250hp 305 Can it be done?

As you all know I just got my Camaro yesterday, and i'm already setting a goal. To build a 250hp Naturally Aspirated 305. So my question is am I on the right track.


Replace TBI with a Performance TBI (From Edelbrock)

Cam Swap....From a 88-92 Z28 or IROC

Victor Jr. Performance Intake

And anything else I may need. I'm new at this so i'd like to do it the right way the first time. So please give me your advice and imput and if i'm on the wrong track let me know. Thanks y'all I really appreciate it.

I myself would just scrap the 305TBI.

It can be done, But why?

For instance run it while you build a 350 or 383.

But since this is probably a daily driver. I will tell you what I would do.

Buy a better cam and lifter set than what came stock in the 88+ 3rd gen's. Someone will chime in with a good one.

Try the for sale section and/or ebay good deal's can be had.

I would also buy some header's, Used is fine.

But down the road, I will warn you. You will kick yourself in the ass for wasting money on a 305.

I know you have heard this before. But a junk yard block is only 100 bucks, then machine work is about 125-200, then rod's, cam, crank, piston's, head's and intake. and you're pretty much set after a carb.

And you will have almost double the HP & TQ with the 383.

Plus N20 if you are brave.

Just my $0.02

Frank

I've already reached 250 at the crank (213 RWHP). Edelbrock Performer carb intake, Holley TBI adapter, LT1 cam, World Torquer 305 heads and loades of custom prom work.

I don't beleve you'll make 250 HP with stock swirl-port heads.

250 HP is also pushing the limit of what the stock injectors and throttle body can support. My car starts to lean out at 5000 rpm and the MAP numbers start to drop at about 4500 rpm under full throttle.

250hp? Piece of cake.
Headers, Exhaust, Intake manifold, better TB, Cam, and heads, and you are WAAAAY over 250..
Or even port it, and get the Heads machined.

I agree with the previous statement: Don't bother spending so much cash on the 305. If you're dying to spend money, buy parts that are bolt on and simple and will swap over to whatever you're going to build next. Get headers, get your exhaust... stuff that'll transfer. Then work on building your engine, be happy with the sound and performance of the wussass 305 (Still a sturdy, torquey engine) until you can finish building up a better motor. :)

Yes it can be done! Easily! :D



link (http://www.goingfaster.com/spo/325_horsepower_305_cid_chevrolet.html)

OMFG, sweet mother of christ... 53 horsepower from a goddamn cam. O_O Good bloody lord.

tpi 305 make 280 at the flywheel stock........"why??" u ask? cause 5.0's rule..they last for ever and are very underestimated and most of all, are most definatly capable of good power.......am i sayin 350's or 383's suck? f*ck no, they rule... just dont go and say 5.0's r worthless, ive seen modded five oh's spank 350 ass

280 horsepower at the flywheel, stock? The official stats for a 305 TPI is, at most, 230 horsepower. Most were less... around 190-210. The 350 TPI's didn't even make 280. The LT1's make 280 stock...

Originally posted by chevyman502bb
tpi 305 make 280 at the flywheel stock........"why??" u ask? cause 5.0's rule..they last for ever and are very underestimated and most of all, are most definatly capable of good power.......am i sayin 350's or 383's suck? f*ck no, they rule... just dont go and say 5.0's r worthless, ive seen modded five oh's spank 350 ass

LB9's only EVER made 230 at the wheels...

I've also seen a good running LB9 give an L98 a run for its money. Good motors, no doubt.

-Rippin

maybe i got confused with the tpi 350......my bad.....besides that the point still stands

Yeah wasn't dissing your engine choices, just wanted to bring out facts so everyone had 'em handy. :)

I've had three 305-powered "sports cars" in my life, and none of them have ever given me problems. They're durable as hell, even if their output isn't insane.

