402w dyno results

[BuckeyeDemon 211]

i can download it on here if i can find the time. let me see if i can post the first and last sheet.

 

any time to post the data?

[sportsroof69 13]

I copied the setup Maxum96 is using to get my Vic Jr to fit, and there is room for a 1" spacer. I'm running stock mounts, with a torque link. There is no room for drop mounts, because with the stock ones my 7 qt pan was rubbing the crossmember, and it had to be clearanced.

 

 

 

 

[strokedwindsor 11]

hey thanks sportsroof69. what air cleaner is that? quess ill have to cut out my hood or just go with another kind of hood?? not sure what i want to do yet.

[sportsroof69 13]

It's an Edelbrock Pro Flo. I'll have to look up the part #.

[sportsroof69 13]

Here it is.

 

http://www.summitracing.com/parts/EDL-1236/

[strokedwindsor 11]

thanks bro..

[BuckeyeDemon 211]

fwiw,

 

i had looked at all kinds of filter shapes when i was trying to figure out my shaker so i had performed a little research.

 

the small oval air cleaner (i really like the look as it shows off the engine) has an effective surface area (ignoring rubber seal area) of around 87 sq in's. A 14 X 3 setup has an area of 132 sq in's. (hopefully i did the math correctly)

 

If a person can believe K&N's flow figures, then they advertise 6 cfm/sq in of effective filter area.

 

That equates to filter flow rates of 525 cfm vs 791 cfm.

 

if you subtract some area for the rubber seal area or what K&N advertises as flow rates for other filter types then it gets worse.

 

is any of this information real or does it really effect performance on a motor like yours? does a drop base air cleaner hinder flow more than just using a smaller air cleaner? i don't know.

[sportsroof69 13]

Well, it all depends on who talk to about if it makes a difference. From the idffering reports I get, I can put together my own conclusion, that if you're a good, consistent driver on the track, you may notice a small difference in trap and ET. I think the average weekend warrior will never notice. I contemplated all of this too, but the larger oval wouldn't really fit under the scoop. From what I understand, a drop base will affect it as much as anything, but again, it just depends on who you talk to.

 

 

I'm going to make passes with mine like it is, and without an air cleaner and see if there's a difference that I can tell. I also considered making a cowl seal so to speak, so that when I close my hood, it seals the air filter off from the engine bay, and pulls all the air from the scoop. That should give it some ram air affect, along with pulling only cooler air.

[buening 63]

Nice numbers! I'm kind of surprised to see the torque smaller than the hp figure, as the strokers tend to be torque monsters. Either way I'd be very happy with those numbers.

 

My only concern with the air filter setup shown above is the hood shrouds much the air filter. You have a small area exposed in the scoop and the bottom rear is open but air turbulence behind the air filter affects intake. The remainder of the filter is shrouded by the hood. How much it affects HP is anyone's guess without a dyno, but even then it'd be difficult because you'd either have to lose the spacer, use a different air cleaner, or remove the hood....all making it an apples to oranges comparison. I'd rather see a drop filter base used (if possible) and use a seal to the hood to make it ram-air. The other question is if the 1" spacer really added anything in your desired RPM range. 10hp (which could have been due to the jet change) at peak HP won't get you jack if you plan on using this as a cruiser, and only creates this air filter/hood clearance headache. Something the chew on...

 

As far as the exposed area of air filter, I think it definitely matters especially with a stroker motor that needs a high volume of air. This is strictly speaking at higher RPMs. Puttin' around town you won't see any difference most likely. A larger differential in area would be like driving around with the choke half on. Another example would be comparing a holley carb with the choke horn vs. one with a choke horn removed, as both affect the CFM of air coming into the carb as well as turbulence. There are hp differences, but again at RPMs not typically seen cruising.

[strokedwindsor 11]

looks like the second to last run they didnt use the 1'' spacer but im not sure. have to call them. peak HP was still @5900 rpms with 555. torque was@5200 with530.. last pull made 562Hp with 535 torque. i may not use the 1'' spacer if it causes fit problems. i have 3.89,s with a 10'' converter which im sure with the full manual c-4 with get her moving very fast...

[sportsroof69 13]

Nice numbers! I'm kind of surprised to see the torque smaller than the hp figure, as the strokers tend to be torque monsters. Either way I'd be very happy with those numbers.

 

My only concern with the air filter setup shown above is the hood shrouds much the air filter. You have a small area exposed in the scoop and the bottom rear is open but air turbulence behind the air filter affects intake. The remainder of the filter is shrouded by the hood. How much it affects HP is anyone's guess without a dyno, but even then it'd be difficult because you'd either have to lose the spacer, use a different air cleaner, or remove the hood....all making it an apples to oranges comparison. I'd rather see a drop filter base used (if possible) and use a seal to the hood to make it ram-air. The other question is if the 1" spacer really added anything in your desired RPM range. 10hp (which could have been due to the jet change) at peak HP won't get you jack if you plan on using this as a cruiser, and only creates this air filter/hood clearance headache. Something the chew on...

 

As far as the exposed area of air filter, I think it definitely matters especially with a stroker motor that needs a high volume of air. This is strictly speaking at higher RPMs. Puttin' around town you won't see any difference most likely. A larger differential in area would be like driving around with the choke half on. Another example would be comparing a holley carb with the choke horn vs. one with a choke horn removed, as both affect the CFM of air coming into the carb as well as turbulence. There are hp differences, but again at RPMs not typically seen cruising.

