A&A Si trim SC - pulley options and lbs of boost?
#1
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A&A Si trim SC - pulley options and lbs of boost?
I have an A&A Si trim with a 3.8" pulley that I am getting tuned for on Saturday. As I understand it the 3.8" pulley offers just under 9psi of boost. Can the Si trim handle a smaller pulley and if so, how much boost will it produce?
Backstory: my mod list (the ones that matter) include long tube ARH headers, NPP exhaust, weaponX ported throttle body, 170* T-Stat, and alky control meth injection (spraying 100%). I have a stock block and am looking for 700RWHP. From what I read, I may only get about 600-650 with this setup. So I'm looking at what I can do to fill the gap.
Chime in please. Dyno sheets welcome as long as they are specifically for A&A Si trim and NO internal mods such as a cam.
Ant
Backstory: my mod list (the ones that matter) include long tube ARH headers, NPP exhaust, weaponX ported throttle body, 170* T-Stat, and alky control meth injection (spraying 100%). I have a stock block and am looking for 700RWHP. From what I read, I may only get about 600-650 with this setup. So I'm looking at what I can do to fill the gap.
Chime in please. Dyno sheets welcome as long as they are specifically for A&A Si trim and NO internal mods such as a cam.
Ant
Last edited by FYREANT; 09-13-2015 at 06:09 PM.
#2
Ant, my belief is that your current combo will net you around 630 - 640 RWHP SAE 5 on a normally calibrated dyno-jet. For you to approach near 700 RWHP SAE 5, I believe that you will need at least a moderate to aggressive cam in the mix, at the minimum. C7BB has a similar set-up with the addition of a cam, and got 697'ish RWHP, however, those numbers were STD, versus SAE.
If you want to comfortably approach 700 RWHP SAE, you may want to upgrade to a V3 TI head unit, and select a pulley size that will NET you around 12 - 13 pounds of boost. However, It is my belief that even with METH, that is too much boost for a stock non-forged bottom end. OR. you can just cam the engine, and see what you get as-is...
If you want to comfortably approach 700 RWHP SAE, you may want to upgrade to a V3 TI head unit, and select a pulley size that will NET you around 12 - 13 pounds of boost. However, It is my belief that even with METH, that is too much boost for a stock non-forged bottom end. OR. you can just cam the engine, and see what you get as-is...
#3
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Ant, my belief is that your current combo will net you around 630 - 640 RWHP SAE 5 on a normally calibrated dyno-jet. For you to approach near 700 RWHP SAE 5, I believe that you will need at least a moderate to aggressive cam in the mix, at the minimum. C7BB has a similar set-up with the addition of a cam, and got 697'ish RWHP, however, those numbers were STD, versus SAE.
If you want to comfortably approach 700 RWHP SAE, you may want to upgrade to a V3 TI head unit, and select a pulley size that will NET you around 12 - 13 pounds of boost. However, It is my belief that even with METH, that is too much boost for a stock non-forged bottom end. OR. you can just cam the engine, and see what you get as-is...
If you want to comfortably approach 700 RWHP SAE, you may want to upgrade to a V3 TI head unit, and select a pulley size that will NET you around 12 - 13 pounds of boost. However, It is my belief that even with METH, that is too much boost for a stock non-forged bottom end. OR. you can just cam the engine, and see what you get as-is...
#4
Team Owner
Your going to need a 3.4 pulley to get to near 700!
I think ECS use's even a 3.25.
I think ECS use's even a 3.25.
#5
ANT, ECS uses the SL 1500 head unit as standard, which is equivalent to the Vortech V3 TI head unit, versus the SI. Furthermore, the ones that reached 700 RWHP SAE 5 on a DYNOJET, are usually running around 12 to 13 pounds of boost, from the dynos/threads/posts that I have seen.
#6
Look at post 13. These are realistic numbers, and this is with the SL 1500 head unit without the restrictor plate, with a pulley size that will generate about 10 pounds of boost.
https://www.corvetteforum.com/forums...post1590451081
https://www.corvetteforum.com/forums...post1590451081
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#7
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ANT, ECS uses the SL 1500 head unit as standard, which is equivalent to the Vortech V3 TI head unit, versus the SI. Furthermore, the ones that reached 700 RWHP SAE 5 on a DYNOJET, are usually running around 12 to 13 pounds of boost, from the dynos/threads/posts that I have seen.
Look at post 13. These are realistic numbers, and this is with the SL 1500 head unit without the restrictor plate, with a pulley size that will generate about 10 pounds of boost.
https://www.corvetteforum.com/forums...post1590451081
https://www.corvetteforum.com/forums...post1590451081
#9
ok that's a pretty good example there. So, the A&A has a 3.8 pulley that came with it (they are shipping with 4.0's now). The 3.8 supposedly generates about 8-9lbs. What is the smallest size that the Si trim can safely accept? will the 3.4 work? I don't want to run 12-13#. That's too much on stock block for sure. I should be able to do 10ish though without issue. Dangerous territory appears to be above 750RWHP from all the threads I read in the past.
#10
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Remember that you do not want to spin the SI beyond its efficiency range. Perhaps a 3.6 inch pulley along with a cam and all of your other previously mentioned mods. will get you to 700 RWHP SAE on a dynojet. I believe that the SI head unit will run out of breath beyond that range.
