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305 tbi power frustration

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Old Mar 11, 2010 | 02:00 AM
  #1  
dfitch's Avatar
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From: Niceville (not a joke) Florida
Car: 92 RS, 01 huyndai, 96 acura, ect...
Engine: 305 tbi
305 tbi power frustration

So I just got my first Camaro... a '92 RS pushing a whopping 170hp. I'm not new to cars or turning a wench (my of the people on site in a similar position seem to be). I just can't seem to understand the lack of performance parts. I knew the car's modest power rating when I bought it,but knowing the shier displacement of the engine I though it would be an easy fix. I never had racetrack goals for the car,I was just hoping to but the thing in the 230-250 range without dong a motor swap. Just a good, relatively efficent, daily driver. It handles well, it looks sharp, but I can't stand having by doors blown off by a Honda with an engine a third of the size (not to knock inports I have two).

So on to what I'd realy like to ask y'all, Where can I find that extra few ponies? I was think th Hooker 2055's (I think that's the number), in combination with the manaflow cat and 3in all the way back. Any one know if they make true duals? I haven't seen down pipe in a confiuration other that "Y". Any advice or setups you're running would help me out a lot in making a decision.

Now that's exhaling, on to inhaling. I'd like to run a 360 air cleaner, there are three issues I'm worried about; clearance for the hood, the oil re-breather on the left valve cover, and the ECU getting confused by the increased air flow. Has anyone used a 360 air filter and had any issues? Would you recommenced any specific brand or size? Have you had clearance problems with the hood?

Now on to the place where I think I'll see most of the gain, a cam. I love the rough sound, but I have no idea how that would effect daily driveability, Or what to look for when buying one. I have no idea what kind of lift and duration the stock one has, or what to look for in a new one. Anyone feel like sharing the ins and outs of cam shafts? Would I need new rod's and lifters? What's the best strategy to install it? I was thinking put it on a lift and drop the motor and tranny on jack stand, or remove the radiator and front clip. And on that note I've hear stories of plastic timing gears. Is that true, ad if so does anyone make steel replacements?

An all this brings me to the final issue, that annoying little chip under the dash.What the heck should I do aboutht that thing? Flash it with a new .bin file from what a gather from the tech fourms. But I won't lie, even with a military computer electronics background I'm a little scared to do that. I've been having a hard time finding a new one online. Any programing made easy device I can buy? What will ahppen if I do the modifications an don't touch the chip? Will it still run correctly, and will I get all the potential power gain?

I hate to ask too many questions in one post but it's hard to sort through all the data and make sure the people are running the same engine. I'm really looking for that one guy running a '91-'92 with the same intentions for his car who's done these things
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Old Mar 11, 2010 | 02:43 AM
  #2  
skirkland1980's Avatar
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From: morrow, ga
Car: 82 S10, 83 280ZX, 84 Z28
Engine: 355 smallblocks..na, 2.8 turbo
Transmission: 85:th350, 84:700R4
Axle/Gears: 85:ford9 4.85, 84:stock 3.24
Re: 305 tbi power frustration

if you want a lopey cam you'd be better off switching to a carb. the problem with the 305 is that the bore is too small to stuff big valves in the heads to get more power. and i think a single 2.5" exhaust is plenty for a 305 with 1.5" primary headers. i was running low 14s in the quarter with this exhaust setup with a stock 350. unless you just really want to do all this work with minimal gains thats fine, but i see good running 350s for sale all the time for cheap.
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Old Mar 11, 2010 | 05:21 AM
  #3  
Daphi's Avatar
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Joined: Mar 2010
Posts: 23
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From: Halmstad, Sweden
Car: Firebird Formula
Engine: 305 TBI
Transmission: M5
Re: 305 tbi power frustration

Originally Posted by dfitch

Now that's exhaling, on to inhaling. I'd like to run a 360 air cleaner, there are three issues I'm worried about; clearance for the hood, the oil re-breather on the left valve cover, and the ECU getting confused by the increased air flow. Has anyone used a 360 air filter and had any issues? Would you recommenced any specific brand or size? Have you had clearance problems with the hood?
I just mounted a Edelbrock 360 air cleaner on my 305 TBI and everything works just fine. If you buy the 3" non-drop you will have no problems with hood clearence. Just keep the stock distance-ring and make sure your filter-base doesn't have any contact with the coil wire. Turn the breather tube away from the engine and put a canister or a filter on it. I put an aftermarket filter on mine and it works great. Don't forget to plug the vacuum-hose going from underneath the throttle body. Haven't got any issues with the ECU getting confused at all.

I'm installing a new map sensor and I'm going to check all components under the hood to make sure everything runs fine.

I bought the Magnaflow stainless 3" cat-back exhaust and noticed a nice power gain and sound. I'm about to install a full flow catalyst (not sure what you call it) and expect a nice gain there aswell.

