I just acquired a Superram plenum and runners. It will be going on my otherwise stock 1988 L-98. Is it worthwhile to find a matching base? I see that LPE has it for $399.00 and they have the Edelbrock base for $398.00.

 

Get the SR base. When I bought my used SR it came with edlebrocks Hi-Flo base. I have had issues with having had to notch the valve covers to get them past the runners as well as the SR gaskets not fitting the runner ports on the edlebrock base well at all.

 

Let me refine the question. For my application should I use the factory base or would it be better to use the Accel base?

 

Super port the stocker or get the larger base!

 

It would be better to use any of the aftermarket bases over the factory base.

 

Wouldn't it depend on whether other engine mods were being used?

Stock base flows 200cfm. That's more than the heads. I understand that the shorter runners and bigger plenum of the SR will change harmonics -- moving power up in the power band. But, having a bigger base?...

I kind of look at it like the TB issue. When people put a 52mm or 58mm TB on an otherwise stock motor. It increases the air flow "potential", but isn't really needed.

If the stock base were ported to match the SR on the intake side.... I'm thinking good enough. (might even improve velocity with a smaller base). Unless other engine mods were being installed, should we recommend the extra $400 expenditure to this guy?

 

Thank you, that's what I'm interested in. If I go all out on this car it will be an LS transplant. Right now I've got a good running 112k mile engine. The intake was a good price. The guy I bought it from has a tube frame Porsche 914 with a twin turbo aluminum small block dynoed at 1100 hp. sitting in his garage and some other absurd vehicles. Anybody interested in an intercooled twin turbo fuel injection set up for a big block?

 

I think its pointless to put the SR on an engine and leave it with one of it's most restrictive parts, the base.

You're putting an intake on it which wants to rev a little higher, but keeping the stock intake chokes much of it out.

Plus the aggravation of installing a SR should be forced on someone as few times as possible, so doing the base and the rest at one time is preferable.

 

Unless you plan on changing the heads and cam you really don't need an aftermarket base. You could port your stock base and save a few dollars. You will need a base with an EGR if you plan on passing a Cali smog.

My stock 88 L98 with a superam has run a 13.7. That's .7 faster than stock. All I did was open up the intake. The exhaust is smog legal 2 1/2". The heads and cam are stock. I have a few bolt ons.

 

If you want to maximize your HP gain you should have the aftermarket base. A good rule of thumb to follow is that the intake should be able to flow 20% more air then the head for the intake to not be a restriction to the head. The stock head can flow around 200 CFM at 1.5" of pressure so the intake should flow around 240 CFM.

 

Check out the flow numbers, you'll see the bases really need help! Port even the large base.

http://temp.corvetteforum.net/c4/vader86/flow.html

 

I don't know if I dig harder than others, but I find info that supports a different conclusion than the prior two posts.

I can't link it directly, but Vader's website also has a page on 113 flow specs. So does StealthRam's website. Compare them and you will find the same data. IIRC, it came from TPiS?

This post in 3rd gen reprints a tech mag's results on the 113 heads.

The link in 3rd gen shows the 113 heads flowing @ 176 cfm with stock cam lift. It's unclear what the stock base flows, but I'm betting it to be the 211cfm # posted on Vader's website (linked by Aardwolf above). After all, the combined runner/stock base flows ~200cfm (per all these links, so you can be sure the base alone flows more. (The longer, bending stock runners have to bring base numbers down).

15% more than 176cfm is just about 200cfm. That's why I believe the stock base is big enough for a stock motor. Even if the 113's flow 185 -- like some want to believe, the stock base still flows more.

113's = 200cfm? In the past year, I've spent a ton of time looking at specs, mods, and numbers for the 113-headed L98s. I've never seen claims this high!

gp

 

My vote is that the data came not from TPiS, but was compiled by former
member GV, whom is now a mod at DC. He was/is active on many boards
and posted that information in several places.

I've seen some.

.

 

I've also seen some flow that, as high as 203, also as low as 180. 195 being pretty common. Just cleaning up the large base is a help, there's a ton of casting ridges.

 

Paaaalease....

Let's see those links. Show us where the 113's have been flowed 190-200cfm at .415" lift. I'd like to see that. (Remember this post is about a STOCK MOTOR!)

Is it anywhere near the AIRFOIL=20hp post?



To the OP... Clean-up (ridges/casting flaws) and port the stock base if you pull it off. Otherwise, just mount your SR on top of it.

 

Paaaalease.... don't take this advice... Waste of time and money!