vic Jr versus Standard intake question....
Originally Posted by Patrick G
Most dynos I've seen with a single plane intake on a 346 have been disappointing. Some of it is because the manifold had a restrictive elbow on top, limiting total flow, but a lot of the poor performance comes from running a cam with too late of an intake valve closing point.
All you have to do is think about how you'd tune a 346 with a single plane and a carburetor. You would not run a 114LSA cam in it. It would probably be more like a 106 or a 108LSA cam bringing an earlier IVC and better dynamic compression. Try swapping a 230/234 108LSA, 108ICL cam and see how it does then. Bet you pick up a lot of bottom end (with better valve events) and pick up top-end with better breathing.
All you have to do is think about how you'd tune a 346 with a single plane and a carburetor. You would not run a 114LSA cam in it. It would probably be more like a 106 or a 108LSA cam bringing an earlier IVC and better dynamic compression. Try swapping a 230/234 108LSA, 108ICL cam and see how it does then. Bet you pick up a lot of bottom end (with better valve events) and pick up top-end with better breathing.
Rick
Originally Posted by HALLZ
People say I am nut and think I am crazy when I mention what you just did. A 108 or 106?.... Then they dismiss anything said afterward l(lol) Besides,.... "how will you get it to idle" "you will bleed off to much cylinder pressure on the bottle like that!"
Not to mention who puts old technology on a LS1??
Not to mention who puts old technology on a LS1??
As for porting, we just wanted an out of the box experiment, we felt most will be doing that 90% of the time anyways. Its fun still to fool around with this stuff and learn alittle. Never hurts.
Rick
Hawk,
I under stand the issue with the LSA. I was just repeating the associated comments I usually hear when it's even mention to lower the lsa to 112 or less.
No porting was done or needed on the heads, but the intake was opened up more that most expect for those heads. Not sure why the pic's look like that, but your right it does appear that way in the pic. (not so)
If you search you will find that in this case it was not that different than others had to do. After inking the intake we were shocked to see that in some places you would have to take material away right up to the gasket leaving only about 1/32-1/16th to retain the gasket. I am sure Chris's finish job did not go that far though. I do not have after pic's, He may.
Also what you cant see but may have noticed or you may look at is how you can shift the intake a little forward or backwards and possibility offsetting the sides of the runners even after matching the intake and heads.
I would think a shank ed mounting bolt should be provided with the intake or if you go through the work of matching it maybe set a dowel pin in a head or at the least scribe the head to be 1005 sure its seated right.
Has anyone else noticed or had that issue with the Vic jr intake?
I under stand the issue with the LSA. I was just repeating the associated comments I usually hear when it's even mention to lower the lsa to 112 or less.
No porting was done or needed on the heads, but the intake was opened up more that most expect for those heads. Not sure why the pic's look like that, but your right it does appear that way in the pic. (not so)
If you search you will find that in this case it was not that different than others had to do. After inking the intake we were shocked to see that in some places you would have to take material away right up to the gasket leaving only about 1/32-1/16th to retain the gasket. I am sure Chris's finish job did not go that far though. I do not have after pic's, He may.
Also what you cant see but may have noticed or you may look at is how you can shift the intake a little forward or backwards and possibility offsetting the sides of the runners even after matching the intake and heads.
I would think a shank ed mounting bolt should be provided with the intake or if you go through the work of matching it maybe set a dowel pin in a head or at the least scribe the head to be 1005 sure its seated right.
Has anyone else noticed or had that issue with the Vic jr intake?
Originally Posted by Rick@Synergy
We are using an accufab 4150 1200 cfm TB, so we are not using the elbow. We wanted direct flow. I am sure there is a ton more work to be done to make this setup work better, but we are trying to understand if its justified to hack up the car anymore to realy get another 20-30 on top of what his fast was already doing. What do you think?
Rick
Rick
I personally don't think it would with that cam or the cubes. But it would be great if it somehow did. From my understanding Kevin thought about it also for a small cid motor and decided against it. It was the right choice IMHO.
If the motor does not need the air and can get it from a LS6 or fast what gains can be expected from the Vic, jr?