Last edited by Daphi; Mar 11, 2010 at 05:26 AM.
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Old Mar 11, 2010 | 05:38 AM
  #4  
thomas1976's Avatar
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Joined: Jun 2006
Posts: 2,199
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From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: 305 tbi power frustration

With the moods in my sigh it will put you in to, 91 5.7L z28 + full exhaust (including edelbrock headers) territory, though that does not impress more moders sporty cars, except maybe for the hp/$ ratio.

A healty 350 is a wery good idea, if you whant to run with sport cars.

A little EBL http://dynamicefi.com/. upgrade to start with will allow you to tweack in every upgrade easely.

(Make sure you geta flat base air cleaner)
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Old Mar 11, 2010 | 12:34 PM
  #5  
dfitch's Avatar
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From: Niceville (not a joke) Florida
Car: 92 RS, 01 huyndai, 96 acura, ect...
Engine: 305 tbi
Re: 305 tbi power frustration

Maybe I should go a ahead and buy the 350. It sounds like that EBL unit will handle the motor swap too but I need to email the guy. Thanks for your help.
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Old Mar 11, 2010 | 04:24 PM
  #6  
thomas1976's Avatar
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Posts: 2,199
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From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: 305 tbi power frustration

Yes, tuning the new engine with EBL will be a relaxing vacation compared to the engine swap.
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Old Jun 22, 2010 | 07:43 PM
  #7  
andr3i's Avatar
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Re: 305 tbi power frustration

about how much hp will a 305 bored .030 produce?
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Old Jun 23, 2010 | 01:21 AM
  #8  
ericjon262's Avatar
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From: South Carolina
Car: 85 2M6, 87 'Bird 88 'burb
Engine: LX9, LG4, L05
Transmission: F23, 700r4, 700R4
Axle/Gears: 3.63, 2.73, 4.10
Re: 305 tbi power frustration

Originally Posted by andr3i
about how much hp will a 305 bored .030 produce?

boring an engine isn't for HP, its to make the cylinder walls the correct shape.
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Old Jun 23, 2010 | 10:11 PM
  #9  
dfitch's Avatar
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From: Niceville (not a joke) Florida
Car: 92 RS, 01 huyndai, 96 acura, ect...
Engine: 305 tbi
Re: 305 tbi power frustration

I think that would leave it as a 338 but the number really isn't important. ericjon is correct that you don't bore a block just to create power, though adding displacement will allow the engine to produce more power with the proper components. However, if all you did was increase the displacement (with no alterations to the heads) you would reduce the compression ratio and thus lose power. Practically speaking, boring your block is pointless. If you want a nice daily driver; give her a good tune up, slap some a descent exhaust system and on and enjoy the hp it will produce. For the cost of having the engine bored you can buy a carbonated 350 out of a wrecked truck and have it in the car with less effort than you'd put into removing, tearing down, and reinstalling the 305. I suggest carb because if you do anything to build power in these cars and stick with fuel injection you have reprogram the ECU, that isn't very easy, fuel mapping is always a real pain.

If you really want to go fast, you have two options a new engine or a new car.

Read my post from a few months ago, I went down this road. Power wise, the 305 is a dead end unless you want to spend big money for parts.

Last edited by dfitch; Jun 23, 2010 at 10:17 PM.
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Old Jun 23, 2010 | 10:51 PM
  #10  
d00012's Avatar
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Posts: 559
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From: Everett, Washington
Car: 2006 GTO
Engine: LS2
Transmission: M6
Axle/Gears: 3.46 LSD
Re: 305 tbi power frustration

Trick Flow Super 23 175 heads work on the 305s. Those are all I know that work and are around $1,200.

http://www.summitracing.com/parts/TFS-30300002/
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Old Jun 23, 2010 | 11:07 PM
  #11  
Ron U.S.M.C.'s Avatar
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Joined: Apr 2006
Posts: 4,482
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From: Northern, CA
Car: 1989 Iroc-Z Camaro
Engine: TBI,5.0
Transmission: Automatic 700R4
Axle/Gears: Eaton Posi,3.42,LPW Ultimate Cover
Re: 305 tbi power frustration

I did a little research on your car and found out some info on your gearing. If you plan on keeping the car that you have . You ether have a auto with 2.73 rear or a manual with 3.08 rear. I know you said HP but what I did was change out my ring and pinion with a 3.42 ratio and a Eaton Posi. That with a open element and a high flow cat with a 3in. cat back helped wake my car up. That 2.73 I had in there really was holding back what HP I do have. Details in my signature.

Last edited by Ron U.S.M.C.; Jun 23, 2010 at 11:08 PM. Reason: add info.
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Old Jun 24, 2010 | 03:09 AM
  #12  
thomas1976's Avatar
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Joined: Jun 2006
Posts: 2,199
Likes: 1
From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: 305 tbi power frustration

Originally Posted by dfitch
you have reprogram the ECU, that isn't very easy, fuel mapping is always a real pain.
No, the EBL flash comes with many stock and coustom calibrations, one of them will run your upgraded engine, just make sure you pick a computer friendly cam.

Setting up the necessary fueling numbers and playn with the SA tables is really easy. EBL does the VE tables learnig for you!
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