I think of myself as an ignorant camaro enthusiast. Im not a tire kicker after looks though, i know my way around engines, and know alot about 3rd and 4th gen camaros. At least i thought i did.
I recently bought my first car, a '92 Camaro RS. My deal is that i thought i knew exactly what i was buying, but i didnt. I have no complaints about the car, almost everything about it is great, and it was definetly an awsome purchase for a used car, and for what i spent. But i recently was doing some more research into my engine and i kinda wanna bang my head against the wall.
Basically i thought the RS i was buying had the LB9 under the hood. I thought i was buying a 5.0 TPI making 230 or 245hp and around 300lb/ft. Now i had driven it, and talked to the guy about the injection before. I knew about camaro TPI but had no idea about TPI. When i asked him that it was TPI he correctly told me that it was TBI. Now i shrugged this off as all i saw in my head was a website that listed the numbers of the model i was buying. It listed them "something" this:
5.0 V8 170 bhp.
5.0 V8 215 bhp.
5.0 V8 245 bhp.
And since it didnt list the injection type (i just new these maros were using TPI) when the seller told me it was TBI, like a moron i figured it was the injection used in the 215 or 245hp engine.
So now i know the true stats of my car:
92 RS M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4000 255@2400 TBI 3.08 ---- 2.73 ----

and im trying to decide how disappointed i should be. Im two sided now: on one side; when i think of 170hp, i think of some late model import commercial, not of a american muscle like a camaro. But on the other side; Theres a '97 30th Ann. Z28 in my family that i drive, and i know all the specs on that. Its a beast, its stock LT1 is making around 300hp and 330ft/lb of torque. Now i listed this because when i compare driving that, to driving my 170hp Lo3, im suprised by my car. Of course my car Lo3 doesnt compare to the LT1, but i dont feel like im going from flying a jet, to driving a go cart. My car feels powerfull, it performs well, sounds just as beastly (nicely done exhaust) and overall doesnt feel like 170hp. So i really am suprised by finding out its only making 170hp and 255lb/ft.

So should i be losing sleep over my dissapointment, or is it not as bad as it seems? Is it all bark and no bite? If i take my almost bone stock LO3 to the track will i be dissapointed, or suprised? Does my car really benifit in gas milage like ive read some places?

Im gonna go lose sleep now, hope to read what you guys respond when i wake up. Thanks

 

I also am new to the exact same car and engine type you have. There are threads here on this site that help you put more punch into your car. However, I never planned on going to the track. I purchased this car for my wife because I did not want another car payment. It turns out after driving this car, I have grown to really enjoy it even though it is not the fastest. The car is just really fun to drive. I have done some research on the TBI setup it looks to me that w/o changing out your moter and fuel system, you are not going to be a Mustang eater especially if you are intending to keep your emission control setup. This car is also relatively cheap to maintain. It seems to me there are a lot of guys here at TGO that want to make their cars superfast and if I had one of those factory manufactured cars such as you spoke about, I would be thrilled. However, there is a lot to be said for the car that you have, although ultimate speed demon may not be one of them. Good luck with your car.

 

It's too bad that you thought you were getting TPI instead of TBI. Just as a reference, the 305 TBI was the "biggest" engine you could get in a "RS" model. There was no 305TPI or 350TPI available with an RS. If you're interested in getting better performance, there are many things you can do without even pulling apart the engine....a nice exhaust and induction, along with differnet gears and chip tuning will make a big differerence if you're interested in doing that.

 

Rossi, the L03 makes "a lot" of torque down low in the RPM band, so it has very good throttle repsonse and feels pretty "powerful" cruising around town. However, it begins to die quickly and at about 3500 RPM you can really feel the car getting weak. It's deceptive for newbies to high-perf cars because these cars really feel "powerful" at low throttle.

These cars had a lot of "bottle necks" built into them which severely limited their output. The TPI cars had better heads (for higher RPM), better camshafts and better exhausts. These are the reasons why the TPI cars had higher outputs - not the TPI system itself.

If you put on headers, a free-flowing exhaust and do some simple modifications to the TBI system and air intake you'll be making just as much power as most stock TPI 305 cars and it shouldn't cost you an arm and a leg.

If you really get ambitious and change the heads and cams these cars can make well over 300 hp. But, as they are, stock, they are really weak in the top end (but have excellent low-end and throttle response ...as you've already noticed). By the way, if you change more than the exhaust and intake you'll need computer tuning (and even with the simple modifications computer tuning is worthwhile).

