IMO a sheet metal only reduces the % of loss to the head flow. If ya got a stroker and want BIG power ya go to BIG heads.330CFM head flow is capable of making about 680FWHP everything else being spot on. A GOOD sheet metal will cut 2/3% off of that and a stock LT1 will take off 12/15%. That's using the rule of thumb formula on the HP-head flow numbers.
Buy the BIGGEST set of heads ya can afford and build the engine around them.But don't expect a set flowing 280CFM to support a 396CI.If ya got 280CFM heads build a 356 with good compression and a GOOD intake,cam it accordingly and have fun.

 

Steve,
Could I ask what materials you used to fab that 4 inch CAI, especially that elbow? Did you paint it or have it coated? I've been considering something similar for mine, since I removed the ABS and have the space. Thanks.
Tim

 

Tim,

I used Mandrel bent uncoated steel tubing and Tig welded sections together. Then had it powder coated. The Filter is a K&N:

RD-1460 Product Specifications
Product Style: Round Straight Universal Air Filter
Flange Inside Diameter: 4 in (102 mm)
Flange Length: 1 in (25 mm)
Flange Type: Centered
Height: 9 in (229 mm)
Outside Diameter: 7 in (178 mm)
Top Style: Rubber
Top Material/Finish: None
Filter Re-Oiling Amount: 2.24 oz (66 ml)
Flanges: 1
Inner Wire: No
Weight: 2.4 lb (1.1 kg)
Product Box Length: 14.4 in (366 mm)
Product Box Width: 7.4 in (188 mm)
Product Box Height: 7.8 in (198 mm)


It's about the biggest you can fit in the fenderwell and keep all of the OEM plastic in tact.

The Elbow is fiberglass. There was a guy on E-bay making and selling these. He makes them with a 3.5" diameter inlet and he custom made me one with a 4" inlet to match up with the rest of the system. His quality is pretty good but not perfect. I had some cleanup and smoothing on the inside of the elbow. The elbow came in black and I did no painting on it. This is his Ebay name is
lt1pilot. I'm not sure he still makes them.
The 4" elbow really didn't pick up anything on the dyno or make any difference in my loss of MAP at 6800 over a stock GM elbow.

 

A couple of you dummies are stinking up this thread. If you have a problem with people discussing advanced tech stuff like exhaust valves and variable resonance intakes then maybe you shouldn't be in this area.

http://www.aperaceparts.com/tech/05gsxr1000.html

http://www.motorbyte.com/mmm/pages/2.../review64a.htm

If you don't want to click on the links that's 175.5 crankshaft horsepower for the 05 GSXR 1000 and 184 for the Suzuki ZX 10 which is also 1000 cc's. If you're not good at math that averages out pretty close to 180 horsepower per liter. Pulling the exhaust valve off the sport bikes is an OK thing if you're mainly after peak power. If you were interested in midrange and low end throttle response as well as topend( that's what this thread is about) then you'd be stupid to pull the exhaust valve because you just hamstrung your lowend by tearing off some very effective technology. Some people confuse the modest peak horsepower gain they get from a loud exhaust on these bikes with the slight increase made by removing the exhaust valve. Replacing a quiet and somewhat restrictive factory exhaust with a straight through racing pipe is bound to give you a few horsepower, but just because your threw away the exhaust valve at the same time doesn't mean the exhaust valve made all the power.

As for racerdude, I think this section is for advanced tech. If you want to put people down for thinking out of the box then you're posting in the wrong area. There is a turbo and supercharged area for people to brag about how fast the cheater engine somebody let them change sparkplugs on was.
You two should look around, not everybody is only interested in max effort race engines. A fair number of posts on here are about people buying a new set of 195cc heads or a small cam by CHOICE. If you don't have something constructive to offer about the original topic, longer runner intakes for LT1 engines or some other related midrange torque builder for NA, street driven engines then buzz off. That's what we're trying to discuss here and the bull**** is getting neck deep.

 

Magazine racer I see, those bikes dont make that power, the newer "liter" bikes make mid to high 150's at the wheel on the average dyno-jet, so they lose 25 to 30 hp through drivetrain loss? Umm ok. 184 ram air assisted hp? Wonder how they ACTUALLY tested that figure?

As far as I know 95% of people on this board are after bang for the buck IOW what works. If you want to develop a new wheel more power to ya. I now a "little" about bikes in the real world. I am out, over.

BTW your top link in INOP


David

 

I have owned two vehicles with variable runner length intakes...an 89 SHO, and my 3.8 Minivan. My SHO would suprise alot of 5.0 jockeys....I loved that engine!
My 3.8 ford is a split port really simple design with blades that open a shorter runner. 138,000 miles witout a problem..... lots of torque.
Now making it work on an LT1 will be difficult...hell no one has even come up with a fixed longer runner manifold. If you can pull it off....I say go for it! There is an advantage to this...otherwise the factory's would not bother, but most average people do not have the budget or resources to engineer this; however, hotrodders have always proven experts wrong! If you can get the torque of the superram and the hp of a super victor and then fit it under the hood.......may be impossible? Don,t get me wrong I do not mean to be discouraging just giving my 2cents.

