Jus wondering what the most HP someones gotten out of a 305 and what they did to it??

 

on my supercharged 305 TBI, I would pull on my dad's mildly modded 98 LS1. When I took it to the track I smoked the clutch though, so I couldn't tell you for sure

ATI procharger running 6 #'s
mild port and polish on factory head castings
mild cam
ported and polished TB
MSD 6AL
MSD 8.5 MM wires
aluminum driveshaft
boxed LCA's
welded in SFC's

I'm sure there was more stuff, but it was a while back and I don't remember to well

Matt

 

There was a white Firebird here awhile back that had a 305 N/A into the 11s or 10s or something. Thats at least 500hp.

 

23.67..Dyno tested, dyno proven

 

Are you talking with power adders or NA??

 

 

it's not bs, it's true. It was discussed a while ago and what he says he has done is true.

 

i was talkin N/A... but its nice to kno about the HP w/ the power adders

 

It's rude to open your mouth without thinking first. That's one of the problems with these boards, it happens to much. Do a search under my name dick. Pictures and everything... Just because you haven't seen it before doesn't mean it can't exist. But you're the expert, what do I know :hail:

 

https://www.thirdgen.org/techbb2/sho...hreadid=195076

Here's a thread for you to check out Low 13's on motor, and mid 11's with a 150 shot. Pretty impressive There is also a guy on here by the name of ***** running a procharged 305 TPI hitting consistant mid 12's. If I remember right he uses alcohol injection also. Both are power adders, but impressive nonetheless.

Matt

 

I don't see any problem running 12's w/SC 305 the 305s only problem in valve shrouding from small cylinders. force the air/fuel in and the thing moves. no big deal there

 

Mines getting around 340hp naturally aspirated. It's possible to do great with a 305.

 

not to be a pest but what do ppl have done to your 305s?

 

My mods are in my sig. It should do mid-14s.

With a 305, in addition to the usual mods, you are going to have to have 3.73 gears and a good 2500 rpm TC to get it into the 13s.

 

Pretty confident mine would be somewhere in the 14's....but I haven't officially ran it.

 

according to the great desktop dyno my 305 should be putting down 380rwhp on a 100shot of go-go juice.

 

what all have you done to your car N8MAN? My current project is a 305 TPI, and I'm gonna be looking for ideas. I'm going all motor this time

 

yea... pleaz tell us what u hav done to put down that rwhp

 

I didn't post on this thread earlier because the topic said "most HP". thunder expanded it a bit with later questions.

DDD does rwhp? When run on my combo (mods in sig), it said 362 gross flywheel hp @ 6000. Using the sea level calculated ET/mph and a couple of different HP formulas, it appears to be ~250 rwhp, which would be about 300 net flywheel hp (what the factory uses for their published numbers). So, almost doubled the factory HP, NA, w/o touching the shortblock.

The stock LG4 would float the valves at 5200 RPMs. After the mods, with my 2-3 shift problems, I go through the traps in 2nd at 6200 RPMs - still pulling (but fading), still hummin'.


On a side note:
I highly recommend the mud slingers cool their jets. We're watching, you know...

 

no.
i took the #'s it was giving me, then threw in a 17% loss factor. i think it really gives me something like 378, but hey..380 sounds better. who knows...maybe on a cold day it'll pull that.

what i have is pretty basic.
305, aluminum L98 heads, zz3 cam, headers w/ cut-out, and 100shot of nitrous.
i'll post a screen shot of the curve and all that tonight.

granted, it's all theoretical and all, but the program should be close.

 

Did you have to shave the heads to keep your compression?

 

i've heard things both way about the compression.
shave 'em to keep it, don't shave b/c it will stay the same, use a thinner head gasket.

dunno. these items aren't installed yet.
i just got flow #'s from other people, plugged them into desktop dyno, and it gave me the #'s. 280rhwp isn't hard to believe for a heads/cam/intake/exhaust car, so it looks ok to me.

i just bought a house with no garage
it has everything the woman wanted, and the only thing i got that i wanted was land. oh well. i'll build a garage next year.
once i finish moving, i'll put it all back together and let it sit until i can afford a paintjob.

 

Sitting Bull,
Isn't 3:73 gears over gearing the 305? I would think that 3:42 gears would be good for our motors, and have always heard that the lower gears would be to much.

Just curious, Scoty

 

I saw that keith black sells 305 pistons for comp up to 10.3/1 for 64cc heads, but I was wondering if you could run 2.02/1.60 valves in a 305.

 

Hey Scoty,

No, for the quarter mile with a carbed engine you are ok with 3.73s. With a TPI engine it is too much for good quarter mile times due to the 4500 rpm limit they have. You run out of revs before your run out of 1320.

I use 3.42s because I want to retain some good mileage. Which I get, too. 19.5 mpg around town

But 3.73s would knock another 2/10s or so of my ET.

 

Yeah, but try getting 19.5 MPG around town!! Trust me, I know!!

Course, I don't mind winding it out a bit!

 

But I DO get 19.5 around town.

I don't get your post???

 

Sorry - I meant with 3.73:1 gears...it was late.

 

he's confused

 

My Trans Am came from the factory with 3.73 posi and a L69. No problems at the strip with that engine or the new 305 I have in it now. Around 340hp naturally aspirated. Much better on the highway now that I swapped to a 5spd though. hehe It's carbed also though so it flows better than a tpi motor would.

 

You bet!! I had an easy time making up a screen name!

 

TA5LiterHO- what do u hav on your 305?

 

My L69 in my 84 loves the 4.10's I put in it. As the times in my sig will show you....all stock other than the gears. It came from the factory with 3.73's. Traction is also a bit of an issue.

 

343 HP is the highest I have seen out of a N/A 305.
Not worth the effort if you ask me. Vortec heads with mod'd springs from SDPC are $319 each. Add a decent flat tappet cam and you are at 400 hp with a stock 350.

http://www.hioutput.com/tech/343hp/343hp.html