I have a mild 383 that still has the factory TPI on it. Yes, it's in a Vette, but please don't hold that against me. I owned a 1989 Formula previously... Engine is a mild 383 with Eagle crank and 10ish:1 dished Sealed Power hypereutectic pistons, cleaned up stock heads, 212/216 (I think...I'll have to dig through receipts) cam, and Hooker LTs.
She made 266rwhp/370rwtq on the dyno, but fell off a cliff at 4500rpm. This is through a 700R4/2.59 gears.
I wanted to upgrade the intake as I know that I'm probably leaving some HP on the table. The problems are:
a) I don't want to spend a butt-ton of money
b) I don't want to lose a ton of torque (A4)
c) I don't want vaccuum leaks, or added install/removal hassle

If I could get some real world experience with set ups (like SLP/Edelbrock runners & ported base, FIRST intake, SR & MR, etc...), it would really help my decision. I don't mind looking for used stuff to keep the price down.
Magazine articles don't always put things into perspective, so if anybody could spend a couple minutes and share their set-ups, numbers and reviews, I'd be greatly appreciative. Thanks!

 

Do you need to pass a visual inspection? How about on the rollers? If so, you might not want the HSR (stealth ram), MR (miniram), or converted LT1 intake.

HSR doesn't fit in the vette unless you modify it a bit.
LT1 takes some work and knowhow to convert yourself, but can be bought pre-modified.
MR is not a good match for your cam.

I would lean towards SuperRam, or (if you want to keep the TPI look) some Large Tube Runner (LTR), like AS&M, Edelbrock, etc...

 

The inspection guys only do a visual for the cats, so an intake wouldn't matter. I'm leaning towards the ported base, hogged plenum and LTRs...especially if I can find them for cheap.

 

If your staying TPI just go FIRST.

For $1k, u get the intake, runners, plenum, tb, and fuel lines to swap it right on no rigging stuff up no clearance hassles and it will let that engine run out some more too.

It will beat any other TPI top end you could swap on there also,

later
Jeremy

 

A test was recently done on a First Intake manifold. It flowed 301cfm right out of the box. That will flat get it done.

 

I cut and pasted the following from a previous post. I've run a fully ported stock base with SLP runners cut back t oabout the halfway point, the Stealth Ram, and the FIRST on a "420 horse" 355. This is my spin on the intakes.
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If I never raced the car, I would have kept the ported stock base and modified SLP runners on the car (5500/5300 shifts). Absolutely violent throttle response off idle and around the stall speed. The thing would skate the street tires from a 2nd gear kick. An absolute blast to drive,, but it dropped off really fast around 5700rpm.

If I only raced the car, I would have kept the StealthRam on the car (6400/6200 shifts). You couldn't screw up a launch with the thing at the track, but it was just not that fun to drive around town compared to the TPI/SLP combo. Plus, I didn't like running the stamped steel rocker arms up that high. It's without a doubt the intake to run if you don't mind running a lot of cam, gear, and converter. You can make some serious power and with the right combination,, serious ETs with it.

Since I like to drive and race the car occationally,,, and don't want to run a lot of cam, gear, or converter,,,, the FIRST unit is a perfect medium (5800/5600 shifts). My IROC was .1 seconds faster at the 60ft mark than the HSR, .2 seconds faster at the 1/8, and runs about the same ET in the quarter (box stock intake). It's not as violent as the TPI/SLP combo (peak torque is higher in the RPM band), but it has much more throttle response than the HSR and a blast to drive around town. It runs about the same ETs shifting as high as 6000,,, so it's not that it isn't still pulling at 6000 rpm as much as by shifting at 5600 or 5800 rpm, you're able to take advantage of the huge torque boost from the intake. In fact, I have to shift the car at 5800 out of 1st, because at 5600 rpm the slicks will lay down 2-3 feet of rubber.
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Needless to say, I really like the FIRST. Considering it comes with a 780 - 800cfm t/b,,, at $1000,, it's no more expensive than a Edelbrock intake ($385), AS&M runners ($395) and a 52mm T/B ($280). As Allen said, the base flows over 300cfm right out of the box. With your combination, about all you would need to do is bolt it on and go. However, the main benefit by going with the FIRST is there is more than enough material to port the thing to support 550 or so horses just in case you wanted to build something like that later on down the road.

