1991 RS 305

I have been searching for a couple days on this board to figure out what intake I want to go with. I purchasd some vortec heads and now need the intake. There are tons of posts on intakes. I am finding that people like single plane intake manifolds with the TBI. I'm seeing Edelbrocks Vortec super victor, which has aan RPM range of 3500 to 8000. I know that with TBI you can move that band down 1000 rpm's vs a carb. But even 2500 RPS's seems a little ways up the band for an engine that only revs 5500. Is this really a good intake to go with vs say the Performer RPM dual plane. Any other suggestions. I am not worried about EGR, no smog police here. Other mods to car will be headers/exhaust, possibley upgraded TBI (Havent gotton to my research on this yet), Cam is out of a 97 LT1, I will be burning the PROM. Engine will be a 305, not swapping to a 350 or anything and it's a manual car if any of these things matter.

Thanks for any help. The next couple months should be fun seeing what this 305 can do.

flaming-ford

iTrader: (7)

the victor intake would be a bad choice imo. I'd go with something like the edelbrock performer rpm as you said. Single plane vs dual plane has been disccused a lot in here but, imo dual plane is going to be better for you in a street application.

bluers91

There is also the GMPP vortec intake, but its rather pricey at over $300. Performer probably your best bet.

Ronny

iTrader: (1)

i dont see anything wrong with a dual plane on a TBI. my Holley Projection TBI intake seems to work just fine. it is a dual plane high rise per Holley. i would hope holley has the engineering skills to develop the manifold to a tbi application and get it right.

i agree the victor is overkill. venturi velocity is somewhat important. may be lacking in the victor unless you are up in rpm scale. lack of velocity low mph operation may cause erratic 02 readings. that is why i am open loop to improve idle and low speed operation. seemed to help me.

BMmonteSS

The performer RPM will make more power than a Victor Jr. every where below 6000 rpm, above that the victor has a 10 HP advantage. Below 3000 rpm the RPM can have as much as a 20 FT/LB advantage.

So basically it's a no brainer which intake you have to run, your only problem is going to be getting it to fit under a stock hood. My brother got the GMPP intake to fit with a drop base air filter and a 2" filter. I believe the RPM is 1/4" to 1/2" taller. A thin adapter plate will help considerably.

1991 RS 305

Thanks, Matt.

galvarado

I've got a GMPP Vortec TBI intake with flat base 3" open element and it fits under my stock hood. It does hit the hood insulation but so did the stock air filter housing.

Gene

BMmonteSS

I guess I shoulda mentioned my brother has a carb, but his carb is the same height as my TBI with my thin adapter plate. What type of adapter did you use?

DM91RS

Performer RPM Vortec....

Here's an old pic but it will fit under stock hood with some mod's. Used a 3/8 or 1/2" adapter. Note hood above filter area. Use of a shorter filter will add alot to clearance. This one is 1" taller than stock.

galvarado

I didn't use an adapter plate or a spacer. It's a TBI intake so it wasn't necessary to use an adapter.