 

Yo,listen up.
I HAVE a long runner intake.I DON'T diddle.
Those pictures are of some I have worked on. Post your little cam,runner pictures with the times.
Re inventing a SBC is useless.

If it's neck deep on your end ya need to stop producing the BS.

Giving those that don't know, the wrong info doesn't make their life easier. If ya want to diddle go for it but don't try to say it's the spot on thing to do.

 

Well, without trying to encourage arguement...

I can see a real benefit to variable intake runners/exhaust pressures on the street, if not on the drag strip.

I'm not saying the exhaust valves really help the sport bikes that much. Some of the better 1 liter bikes weigh around 370lbs. so low-end torque only matters so much. Heck when I ride my roommates YZF R1 I am pretty happy about the lack of torque down low, but I'm not a great rider.

Still, if some of us with the knowledge and ambition to re-invent the wheel want to give it a try then just let us. Those of us who really are motivated will do it no matter what anyone else says, and those of us who are full of crap will probably never even attempt it.

1racerdude, you are obviously more experienced in racing and building race motors than I. Maybe someday you will get tired of doing the same old thing and try something a little more unorthodox. Of course, I wouldn't blame you if you didn't, I doubt sub-9 second quarter-miles gets old very fast.

Respectfully,
Jeremy

 

No.. 8/9 second passes don't get old,neither does dirt track sprint cars, but at my age can't stand the rush. Old heart and lungs go crazy.
Don't really care what is invented,just don't want the younger guys that don't know any better 'bout an LT1/SBC to get the idea this is the correct R&D.
I try to steer them to get the most BANG for the buck and to not spend money/time on the trick of the week.


Like I said earlier ya can get a SBC to run in the 6's and if that ain't enough build a mountain motor.
Don't think flappers installed anywhere would help them and people like Kasse,Shaftroff,Rhear-Morrison,ect don't use them--knowing if there was benefit they would be,knowing they are aware of the set up.That kind of backs up my position.

 

Yeah, I don't think it's really going to get me into the 10's or anything on motor. But if my 355 with a GM 847 cam will get a little of it's low end pull back from an exhaust flap I scavange off of a bike...I'll give it a try.

But the variable length intake runners, I don't think you can argue that on the street. It's not going to be the best low-end for stump pulling or High-end for drag racing, but good power all across the board is all i'm looking for in my daily driver. A little more than the guy beside me anyway.

 

If ya want more low end do it with a cam and open up your intake SYSTEM and give it the max 9.0 DCR all good for low end.
Did I mention a gear.

 

But that is the problem with a cam, getting more low-end will usually sacrifice top-end. I like the top-end power, there are times I go through a particularly curvy stretch of road and never drop below 4500 rpm. I have a nitrous cam I am about to install that will be killer on the lower revs but I doubt it will be as powerful (peak power) up top. Of course, that's why I'm going to spray my way into the 9's, while still retaining daily driving fun .

 

 

It seems fairly obvious why Reher Morrison or most other RACE ENGINE builders don't fool with flaps or valves in the induction and exhaust system. In many instances the rules don't allow it. Even if they did race engines are a specialized piece of hardware that by their very design aren't called on to produce strong output over a wide RPM range in most cases. You can bet if the engines were used in such a way that a broader power delivery would help win races( and the rules allowed) that all the race engine builders would have flaps in their exhaust and valves in their intakes.
No one has claimed that having a dual length intake or variable back pressure exhaust would do much to help you outrun your buddy. What has been said is that they can make the vehicle more pleasurable to tool around the street in. Someone would have to disregard just about every other section on this site where talk is dominated by heads, cam and exhaust to come up with the notion that resonance tuning is going to be a fruitful way for them to better their quarter mile time.
It doesn't take a rocket scientist to deduce that the the broader your power range the more satisfying an engine will perform as a daily driver. A 454 with the same peak horsepower as a 302 is going to be much more fun to blitz around the street on because the power is right there anytime you tickle the gas. You're not wide open or throttle closed at all times in a daily driven performance car. Ferrari, BMW, Lamborghini and many other lesser makes use this stuff for a reason and they build very fast daily drivers that still have good midrange torque.
If you like to tinker and have a daily driver that you will only tolerate a certain amount of cam/heads on then there is nothing illogical about tinkering with the intake or exhaust. It's been proven many times over that the flexibility and part throttle torque of a high performance engine can be improved a great deal with the proper use of these devices. If you have the time and motivation and enjoy building things then it makes perfect sense to me, assuming you don't have any goofy notion that the reason you're doing it is to make the car faster down the drag strip.
Regards, Michael

 

grammerman, you've got the talk, lets see the walk. Every thread you start always ends up with you having all the answers. My simple little question to you is, why do you even ask? If you have the know how and the money to experiment with your ideas, JUST DO IT. Let us know how it works out and if the results are worth the bang for the buck you'll be our hero and some of us will follow suit. Have a good day. Really!!!