Alright guys I have been researching possible intake manifolds and I have come up with nothing but confusion and contradictions. Hopefully this thread will clear up some of my confusion.

History
-First of all my intake manifold gasket is leaking so I really think I should replace it before something decides to go bad.

-Secondly I am looking for a manifold with EGR, I dont know where I am going to wind up after college and dont know what emissions are going to be like so I figure I should go the safe way and keep the EGR so I dont have to swap in another manifold later on

-The car (92 RS) is basically stock. I plan on doing cam work in the future. So I would need a manifold to match the cam I plan on getting a LT1 cam or mild XTreme Energy comp cam

-I am still looking for a single plane manifold, from what I read those tend to do the best.

I was thinking about these.....
EDELBROCK PERFORMER RPM........... but no EGR

EDELBROCK PERFORMER........doesnt seem to be that much better than stock, doesnt seem to have that good of a reputation

"Theres no contest here anyways everyone knows the preformer TBI stinks."
-Pablo
WEIAND #7525 (this is what I found when I searched)

"way too much for a mildly modded motor" - RScamaroguy92

WEIAND #7546.......no EGR

WEIAND STEALTH

"do the ultimate TBI mods, get bigger injectors, get the Edelbrock TBI intake, the stealth has given people nothing but trouble, from vaccum leaks to odd placed TBIS" -Tas

I really dont know what options I have. Does a quality manifold with EGR exisit??? Am I just missing "the one" I just got confused and I was hoping that you guys would point me in the right direction of finding a good manifold without loosing my EGR

Thanks
Jason

 

Well, I liked my Edelbrock Performer intake. It was much better than the stock one and required no fabrications. Edelbrock rates it from idle to 5500rpm.

 

GM performance parts makes some nice manifolds, dont know if the make any singleplane egrs.

I was under the impression that single plane's did better at higher RPM than dual plane's. I also thought that higher rpm usually means a bigger cam which usually means no smog. I do have a fairly uninformed opinion though.

Charlo

 

True, if this is gonna be a daily driver 305 with only mild mods... a single plane intake is probably not the way to go.

 

It may also explain the lack of single plane manifolds with egr's.

Charlo

 

GM Performace Parts ZZ4 intake manifold has EGR provisions, but it is a dual plane manifold. Its for carbs so you'll need the adaptor.

 

So stay away from the single plane and look for a dual plane?

 

Well if Pablo said it, then it must be true. :lala:
I think those intakes work fine if ur staying mild and nothing crazy. If your gonna try and go nuts with ur 305 then i would get one of the other nice ones u mentioned. I heard good things about thw Weiland Stealth intakes.

 

Yes. You've got to have quite a cam and heads to need a single plane. There is the exception of the "low rise" single planes some companies sell, but IMO, those defeat the purpose of either design.

Too many people get caught up in the "idle-5500" thing. This doesn't mean the at 5500 RPM the engine's gonna fall on it's face. It's not TPI.

It'll run fine up to 6000 (which requires a lot more mods than a lot of us will ever do), it's just the intake is not as efficient up there. Besides, most of the statements like "idle-5000 RPM" is a ball park estimate recommendation. Nothing more. It doesn't mean the motor won't rev higher than that, nor does it mean that intake will automatically make your engine rev that high. You gotta have the cam/heads/exhaust, etc. It's a package deal.

 

and those "idle-5500" are usualy on a descent 350, not a 305, so your powerband should be several hundered higher.

 

So the Edelbrock Performer isnt that bad as long as I dont go nuts with the cam and heads. Would there be a difference if I get the Edelbrock Performer manifold made for a carb or the one made for tbi. I know if I get the one for carb and still run the TBI I need an adaptor plate. Just wondering if the carb design would work for better performance or should I just save myself the hassle and get the one made for TBI cars

 

If the one for the carb worked better for the TBI I dont think they would have designed one for the TBI. I would get the TBI.