I've watched my buddies go through 350's like fat men through a box of oreos... Don't know. Maybe they are more reliable, or maybe its just coincidence. I've certainly had a helluva pile of luck with them if its coincidence. :)

Basicially I just want to get good power out of what i have right now. Which is why i'm willing to put money in the 305. But it's good to know that I can easily make 250hp. And i'll probably stop there just for the sake of my wallet. But later on a 383 or an LS1 mite be in the works. Who knows the possibilities are endless. But thanks for your opinions I really appreciate the imput.

treat a 5.0 right (change oil ect.) and it WILL last u forever.....my couzins trans am tpi 305....180k with its whole life literaly WOT, my dad truck with 305 tbi 293k...thats right i said 293k.....in a 96 sierra.....and has at least 50k left baby.....junk? not in the least

again, dont think that im saying a 305 is THE engine, no no no.....the 305 is a great engine, very reliable and capable of good streetable power

Ya, 250 in a 305, or most any V8, so long as it is not a damned for 4.6, is fairly easy!
On my Z-28 for example; all I plan on doing is Full exhaust (Headers, cat-back, and all) Bigger carb, Intake manifold, and hopefuly a cam, and I am near 300 horse already.
Parts off of camaroz28.com and E-Bay, I expect to spend less than 1500-dollars for EVERYTHING.

You can buy a brand new 350 (4-bolt) 250 hp engine from Scroggins Dickey for $1280 plus shipping. You get a engine warranty also and then you have a good foundation to work from in the future. All your add-ons will probably come close to the price of this new engine.....

For about 1,280-dollars, I can make 300 plus h/p, and "maybe" even have a lil left over.

OMFG, sweet mother of christ... 53 horsepower from a goddamn cam. O_O Good bloody lord.

Is that a lot of h/p from one? I have seen some (Comp, I believe) that offer up to 75 h/p, and even a cam (don't recall what brand, though..) in this months Hot Rod mag. offering 105+ h/p! (lol)

I had approx. 250hp at the wheels with my 305.
It trapped almost 100mph in the 1/4.
I had a bunch of bolt on mods on the car at the time.

pay 1200 for a motor? sure y not.....OR u could do what i did.....go to the junkyard and find a wrecked iroc and rip the beast out, even if it is a 4 BBL 5.0 u will still have a block to build on.....and i only paid 350$ for mine....runs great, 70K on it.

Comp cam's "Magnum" is suppose to offer 150+ Horsepower though I've never heard of anyone using this. 50 Horsepower for a $90 cam just seems an incredible power gain, though I suppose our stock "peanut cam" was pretty crappy so anything would give a sizeable increase.

Most of the cams I've seen have only netted people 10-20 horse, though they're usuall fairly streetable.

In that link about the 325 horsepower 305, is the cam they use streetable? Or would idle be extremely ****ty?

I'm looking for the most power for my buck, obviously, but I want something with a mild idle. I like my car to run smooth when it isn't moving. ;) Like zeph's cars idle... that's about as extreme as I'd want.

I too say the 305 is a good engine I change the oil every 3000km and with 285000km she still purrs she goes though at least 5 5000rpm shifts a week that little 305 has even seen 5500rpm and has held togher

But 250hp is very easy to get a good set of L31 Vortec heads and the intake you want with a comp cam say about .480 lift and you should be there. But I`d go with a carb there so much easyer to work with then the TBI Oh and a 2.5 or 3 inch Flowmaster cat back and Headers are a must

ill have close to 400 after christmas. alittle bit of laughing gas anyone? :cool:

i myself am not a fan of our friend nitrous oxide, to me its cheating..lol.....only form of forced induction i like is s/c cause they run much cooler than turbo's and are simpler.......

some of you might say that nitrous isnt forced induction, well if you knew what your talking about you would know....(just to prevent a future arguement)

i should still have about 275 n/a not bad for a lo3

Just wanted to point out those numbers for that link posted are FLYwheel hp, not RWHP. Notice, the engine was taken OUT of the Camaro. So that engine is about a 275 rwhp engine in a car. Still not bad at all for a 305 though. :)

What would it take for my LB9 to get into the 13's?

Giggle gas, and you're there.