I know the 105 tb sits pretty close to the cowl but i am sure you had the hood open and there was no obstruction to the intake flow correct? (just throwing things out there. But again, i would be surprised to see much if any gains on the dyno form a mild set up like that, even though it has been reported.
Good luck, keep us posted and experimenting for our benefit!
Originally Posted by ChucksZ06
What size of throttle body were you using? Or was it a carb and if so what was the cfm of the carb?
Rick
I have read that the stock Victor Jr flows around 275cfm.
https://ls1tech.com/forums/showthrea...ast+intake+cfm
https://ls1tech.com/forums/showthrea...ast+intake+cfm
Originally Posted by Patrick G
Stock heads don't flow that much so an LS6 intake doesn't knock down the flow numbers that much more when bolted up. What I mean is stock LS1 heads flow around 230 cfm and the LS6 intake might knock the flow down 10 cfm. A FAST intake is not going to help a lot in this application.
Well-ported heads on the other hand flow more like 300 cfm and the LS6 intake will knock down the flow into the 260 range. A FAST 90/90 will only knock it down to the 280 range. The better the heads, the more the FAST intake works. It's not really cam related. If you'd like to see where I gained 28 rwhp with the addition of a FAST 90/90, click on my signature and look for the dyno sheets.
Well-ported heads on the other hand flow more like 300 cfm and the LS6 intake will knock down the flow into the 260 range. A FAST 90/90 will only knock it down to the 280 range. The better the heads, the more the FAST intake works. It's not really cam related. If you'd like to see where I gained 28 rwhp with the addition of a FAST 90/90, click on my signature and look for the dyno sheets.
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Originally Posted by 93LS1RX7
I see a few folks say this but where did you read it?
Patick G. is on the right idea about valve events.
Richard
Im the "Chris" guy HallZ and Rick are talking about.
You guys really have me thinking about the cam I just put in. I left it in the hands of Brian over at Hi Tech Motorsports and Shaun (93pony). They came out with 242/248 595/610lift 114LSA. This is for a 4.060 bore iron block 3.70 stroke 383ci with a 250+ nitrous shot. Now Im reading that 114 is not a good choice. Is this method of thinking just for N/A or does the nitrous shot change the LSA??
Rick, I have the 225 ETP's and that pic shows the exact opposite of what I had to port on the floor of the intake. It was an 1/8" easy on the floor of each port. Some ports sidewalls were off by quite a bit also, but I didnt want to get close to the gasket grove. Overall I did take quite a bit of material out of the intake and I could have taken more, but got sick and tired of porting. (it sux)
If anyone needs specific pics or anything, I would be happy to post them. I know when I did my reasearch on this intake there werent that many posted up.
BTW, Mike, I finally started it! Ran like **** for maybe a minute and died. lol
You guys really have me thinking about the cam I just put in. I left it in the hands of Brian over at Hi Tech Motorsports and Shaun (93pony). They came out with 242/248 595/610lift 114LSA. This is for a 4.060 bore iron block 3.70 stroke 383ci with a 250+ nitrous shot. Now Im reading that 114 is not a good choice. Is this method of thinking just for N/A or does the nitrous shot change the LSA??
Rick, I have the 225 ETP's and that pic shows the exact opposite of what I had to port on the floor of the intake. It was an 1/8" easy on the floor of each port. Some ports sidewalls were off by quite a bit also, but I didnt want to get close to the gasket grove. Overall I did take quite a bit of material out of the intake and I could have taken more, but got sick and tired of porting. (it sux)
If anyone needs specific pics or anything, I would be happy to post them. I know when I did my reasearch on this intake there werent that many posted up.
BTW, Mike, I finally started it! Ran like **** for maybe a minute and died. lol
That's to bad that the intake is so far off on the ports like that. It seem's fairly mandatory to port these things then.
Chris, unfortunately we are the guinea pigs here and the only way to be certain about the LSA is to run yours and then swap it to see.
At this point, I don't know if it's worth (for me) hacking the Cowl up and loosing a windshield wiper over it for a shot in the dark it being better than the 90/90 setup after I port the Vic jr. and change the cam again. If it truely only flowed 275 cfm, I'm a little dissapointed.