Charlo

 

91Bird305 That comment seemed a little uncalled for.
If you are implying that my opinion on things is generally less than informed you are mistaken. Especially when relative to the amount of experience I know you have (very little).

FYI There is a difference between the performer and performer TBI. The performer TBI is a terrible value. I dont know how much its selling for now but if i recall correctly it was around 200 dollars. It does not perform as well compared to any carb manifold adapted to TBI that I have heard of and there is a mountain of empirical evidence to support this. Do a search.

The carb performer with adapter is cheaper and performs better if that is the sort of manifold you are looking for. For just a stock replacement it would probably do allright. If you are looking at modding your motor further I would suggest looking into something a little more performance oriented though.

The subject of single plane and TBI has been discussed at length and I can corroborate the claims that TBI does not lose low end like a carb does on a single plane. I have run both on the same engine. Try searching for single plane TBI posts.

 

I have limited experience with TBI, but have a good bit of experience with single plane intakes on carbed apps, even computer controlled carb apps.

On a 305, the Weiand 7525, which is a med rise single plane, MIGHT be pushing it a BIT.

BUT, if you have, or plan on making some other mods, like a cam, headers, etc, it would work fine...ESPECIALLY if you plan on moving up to a 350 or bigger in the future.


We used this intake and an adapter on a friend's TBI Chevy Trucks w/ 350, and had good gains across the board.

For the $$$ vs power, the Performer isn't that great of an intake, over say a GM L69 or equiv.


If you still want to go dual plane, hands down, my pick would be the ZZ4 intake. You can get 'em cheap, and they are proven to work.


HTH

 

Personnally I don't think that the Edelbrock is that bad, it worked well for me, but the car just has to be tuned right. The Weiand that you quoted me on was too much intake for me, and I run consistant high 12's now. So I know it won't be super great for a slightly modded 305.

Sometimes alot of people look at an intake and say "The bigger the better, more air means more power. That's not always true. If you have an efficient intake on that has small runners, but say a swirl design, you get better fuel mixture, better fuel milelage and better combustion=more power. The air in a smaller intake flows to the cylinder at a higher rate of speed than in a big Weiand Stealth. Thus more air gets into the head in a quicker amount of time. Look at it this way, you can only squeeze however much air into the head at a maximum the size of your intake valve on the head. Smaller intake runners that are designed well will carry the air flow in a pattern that follows the head, whereas the air in a large intake will slam into the head and stop where it can't get into the cylinder due to the valve. This creates more restrictive air flow into the head.

I hope that I might have help clear some things up that most people over-look when the talk about intakes. In this case, I don't believe that "BIGGER IS BETTER"

 

any one think of the holley projection intake

 

I got a Weiand 8000. Has EGR - won't match to stock head bolts - but - stock heads suck anyway - I'm porting/polishing a set of #416 heads, changing to 1.94 valve, 1.6 roller-tip rockers, adding LT1 cam, and headers/3" pipes/hiflo cat/hiflo muffler.

From what I understand - Intake not much good without better heads, better heads not much good without cam, none of it good without exhaust.

 

Aye, camaronewbie is very correct. While adding separate parts will increase power, you're still choking (sp?) yourself with the stock cam and stock heads, esp if you're running exhaust manifolds. However, I can definitely see your interest in switching manifolds while its off. I run the Performer RPM and like it, a lot. There's a shist load of volume over the stock runners, but its on top of some Vortecs and an LT1 cam so Im using it. The pro-jection is a solid piece, too. My friend greg is running it with good results. It has 2" bores on it, or at least his did, there might be one with 1 11/16" bores. His car went 15.4 with stock heads, cam, gears (2.73) and crappy dynomax headers at 90 mph if I remember right. No doubt with some gears he woulda been solid 14s.

 

Over the years I've run the Performer, RPM Performer, 7546, 8016, and the 7525.
On a 350.
For my driving style and set up the 7525 was much better then the others. Yep, the dual planes give some better grunt just off idle, but for me that was a poor trade.

305 with 2.x's you might want a dual plane, but a 350 with 3.23s sure was nice with the 7525.

