92 305 BIRD

i was thinking about getting a intake manifold. and i was wondering who makes a good one for tbi or a 4 bbl with the tbi adapter.how much does the manifold give you? or is there some thing eles around the same price that would be better to get? my current mods are listed in my sig. any feed back would help thanks.

vjo90RS8

iTrader: (1)

since you live in CA, you might want to go with the CARB legal Edelbrock Performer TBI but you might be able to get away with using the Edelbrock Performer carb intake with EGR and an adaptor plate. The carb intake would be better for overall performance but the TBI intake will be a direct replacement.

ShiftyCapone

iTrader: (7)

If you aren't going with a crazy heads and cam set up than the Edelbrock TBI manifold will be fine. It is a great bolt on and can be done in a couple of hours. If this manifold had 2" bores than it would be perfect to use on a heads and cam lo3. But most heads and cam cars need a little more air than the stock bores allow. I would save your money right now and invest in some headers. You really won't see any gains with this manifold with the mods you have now. I put it on before I had headers and I felt Zero gains. It did pull a little harder up top but the stock intake was more than adequate to supply the lo3 with air.

txhotRS

I have the edelbrock TBI performer intake... it'll make a difference (not very noticable though).. it'll help some with mileage, and upper end, with a little bit of response... it'll help WAY WAY WAY more if you also have heads, cam, headers( or any combination there of)... plus, like the other guys said, it's 50 state street legal.. which is a big +++ in my book..
if you are going to go that route... spend some money on a 360 intake with a K&N filter... you won't be disappointed.

txhotRS

remember that an engine is ONLY as good as it's worst part, the old intake is ridiculously restricive... and basically not a very good design. and if you are going to do other mods... the edelbrock TBI performer a great place to start

ShiftyCapone

iTrader: (7)

If the thing had 2" bores it would be great. I too have it and I would have never kept it with the heads and cam set up I was going with. My buddy has an LT1 cam and vortec heads on his LO3 he cannot get enough air. He has a carb performer vortec intake with the stock TBI. If the TBI unit connot supply enough sir with the stock bores than neither can the Edelbrock. It is great as for street legal concerns and ease of installation. That is why I got it. Any heads and cam set-up should implement another intake option.

DanRS

What's a good one with 2" bores then? (preferrably bolt on or slight modification required) and wouldn you need a new TBI unit to match it?

MrDude_1

exactly.

the problem is, every part on the l03 sucks.

thats not a put down... its a fact that not a single part on here was made with any kind of performance in mind. lol..


things have to work together in the engine, and right now the most restrictive point on your car is the exhaust. after that, its usually the cam and heads..

while the TBI and intake would choke any decient engine, the l03 isnt a decient engine... therefore you have to make more power (or atleast have the potental there) before they become a real restriction.

Dewey316

yup, hit the nail on the head.

to get what most people want out of an L03 you have to replace everything. kinda a bummer, but when you are doing all that you can go as wild as you heart desires (well or as your computer skills allow your heart to desire)

r90camarors

The Holley TBI Projection intake is great. Only slight mods needed to make it work, and you can use the stock tbi if you want to i guess. There was a huge sotp difference when I installed it along with the 1.6 roller tip rockers. Part # is 300-66 if I remember right

MrDude_1

now wait a sec.

what do you think made more of a diff..

the intake replacing the stock one, that, like i pointed out above, isnt the first, or even second restriction on the power of the car....


or the fact that you replaced GMs peanut cam specs, the smallest cam they ever put in a SBC, with 1.6 rockers giving you some decient lift???


when you change 2 things, you cant pretend that you can tell the diff between witch made what power.

r90camarors

Actually, the two work in conjunction.

I could have replaced the cam or just installed the rockers but left the stock intake on there. Or vice versa. But doing so wouldn't have gotten me the results I was looking for.

For example, and only example:
Say I only added the 1.6 rockers and yielded a .1 second gain

Now say I only added the intake (no rockers) which yielded a .1 second gain as well

So the math would say that doing both would yield a .2 second gain. But in reality the two work together and I get a .4 second gain
Like I said, for example only. However, the stock intake does suck, and I will stand by that. I set up my old 305 to breath, i.e., full exaust, holley 670, open element, and ignition, so the next step was cam and intake. Cam swap was to expensive (after you add EVERYTHING up, so I just opted for some inexpensive 1.6 roller tip rockers and the intake, and it really woke the engine up.

