I'm building a new motor for my 70 GSX. I'm pulling the origianal, matching numbers Stage 1 and storing it. Looking to build a solid 500+ hp street motor to replace it with. I'm well on my way and have run into a snag with the proper choice for the intake manifold. I don't think there is a manifold choice that will allow me to continue to run the stock Ram Air set-up and make 500+ HP using TA Performance Stage 2 Street Eliminator aluminum heads and a square bore carburetor. If you've found one please let me know!! But I do want to keep the stock Ram Air hood. My research has led me to the SP-1 manifold from TA Performance. My concern is with the note that indicates that it is 1-3/4" taller then stock and that "using a drop base air cleaner with a 3" element in most cases allows adequate hood clearance". This is why I'm reaching out to you. Is anyone using the SP-1 manifold on a 70 GS with the Ram Air hood? Does it fit with a 3" air cleaner? What type of carb are you running? Did you notice a significant performance improvement? Thanks in advance for your response, Frank
No hope on an SP-1. I am one of the cases that a 3" element aircleaner and a 2" dropped base will not work.
Edelbrock Performer --Not the B4B-- would be a good choice if you want to retain the factory "Ram Air".
Edelbrock Performer I know the Performer works with the stock Ram Air Cleaner assembly, but it's only good up to maybe 450 HP. Is anyone pushing more then 500 HP with a Edelbrock Performer? I also think it only comes made for the spread bore design like a Quadrajet. I'm not aware of any new carburators that are larger then 800 CFM that come in a spread bore design. Do you know of a company that makes a new, large spread bore carburator? Frank
SP-1 doesn't fit Doug, Wow, that's not what I wanted to hear. What type of carburator are you running? Just wanted to confirm that you have the Ram Air hood as well? So now what are you doing for an intake and hood combination? Frank
Frank, Give Jim W. a call. I know for a fact several engines have come through his shop that made 500+hp with the performer, quad, and cast iron manifolds...of course using a set of good flowing heads like the ones you mentioned. So yes you can have your cake and eat it to. If you want more details, pm me.
My engine has the weird combination of Stage 2 heads with an Edelbrock Performer.It was dynoed at over 500 hp.It has a square bore carb(Bigs 950) and a 4" aircleaner assembly with a 1.5 inch dropped base.It all fits under a GS hood.The whole thing works pretty well. Rod
Using that triangular shaped Edelbrock foam air cleaner now. Have a stock GS hood, does not give any more room. Working on a custom design now. Who know when it will get done.
Frank, Yes, you will have to use a Performer to make your GS air cleaner fit, and yes, you can get 500 HP with one.. Since your running stg 2 heads, your obviously going with headers, and you won't have an issue getting the power you want, as long as the heads flow around 315 on the intakes, which is just a bowl/chamber job, with a good competition valve job. About a month ago we dynoed such a motor for a 68 Riv, it made 525 HP if I recall correctly, with 10.4 to 1 compression, a 230/234 cam on a 110 lobe center STG 2 SE heads that flowed 317 on the intake side and 250ish on the exhaust, and ran it thru TA 2" STG 2 headers. Performer and an 800 cfm Q-jet, and a 950 Holley only picked it up a couple HP.. All sitting on top of or basic level 1 shortblock, which is a stock rod deal, with a zero deck height, and Speed Pro forged pistons.. nothing exotic. At the track a 1" spacer is worth about 10 HP give or take a little.. install your air cleaner in the trunk.. :grin: And yes, we have made over 500 HP with STG 1 Alum heads, Performer, cast iron exhaust manifolds and a bit bigger 238/248 cam. All of these motors are pump gas and vacuum accessory friendly. Watch the performer manifold carefully, they had a core shift issue on the last two I saw, and I actually had to fill in the bottom of the ports on just one side of the manifold, (# 5 and 7 if memory serves) as the cores had shifted, and caused the manifold not to match with the head, on the bottom of the port. No biggy if you catch it, fairly easy fix, just a couple hours of fooling around. You will have to do a fair amount of porting to the intake, as the exit size of the manifold is very small compaired to the TA heads. That work is worth around 15 HP on a 500 HP combo. Port match it, while leaving a bit of material in the ports, to make sure they are a touch smaller than the heads. If you have the engine all cut to make everything fit perfectly again, then you can do a nuts on port match, but that is a horse of another color. That should help you on your way, good luck. JW
I used to have a Performer intake on my engine. It fits fine, but does sit a bit higher and the carb is slightly moved. But you can use the factory air cleaner assembly. I now run an SP1 on my car. I had to get a drop base chrome air cleaner with a 3" element. I still had to "trim" the drop base another 3/8" or so to keep it from hitting the top of the hood. Forget about using the stock setup. I now have a Stage 2 scoop on a Skylark hood on the car. My engine runs pretty good. I've done some simulations with Desktop Dyno and am thinking of going with a Gessler prepped Performer intake and q-jet Edelbrock carb. Supposed to make the car even quicker as I never take the engine past 6000 rpm's anyway and the Performer will give me more torque down low where I need it. Unless you're going to be revving your new engine past 6000 rpm's on a regular basis, you'll probably be better off with a dual plane intake.