If your even thinking that long term you might want to go with gears and 350 then the 25 is the only answer to me.

 

I'm going to chime in. I ran both the 7525 and edelbrock performer egr on my mild 350 tbi. On this motor I could not feel a difference in low end between the two and with the 7525 there was a noticable differance in the top end. Something I did not expect was that the throttle response improved by an order of magnitude with the 7525. The car had a 3.50 rear gear 2050 stall converter (ala vortec v6 s-10) home ported 70's smog heads and a 219/227 @.050 .480 lift hyd roller cam.

 

Well guys I think I am going to go with the Edelbrock Performer for a carb and run the Holley #17-45 adaptor plate. It has EGR and seeing that my car is completly stock it is not too much overkill of a manifold. Down the line heads, cam and all that good stuff will come but for now I cant afford all that stuff. Hopefully exhaust and gears will be next.

I also plan on doing all of the ultimate tbi mods at the same time of the manifold and Get or make an AFPR and possibly 350 Injectors. I was reading up on the injectors and Pablo said that if I run the 350 injectors I need to get a new chip. Does anyone have any experience with this? Will my engine start acting goofy if I throw all of this stuff on their at one time and not make any adjustments?

Thanks
Jason

 

IF your going to change the injectors and add a AFPR, then you really should adjust your timing and the fuel pulse rate on the chip(That's if you aren't gonna get a new one.) You really should take the bone-stock car and program a chip to make it work really well. Then when you add 1 piece of new aftermarket equiptment or modify what you have, you should recalibrate your chip to run optimal levels. If you put too much performance stuff on and don't redo the chip until after it all, its gonna be quite difficult to get the settings close. Some people would disagree, but more people do the same in my opinion.

 

NOOOOO!!...................not PROM, man I tried reading up on that and got really confused. Burning a chip seems a little out of my league right now, but adjusting the timing and fuel pulse rate (is adjusting the fuel pulse rate a PROM thing with the stock chip, or what..........I am kinda confused still)should be done.

 

On a stock 305, 350 injectors are gonna be WAY overkill unless you were running a better cam, intake, heads, and full exhaust (which I know you aren't). Adjusting the pulse rate and timing maps requires burning a new PROM and, as you said, you don't want to get into that right now. Adjusting your base timing is easy. Just disconnect the brown wire over by the heater box, start car, adjust timing, and then reconnect the wire. I've got my base at 6*BTDC... but may take it back to 0* so I can run 89 if gas prices keep going up

Later,
Harry

 

I agree here, I'm still running rich, 11:1 after going from 16.0@85 stock to 14.7@93 mph, it even still seems to be rich enough after a cam swap.

 

Alright then, so no 350 injectors. Well I have everything to install the new manifold now. I read the Chiltons manual and it seems pretty easy to do. Is their anything qwerky about doing this swap? Anything I should look out for or words of wisdom? I heard not to use any gasket sealer.

Thanks again
Jason

 

so im guessind that the 7525 wont work with vortec heads? without making the holes wider on the intake

 

The 7525 is a great intake. I'd use it if I didn't have vortec heads. Just about any vehicle with an RPM manifold made as much if not more hp/torque across the whole power range than the performer version. That includes some stock Lg4 305's with just headers and exhaust. Only problem is that the high-rise carb intakes plus an adaptor plate leave you with little to no room under the stock hood. You could run a small air cleaner but you'll just end up going through more filters that way (not loosing hp like people think). You can definatly fit an RPM manifold with a 14x3 drop base without the spacer. Just requires a little hammer work on the base to clear the IAC and TPS weatherpack connectors. Even clears the stock coil.
In general I'd stay away from the performer unless you'll be getting it used. Which in that case go for it. They can be picked up for dirt cheap on ebay.

 

what intake r u runnig jprevost? since you seem to have a similar set up that im goin for?

 

Plane jain edelbrock RPM. No fancy air-gap, just a high-rise. At the time (3+ years ago) there weren't many choices.