KHShapiro

iTrader: (10)

Back on the subject, i have been kicking around this idea for the past few days, i am going to try and run as many channels(egt and wideband) as i can and maybe i can convince someone to do some extra pulls and tune with a stock style intake......maybe.

kp

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OK I cleaned that up a bit, lets keep it civil guys. Got a problem, take it to PM.

gametech

iTrader: (1)

Back to the original poster's question. Let's see some dyno charts or individual cylinder EGT data or burst pressure data to prove or disprove any benefit to a carb style intake over the gm plastic.

KHShapiro

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cross quoting from another thread so these wont show up in the ls1tech email reminder of the thread, you are just going to have to visit this thread live to read this.

thank you for your input Jose


and here are some if not most of the information kp shared , thank you as well





since half of the runners are different sized The flow is "controlled" by the length and width of the runner, So in a perfect world the flow is the same, correct?

What intake is ?


i have thought about that before but until you wrote it down i guess i never really wrapped my head around it. I sure wish someone( not me) like one of the heavy hitting sponsors would do some back to back fi dyno pulls using some of the different intakes including a sheetmetal intake

as far as Egts and wideband, 8 egts and 1 wideband, sound off?
i figure with 8 egts you could see if one cyl is off and correct it ..??..

One of the other questions i have is the use of sheetmetal intakes. i choose to use a carb style intake and have just about as much invested in it as i would have with a sheetmetal, does anyone have any hard data or are most of us playing the guessing game....

kp stated something i also found very interesting it is about the #7 cyl which was one of the reason i also went with a carb style intake... can anyone else debate this?

*most of this was posted in another thread a day or so ago*

HotRodKid

in a perfect world, yes

in the real world, this only works perfectly if the engine is only run at one constant speed. but in a car, where the intake has to operate from idle to redline, with constantly changing vacuum or boost pressures, theres still a difference in airflow between the cylinders

lets change the situation a bit, lets say were talking about moving air through air ducts in an office HVAC ...the only way to pump the exact same amount of air through 2 different sized vent shafts under all conditions (hi speed, low speed) is to have 2 different fans on seperate contols

run both systems off the same fan (cough same size cylinder on an engine) and youll have different air flows at different speed

This is why ITB's are used in alot of the "money is no object" road racing classes ... because all the ports are the same length / shape behind the butterfly plate, and the plenum has much less effect on airflow (if any)

KHShapiro

iTrader: (10)

i "think" i understand what you are trying to say , is it two completely different shafts or one main shaft?
in my mind here is what i think is happening , with a stock style intake the intake charge has to hit the back of the intake before its pressurizes to even out the air flow , thus forcing more air into the rear cyls until it does, while only for a very very short time, with FI thats alot more air then a N/A. With the carb style intake the charge hits the bottom plenum which has a "more" even spacing between runners. now even though the runners are different sizes flow should be controlled by length and width. i understand your statement about idle to WOT changes but wouldnt that make an even more differance between the two types of intake?

ITB? not quite sure i know what that is can you explain that.

kp

iTrader: (34)

Individial throttle body.

I doubt the boost hits the back wall and causes more air to get to the rear cylinders with 6 other cylinders before it leaking some of that air. IMO the #7 thing happens the most on NA cars with a wet shot at the TB. How many 700hp+ well built FI engines have killed the #7 cylinder? I check my plugs pretty often and number one always seems the leanest for some reason and the leakdown is pretty even across all cylinders so I dont know..

Pro Stock John

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I like Stevieturbo's comments, I think his retuning shows how the carb intake impacted his old tune. Stevie, did you go faster?

KHShapiro

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kp how lean have you seen the #7 and what is your opinion as to why as you mentioned reversing the intake had no effect on #7.
About my statement , is it off base? does it not at least sound right?

LS2Camaro

iTrader: (5)

I would really like to see some bench tests on this. Reading the GMHTP latest issue, the article "Ohio Boys 8 Second turbocharged CETA", it mentions that the original block it had (Stock bottom end) Single 91.5mm turbo, and with new heads that were flowing better than previous (366cfm at .650-inch lift on the intake side), they noted that the LS6 intake and ported stock throttle body were deemed "insufficient. They threw on a Vic Jr and the Elbow, and noticed a drop off in boost at high rpm due to better flow. Obviously the car was already pushing im sure close to 1000rwhp or more as it was already running mid 8's before the switch. But they did notice better "flow" with the "Carb Style" intake? I guess I like to be proven with numbers.