Considering that these cars have 305 V-8s, and the youngest ones are almost 15 years old, they are very reasonable on gas. The rear-end gearing and the transmission top gear really helps here.

If you take your car to the track you'll probably run the 1/4 mile in the 16's. If you're a good driver, the car's in good tune, and the weather is right, you might get into the high 15's.

You've come to the right place for information anyway. There's a HUGE amount of info on L03's here. Right now, it probably seems like a terrible mountain to climb ...you've got a Camaro that is slower than most Nissan family cars . It came with a "bottom of the bin" TBI 305 and you need to be a mechanic and a computer programmer to do anything with it. However, it isn't as desperate as that. These cars are relatively "simple" to work on (if you get the right info - which you've found the right place for here). They're fun to drive and to look at And they can be modified to make 275 or more horsepower, relatively cheaply and without having to take the motor out. Like I said, 300-350 horsepower is attainable with these cars - but it takes a lot of knowledge and know-how (and computer tuning).

With that said, I think you'll really enjoy your Camaro if you look at it as a hobby. You can learn a lot about cars, be wise with your money and make some horsepower.

On the other hand, if you don't want to get into modifications, you already have a beautiful car, that's fun to drive and has excellent throttle response ...and it has potential.

 

Thanks Casey. Any other thoughts are appreciated tool.

 

Since you are brand new to the boards (welcome aboard, by the way)... chances are you haven't read the article written in Chevy High Performance (Click Here)....

Should give you 'some' inspiration with you're recent purchase. To be quite honest, you have an excellent starting point. Have fun with her, and please don't get like the rest of us (we're all hung up on numbers, numbers), just enjoy you're new car for crying out loud!

 

if you're just driving it as an enjoyable car, you probly wont be too disappointed in it.
if you intend to race it or take it to the track.. its going to be honda civic slow.. Casey Butt said it well.. it FEELS fast down low, but its full of bottlenecks.

honestly, if you want it to be truly fast at the track, you either have alot of work infront of you, or you want another car... if you want it just to be a fun car, then just enjoy it for what it is now.

 

Well, just this...

The 305 got a horrible reputation since its "birth" in the mid-1970s. Most of that was because of cylinder head problems (which have since been fixed) and restrictions placed on the 305 to pass emissions and the purpose of the vehicles it was put in. TBI has suffered similarly. The fact is that the 305 and TBI were never produced by GM to be a high performance platform. The 305 will always live in the shadow of the 350 and TBI will always be thought of as "low performance" with respect to TPI and the other more "exotic" fuel injection systems.

However, both have huge potential. With the right injectors, fuel-pump and computer (PROM) tuning, the TBI unit on these cars can support over 350 hp and still idle like a kitten purring. That's about the limit that an L03 can handle anyway - above that and you'll need a new crank, pistons, etc to handle the high RPM. With the TBI you can also use the intake manifolds designed for carbs ...a huge market of high-performance options there. You can build the Rochester 220 TBI (your model) to support over double the hp it was intended to support from the factory ...and you can do it surprisingly cheaply and easily.

The 305 has been criticised for everything from being too small, it's stroke/bore ratio is too high, it's valves are too small and are shrouded, stock 305 heads are crap, etc, etc, etc. Don't be discouraged by any of that garbage. The 305 has the same stroke/bore ratio as the new LS1 engines and the 383. That makes it ideal for producing power in the 0-6000 RPM
range ...very "streetable". It's stock valves (the 1.84" and 1.5" heads) are proportionally the same as 1.97" and 1.61" valves on a 350 - bigger than the 1980s Corvettes and the LT1 350. IF shrouding problems exist they can be easily corrected. Most 305 heads, with relatively minor do-it-yourself modifications, can support well over 300 hp. Also, GM made 601 heads, for the 305, that had closed combustion chambers, and excellent squish and quench ...very much like GM's new fast-burn combustion chambers.

"Car people" are often very slow to embrace anything new (and, as with life in general, many of them aren't that bright ), so if something new hits the market and it doesn't have high-performance written all over it, many people declare that it's "no good". It usually takes 15 years for most enthusiasts to adopt something new and for somebody to actually break with convention and make power with a "potential-less" setup. It's only now that the true performance potential of TBI and the L03 is starting to surface. Just a year ago almost everybody was convinced that the stock swirl-port heads on these cars are useless - now people are starting to seriously re-think that.