Ant
#11
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I have a 3.8 pulley on my A&A Si trim. I called and spoke to Josh/Andy at A&A and was told the smallest pulley I could run was 3.46 before it would spin the head unit over the 55k rpm limit. After speaking with Joe@CPR, he convinced me that trying to get anywhere close to 650- 700 rwhp with headers and meth would need the Ti trim head unit. I decided that was the way to go and had him install a fuel pump lash cap as well so I wouldnt have to rely on the meth as much.
It should be going in for the dyno tune later today. I will post results once I hear from Joe.
edit - baseline dyno with the Si and 3.8" pulley and stock exhaust was getting 8psi boost, mind you this is in Phoenix desert air at 110 degrees.
It should be going in for the dyno tune later today. I will post results once I hear from Joe.
edit - baseline dyno with the Si and 3.8" pulley and stock exhaust was getting 8psi boost, mind you this is in Phoenix desert air at 110 degrees.
Last edited by DoubleDown; 09-14-2015 at 07:44 AM.
#13
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All said and done, the car made 625 rwhp and 548 tq with the 3.47 pulley at 9psi.
When Joe@CPR first got the car with the Si trim, it made 487 rwhp with 3.8" pulley at 8psi. Installing the ARH lt headers, methanol and Ti head unit with the same 3.8" pulley it made 7psi and 553 rwhp. Dropping down to the 3.47" pulley finally got it up to 9psi boost and 625/548 while keeping the knock sensors turned on and only 9 degrees of timing.
Video:
When Joe@CPR first got the car with the Si trim, it made 487 rwhp with 3.8" pulley at 8psi. Installing the ARH lt headers, methanol and Ti head unit with the same 3.8" pulley it made 7psi and 553 rwhp. Dropping down to the 3.47" pulley finally got it up to 9psi boost and 625/548 while keeping the knock sensors turned on and only 9 degrees of timing.
Video:
Facebook Post
Last edited by DoubleDown; 09-21-2015 at 03:24 PM.
#14
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All said and done, the car made 625 rwhp and 548 tq with the 3.47 pulley at 9psi.
When Joe@CPR first got the car with the Si trim, it made 487 rwhp with 3.8" pulley at 8psi. Installing the ARH lt headers, methanol and Ti head unit with the same 3.8" pulley it made 7psi and 553 rwhp. Dropping down to the 3.47" pulley finally got it up to 9psi boost and 625/548 while keeping the knock sensors turned on and only 9 degrees of timing.
Video:
https://www.facebook.com/Cordesperfo...9825372489157/
When Joe@CPR first got the car with the Si trim, it made 487 rwhp with 3.8" pulley at 8psi. Installing the ARH lt headers, methanol and Ti head unit with the same 3.8" pulley it made 7psi and 553 rwhp. Dropping down to the 3.47" pulley finally got it up to 9psi boost and 625/548 while keeping the knock sensors turned on and only 9 degrees of timing.
Video:
https://www.facebook.com/Cordesperfo...9825372489157/
#15
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Yes, the Ti only made 7psi with the 3.8" pulley and LT headers installed. Remember that I am in the desert. Car is being tuned in Phoenix AZ at 100 degrees. In cooler weather, with the 3.47", I am hoping it will make 10psi.
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I have an A&A Si trim with a 3.8" pulley that I am getting tuned for on Saturday. As I understand it the 3.8" pulley offers just under 9psi of boost. Can the Si trim handle a smaller pulley and if so, how much boost will it produce?
Backstory: my mod list (the ones that matter) include long tube ARH headers, NPP exhaust, weaponX ported throttle body, 170* T-Stat, and alky control meth injection (spraying 100%). I have a stock block and am looking for 700RWHP. From what I read, I may only get about 600-650 with this setup. So I'm looking at what I can do to fill the gap.
Chime in please. Dyno sheets welcome as long as they are specifically for A&A Si trim and NO internal mods such as a cam.
Ant
Backstory: my mod list (the ones that matter) include long tube ARH headers, NPP exhaust, weaponX ported throttle body, 170* T-Stat, and alky control meth injection (spraying 100%). I have a stock block and am looking for 700RWHP. From what I read, I may only get about 600-650 with this setup. So I'm looking at what I can do to fill the gap.
Chime in please. Dyno sheets welcome as long as they are specifically for A&A Si trim and NO internal mods such as a cam.
Ant
#17
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I called A&A this afternoon and confirmed with Josh that the V3 Si can be spun up with the 3.47 pulley without issue. For each .2 you go down you gain an additional 2PSI. I hit about 8PSI on my 3.8 pulley when I got tuned. Mocing down to a 3.6 i should hit around 10PSI and with the 3.47 should hit about 11 PSI. I going to talk tk my tuner to see if it is safe to do the 3.47 pulley and just crank the meth up from a gain of 6 to 8. Thoughts..?
#18
Instructor
I called A&A this afternoon and confirmed with Josh that the V3 Si can be spun up with the 3.47 pulley without issue. For each .2 you go down you gain an additional 2PSI. I hit about 8PSI on my 3.8 pulley when I got tuned. Mocing down to a 3.6 i should hit around 10PSI and with the 3.47 should hit about 11 PSI. I going to talk tk my tuner to see if it is safe to do the 3.47 pulley and just crank the meth up from a gain of 6 to 8. Thoughts..?
#20
Instructor
I definitely recommend the 3.47" pulley. I am not sure how high my gain is set on the ALKY kit, as it was done by my tuner. If you had to, you could change the nozzle or add a 2nd nozzle to get enough meth.