Intakes and turbos...

ChevyKiller

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There are some seriously pricey intakes out there and they seem to be pretty trick but the question is - are they needed for a turbo car.

I'm just curious because it seems to me the way a turbo makes power, there would be nothing wrong with the stock intake handling anything you can throw at it. Has anyone ever heard of or seen a stock intake 'max out' or run into restrictions with a turbo set-up at ANY power level?

I'm just curious cause they are so expensive. I can see it for an NA build car trying to make max power, but I just don't understand the advantage a 3-4 thousand dollar intake would give someone with a turbo car?
 

Freaknazty

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as far as maxing out that im not sure of but i have seen 1 been pushed to 27psi and stand strong , although it is getting pulled and swapped with a jpc very soon

i dont know the specifics but i think it had alot to do with a lean issue on some cylinders on forensicsteve's car
 

ChevyKiller

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Ahh - but the question is was the leaning more related to throttle body than the intake? I mean, if that occurred on Steve's car, I would think because of mass and volume, it would the TB before the intake?
 

Freaknazty

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ahhhhhhh may be i dunno im almost positive they are running the gt500 ( i know a big mono would help but yea lol ) but it caused or something caused lean & rich cylinders , this is the only reason i said intake instead of tb
 

Androdz

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with a turbo not much because remember you are forcing compressed air thru them. It is different trying to flow huge volumes of air thru the intake which really affects it. But with a turbo car meh it can help but it isn't something you cant offset with just 1-2 psi more.

Andrew
 

GI Joe

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are they needed for a turbo? NO But if I were in your situation with what happened would I put the best on? Yes...and it will make a big difference on top end.........you know the one.....
 

Freaknazty

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are they needed for a turbo? NO But if I were in your situation with what happened would I put the best on? Yes...and it will make a big difference on top end.........you know the one.....


+1 if your going to going for the gusto id deff run 1 jmo
 

SD07GT

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There are some seriously pricey intakes out there and they seem to be pretty trick but the question is - are they needed for a turbo car.

I'm just curious because it seems to me the way a turbo makes power, there would be nothing wrong with the stock intake handling anything you can throw at it. Has anyone ever heard of or seen a stock intake 'max out' or run into restrictions with a turbo set-up at ANY power level?

I'm just curious cause they are so expensive. I can see it for an NA build car trying to make max power, but I just don't understand the advantage a 3-4 thousand dollar intake would give someone with a turbo car?

Talk to Mihovetz over at Acufab ...if you get the chance He will tell you all you need to know on Sheet metal intakes (Hogan) etc ! on turbo cars !
 
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MSgt46270

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Hey Mark, what about this.

16ab_3.jpg
 

US-1

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There are some seriously pricey intakes out there and they seem to be pretty trick but the question is - are they needed for a turbo car.

I'm just curious because it seems to me the way a turbo makes power, there would be nothing wrong with the stock intake handling anything you can throw at it. Has anyone ever heard of or seen a stock intake 'max out' or run into restrictions with a turbo set-up at ANY power level?

I'm just curious cause they are so expensive. I can see it for an NA build car trying to make max power, but I just don't understand the advantage a 3-4 thousand dollar intake would give someone with a turbo car?
The limit of the stock intake hasn't been "really" tested. Most people using the sheetmetal intake have done so because they felt like they needed it with the power they planned on making. Nobody really pushed the stock intake in dyno testing. I can see the stock intake becoming a problem somewhere around 900 hp or so. Runner volume would be the main problem. While some people believe that turbo or superchargers don't care about intake volume these same people won't be pushing that type of power. Once runner volume becomes problematic, horsepower will suffer due to turbulence in the runners and overpressurization of the plenum/runners which causes pulsation and reverberation in the intake/exhaust tract. Also, tuning the engine once it reaches this state is highly problematic because it won't show you the same thing twice. A/F ratios would be all over the map.

A larger plenum and runner combination will ease this problem and lead to more power. The engine will run smoother in the higher horsepower regions and tuning will be easier and more consistent. The C&L intake would ease these problems up to around (based on the preliminary numbers I've seen on the intake) 1100 hp or so. I do believe a single blade throttle body would be a requirement over 900 hp for airflow reasons. At this level you start looking at restrictions to airflow instead of looking for "bigger is better".