I have to agree w/ ChevyMan502BB.. I HATE nitrous! I "also" see it as a form as cheating; which brings me to the point of watching 2-slow 2-gay today!
The ONLY reason I like that, and the first one, was for the American Muscle on it!
I have Tivo, so after recording it, I kept replaying the part of the ricer in his ****ty-assed Mitsu****y, thinking he is all bad and he is gonna beat the **** outta the Hemi Challenger. The Challenger then revs HIS engine, and it sounds SOOOOOOOOOOO ****in awesome! That almost made ME **** MY pants, RIGHT THRU THE TV!!!!! Lol.. looks like the Black dude that was gonna race him **** his pants, also! (BTW.. my g/f was about ready to kill me after REPEATEDLY replaying that scene!)
The Yenko if ****in' awesome, also!!!!! What size engine that beast have it it, a 427.. wasn't it?
BTW.. How did the dude get his Challenger to sound like it does? Like ****ing thunder..
I relize that this is T-H-E most unrealistic movies around, but still.. how do they get the Challenger to sound so SCARY! (also, what size engine does the Chally have in it?)

COPO had an aluminum block 427
Yenko had a 427 but im not if it was aluminum block or not

and yes, that scene does rule, agreed....well more than rule, its pure ungodly american muscle-ish....amen?

what pisses me off is when a little civic pulls up next to me when im in my s10....they got a cold air intake, an over sized soda can muffler and a nitrous sticker and they think they got somn.....my s10 sounds SWEET, but i know i dont have more than 95hp and i admit it.....but what pisses me off is when a 120hp civic pulls up and acts like they have 450hp....f*uckish if u ask me, that wont happen when i drop my motor in my camaro now will it? lol

Yes, that scene is SOOOOOOOOO *****NG AWESOME!!!!!!!!!
In fact, I do believe that after I am done checking my email, I am gonna go and replay that scene another 10-times!
I KNOW EXACTLY WHAT YA MEAN.. I HATE *****N RICERS!! DAMN BASTARDS THINK THEY OWN THE *****NG WORLD!
LOL, I bet they will be ****tin their pants, just like w/ that Challenger on 2-slow 2-gay! lol.
But HOW THE HELL OR WHAT THE HELL did the dude w/ the Challenger do to get it to sound so ****in' mean? I mean.. come on.. that is just plain SCARY!!

that hemi chalanger is bone stock buddy, dont ya love them hemi's?! (tim allen grunt)

BULL****!! There is NO ****in' way that Hemi has the stock exhaust! I DEFFINENTLY believe the performance aspect, regarding being stock, but there is NO WAY IN HELL that the stock exhaust is on it! BTW.. what sized block is that? 426, isn't it? Or no.. I don't remember..

And when I said this..
LOL, I bet they will be ****tin their pants, just like w/ that Challenger on 2-slow 2-gay! lol.

I was regarding dropping the BB into one of your 'Marrows!

426

and i will bet my weeks pay check its stock, the 426 hemi/440 6 pack chargers/chalangers ect had kick ass exhaust anyway man, i know this, my dad had a 73 charger r/t 440 6 pack....trust me....who needs mods with a hemi? even exhaust, if youve herd a hemi up close you'll know what i mean

It was stock. :) The mopar muscle that rolls into the car shows all sound mean like that or meaner. ;) Sexy.

Ok guys, enough of the hijacking ;)

For the question at hand, I also think you should go the junk-yard 350/383 route. BUT... if you persist in wanting to keep the 305, here's what you can do...

Cam: LT1 cam. Used it'll cost you $30. That's $30 for around 20 hp
Heads: See if you can find some Corvette L98 heads. They flow great, plus they're aluminum
TBI: I guess you could go Edelbrock. I don't know too much about that model, but what you COULD do that would be cheaper, is take a TB off a 454.
Intake: I believe you can get a Performer RPM intake manifold for the 305 TBI, if so, do that. As far as cool air, I don't know what you have for ducting, but you can always go open element. I noticed a SOTP difference when I put one in my old Camaro.
Exhaust: Really doesn't matter too much here, as long as you free it up. Any brand shorty headers, !Cats if you can, then a catback.

After all of this, you're gonna need a chip tune, especially after the Cam and 454 TB. But you'll be WAY over 250 hp. Probably closer to 270.

Now, you're going to have the power, so the next thing you want is to get it all to the ground. Don't forget suspension mods. Tranny mods do wonders too.

Hope all this helps.

:cool:

Speaking of LT1 cam, I have my stock LT1 cam, rocker arms, springs, and push rods in my dining room sitting in a box (they dynoed 292.3 rwhp w/ just bolt ons and shorty headers, through a cat). If you're interested, email me zcarmenb28@yahoo.com

thanx for the backup knightrider, lol....IM me again sometime

*listens to Sevendust : Break the walls down* lol

i myself am not a fan of our friend nitrous oxide, to me its cheating..lol.....only form of forced induction i like is s/c cause they run much cooler than turbo's and are simpler.......

