What is the best alternative intake manifold for LTx?
09-10-2010, 08:07 PM
#61
Not sure who I would trust to do injector bosses.
Both engines that lost power were 383"s.
Anybody that thinks there is an intake 80 na hp better than a PROPERLY ported LT1 intake is really gulible. Aint no such animal. You can talk about short runners, etc, all you want but actually make one go down the race track a lot quicker than a correctly prepped factory casting is not that easy. Especially for me since I have to have a bone-stock TB in the original location. I hope I'm not throwing about two grand away on this deal, but I may very well be. I have to know. I'm wired wierd. <G>
I knew that was a Dave Layer intake, I recognize his raised oval ports. I have a set of those heads. About 47 lbs of epoxy. <G> My Hogan manifold was small at the head, you are supposed to do the final match up, on your block.
09-10-2010, 09:57 PM
#62
i'd appreciate the contact info Ed. yea im wondering about the injector bosses...... most EFI conversions ive seen advertised seem like no thought was given to intercept angle, distance from the valve, injector size, etc.
im curious about using a 4500 super vic with a ~1600cfm tb, i hear they're worth about 10 hp over a 4150 manifold. not sure on the difference with a worked 4150 thats seen a bridgeport and alot of plenum/divider work
another thing is the e85 i'm running... i want to run about 200 dry, and thats going to require an 83# injector that will probably need to be higher in the intake tract to better "atomize." it's above my knowledge and experience level, but im not spending 3k on a hogan, wilson, reher, etc manifold for my street/strip bracket motor.
im curious about using a 4500 super vic with a ~1600cfm tb, i hear they're worth about 10 hp over a 4150 manifold. not sure on the difference with a worked 4150 thats seen a bridgeport and alot of plenum/divider work
another thing is the e85 i'm running... i want to run about 200 dry, and thats going to require an 83# injector that will probably need to be higher in the intake tract to better "atomize." it's above my knowledge and experience level, but im not spending 3k on a hogan, wilson, reher, etc manifold for my street/strip bracket motor.
09-11-2010, 01:33 PM
#64
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Ed, You found less HP with the 4 barrel TBs VS Elbows???? Ed, I want to be absolutely clear here so please excuse if I come off kind of ****. Are you saying that with going to the 4 barrel TB there was a 15-20 RWHP loss both times that you have done it.??? And that the loss was the result to a loss of plenum volume. (Which means there is more plenum volume with the elbows) How the big carb spacers have to be to restore the desired plenum volume??
09-11-2010, 01:49 PM
#65
Ed, I want to be absolutely clear here so please excuse if I come off kind of ****. Are you saying that with going to the 4 barrel TB there was a 15-20 RWHP loss both times that you have done it.??? And that the loss was the result to a loss of plenum volume. (Which means there is more plenum volume with the elbows) How the big carb spacers have to be to restore the desired plenum volume??
09-11-2010, 04:10 PM
#66
He may have been talking about on his own car which has to use the TB in the stock location. That would make for quite a bad turn for the air to have to go to make it straight down into a 4bbl type of manifold when the TB is up near the thermostat set real low. He did say a spacer and cutting the cowl might help.
Both cars lost about the same, no improvement in idle, drivability, or anything else. I'm only guessing about the reason. I can not imagine loosing that sharp turn into the manifold hurting anything. I can't think of another reason. Bret mentioned the volume deal before, and I think he is correct.(Surprise, surprise. <BG>)
I always ended up with 2" to 3" worth of spacers under my carbs with my old race cars, nothing unusual there. I'll leave it to the guys running that stuff to test it. Simple math will give you how much spacer it will take.
09-21-2010, 05:17 AM
#67
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Actually that is a Victor EFI... not a Jr. That picture is of MY intake, not sure where you got the photo.
As for the elbow being "garbage" it made well over 1000hp, so while there may be better ones out there, it aint bad.
There is, it is actually rounded & is over 1/2 higher than the mounting flange, it is not a flat plate on the bottom. You can't see it because of the bolt stuck in there that was not tightened.
As for the elbow being "garbage" it made well over 1000hp, so while there may be better ones out there, it aint bad.
There is, it is actually rounded & is over 1/2 higher than the mounting flange, it is not a flat plate on the bottom. You can't see it because of the bolt stuck in there that was not tightened.
lol
03-11-2011, 06:31 PM
#68
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Thread resurrection......LOL
Instead of the usual elbows, what about a box type plenum that actually fits lower than the cowling, but also increases plenum volume? My paint drawing below is crude, but I included the original pic to give you an idea of what I changed. Ya'll can comment on my idea AND laugh at my photoshop skills.......NOW. LOL
Instead of the usual elbows, what about a box type plenum that actually fits lower than the cowling, but also increases plenum volume? My paint drawing below is crude, but I included the original pic to give you an idea of what I changed. Ya'll can comment on my idea AND laugh at my photoshop skills.......NOW. LOL
03-11-2011, 06:34 PM
#69
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Also, what about having the side of the plenum box/elbow rounded out on each side instead of just being flat/vertical as much as the fuel rails would allow. It looks like they are below it in the pic I attached anyway. Wouldn't that aid flow as well as add volume?