r90camarors

Also, I would argue that the stock restrictions look like this in order: 1)STock air cleaner and exhaust 2)stock ignition coil...the stock one falls flat on it's face after 4,500rpm-the msd one will supply the voltage needed 3)stock intake 4)peanut cam 5)1 11/16"TBI 6)swirl port heads

seanof30306

iTrader: (4)

i talked to jim jones awhile back. he's currently head of engine development for callaway corvettes. he used to own traco engineering. in 1989, they took an 89 camaro rs l03 5 speed and got well over 300 hp with the stock short block, aluminum vette heads, custom ground cam, custom chip, 350 injectors and the stock tbi unit!.

he said they dynod the engine with the performer tbi and the performer carb intakes. according to him, the performer carb intake was worth over 20 peak hp and almost 35 lbs ft torque over the tbi intake and performed better all through the rpm range. he said the problem with the performer tbi intake is plenum volume. according to him, when you're running a throttle body that small, plenum volume becomes critical.

btw, the only reason you'd need 2" openings in the intake would be if you were going to run a 670 holley or a 454 tbi. i read somewhere that you couldn't take the edelbrock tbi intake out to 2", but i talked to a machinist who said he's done it several times with no problem. all he needs is a gasket to use as a template and 20 bucks.

i

va454ss

iTrader: (1)

Just for kicks, I measured the plenum depth of the Edel TB manifold and the Edel RPM Air Gap and they are the same.

I also had the bores in the TB manifold increased to 2.2 inches, to match my TB.

The intake swap alone made considerable difference on my truck throughout the RPM range. The TBI manifold had also been Extrudehoned, so it was at its extreme limit.

Anytime you can increase plenum depth, it is beneficial. I believe this is the reason the TB spacers are touted so much. They may have merit on the restrictive stock manifold, but the jury is still out on the aftermarket manifolds.

Of course, all my comments apply to a BB, but should be similar for a SB.

r90camarors

That's interesting stuff sean. I always thought the performer tbi was modeled after the performer intake

r90camarors

I am still amazed that you got 2.2" outta the tbi va454. That is amazing, I have hought about attempting it, but there is already almost no extra room to play around with as it is.

va454ss

iTrader: (1)

Personally, I didn't get it myself. A fellow club member does the mods. The bores are so large that they extend into the 2 rear slots for the mounting bolts, and reduced diameter bolts must be used.

The guy that does it made the first one to use with the Edel Multiport conversion. I was the first to use one with the injectors in the stock location.

I am one of the diehard TBI guys in the truck club and am determined to push it to its limits!

There's much more experience on this site with TBI, and that's why I'm a member here.

r90camarors

Sounds good va454. I definetely compliment you for your efforts. I love to see people pushing the limits of tbi.
Just outta curiousity, do you have problems with the adapter as far as sidewall clearance goes? I know if my bores were any bigger, they would over lap the intake edges and the center divider.

va454ss

iTrader: (1)

Yes, I had to do a little blending to get the adapter bores to blend smoothly to the intake.

My truck has been a best of 13.42 @ 99.92 mph. Since then, I have installed 3 inch duals with H pipe, 2700 Vigilante convertor, homemade ram air, RPM Air Gap manifold, alum driveshaft, 4.10's, 315/60 drag radials, and big cap Perfomance Distributors HEI.

This was also with an off the shelf Hypertech chip.

Now, I'm way lean and need to upgrade the fuel pump and get this thing tuned.

Oh yeah. I was running 8.0 CR on the 13.42 with iron heads that only had a cleanup of the bowls. I will be installing a set of ported iron heads and an increase to 9.0 CR.

Do ya think I'll make it to the 12's?

r90camarors

without a problem especially with all those mods you've done since last time you've ran. Chip tuning is key though, and may be the deturmining factor.

How did that rpm air gap help you? I'm swapping to one next week from a performer

va454ss

iTrader: (1)

Not sure exactly what you're askin', but here goes.

I have a mild hydraulic roller cam that is rated to 5200 rpm.

With the TB intake, the engine was pretty much done around 4700 rpm.

With the Air Gap, throttle response is improved and the engine pulls hard to 5200 or beyond.

Bill

va454ss

iTrader: (1)

Here's something else to consider.

Others have successfully used single planes with TBI. The loss of signal strength at low rpm's doesn't have the negative effect on TBI that it has on carbs, so low end response is not affected.

I don't know this to be fact based on my experience; just what I have heard.

On that note: If an engine is equipped with an 800 cfm carb (or TB) each cylinder has access to 400 cfm if used with a dual plane intake. If a single plane is used, each cylinder has access to 600 cfm.

Again, this is something that I have read.

But, I will find out myself, as I have a single plane waiting to be tested on my combo.

357mag

Don't know if any of you have seen this, but it makes for good reading.

Never mind...