One argument that you'll hear a lot is "you should get a 350". I don't agree or disagree with that statement. Yes, a 350 has more potential, and it can make power more "cheaply". But if you "only" want 300-350 hp at 5000-5500 RPM then I see no reason to abandon the 305 ...and you can get there "cheaply" as well. So, take that advice in context ...just ask yourself what you want your car to do. If you want to leave the engine in the car and stay with "bolt-on" modifications, you can probably get your car close to 300 hp (if the mileage isn't too high already and your motor's in good shape ...and you know how to select and modify parts). But if you want 350 hp you'll probably have to take the motor out for a rebuild ...this is when you should start considering a 350 (if you want to, of course).

Also, be aware that acceleration and speed can be greatly enhanced by things other than the motor. The rear-end, transmission, mounts and chassis are all areas where hidden "performance" lies. I changed the rear-end and installed a shift kit and polyurethane mounts in my car last year (1988 IROC) and the difference was eye-opening. I never got a chance to run the 1/4-mile with the changes because I took the motor out for a complete rebuild a week later, but I can tell you the car felt like a completely different animal. Don't underestimate the "potential" of a good shift kit (stay away from the B&M kit ...it might shorten the life of your transmission).

Anyway, sorry for the essay ...but I hope other people in your situation are reading this and we can address some of their concerns here as well.

If you have any questions just ask.

 

The 305's bad reputation had to do with it's factory block design. It honestly had nothing to do with it's cylinder heads (although the problem had to do with valve shrouding), it was it's severely limited cylinder bore being the culprit. If you take the same cubic inch displacement, only with a four inch bore, and three inch stroke, it'd be an entirely different story. That's not to say that the anemic 305 blocks can't be built appropriately... nowadays, especially.

 

The 305 blocks haven't changed in the bore since they were first released. The blocks have changed significantly only in the rear main seal area and to work with hydraulic roller lifters. The 305 block has no more or no less potential now than it did in 1976. The early 305s were riddled with head problems ...I had a 1979 305 pick-up and they were notorious for cracking between the exhaust and intake valves.

 

Don't get too hung up on HP & TQ numbers... If the car looks good, has a good stereo, and is fun to drive then that's all you really need.

Look at this as an opportunity to learn... Do some reading on this site. Get out your wallet, buy some after market parts, and roll up your sleeves!

 

I didn't say that they did, I was only pointing out that the problem lies within it's anemic bore, not it's cubic inch displacement, nor it's heads. When I mentioned a four inch bore, with a three inch stroke, I was referring to an entirely different animal.... the high winding 302 chevy.

Bottom line to what I was trying to point out, is that most people avoid 305 blocks not because of it's factory valve-train, but because of it's factory limitations (in reference to cylinder boring)....

 

bingo.

 

I agree. I've heard this argument many times, and each time I heard it, it was incorrect. The 305 stroke:bore ratio is the same as a 383 and is completely in line with the modern trend in engine design. Ford replaced the 302 (4" x 3" bore x stroke) with a "square" motor (3.552" x 3.543") in it's new Mustang. And the LS1 (346 CID) has the same stroke/bore ratio as the 305. The Mustang makes 300 hp from a 281 CID engine, and the LS1 Corvette makes 350 hp at 5200 RPM. Of course, there are other factors at play here, (connecting rod length, etc - heads being the biggest one), but it does prove that a 3.736" x 3.48" engine (305) does not have a factory limitation with regards to cylinder bore (other than limiting its displacement to only 305 CID). A 0.93:1 stroke:bore ratio doesn't limit the motor's volumetric effeciency and therefore isn't "anemic".

If it did, both Ford and GM wouldn't be adopting longer stroke/smaller bore motors in their performance cars, and there wouldn't be several members on here with 300+ hp 305s.

I think the whole "305's bore is too small" claim started in a era of restrictive emissions limitations, before hydraulic roller lifters, before more efficient fuel injection systems, and before the 305 had decent heads available for performance applications. The 305 hasn't able to shake that reputation simply because the 350 has always made it is financially unwise to ring the potential out of a 305. It has no bearing on the fact that an L03 can produce just as much power below 6000 RPM, proportionally, as any other small block.

Of course, this has been debated a thousand times, but as long as people actually have 305s producing more than 1 hp per cubic at under approx. 5500 RPM then it's simply a proof by contradiction case. If the volumetric efficiency of the 305 was somehow limited by its stroke:bore ratio, then these motors simply would not make this power.