03-11-2011, 07:01 PM
#70
The single planes still have their own distribution issues, unless you correct the plenum and dividers the flow gets alot more even. Still, with an elbow on top you'd have to shape the plenum and dividers even differently if we're trying to get the single plane to 100% on these cars. With a properly designed longer runner, larger plenum manifold, and the appropriately designed cam to take advantage of the now stronger Helmholtz resonance, I'm sure there is some substantial power to be made. Packaging is the issue in these cars.... I'm right at the 3rd harmonic with my stealth ram and a 7000 rpm hp peak, which is 12.8" valve to plenum. You're at the 4th with a super victor. And 5th with an LTx manifold. The camshaft requirements are quite different between the different intakes to reach a 7000 rpm peak...
03-11-2011, 07:19 PM
#71
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My thinking on extending the elbow (which would now be more of a box than just an elbow) past the 4150 plenum opening and underneath the cowl was that it would give more plenum volume as well as not force air to turn suddenly back there. I am sure alot of it would still make that turn anyway, but it would at least give a common area for the 4150 plenum to draw air from. I'd also think that using a 4500 based intake would help out with distribution also. ??? I could be wrong about all of this.....I'm just speculating. Did you ever give any more thought to the offy 2x4 single plane NON-tunnel ram intake with a plenum box added similar to the way the HSR adds one to the old Weiand Hi-Ram tunnel ram base? I know that it wouldn't compare to the HSR, but it seems like it could be an alternative for someone not wanting to cut their cowl. Not that I think the stock LT1 intake isn't pretty good for most of us.....I just like to think outside the box and try new stuff.
03-15-2011, 07:17 PM
#73
The LT1 Super Stock racers have seen near zero difference from their fabricated sheet metal intakes versus the single planes. The fabricated manifolds look trick, but I'll bet that Dave Layer LT1 intake shown here is less than a tenth of a second slower than my $3200.00 sheet metal Hogan intake, if any at all.
I'm having two Victor EFI manifolds drilled for LT1 heads this week (one is for a friend in Texas), then going to a cylinder head shop in Arizona next week for $1200.00 worth of welding & port work). I'm not convinced there is anything there, but have to know for sure. I'll let you guys know how it turns out.
It's probably not going to help my application, but I'm always interested to hear how things like that work out.
08-20-2011, 09:16 PM
#74
Absolutly no gian over my Hogan. After 7200 power drops like a rock. It made one pull at 591, 500 ft lbs. My Hogan made 590, 507 ft lbs. The Hogan made 36 more hp at 8500. Hogan's torque curve was flatter, with 13 more average hp, 567 vs 554. Torque average was better with the Hogan, but I don't remember the numbers. Like 10 ft lbs. The manifold, Wilson elbow and CNC TB adapter, welding and port work set me back about 2K. For nothing. Last dyno day was yesterday. Just got it back in the car & running today.
Of course, if I did this first, I would have a hard time paying $3200.00 for the Hogan for the power difference.
Of course, if I did this first, I would have a hard time paying $3200.00 for the Hogan for the power difference.
10-01-2011, 12:33 AM
#75
So peckers for all these manifolds?? the stock is still best?
Anyone check this out?
http://www.cpgnation.com/forum/ingle...take-3470.html
The damm throttle bodies look expensive though....not sure how this might help with gains or not?
Who ports the Lt1 stocker "correctly" ?
Anyone check this out?
http://www.cpgnation.com/forum/ingle...take-3470.html
The damm throttle bodies look expensive though....not sure how this might help with gains or not?
Who ports the Lt1 stocker "correctly" ?
10-01-2011, 07:17 AM
#76
Tell Ed to buy one and test it out, lol. He said he's wired weird, so maybe he'll be intrigued enough to do it. It's only $549, then figure all of the carbs, or if you want to stay EFI, fabbing injector bosses into it, and turning each carb into a TB, piece of cake!
10-01-2011, 07:53 AM
#77
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Stock supports tons of HP, a LE ported stock intake is the best option. It produces the best numbers and is also actually the cheapest route for sure. I think the HP increase with a LE port job is up to 20 rwhp?
10-02-2011, 09:54 AM
#78
Altho yea it seems their injecting fuel very early on....rather than right before at the or before the valves. it injects at the very beginning close to air intake.
I would think the design would have an advantage since it extends the runners plenty...isn't that that the design advg of LS manifolds? but then again older TPI manifolds had longer runners as well.....so its hard to make heads or tails out of all the GM designs what works better and why is fairly mysterious....all tho the older schools don't seem to be too mysterious...the Super Vic designs seem to just work.
Last edited by License2Ill; 10-02-2011 at 10:01 AM.
