ss performance

iTrader: (17)

I'm trying to decide which intake to use on my 454 build, 4.185 X 4.125. It will be NA and I will be spinning it to about 7K. I'm using a sleeved LS2 block & LS7 heads. The rotating assembly is out of a LSX454. I will be getting the heads ported. This engine will be used for road racing.

I know there are a bunch out there. I can't afford some super high end intake. Basically I'm considering, Holley Hi-Ram, Edelbrock EFI, Edelbrock Super Victor, maybe the new MSD/Atomic (waiting on better info), Vararam (haven't seen any pricing yet & I'm not sure if its available), or a stock LS7 intake. I haven't been impressed with the FAST for the LS7.

I'm sure there have been threads about intakes but I haven't seen much recently and there are some new players in the game.

If you can backup your opinion with facts that would be a great help.

Thanks

D9HP

I'm building a 454ci LS7 for road racing myself but mine will spin up to 7500RPM.

I am going to run the Holley Hi-Ram EFI w/ 105mm throttle body.

It was between that and a ported LS7 intake. The holley hi-ram will sacrifice some down low torque but make more power over 6k RPM from everything I've read. It's comparable to nice sheet metal intakes. John B has a very detailed thread on the subject.

https://ls1tech.com/forums/generatio...-102mm-tb.html

ss performance

iTrader: (17)

Thanks for the link. I missed that one.

I have been leaning toward the Holley but was looking for some hard data.

I might spin my 454 higher depends on what my engine builder says.

What is your HP goal? What class are you running in?

ringram

depends on where you want your power. For street use the Fast or MSD will be best. For track etc one of the short runner setups. Mast, AllPro, Victor etc carb intakes seem best for outright power.

lil john

Above post is so True.

gnx7

iTrader: (28)

JohnB's sharing of info with how intakes perform is awesome. Helps to justify the high $ intakes.... or not.

I'm also doing a road race build with a 13:1 e85 4.190" bore and 4" stroke. I don't want a longer stroke as I do plan to spin it to 8K or more when needed.... ie not upshift prior to a corner or passing/holding someone off. I have AllPro Ls7 430cfm heads and single plane full ported AllPro intake. It's main downfall is the height and it will give up some low end power. I figure I won't be under 3500rpm much and my lightweight won't need the missed tq down low. Shooting for 2850lbs with driver.

If the intake is ridiculously tall I am looking at the new MSD intake. If I run the single plane setup and duct the back side of the radiator to the hood (the exit) real downforce can be realized. My car is a 9 second car all motor.... so I need to focus more on downforce now.

Also note that any major bend in the intake stream takes a HP hit. My previous straight shot intake feeding an LS7 intake manifold over the radiator like a Corvette.... makes more power than one with a 90* bend in it like you see in most conversions. The Howe dual pass radiator lays forward at a 60* angle with a Ford Taurus 40000cfm fan fully ducted. No cooling issues at all. I use a coolant vacuum pump to add a tad more coolant.

I real dry sump system (not a production LS7) will create crankcase vacuum and help with blowby. If you aren't dry sump look into the GZ motorsports vac pump or similar. Improved Racing makes a nice oil pan baffle..... that with an Accusump can save your motor.... but not much cheaper than doing the real thing in the end.