Tim sends

r90camarors

Never mention that article again!! The best thing you can do Tim is to go back and edit that post and delete that link. Trust me on this one

seanof30306

iTrader: (4)

ha ha ha ha .... he's a little intense, isn't he?

actually, it's not THAT bad. there's a link on one of his pages to an old car craft article that shows a cheap way to make a power bulge hood a functional cowl induction hood that flows A LOT more air than the 83-84 unit. here's the link:

http://www.hioutput.com/tech/air.html

r90camarors

It's just that that article has been discussed so many times I cannot count. There are some descent points in it, but nothing out of the obvious. I read that article when I was a newbie and was set to run 12s on a N/A 305 tbi....then reality hit

seanof30306

iTrader: (4)

i was the same way with the "f-notes" project in hot rod back in 1989. thing is, i still believe it's a great base ... they got over 300 flywheel hp out of a stock short-block 305 with 14 year old technology. with the advances in head and cam design today, i believe there's more there.

r90camarors

I agree with you there. 300hp is a great feat, especially given the the time era

88Camaro350

If it was me I would just get a carb intake and the adaptor plate. When I had my l03 in I had the edelbrock TBI intake. I was not impressed. It was tiny when placed side by side with my holley street dominator intake. Also if you get the carb intake you could reuse it if you ever switched over...(don't bash im just saying you could).

Edelbrock RPM is a good intake...the peformer isn't to special tho. Basically like a stock replacement that flows a tad better.

Gunny Highway

iTrader: (1)

Yeah, but does the Performer RPM fit underneath our hoods?

ShiftyCapone

iTrader: (7)

Yes they do. You cannot run a gigantic spacer or anything but a stardard performer intake will fit. It is tight, but fits.

Gunny Highway

iTrader: (1)

And that includes having a tbi - carb space adapter? And what size of air filter are we talking here? I would think that a 14 x 3 would be too tall. I already have a dropped based filter, but it's tight as hell in there now.

And 2nd, what about EGR provisions and things of that nature? Does the RPM have the straight bolt-on capability as the Performer TBI?

Gunny Highway

iTrader: (1)

ttt

DanRS

RPM doesn't have EGR.

ShiftyCapone

iTrader: (7)

I have the Performer TBI manifold which is .25 inches higher tyhan stock and a .5" TBI spacer. So I my TBI unit is .75" taller than stock and I have a 14x3 open air element. It fits and I still havwe the stock hood insulation on the underside as well. my buddy have a vortec performer TBI intake with a carb adapter and he has plenty of clearance as well. His is tighter than mine but his hood still shuts no problem. You do have to be careful what nut you use on top. I am using one that is almost flush with the top of the open element.

badbird88

Granted I don't have a 305 but the best thing I ever did was go to the Holley Projection Intake over stock...however, you will want to throw it out the door on the mods you have to do to it but it was worth it compared to the stock intake. I could rev on up to 5500rpm with no problems. I also picked up low end and didn't loose any as you may with a single plane intake. After reading all these mods you can decide what you think about going to Holley Projection.

1) DO NOT use the stock intake manifold bolts unless you add 2-3 thick washers to them. The stock intake has raised bolt mounting surfaces and the Holley does not. The stock bolts will hit the rocker arms in some of the locations so go buy a set of standard small block chevy bolts.

2) You have to have a spacer with the Holley projection manifold even if using the Holley TB because the fuel lines will not go on the TBI due to hitting the intake...wonderful engineering there! I also had to cut my stock fuel lines and used braided line in between the TB unit and the part where it connects to the rubber flex hose near the power steering pump. I left about 2 inches of aluminum line on the connectores and simply clamped the new braided line to those to eliminate having to find new inserts for the TB and the stock fuel line connectors.

3) I have to use a 14x2 element to keep from hitting the hood.

4) This does have EGR so trying to find one is like trying to find the winning lottery ticket...even Holley couldn't tell me what was the correct EGR valve to use. However after trying 3-4 I found the correct one and it eliminated the EGR code being set in my computer that I had since I put the motor in 3 years before all this. THe part number is EGV328 and is made by "Standard". You may have to massage the edge of the EGR valve where it mounts to the manifold because once again Holley didn't machine it to specs or the Standard EGR valve wasn't made to specs...either way one grinder and 2 minutes later problem solved.

5) I used a .75 or 1" spacer if I can remember right that was homemade so it's not the best looking but it works and only cost me $5 and it's aluminum. Anything smaller and I had fuel line clearance issues. You can measure it before you buy to be sure though.

6) You need to make a extension to get the throttle cable to hook up to the Holley TBI due to it moving the throttle cable bracket back about .5". Not sure if this is an issue with the stock TB but even on the stock manifold the Holley TB had to be modified on the throttle linkage hookup b/c it is designed to replace a Truck TB not a car.

I have pics of my setup from most angles so if you need them let me know.

badbird88

oops, double post