Turbos are not that complicated, they just require management to control the boost. I personally think its cool to be able to increase boost with the turn of a knob. I dont understand why people consider nitrous cheating, is it because you can get a setup for less than 25% of the cost of a supercharger? So, if I put together a purpose-built engine with low compression, a low rpm peak, huge exhaust valves and ports, then put a 250hp nitrous setup on it, that makes me a cheater? :confused:

no, cause like you said, its purpose built, the cheatsers r the cocks with the stock engines with 125 shots, thats retarded, if your BUILDING your engine with low comp, and so on THEN u do the nitrous then its all good......what pisses me off is the lil crx's with bone stock motors with 125 shots of nitrous....THATS cheating....in the crx's case, its the pussy's way of power........and still im not a big fan of nitrous cause it only gives you top end power, i myself dont need 250 extra ponies when im doin 145 down the interstate, i dont have a drag strip so i have no need, what i DO want/need is low end torque, something nitrous will NOT give you....this is when u need a supercharger, yes it takes power to turn the rotors in the s/c, but u have little or no lag, like you do with a turbo (turbo lag), i got nothing against a turbo, sh*t id like a turbo in my 88, but its not my 1st choise.....

How do you figure its topend only?

You can tap it off the line if you like, at 30 MPH, at 60...whenever you want and for however long you want. Its inexpensive, and excellent for those that want the power of a supercharger without the constant fuel economy loss---and for those who don't want to deal with custom-fabbing a turbocharger.

inexpensive, it CAN be, it depends how much u use it, filling a bottle isnt cheap, trust me, i almost put nitrous in my s10, and u cant give it juice at low rps or *boom*...if u dont believe me, feel free to install a 700$ nitrous system in ur car and push the lil go-baby-go button at about 1100 rpms a couple times and let us know how many pieces of your engine you come back home with.....

i did alota research on nitrous oxide when i was interested in putting it in my lil truck, i know the lilitations of nitrous and the consecuiences (sp).

Cheap 305 combo:

Stock shortblock

97 305 Vortec heads (available, mostly considered boat anchors but they work well on 305's). Get the springs upgraded and the necessary machine work done to get them to fit.

ZZ3 camshaft

Edelbrock performer RPM intake

650 Holley or equivalent

1 5/8 headers

This combo should make close to 300 HP.

Just a pipe dream I had if I buy another 3rd gen that has a 305.

My friend hits nitrous at 3K in first, and holds it until the race is over. He's had no problems, and has been going through a bottle every other week (during the summer) for about two years.

Wow.. that is just SOOO ****in' awesome that BONE STOCK, a car can both give you a hard-on, and make you **** your pants, all at the same time! Even the Cuda's, etc, w/ the 440 sound that nice?
My uncle used to have a '69 Charger R/T, 440 4bbl, 4-on-the-floor.
He also put a set of Hollywood Pipes on it. (I am thinking that only the slight older than 16-year-old-crowd knows what Hollywood's are, as I have never heard them, just OF them.)

Yeah dude, this cuda came to the show with just an aggressive cam and stock 440...and that bastard had everyone's attention. It was SO menacing with the slight shudder of an idle... Angry/powerful sounding. I love true american muscle. :)

Wow, that is awesome man!
The Cuda sound like the Challanger from 2-slow 2-gay?
Is that what GTO's, 442's, etc sounded like also, or not "THAT" powerful?

Cuda sounded a helluva lot meaner then most of the chargers/challengers I've seen, stock...maybe he had different mufflers, I don't know. It wasn't so much loud as just incredibly deep and menacing. :)

A lot of GTO's have that same sound, though the "original" exhaust system on most has been replaced already so its really whatever noise level the owners desired. :) Love those cars... They just line up in a big row next to the road I cruise/race on... Most of the time they just sit there, but every now and then they'll come out and tear **** up for a few laps. Simply awe-inspiring.