On a side note, the car runs really well with the Vic Jr and Accufab TB. It runs alot smoother than the 90/90 set up does, very impressed.
Dan
Chris, unfortunately we are the guinea pigs here and the only way to be certain about the LSA is to run yours and then swap it to see.
At this point, I don't know if it's worth (for me) hacking the Cowl up and loosing a windshield wiper over it for a shot in the dark it being better than the 90/90 setup after I port the Vic jr. and change the cam again. If it truely only flowed 275 cfm, I'm a little dissapointed.
On a side note, the car runs really well with the Vic Jr and Accufab TB. It runs alot smoother than the 90/90 set up does, very impressed.
Dan
Well it would seem that like I said originally (or inquired about) the intake valve must be opened and closed earlier with these short runner intakes. Now to do that with the cam you have you'd have to advance it quite a bit. When you advance something with such a wide lsa though it will end up opening the exhaust valve very early, possibly hurting the lower half of the power stroke. With an enormous shot of nitrous that may not be a problem, but I wouldn't call what you have an enormous shot. I think the tight lsa's are a byproduct of that fact that to maintain a decent exhaust opening point with an early IVC you'll have to run a tight lsa or just run less duration on the exhaust side. I don't know if these intakes by themselves warrant more overlap or not. Do these intake impact low lift flow more so then that of the lsx intakes hence causing the need for more overlap to take advantage of the "5th cycle"?
did those guys come up with those specs based on the use of the single plain intake?
did those guys come up with those specs based on the use of the single plain intake?
Well in that case I think it would be interesting to just try it first. If it doesn't perform like you want it to then just swap the cams. I wouldn't give up on this intake without atleast trying another cam or two though. Good luck!
! 
Wow..... that's all I can say right now.
First off there are some guys doing things with cams right now that have no concept of overlap and how you get there from here. The intake runner length is going to dictate changes in the camshaft, but by all means low LSA's being old tech makes me laugh, really, really hard.
I love seeing that, just shows how people don't have a open mind enough to really look at what is going on with N2O motors... oh well.
Now on the intake debate... every single plane intake out there needs some work to make them work and flow properly. This is not out of the box stuff. This hobby/sport has made guys LAZY and expect WAY TOO MUCH out of off the shelf parts. Everything needs to be plug and play or the next thing you know it's all over the internet that it's junk. That's crap IMHO. If you want parts that can be made to work with a lot of different pieces at a good price, well then you need to be a little bit more flexable.
As far as the intake design goes.... guys really need to start looking at this much more scientifically. A longer runner LS1 style intake vs. a single plane intake should be used in different situations. Flow can be improved on both setups, but the basic design of cross sectional area, runner length and tapper are what you are basically comparing. The single plane vs. the LS intake is going to work at a higher RPM band, but it's also going to be much narrower as well.
Bret
First off there are some guys doing things with cams right now that have no concept of overlap and how you get there from here. The intake runner length is going to dictate changes in the camshaft, but by all means low LSA's being old tech makes me laugh, really, really hard.
"you will bleed off to much cylinder pressure on the bottle like that!"
Now on the intake debate... every single plane intake out there needs some work to make them work and flow properly. This is not out of the box stuff. This hobby/sport has made guys LAZY and expect WAY TOO MUCH out of off the shelf parts. Everything needs to be plug and play or the next thing you know it's all over the internet that it's junk. That's crap IMHO. If you want parts that can be made to work with a lot of different pieces at a good price, well then you need to be a little bit more flexable.
As far as the intake design goes.... guys really need to start looking at this much more scientifically. A longer runner LS1 style intake vs. a single plane intake should be used in different situations. Flow can be improved on both setups, but the basic design of cross sectional area, runner length and tapper are what you are basically comparing. The single plane vs. the LS intake is going to work at a higher RPM band, but it's also going to be much narrower as well.
Bret
Any kind of negative impact with not having sufficient space around the TB to be sucking in air compared to the 90/90 sucking it in from up front? Just tossing out other things that have me thinking about my decision.