Saying all that,,, for what you have right now, if you can do your own porting, hogging out (not siamesing) the stock base and plenum along with a set of SLP runners cut back to about the halfway point,,, is hard to beat the bang you'll get for the bucks. If you have to pay someone to port it right (I get $250 for an intake, $200 for the runners, and $80 for the plenum) then you're back at the FIRST not being any more expensive than the ported stock stuff with SLP runners ($330).

 

I would highly recommend before you spend any money that you siamese your lower intake. This will ALWAYS pass visual smog since it's still stock and cost nothing but material. It will shift your power band upwards and you won't lose to much torque. The good thing about this mod is that it can be done for just some labor, a saw zaw, and some carbide bits. If you don't like it you can always spend some money and move onto something different.

 

Who sells the complete First setup?

 

You get the TB and rails included? ! did not know that and that is a major plus! I'll get busy looking into the FIRST.
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Hmmmm. Yet another vote for the FIRST. This is far different from the responses on the Corvette boards. You guys rule!

 

This is the kind of review I am looking for. The HSR is kind of out of the question for me anyways, as I'd have to get a new hood. The FIRST is looking like a better option all the time! Thanks for your review and, by any chance, did you dyno any of those three combos?

 

Go to http://www.firstfuelinjection.com/. Pretty impressive info. I'm in a quandry right now over what to do with my Z. With local government regulations so fickle I don't want to stray too far from the factory design. In spite of what I've said in the past about the excellent HSR and also the LT1 mod intake I keep leaning to buying an Edelbrock or TPIS and porting my SLP siamesed runners. I've already siamesed the upper intake plenum to the SLP runners. I may open them up to the mid point and use the TPIS Bigmouth manifold. This car sees about 98% of its time on the street so honestly I don't need much more than that. You've got to be honest with your self about what you are doing with the car.

 

No problem. I dynoed the StealthRam combo and it made 330rwhp at 5850. Torque was around the same at 4600 (which was out of the range of the torque multiplication factor of the 3000 stall). The StealthRam combo (TH350 transmission and 3.23 gears with 26x11.5 ET Streets) ran mid 12.30s in 48 degree temps and mid 12.6s in the 90s. Same combo with the FIRST ran high 12.5s in the 90s and was much more fun to drive on the street,,, although probably a little slower from traffic light to traffic light as the street tires hooked fairly well with the HSR and you had to work the throttle with the FIRST. Torque was definitely up,, I guess somewhere around 370 lb/ft at 3600rpm and somewhere around 308 rwhp in the neighborhood of 5300 rpm to run similar ETs.

 

Thanks so much gentlemen. I may be a FIRST customer...

 

in your neck of the woods do they just check the cats or do they check for the air tubes on the headers too? i kinda want to get rid of those and clean up the engine bay a little bit.

by the way when i made my hsr swap.....i didnt lose but maybe 10 ft/lbs of torque......

 

I have a 383 set up similar to yours and i had good low end power with a modified TPI. It was realy strong through 1st gear and dogged at around 3000 in 2nd but took off like a bat out of hell in 3rd. I put a stealth ram on it over year ago, but sadly i havent drove it yet. I had it running for about 1-2 minutes in the garage ( it sounded better and more powerful as wierd as that may sound) then i riped the harness out to start working on it and havent touched it since. I know someone else who did the same and he had great inprovements with the stealth ram. I would highly recemend it and only cost around $500.

 

The last inspection, they just did a cursory look under the car, saw the big cat and were cool. I don't have smog fittings on my LTs...
I think the HSR would require too much "massaging" to fit under the Vette hood.

 

Again, the SR needs some serious work to fit a Vette
FWIW, I contacted FIRST and they said that there have been Corvette hood-issues with their intake as well. Not everytime, but enough to make me worry. I'm also looking at the BBK development...

 

First is a great TPI setup but you have a very small cam for that 383. i'd stick to a used runners base modification first before dumping all that money on a FIRST. you'll save money that way and gain great performance. the 301 cfm FIRST is overkill for that cam. if it was bigger cam, i'd say FIRST all the way