 

THIS HAS NOTHING TO DO WITH ANY RATIO! lol

dude.
look at how close the valve goes to the cyl wall.. hell, the good SBC heads dont even bolt on because the valves hit the bore. the ones that do clear and fit in there are shrouded by the wall that is the bore of the motor.. remember air comes out the sides of the valve.. and half of it is covered in the 305.

is it directly its bore size? no.
its a combination of the SBCs 23* design with that bore size... you either need to move the valves so they arnt shrouded, or make the bore bigger.

but none of this has to do with any bore/stroke ratio.
----------
btw, the LS1 is the 305 of the genIII/genIV world.. if you ever ditch the SBC and jump to them, you'll find the guys like to run the bigger 4" and larger bore motors... then they start making 2+hp per CI, naturally aspirated.
(and by that i mean the limited few that try to do that.. just like the limited few who try it and succeed with the 305.. sure theres more of them then 305hp 305s, but you get my point... they're both minoritys.)

 

btw, this automerged double post thing on this board is bs.

mod edit: Automerged double post is to prevent trolls and post-****** from cramming threads with useless posts. Not the best, but it does serve its purpose.

 

The proximity of the 305 valves to the cylinder wall is not a factor in the operating range of street-driven 305s. If it was then these engines would not be able to produce 350 horsepower. The "good" SBC heads are not necessary on a 305 because several stock castings can be DIY ported to flow enough to support over 300 hp. Again, if shrouding, or anything else was a significant factor, it would show up as a decrease in volumetric efficiency. But this doesn't happen, as anyone who's tuned the PROM of a modified L03 can attest. If it did, these engines wouldn't be able to produce proportionally the same hp below 6000 RPM as any other SBC.

 

Im definatly starting to see how true this is. To make myself look like less of a fool, the reason i bought it without doing tons of research is pretty clear when you look at what i paid. 1992 25th RS, 83k original milage, very well maintained, interior is nice, regular engine maintance, and it has a sound system. Two 4x6s in the dash, two in the stock speaker location (on the side wall above the rear seats), a 250 watt amp, and two 10 inch subs. And like i said im no expert, but i believe that these cars have a uni-body fram, like one piece, and this car has void of all rust and doesnt rattle. Put all that goody stuff together and i only paid 2500. Thats unbelievable around here.

Thanks again casey and folks, im enjoying what im reading and learning alot too.

 

ok, im going to have to pick this apart...lol

ok, what the hell is "the operating range" of street driven 305s?? if you want to keep limiting down to some ****ty sub 5,000rpm motor, its not going to be the "high horsepower" motor you're talking about.. you need to spin the **** out of it to make power.... and it needs to breath up there. before you say something stupid like "race motor", keep in mind 90% of the engines on the road today spin past 6k like nothing.. no reason a performance v8 shoudlnt.
and you know you cant make a 305 breath up there.. why dont you DO IT before saying it can be done easily.

350hp? id expect more then that at the rear wheels with any motor im working on for a daily driven camaro... not to mention, i have yet to see any 305 do that... prove me wrong. i dare you.
btw, 4" bore short stroke motors that happen to displace 305s dont count.

heres a hint. you're talking to someone that thinks the current 23* AFR heads flow bearly adaquate. you're never going to convince me that ported swirl port heads are going to give me big hp.



ok. VE at what RPM? LOL... you can have 100% VE at 3k, and it'll feel fast.. but you need it breathing up top..... and it chokes there. not to mention, id rather have 95% VE at 6700 then 100%VE at 5000... if you cant figure out why, then say so and i'll link you to some good info online...





seriously though i know im talking to a brick wall.. you keep going slow, and i'll keep doing and learning.
btw, if you want, post up your VE table for a 305 TBI, and i'll convert my VE table to match a 305s (aka the peak VE will be way over 100%, but they would match where they flow the same.)

 

Calm down MrDude_1. Nobody insulted you or questioned your intelligence or knowledge ...at least not until your last post. Condescending posts don't defend your position. Try to stick to the facts and people will take you more seriously.

 

Hell, my STOCK 1994 L03 would pull to about 4,800 with ease. With retarded cam timing, a new high flow cat, custom chip tuning, 1.6:1 roller rockers, increased fuel pressure, and TBI mods it would pull EASILY to its 5,600 RPM shift point. When I put the LT1 roller cam into it, I discovered that it had factory 081s on it.