Least restrictive LT1 induction?
Least restrictive LT1 induction? I'm looking for experience on the least restrictive ways to get air into the engine short of a sheetmetal intake and snorkel. We just dyno tuned my 394ci LTx and it was choking around 6500 rpms. The curve never dropped off, just flattened out and couldn't pull any more air in. It's a solid roller cam spec'd to make power up to 7-7400, LE ported AFR 210s, LE ported LT4 intake and AS&M monoblade, so it should pull to 7k even with the stock style intake.
My current CAI comes off of a 1LE elbow, narrows significantly where it has to clear the radiator bracket , widens back out, and goes to the biggest cone filter I can fit inside the fender. I appreciate any advice!
My current CAI comes off of a 1LE elbow, narrows significantly where it has to clear the radiator bracket , widens back out, and goes to the biggest cone filter I can fit inside the fender. I appreciate any advice!
Sounds like the CAI is a bit of a restriction. Maybe look into a lid swap, then a single plane manifold. The lid flows a whole heap better that the LTx routing. Worst part is having to either cut the core support or purchasing a hood to clear it.
I would have removed the CAI completely for a run on the dyno; and see how much of a restriction it really is and confirm it's not valve float or something of that nature a an experiment. As mentioned, the LS1 style lid is best (or a ram air setup). Unfortunately for you, the SS Camaro ram air setup is inferior to the WS-6 or Firehawk style ram airs due to the shape of the intake tube doing a 180, Firebirds basically have a straight shot through the hood to the filter. They sure look a lot better than the plain jane stock hoods IMO though.
Agreed. That was my issue though, as I was in San Antonio with Moe and had to get back to Houston that night for work in the morning. Moe seemed to be pretty confident that the CAI was the restricting factor, though.
I would have removed the CAI completely for a run on the dyno; and see how much of a restriction it really is and confirm it's not valve float or something of that nature a an experiment. As mentioned, the LS1 style lid is best (or a ram air setup). Unfortunately for you, the SS Camaro ram air setup is inferior to the WS-6 or Firehawk style ram airs due to the shape of the intake tube doing a 180, Firebirds basically have a straight shot through the hood to the filter. They sure look a lot better than the plain jane stock hoods IMO though.
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Doubt very seriously it's valve float. Lloyd spec'd my whole top end and matched my springs to my cam. I currently have the Stingray style Big Block hood, and the flat front of the cowl is ahead of the throttle body. I don't think it will be far enough forward to accommodate the MAF and filter though. I've looked at the LS1 WS6 style hood as an option.
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Verdad Gallardo You're probably right, but it never hurts to make 100% sure! I too have a crappy restrictive CAI choking my 383 (the old school 1994 G2 elbow) PCM for less told me it was holding mine back when they dyno tuned it, and I had valve float at 5800 due to reusing some worn out triple valve springs like a dumbass. My valvespring issue has since been rectified and it spins freely and hard to 6700, but I still need to put a lid or at least a K&N elbow on it and re-dyno it (both with and without a CAI) That's my final engine related project for my car. Just curious, what CAI elbow do you have?
When you are chasing this do not rely solely on the MAP reading far as seeing a restriction. IMO the MAP location lends itself the the Bernoulli effect where air rushing past the hole in the MAP makes it look like there is more vacuum than there is. Guys have seen MAP readings indicating restriction even with monoblades and open induction which just shows the reading is wrong not that the there was any actual restriction.
I have seen too many people chase the MAP vacuum reading to no gain.
Far as single plane, if you are hunting 9s NA it MIGHT be worth visiting that idea, but even at that guys have gone 9s with less material removed from LT1 intakes.
I have seen too many people chase the MAP vacuum reading to no gain.
Far as single plane, if you are hunting 9s NA it MIGHT be worth visiting that idea, but even at that guys have gone 9s with less material removed from LT1 intakes.
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Try the Honker?
http://www.moroso.com/catalog/catego...?catcode=34001
http://www.summitracing.com/parts/mor-65845/overview/
http://www.summitracing.com/parts/mor-65840/overview/
cardo
http://www.moroso.com/catalog/catego...?catcode=34001
http://www.summitracing.com/parts/mor-65845/overview/
http://www.summitracing.com/parts/mor-65840/overview/
cardo
Last edited by cardo0; Feb 15, 2014 at 12:12 PM. Reason: add correct part number/link
If my calculations are correct, (cfm = rpm x displacement / 3456)
6700 x 383/3456 = 743 CFM x 88 MPH....I should be able time travel in the firebird.
Seriously though, that seems more than enough CFM capability for my needs, good find! OP, yea, you might be pushing it since you need 848 CFM and no telling how good your CAI is.
Last edited by ahritchie; Feb 15, 2014 at 12:32 PM.
When you are chasing this do not rely solely on the MAP reading far as seeing a restriction. IMO the MAP location lends itself the the Bernoulli effect where air rushing past the hole in the MAP makes it look like there is more vacuum than there is. Guys have seen MAP readings indicating restriction even with monoblades and open induction which just shows the reading is wrong not that the there was any actual restriction.
I have seen too many people chase the MAP vacuum reading to no gain.
Far as single plane, if you are hunting 9s NA it MIGHT be worth visiting that idea, but even at that guys have gone 9s with less material removed from LT1 intakes.
I have seen too many people chase the MAP vacuum reading to no gain.
Far as single plane, if you are hunting 9s NA it MIGHT be worth visiting that idea, but even at that guys have gone 9s with less material removed from LT1 intakes.