Anything over 1000 hp in a modular engine should use a bottom feeder type intake manifold and a monoblade throttle body. Bottom feeder styles will cure airflow reversion problems typically associated with sheetmetal intakes on a modular engine. You can't look at a pushrod intake manifold and try to copy it onto a modular. You'll fuck it up.
 

ChevyKiller

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Awesome explanation SD - thanks...:beer:

However, I think the 'off the shelf' 3-4 grand intakes out there are overpriced. I'm sure a fabricator could make a just as effective sheet metal intake for a lot less...:idea:
 

forensicsteve

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We're putting the JPC intake manifold on. The stock one withstood 27lbs boost, but car blew head gaskets and pistons. We suspect that although AFR was showing very safe, some cylinders were rich and others lean but the average was OK (problem may have existed for some time). We will be measuring AFR and other stuff for each cylinder separately, using special exhaust gas temperature sensors and upgraded tuning software. Think bungs for the EGT sensors are being welded onto the new headers. The JPC intake was designed to support this initiative. It's not so much about increasing hp, more about ensuring even, equal, and improved flow of gases.

Maybe it's overkill for our car, but it is one of many steps taken to try and prevent a repeat of what happened a month ago.
 

SD07GT

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We're putting the JPC intake manifold on. The stock one withstood 27lbs boost, but car blew head gaskets and pistons. We suspect that although AFR was showing very safe, some cylinders were rich and others lean but the average was OK (problem may have existed for some time). We will be measuring AFR and other stuff for each cylinder separately, using special exhaust gas temperature sensors and upgraded tuning software. Think bungs for the EGT sensors are being welded onto the new headers. The JPC intake was designed to support this initiative. It's not so much about increasing hp, more about ensuring even, equal, and improved flow of gases.

Maybe it's overkill for our car, but it is one of many steps taken to try and prevent a repeat of what happened a month ago.

This is the same problem you get with the Hogan intakes also at 20+ pounds of boost on turbos or blowers ..the even and equal dispersion of the incoming air flow that has that much pressure has a problem of hitting the back of the plenum and causing turbulence/blockage of air to each (8) runners ... more than others causing AFR to be off in each cylinder , therefore using stand alone systems were the only way to go to tune each of the cylinders in both banks ! The only problem is after getting the AFR correct it can be different again on another run or pull on the dyno. Therefore modifications must be made to the runners that are causing the problems ...back in the day Mahovitz blew a couple of motors using Hogan intakes before going back to modified custom ones that he came up with (I'm not saying Hogans intakes are bad or sheet metal intakes in general , you just have to be extra careful when tuning them !
 

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Awesome explanation SD - thanks...:beer:

However, I think the 'off the shelf' 3-4 grand intakes out there are overpriced. I'm sure a fabricator could make a just as effective sheet metal intake for a lot less...:idea:
Oh yeah. The name "Beck" comes to mind. He builds outstanding intake manifolds here in the Houston area and is VERY reasonable on pricing. In fact, if you have even the faintest idea of what you're talking about and discuss it with him you'd be amazed at how affordable the intake can be.

We're putting the JPC intake manifold on. The stock one withstood 27lbs boost, but car blew head gaskets and pistons.

Maybe it's overkill for our car, but it is one of many steps taken to try and prevent a repeat of what happened a month ago.

I don't think it is. Your problem illustrates exactly what my last post was all about. I think it is a perfect example.

This is the same problem you get with the Hogan intakes also at 20+ pounds of boost on turbos or blowers ..the even and equal dispersion of the incoming air flow that has that much pressure has a problem of hitting the back of the plenum and causing turbulence/blockage of air to each (8) runners ... more than others causing AFR to be off in each cylinder , therefore using stand alone systems were the only way to go to tune each of the cylinders in both banks ! The only problem is after getting the AFR correct it can be different again on another run or pull on the dyno. Therefore modifications must be made to the runners that are causing the problems ...back in the day Mahovitz blew a couple of motors using Hogan intakes before going back to modified custom ones that he came up with (I'm not saying Hogans intakes are bad or sheet metal intakes in general , you just have to be extra careful when tuning them !
Most of those Hogan intakes were top feeder or front feeder intakes. John figured the problem was air distribution and decided to try a bottom feeder intake. Lo and behold...equal feeding and fuel distribution.
 
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