need help picking intake between FAST
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Exhausting. It just seems that the 4" TB would let in a bit much air at part throttle for a 346. And yes, I've read the technology behind the FAST designed 102 TB. Will we ever be able to effectively use this much air? (but then again, look at the #'s for the 102 and 243 combo) It just seems like a 4" throat will just essentially be an on/off switch. My car is not a track car, and is designed for streetability with an underestimated cam. I've read reviews from LS3 guys who purchased a 102 and didn't see any gains.
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^ Read through this thread again if you haven't already. Mamo explained the 102 and 92 pretty throughly here. (not trying to be an ***, but it sounds like you didn't read or just skimmed.)
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I wanted the 92, everyone here raved about it so I was sold on the 102, but the local tuner was saying that they're no good, I change my mind and I find this... Uuuugh... (He's on here, but not often)
Exhausting. It just seems that the 4" TB would let in a bit much air at part throttle for a 346. And yes, I've read the technology behind the FAST designed 102 TB. Will we ever be able to effectively use this much air? (but then again, look at the #'s for the 102 and 243 combo) It just seems like a 4" throat will just essentially be an on/off switch. My car is not a track car, and is designed for streetability with an underestimated cam. I've read reviews from LS3 guys who purchased a 102 and didn't see any gains.
Exhausting. It just seems that the 4" TB would let in a bit much air at part throttle for a 346. And yes, I've read the technology behind the FAST designed 102 TB. Will we ever be able to effectively use this much air? (but then again, look at the #'s for the 102 and 243 combo) It just seems like a 4" throat will just essentially be an on/off switch. My car is not a track car, and is designed for streetability with an underestimated cam. I've read reviews from LS3 guys who purchased a 102 and didn't see any gains.
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once again by porting and playing with the runners you can get the intake to act in diff ways. just talk to the right people and they are always more then happy to share there info and help. I will be using a 102 and will be playing with porting and the runners by shorting them up for better power and to hold and make more h/p up top maybe even Advance my cam if it likes the changes i do. we will see.
#49
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something to make the lid not be the restriction any more when I go to a 102mm...hopefully worth a few hp
http://www.yellowbullet.com/forum/sh...1&postcount=16
#50
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I wanted the 92, everyone here raved about it so I was sold on the 102, but the local tuner was saying that they're no good, I change my mind and I find this... Uuuugh... (He's on here, but not often)
Exhausting. It just seems that the 4" TB would let in a bit much air at part throttle for a 346. And yes, I've read the technology behind the FAST designed 102 TB. Will we ever be able to effectively use this much air? (but then again, look at the #'s for the 102 and 243 combo) It just seems like a 4" throat will just essentially be an on/off switch. My car is not a track car, and is designed for streetability with an underestimated cam. I've read reviews from LS3 guys who purchased a 102 and didn't see any gains.
Exhausting. It just seems that the 4" TB would let in a bit much air at part throttle for a 346. And yes, I've read the technology behind the FAST designed 102 TB. Will we ever be able to effectively use this much air? (but then again, look at the #'s for the 102 and 243 combo) It just seems like a 4" throat will just essentially be an on/off switch. My car is not a track car, and is designed for streetability with an underestimated cam. I've read reviews from LS3 guys who purchased a 102 and didn't see any gains.
just takes a little searching...and this is a bolt on only car and the fast 102 is not ported at all vs a stg 2 ported ls3
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https://ls1tech.com/forums/dynamomet...t-6-0l-g8.html
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it doesn't really work like that...reread what Tony posted...he explains that the Tb size does minimal compared to the runners...
something to make the lid not be the restriction any more when I go to a 102mm...hopefully worth a few hp
http://www.yellowbullet.com/forum/sh...1&postcount=16
something to make the lid not be the restriction any more when I go to a 102mm...hopefully worth a few hp
http://www.yellowbullet.com/forum/sh...1&postcount=16
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My heads won't flow past 280cfm, I think. But the ported 102 will. Is that correct?
#53
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Guys,
I think this may be a helpful post in here....I just copied and pasted this from another thread but alot of it may be helpful for the folks reading this thread as well pertaining to the 102 and intake manifold theory and misconceptions.
I think this may be a helpful post in here....I just copied and pasted this from another thread but alot of it may be helpful for the folks reading this thread as well pertaining to the 102 and intake manifold theory and misconceptions.
Guys...
When we are discussing fuel injected applications.....the size of the plenum and the opening or the TB (size) will have zero effect on "low end" power.
This is old school thinking stemming from the very real and often practiced applications where too large a carb might have been bolted on a particular engine combination.
The problem stemming from the fact the large carb slowed the airspeed down enough in the venturi's of the main body to negatively effect the carb atomization and therefore hurt power, torque, fuel economy, and responsiveness until enough RPM was generated to allow the carb to become more effective again (guys older than 45 will be nodding their heads up and down right now while reading this!).
We aren't atomizing fuel here folks....thats handled by the injectors and the real meat and potatoes of manifold design (runner length, shape, and taper) hasn't changed much from the 90, 92 or 102.....its very similar but the 102 does have a superior shaped runner (although the length is very similar), is slightly taller, and ultimately flows more, especially when properly ported.
Yes....a FAST 102 can flow more than a 280 CFM head but thats always the case with a really good intake....ideally you want ALOT of headroom when selecting a manifold so when you bolt it in front of your heads it flows more net to the cylinder with the ultimate situation to not hurt the port any more than placing a radius plate in front of it. Thats pure theory unless we are discussing extremely optimized straight shot tunnel ram style manifolds.