I'd like to run it in LTX Shootout at some point (cage will probably stop me this year at the new track), so at this point, the single plane is out of the question. It's not a track car though. It's full interior, A/C, power everything, DVD player, Amps, sub, Eibach Pro Kit, 18" wheels, etc. I'd be satisfied with high 10s on motor and 9s on the bottle. Just trying to maximize its power band.
That Honker looks almost identical to my current CAI other than the chrome base plate and oval opening.
Really unlikely something off the shelf for a bolton car is really going to supply a powerful car.
Stock intake might flow 600cfm but most people find gains in an aftermarket CAI, not to say the stock engine flows more than 600cfm. Thing is parts are flowed at a specific "depression" or vacuum level and that is restriction to the engine.
Stock intake might flow 600cfm but most people find gains in an aftermarket CAI, not to say the stock engine flows more than 600cfm. Thing is parts are flowed at a specific "depression" or vacuum level and that is restriction to the engine.
Really unlikely something off the shelf for a bolton car is really going to supply a powerful car.
Stock intake might flow 600cfm but most people find gains in an aftermarket CAI, not to say the stock engine flows more than 600cfm. Thing is parts are flowed at a specific "depression" or vacuum level and that is restriction to the engine.
Stock intake might flow 600cfm but most people find gains in an aftermarket CAI, not to say the stock engine flows more than 600cfm. Thing is parts are flowed at a specific "depression" or vacuum level and that is restriction to the engine.
It is a b-body specific piece called a RAISS. Big sheetmetal box that replaces the upper radiator holddown and houses a cone filter. So I have a coupler and MAF on the TB then the sheet box. I found the MAF readings to be unstable with the filter directly mounted so I bought a cheap "Y" pipe to put two filters further from the MAF, the goofy projection off the back of the chrome "Y" was a spot for an IAT sensor that I plugged. It picks up cold air from over top the core support, just have to remove the seal on the underside of the front of the hood.
I really don't think I needed twin filters, like I said with a single filter mounted right to the MAF the MAF readings were just inconsistent.
The b-body has a lot more room in front of the engine than the f-body.
I really don't think I needed twin filters, like I said with a single filter mounted right to the MAF the MAF readings were just inconsistent.
The b-body has a lot more room in front of the engine than the f-body.
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The curve never dropped off, just flattened out and couldn't pull any more air in. It's a solid roller cam spec'd to make power up to 7-7400, LE ported AFR 210s, LE ported LT4 intake and AS&M monoblade, so it should pull to 7k even with the stock style intake.
Have u done a compression test? U say 7000-7400rpms but what is your cam and compression ratio. U need to do a compression test and see what your static compression is. U need a lot of cam and compression to support 7000-7400rpms for 394 cubes.
cardo
Have u done a compression test? U say 7000-7400rpms but what is your cam and compression ratio. U need to do a compression test and see what your static compression is. U need a lot of cam and compression to support 7000-7400rpms for 394 cubes.
cardo
I found gains in the LS1 style lid setup verses 4" piping with one 90* bend and a 900 cfm cone filter. The bend that has to be made is what kills the flow.. because 3.5" straight pipe flows around 1000 CFM and would be plenty. Air flow drops something like 30% through a 90* bend so on paper a 4" pipe should have been big enough. Straight 4" flows around 1400 CFM. As I said the lid was faster at the track. 10.9's vs 10.8s in similar DA's.
The curve never dropped off, just flattened out and couldn't pull any more air in. It's a solid roller cam spec'd to make power up to 7-7400, LE ported AFR 210s, LE ported LT4 intake and AS&M monoblade, so it should pull to 7k even with the stock style intake.
Have u done a compression test? U say 7000-7400rpms but what is your cam and compression ratio. U need to do a compression test and see what your static compression is. U need a lot of cam and compression to support 7000-7400rpms for 394 cubes.
cardo
Have u done a compression test? U say 7000-7400rpms but what is your cam and compression ratio. U need to do a compression test and see what your static compression is. U need a lot of cam and compression to support 7000-7400rpms for 394 cubes.
cardo
I found gains in the LS1 style lid setup verses 4" piping with one 90* bend and a 900 cfm cone filter. The bend that has to be made is what kills the flow.. because 3.5" straight pipe flows around 1000 CFM and would be plenty. Air flow drops something like 30% through a 90* bend so on paper a 4" pipe should have been big enough. Straight 4" flows around 1400 CFM. As I said the lid was faster at the track. 10.9's vs 10.8s in similar DA's.
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It's a brand new motor. It's 12.5:1 SCR and the cam is a Lunati solid roller spec'd by Lloyd when he ported the heads and intake. Specs are 256/264 .691/.691 on a 108 LSA. The setup was pulling great and still gaining until it flatlined around 6500.
Yes u have to verify your compression pressure as there may have been error in measurements/calculations. For a pump gas motor u will want at least 200psi while 210psi would be better and 220psi max. Oh BTW the compression needs to be done with engine warm - if possible - as it aids ring seal. But yes who can get the plugs out while headers are still hot. Also throttle blade needs to be fixed open - im sure u know this.
Not trying to fault or criticize anything here. U just need to verify to eliminate low compression as an exception.
cardo
Yes u have to verify your compression pressure as there may have been error in measurements/calculations. For a pump gas motor u will want at least 200psi while 210psi would be better and 220psi max. Oh BTW the compression needs to be done with engine warm - if possible - as it aids ring seal. But yes who can get the plugs out while headers are still hot. Also throttle blade needs to be fixed open - im sure u know this.
Not trying to fault or criticize anything here. U just need to verify to eliminate low compression as an exception.
cardo
Last edited by cardo0; Feb 15, 2014 at 09:05 PM. Reason: how to test