So you are saying that most people didn't replace their REAL American Muscle cars w/ the original exhaust, but put quieter after-market on them?
Wow.. that would be so KICK-ASS to have all kinds of American Muscle lined up along a road often traveled (By me, I mean..).. that WOULD be awe-inspiring!
I also LOVE those cars, man! They are so ****in' awesome!

Here is the video of my car with the cam and TPI on my LG4 305,
http://www.transamws6.com/video/ZepherWS6.mpg

That link did not work, Zepher.
BTW.. I checked more of your videos out today.. DAY-UM!!
The one where the car is just siiting in the driveway idling, then you start revving it up.. NIIIICE!
And the one where all the Muscle Cars, and the Crapota ****ra is doing donuts, is awesome, minus the ****ra.. Keep 'em coming Manny!

That Supra is fast and it's going to be really fast really soon.
700+hp from a big turbo.

250hp in a 305 is cake, do the victor jr./edelbrock TBI i thing, but try to find them used on ebay, or post a parts wanted ad here. now, just throw in a comp cams Xtreme Energy camshaft with .495 int\.502 exhaust lift, have a valve job done to the the factory heads and have 1.94"exh, and 1.60" int. valves . put in new valve springs, locks and retainers. If it were me, id get a performer RPM or performer RPM Air-Gap instead of the victor jr. intake. The vicotr Jr. will rob you of alot low end torque. you need more low-end torque in a street car. Headers wouldnt hurt either. This is pretty close to a 300+ HP setup.

parts will probably run you around $700+Headers
Labor will depend on where you get it done at.

Thats my 2 cents, Gene.

damn, lotta posts sinse i went to work and got back (6 hours), im honestly very surprized at ur friends hitting the nitrous like that....

My personal recipe for my 305 buildup is...

400 crank and rods
ported Vortech heads, with a performer RPM air gap to match
gm Hot Cam with 1.6 RR (hyd roller cam)

should be around 400 ft/lbs of torque, 300-350 hp.. and I have a little Cheater plate around here somewhere..


Why you say?

Because I like to be different, and I am working with some odds and ends I already have.

Plus, the smaller bore on the 305 tends to get a little bit better MPG than the equivilant 350, and since this is going in my daily driver 70 Z28 project (with a T56 6-speed), might as well make it fun!

Never underestimate a "lowly" 305!! :cool:

The ****ra may be fast, but I still don't care for it because it is overpriced, japanese crap, that is pretty damned ugly in my opinion.

Originally posted by 85_LG4
The ****ra may be fast, but I still don't care for it because it is overpriced, japanese crap, that is pretty damned ugly in my opinion.

I wouldn't really call it japanese crap. If you ever have the opportunity to drive one, drive it, and then tell me if it is crap.
It may be overpriced, but they hold thier value pretty well.

What is so special about driving them?

They have incredible handling, and when slightly modded are fast as hell. They are really fun to drive, especially with the targa top off.
I can't wait till I can afford to put a pair of turbos on my 86.

Ah.. they "do" have good handling.. I thought they did, but was not positive.
Are they fast stock? What are their times?
What about the ride, any good? Interior.. etc..

They are quick stock, not too fast. 13.9 @ 105mph bone stock 95 Supra TT Auto.
$2.00 t-bleeder mod and it went 13.2 at 110mph.
Downpipe and exhaust and it went 12.8 @ 117mph with boost problems.
Ride is very good, interior is like a cockpit of an airplane and is centered around the driver,
http://www.transamws6.com/pics/supra_dash.jpg

On the highway, the Supra really shines. I've had it up to 165mph and the car was still pulling strong, I had to slow down since there were cars ahead of me and I was coming up on them really quick.

Here is a nice pic I took while cruising down the highway to a hangout one afternoon.
http://www.transamws6.com/pics/supra_ss.jpg
took this pic while riding in my friends 86 Z28.

Now, do have this Supra, or no? You sometimes talk like you own one, but I dunno..
105 in the quarter is pretty damned fast.. lol (was there sarcasm in your typing?)
I think that is a little bit of "bull-****in-****" that a Supra was going 165, as well as "still pulling strong".. strikes me as a little bit TOO fast!
The interior looks decent, nothing special though.
What is h/p / torque on this "monster"?