I can port a Gen I single plane intake and make it flow 400 CFM.....when you place it in front of a 300 CFM intake port that port still loses 20 CFM which is very good all thing considered. Take the same intake unported by me that still flows way more out of the box than the 300 CFM intake port in question (say the intake flows 360 CFM out of the box) and now you may only see 265 CFM when placed in front of the head because it hurt the net flow more.
INTERNET MYTH #1 .....My 102 Fast is too big for my 346
Wrong....its a better designed intake thats going to allow more air to pass thru the intake ports and be mixed with more precisely atomized fuel from your injectors.
INTERNET MYTH #2....Its already big....you dont need to port it (or it might hurt the bottom end).
Also wrong....at least when ported properly. Once again it simply makes a good piece even better but I would be the first to admit that on a marginal set of head the gains from the work would be less as well. The better the heads, the more aggressive the RPM, displacement, etc. the more that ported 102 is going to pay you in spades.
The larger the restriction the intake manifold becomes....the better your results will be when you swap to the better intake.
If your still questioning anything lets get it handled now and please refer other people back to the answers when we see the same questions and bad information in other threads....I wish I had a nickel for the guys convinced their inaccurate theories are accurate....LOL
The ONLY potential negative to the 102 design...well besides the cost of admission with the rails etc.....is the TB (airblade) is so large it can create drivability challanges with the tune but its a much easier deal on a cable operated 102 with an IAC motor. ALso, it tends to be extremely responsive which I personally like, however some have complained its too responsive (on/off) and they have to get used to driving it. No big deal in my book....
Hope this helps!
-Tony
When we are discussing fuel injected applications.....the size of the plenum and the opening or the TB (size) will have zero effect on "low end" power.
This is old school thinking stemming from the very real and often practiced applications where too large a carb might have been bolted on a particular engine combination.
The problem stemming from the fact the large carb slowed the airspeed down enough in the venturi's of the main body to negatively effect the carb atomization and therefore hurt power, torque, fuel economy, and responsiveness until enough RPM was generated to allow the carb to become more effective again (guys older than 45 will be nodding their heads up and down right now while reading this!).
We aren't atomizing fuel here folks....thats handled by the injectors and the real meat and potatoes of manifold design (runner length, shape, and taper) hasn't changed much from the 90, 92 or 102.....its very similar but the 102 does have a superior shaped runner (although the length is very similar), is slightly taller, and ultimately flows more, especially when properly ported.
Yes....a FAST 102 can flow more than a 280 CFM head but thats always the case with a really good intake....ideally you want ALOT of headroom when selecting a manifold so when you bolt it in front of your heads it flows more net to the cylinder with the ultimate situation to not hurt the port any more than placing a radius plate in front of it. Thats pure theory unless we are discussing extremely optimized straight shot tunnel ram style manifolds.
I can port a Gen I single plane intake and make it flow 400 CFM.....when you place it in front of a 300 CFM intake port that port still loses 20 CFM which is very good all thing considered. Take the same intake unported by me that still flows way more out of the box than the 300 CFM intake port in question (say the intake flows 360 CFM out of the box) and now you may only see 265 CFM when placed in front of the head because it hurt the net flow more.
INTERNET MYTH #1 .....My 102 Fast is too big for my 346
Wrong....its a better designed intake thats going to allow more air to pass thru the intake ports and be mixed with more precisely atomized fuel from your injectors.
INTERNET MYTH #2....Its already big....you dont need to port it (or it might hurt the bottom end).
Also wrong....at least when ported properly. Once again it simply makes a good piece even better but I would be the first to admit that on a marginal set of head the gains from the work would be less as well. The better the heads, the more aggressive the RPM, displacement, etc. the more that ported 102 is going to pay you in spades.
The larger the restriction the intake manifold becomes....the better your results will be when you swap to the better intake.
If your still questioning anything lets get it handled now and please refer other people back to the answers when we see the same questions and bad information in other threads....I wish I had a nickel for the guys convinced their inaccurate theories are accurate....LOL
The ONLY potential negative to the 102 design...well besides the cost of admission with the rails etc.....is the TB (airblade) is so large it can create drivability challanges with the tune but its a much easier deal on a cable operated 102 with an IAC motor. ALso, it tends to be extremely responsive which I personally like, however some have complained its too responsive (on/off) and they have to get used to driving it. No big deal in my book....
Hope this helps!
-Tony
#54
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Interesting reading. I'm stuck on the fence to either buy a Fast 92 and have it ported or a ported 102 and run it w/ my NW 92mm TB. What would my gains be with the ported 102 with my 228r cam and stock unported 241 heads?
#55
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it always boils down to dollars/hp and how much you want to push that ratio
#57
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My numbers I state are proven by me or what I have seen on numerous cars...I am not some sales guy answering the phone trying to sell parts...I have no horse in this race...
#58
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Responses like yours is why ls1tech has become what it is...you **** off all the people that give good advise...
My numbers I state are proven by me or what I have seen on numerous cars...I am not some sales guy answering the phone trying to sell parts...I have no horse in this race...
My numbers I state are proven by me or what I have seen on numerous cars...I am not some sales guy answering the phone trying to sell parts...I have no horse in this race...
#59
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I see where you were going with your comment Turk. Whomever quoted those numbers to you should be removed from his or her job. So far fetched with your current set up on factory 241 heads.
#60
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sometimes I read too fast
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quoted before the ninja edit...I came off a little harsh, just thought this was going to be like the rest of the threads where a question is asked and then a good answer is given but the person reading doesn't like the facts and states what he heard from his brother sister cousin friend said it should be...just leaves little motivation to help or answer questions anymore...
I just see this being more and more prominent
Last edited by chrs1313; 02-09-2011 at 03:15 PM.