MyWs62FaST4u

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are there pics or specs on these intakes, or is the vic jr just the way to go? i want to run one on my FI 408, but i might just use the LS7 if anything...

kp

iTrader: (34)

I broke a couple stock #7s with nitrous, the number 7 on this car doesnt seem to run any leaner then the other cylinders but I havent had any EGTs in here. FWIW the head gaskets looked the worst on #3 and #5 then #7 and if it was detonation problems that should be the worst I would think.

As far as turning the intake around I was talking with one of the shops here that do a lot of OE GM stuff and thats where I heard about turning the intake around not making much difference.

I dont know if you are wrong or not, but I do think forced induction isnt as critical as n/a as far as intake distribution goes. If I had an engine dyno and a few hundred hours to spare maybe I could tell you for sure but like most I just rely on experience, real data and a little common sense to draw a conclusion. Dwelling over it and trying to find an answer no one has can make you crazy and no one is going to spend the time or money doing a direct comparison unless they have something to sell and get some return off of the R&D time.

KHShapiro

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this is what i got from Stevies post
to me it seems he didnt have to do much up top because the charge was already stable up top therefore not much needed to be changed
it was the low to mid that he did the most tweaking on when the charge was unstable.
what was the data low to mid before and after?
am i looking into to this too much?
there is just something that is just bothering me but i cant put my finger on it.
my spider sense is tingling .... there has to be something more to this

LS2Camaro

iTrader: (5)

The two popular ones are the Vic Jr and the GMPP Carb Style.

The GMPP is better as far as clearance goes, but needs work done to get the rails to fit. The new Vic Jr's are ready to go to fit the rails, but sit higher and you may have clearance issues.

kp

iTrader: (34)

I dont doubt the LS6 is going to jut 'run out' at a certain point. If the cross section of the runners on the victor is larger then an LS6 then it will flow more. Plus you can really openup those runners on the carb intakes and how many guys are using them off the shelf as opposed to ported. Once you get over the 1000hp/25psi mark I would be looking into something different then a LS6 intake/stock TB myself

KHShapiro

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kp you are right. for some reason this is driving me crazy. truth be told i could not sleep lastnight going over this in my head. if things go right i should be able to hit the dyno mid december, if the bank account allows i am gonna try to find out...
i'll lay this to rest unless someone has something new to add either for or against

stevieturbo

Unfortunately thats hard to say.

Yes I did run faster. But my 10.54 @ 145mph/stock LS6 intake was run on 245/50 Nitto's, and the 10.04 @ 148mph Victor Jnr 85mm TB was on 255/50 MT DR's

So a lot of the faster time, is contributable to the tyres ( and it was a cooler day, although I think the meth would take care of that difference on warm days, as intake temps werent much different )

Traps may be telling a different story though ( although tyres are also affecting gearing, which is limiting my trap speed also, as I am well beyond peak power, but hanging onto 4th.

The Nitto run in July picked up around 33mph in the latter 1/8th. I had 3 passes, traps were 143/144/145mph.
The MT DR runs in October picked up around 36-37mph on average, trapping at 147/148/149 average.

That could be down to extra power.....it could also be down to better gearing due to the slightly taller tyres, as I was still crossing the line circa 7000rpm.

kp

iTrader: (34)

I'll put it this way and this is just my opinion. Under 1000hp I think you would be wasting your time and money switching to a carb intake UNLESS thats the only thing you have left to do and are looking for an extra little something.

Stevieturbo has done a before and after but different weather has a big effect on a blower car. Even though the meth wil lower the IAT in the summer it wont make up for the extra boost you will see in cooler weather. I am glad he looks at things in a more analytical manner and not the 'I ran 3mph more and it MUST be the intake' like a lot will say. Maybe it is the intake that picked him up 3mph If someone could prove to me that near my HP level I could pick up even 20hp average doing the intake swap I would be all over it.

onfire

iTrader: (17)

kp, here's some stats that have bothered me for a while.

LPE 345ci TT gains nothing (per LPE) with a FAST 90 over a LS6 at 16-18 psi.

LPE 427 TT gains 30-40rwhp (per LPE) with a FAST 90 over a LS6 at 16-18 psi with the same GT2871R turbos.

Comments?

kp

iTrader: (34)

I dont know Tom, really

You are looking at a big engine with tiny turbos so who knows whats going on there.