but it should have had one 800rwhp pull.. from dead start?
that could be a possiblity.. i also think the car might make more power on real driving experience as you are getting fresh air...
the only thing the kind of makes me think it might not be the cooling is b.c the guy who made 700.. let the car cool off with a bag of ice and it still did not help...now i do not know how long or how cold the engine got.. but it should have had one 800rwhp pull.. from dead start?
Last edited by vegasredz062; 03-07-2009 at 07:25 PM.
02-23-2009, 11:04 PM
#19
Premium Supporting Vendor
Thread Starter
so, you are saying the weak link is the intercoolers?
that could be a possiblity.. i also think the car might make more power on real driving experience as you are getting fresh air...
the only thing the kind of makes me think it might not be the cooling is b.c the guy who made 700.. let the car cool off with a bag of ice and it still did not help...now i do not know how long or how cold the engine got.. but it should have had one 800rwhp pull.. from dead start?
that could be a possiblity.. i also think the car might make more power on real driving experience as you are getting fresh air...
the only thing the kind of makes me think it might not be the cooling is b.c the guy who made 700.. let the car cool off with a bag of ice and it still did not help...now i do not know how long or how cold the engine got.. but it should have had one 800rwhp pull.. from dead start?
I would hate to use the word weak link. How about "completely engineered upgrade package."
If you're adding more power you need to get more heat out right?
that could be a possiblity.. i also think the car might make more power on real driving experience as you are getting fresh air...
I personally think the bag of ice does nothing. It might draw some heat away from the top of the intercooler housing, but seriously, how much heat could you really be drawing from the entire system?
02-23-2009, 11:15 PM
#20
Burning Brakes
Member Since: Jul 2006
Location: MD (or Ft Benning GA)
Posts: 1,027
Likes: 0
Received 1 Like
on
1 Post
I would hate to use the word weak link. How about "completely engineered upgrade package." If you're adding more power you need to get more heat out right?
I definitely agree with you.
I personally think the bag of ice does nothing. It might draw some heat away from the top of the intercooler housing, but seriously, how much heat could you really be drawing from the entire system?
If you're adding more power you need to get more heat out right?I definitely agree with you.
I personally think the bag of ice does nothing. It might draw some heat away from the top of the intercooler housing, but seriously, how much heat could you really be drawing from the entire system?
Very good political stance too