 

I don't have the 1" spacer on there. When I put it on, the filter should be mostly exposed under the scoop, and as I said, I am considering sealing the filter off from the engine bay. I just got then car running, so it's still a work in progress.

[strokedwindsor 11]

im wondering if a AIr GAP would bring some of that torque down in the lower power band?? should have dyno it with both??

[sportsroof69 13]

An air gap is not enough intake for a 408. You'll leave a lot of power on the table with it. With the proper camshaft timing events, you'll make more torque with the Vic Jr. It's all about the camshaft.

[strokedwindsor 11]

i dont have any torque numbers below 3900 rpms! thats where the sheets start!! just wondering. my cam really woke this puppy up..

[strokedwindsor 11]

i may never see the high side of 5000 rpms when driven on the street with this new motor ?

[BuckeyeDemon 211]

An air gap is not enough intake for a 408. You'll leave a lot of power on the table with it. With the proper camshaft timing events, you'll make more torque with the Vic Jr. It's all about the camshaft.

 

i often read how a vic jr is superior to the air gap for these strokers. however i've never seen anything to support this. i have read some magazine articles showing some comparisons that indicated more average power for the air gap and a little more peak power for the vic jr. perhaps these magazine articles are biased.

 

do you some data that suggests the vic jr is a better intake? any links? or is this one of those common "rules" that gets thrown around?

 

also, what about the camshaft timing would cause it to make more torque with the vic jr?

 

anyways, it would be fantastic if you post some data from your air filter test when you get some consistency in your time slips. that would be great information. it seems that subject is hard to find anything substantial on and without possible bias. it would be appreciated by me. my gut tells me my shaker is grossly restrictive.

[sportsroof69 13]

i often read how a vic jr is superior to the air gap for these strokers. however i've never seen anything to support this. i have read some magazine articles showing some comparisons that indicated more average power for the air gap and a little more peak power for the vic jr. perhaps these magazine articles are biased.

 

do you some data that suggests the vic jr is a better intake? any links? or is this one of those common "rules" that gets thrown around?

 

also, what about the camshaft timing would cause it to make more torque with the vic jr?

 

anyways, it would be fantastic if you post some data from your air filter test when you get some consistency in your time slips. that would be great information. it seems that subject is hard to find anything substantial on and without possible bias. it would be appreciated by me. my gut tells me my shaker is grossly restrictive.

 

Well, I can't say that I have some sheet of paper that I can show you, but I've built enough engines, and been around enough very established race car builders, and racers to know what I've seen, combined with what the top camshaft manufacturers say.

 

The velocity can be controlled by having the right timing events. It's easy for anyone to understand that if you move the same volume of air through two different sized runners, the smaller runner will have more velocity. In a larger runner, the exhaust valve can be held closed longer, creating more pressure, which keeps the velocity up when the valve opens.

 

The professionals engine builders that will tell you a mid rise, dual plane intake that was designed for 351 CID, is too small for a 400+ CID engine, didn't get to be professionals by using accepted rules. They got to be that way by doing what works.

 

 

Will a RPM air gap work on a 408? Sure! But you're leaving power on the table, and would not sacrifice any drivability by using a Vic Jr. I can tell you after driving my car some today, it has PLENTY of low end torque with a Vic Jr.

 

 

I will definitely report back on the air cleaner.

Edited July 2, 2011 by sportsroof69

[strokedwindsor 11]

mine loves the vic jr..

[BuckeyeDemon 211]

mine loves the vic jr..

 

how do you know it wouldn't love the air gap for your intended use (don't know what that is)? just trying to play devil's advocate.

 

i'll assume you have no intent of posting your data.

[buening 63]

im wondering if a AIr GAP would bring some of that torque down in the lower power band?? should have dyno it with both??

 

Get a used Air Gap off ebay and get it dyno'd. I'd dyno the car with the Vic Jr and Air Gap on the same day, to eliminate variances and keep the comparison applicable. With custom camshafts, the intake is taken into consideration. If you told Ed Curtis you were using a Vic Jr, then it will be set up properly to use that intake and will likely lose power with the Air Gap. If it wasn't designed with an intake in mind, who knows which will be better until you get both dyno'd for a comparison.

[buening 63]

Buckeye, does the following thread help some?

http://speedtalk.com/forum/viewtopic.php?f=1&t=26255

 

Granted it is a Chevy motor but at 400ci, it is similar in size to this 402w we are discussing. It also involved a Super Vic instead of the Vic Jr. There are some notable cam/engine builders in that link.

 

As expected, peak torque comes earlier with the smaller Airgap. The curve just shifts left with the Airgap (lighter color line is the Airgap). I believe the Air Gap is large enough to not choke out the stroker motors, but wouldn't go any smaller than that. What is an unknown is how the camshaft was designed in this application, but would still expect the dual plane to outperform a single down low.

[strokedwindsor 11]

ill post the last page when i get a chance! been to busy with work. i wish i had dyno the 2 intakes but i didnt and my motor is home. maybe over the winter if i have the funds ill re dyno it. im sure the torque curve would come down some with the AIR GAP. i had one on it yrs ago. nice manifold.

[BuckeyeDemon 211]

ill post the last page when i get a chance! been to busy with work.

 

any relief from work?

[strokedwindsor 11]

nope..

[manley 13]

LOL. Ahahahahahahahaha!