It's not my Supra, it belongs to my friend down the street.
105 in the 1/4 isn't really fast compared to a lot of the cars that are in my area.
Stock HP rating on the Supra was 320hp.
He dyno'd the first time with the downpipe and exhaust and got 353hp at the wheels. With some fuel tuning, got 395hp at the wheels.

165+ is easy for a Supra with almost 400RWHP.

WTF 'IS' fast in your area then? ****.. I always thought if your car did 105 or more in the quarter, you were haulin' balls..
320 stock? Day-um.. no too bad!
What is a downpipe?
What cylander configuration is on supra's?
What do you think the Supra will top out at?

110+ in the 1/4 is fast.
Here is a link to our local boards Top Dog List,
http://h10013.racknine.com/~tidewaterracing.com/forums/showthread.php?s=&threadid=11034
My user name there is WS6, and I am towards the bottom of the list.

Downpipe is the pipe from the Turbo to the intermediate pipe, it goes in place of the stock pipe and cat.
Supra is an Inline 6cylinder.
His Supra probably tops out at the upper 170's, maybe low 180's.

He converted to a 6 speed and has a larger turbo setup and a stand alone ecm, all ready to be installed. Should put 700+ hp at the wheels with that setup.

In my eyes.. 110 in the quarter is "sh*ttin my pants just reading about it" fast!
Those cars listed were ALL LOCAL? All street legal? What about y0ur friends supra? Is that street legal? Will it be after the 700+ h/p?
180's? That is Viper fast!!
What does his supra sound like? Is it deep, or just the traditional import, ***-crap sounding "Wiiing" sound?

All of those cars are local and most of them are street legal with the exception of the 97 Firebird, which is a full out race car.
Some of the faster ones border on being "legally" street legal.

My friends Supra is street legal and will still be street legal with 700+hp.
The exhaust is deep, doesn't sound domestic, but it's close. And it doesn't sound like rice,.

How is it 700+ h/p and still street legal?

Originally posted by 85_LG4
How is it 700+ h/p and still street legal?

It's a turbo car. Just because a car has a lot of horsepower, doesn't mean it is street legal. My friend daily driven Lighting is puttng 454hp to the wheels.
Also, check out www.supraforums.com, there are a bunch of high horsepower Supras that are street legal.

Ya, but in order to obtain high h/p, don't you usualy run into emmsions problems somewhere down the line? Will 700+ h/p, let alone 550+, be streetable in all reality?

Emmissions vary by state, so one car that is street legal/emmissions legal in one place may not be in another.

What is your definition of Street Legal and Streetable?
My car is technically not street legal in VA since I don't have any emmissions on my car.

Street Legal- By law, your car is cleared to be driven on the street.. such as passing Full Inspection, etc..

Streetable- Not too much power to handle on a daily-basis, such as a daily-driver, it is fuel-efficient, etc..

Linky (http://www.ws6transam.org/305HO.html)

305-powered 14.04 @ 100.8 mph through an automatic

Robvas,

The uplink to that 'linky' has 3 or 4 different projects on it. What year motor was that? Is that carb still computer controlled?

wow 5,500 shifts on a 305tpi i shifted into 4th gear at like 6,800 at english town 3 times in one day and my motor still purrs nicley

Originally posted by Zepher
It's not my Supra, it belongs to my friend down the street.
105 in the 1/4 isn't really fast compared to a lot of the cars that are in my area.
Stock HP rating on the Supra was 320hp.
He dyno'd the first time with the downpipe and exhaust and got 353hp at the wheels. With some fuel tuning, got 395hp at the wheels.

165+ is easy for a Supra with almost 400RWHP.

Supra's don't have 320 hp stock. They're restricted to 276. Just like the Skylines, RX7's, and 300ZX's

As far as pulling 165 traps w/ 400 rwhp :bs:

I might think 120, not much more. 165 would require MAJOR work. We're talking a 9 sec ET.

how much do you get paid dragster? That's a sweetass ride. If joining the military'd net me a car like that, I'd go for it. ;)

Zeph's right about the 320 horse stock... I've seen some "lightly modded" supras do some amazing things on the dyno's here.

And re-read his post... he's not talking about TRAPPING at 165...he's talking MPH on the highway, not at a track. Topend. And a 400 HP supra can easily hit 160+ MPH.

Y'all gotta read **** more carefully...