I got my Dyno results plus it got dyno tuned. Gained 7 Hp and 20 Tq on the tune. My peak Hp was 187.2 at 4300 RPMs and 263.4 Tq at 2800. The Tq stays strong until about 4,000 Rpms then drops alot more, Hp stay strong from 3,800 RPMs all they way to 5,200 Rpms. Kinda dissapointed I was hoping for 210 Hp and 300 Tq, but the curve is very nice for Hp broad curve. I figured out the numbers at the flywheel with a 20% loss to the rear and this is what I got 224.6 Hp and 316 Tq. Not bad considering the stock numbers are 165 Hp and 245 Tq at the flywheel.Looking for advice on mods. Thinking about going with AFR heads and maybe Weiand Supercharger, also need to do some suspension work to transfer the power better and get traction. Well heres the car and mods so far. Wish I had a scanner to show the whole dyno results.
87 Firebird
V8 305, 4 Speed Automatic 42,000 miles
Computer Delete
Edelbrock 600 cfm Electric Choke Carb
Edelbrock Performer Intake Manifold
14" Open Air Cleaner, KN air filter
Comp Cams Roller Cam 260
Comp Cams Roller Lifter
GM Aluminum 1.5 Roller Rocker Arms
New Springs and Retainers
Double Roller Timing
New water pump
Edelbrock Headers and Y pipe
High Flow Cat
Hooker Cat Back
Auburn POSI with new ring and pinions
Stock 2.73 gears
BM Megashifter(rachet)
165 thermostat
Fan on at start
New HEI Distributor set at 35

 

you sure you don't have the hp and torque mixed up?

 

Sorry I corrected the post

 

As for heads on a 305 you only have 2 choices: World products S/R Torquer 305 (pn 042750-1) available from Bill Mitchell Products and GM L31 Vortec available from Scoggin-Dickey with spring upgrade (SD8060A). Remember if you use the vortec heads you should use a vortec specific intake manifold.

 

There are way more than 2 choices on a 305. You can use any small block 350 and smaller head as long as the valves are small enough.

 

AFR 180cc SBC Street Cylinder Head will work to right. When should I be shifting.

 

Damn, I really should check what mine puts down. I'm figuring 205 hp at the wheels from the 1/4 mile times I run. Also not bad since the stocker put out 145 hp at the flywheel lol. AFR 180s on that 305 I think would run into problems with the valve size. 1.95 is about as big as you can run it seems.

 

Air Flow 180 heads will not work unless you fly cut the block on the intake valve side. No 2.02" intake valve head will work on a 305 unless you bore the block at least .060 or fly cut the block on the intake side. It is best to bore and fly cut to unshourd the intake valve.
There are only 2 GOOD heads for a 305; World products S/R Torquer 305 and GM L31 Vortec. Both heads are rough when purchased. Both heads need porting and a good 3 angle valve job before installing.

 

the lo3 heads are soo crappy that the tpi heads will work good on there there is also a thing on the tech stuff on porting the 305 heads and the guy got great results!

 

Hmmm...

And I was a bit disappointed with my 305 at 214 HP @ ~5400 RPM & 282 ft-lbs @ ~3700 RPM at the wheels..... maybe I shouldn't be....

Mine still has the stock carb, intake & dist on it though, and that dyno pull was immediately after the California emissions dyno test (which it passed easily). I've posted countless times that those things aren't where you pick up horsepower on these motors, so maybe I'm not too far out in the weeds after all.

I have flat-tops, a set of lovingly massaged double-hump heads (I know, but I had them laying around), a Comp XR264HR cam, & TES; stock carb, intake, & dist with computer still there; stock exhaust after the TES; stock air cleaner (on the motor as normal for the dyno pulls); stock cooling system except for a Stewart water pump; stock gears (3.73); lots of stock stuff.

 

forgive me for asking but do you have a carb... or tpi??? because on stock heads 214 is not bad!

 

83 L69 It's pretty weenie actually, it's just a 305. Considering what was in it before I moved to California and had to nut the poor car to this point, it might as well be a 4-cylinder.

 

thats still not bad for stock intake and carb... considering the tbi's only put out 170 stock!!! my old 87 300 zx put out 170!!!

 

I guess you can figure out how I'd think of a stock L03 or LG4, if I describe a 260ish HP L69 derivative as "weenie".... I mean, this thing is really kind of tame, it's only about equal to a lightly modded L98. That's weak in my book.

 

yes its week for a v8 but not a 305... but also the car is from 83... using 83 standards it was bad a**... but you now have stock 4 cylinders with 300 hp!!! subaru imprezza wrx sti and yes 4 names make it faster!!! it has a 2.5 turboed 4 it'll do 0-60 in less than 5 sec!!! for 30,000!!! so now days your could be considard weak.

 

Those numbers seem pretty low to me, for a cam swap, intake upgrade, full exhaust 305. What are the specs on that cam, perhaps it's smaller than I'm thinking? You could probably pick up 20ish hp at the crank with a Performer RPM over the regular Performer. It was worth that over the Performer in a carcraft or chp dyno test on a LG4 with headers, still with the stock cam... With a cam (XE262, 218/224 @.050) still with the stock LG4 heads that engine also made 269hp though... As a matter of fact it beat your output with the stock cam still in there (made 230hp with the Performer RPM and headers). I need to find a scan of the article again, I had it up on my webspace but lost my space and all my content... If I'm understanding it correctly yours was originally TBI, are the TBI heads responsible for that disparity? My understanding was they were pretty similar to the LG4 heads...

I would have been expecting alot more than 220ish from your setup...

 

He has a 87 car, probably started out life as a LG4, so it would have 081 (same as TPI & L69) heads..... TBI heads would definitely be a handicap....

 

Read some more magazines no way a stock LG4 with just Performer RPM Intake and headers could add 65hp(You know an LG4 for my year is only 165hp at the flywheel). If you believe everything you read in magazines and in catalogs you'll think you got a 400hp car when its only 250hp. Rule of thumb is cut in half advertised power gains. My car was in mint mechanical conditions when I started moding it and I chose most mods to go with one another. O yea the engine is a LG4

 

That's a very good point, maybe the most important thing about modding a car; and I agree, your stuff as a group is a consistent choice.

Pre: places I'd look for some more RW HP in your car include synthetic fluids in the whole drive train, a L69 air cleaner if yours is one of the aftermarket "drop-base" or flat-base kind, and head porting.

 

What he posted was accurate, but the #'s were flywheel hp. The headers and a little bump in timing were worth close to 50 flywheel hp on an otherwise stock LG4.

 

L69 cleaner is that the dual snorkel one.


65 hp gains from Headers and a Perfomer RPM intake on a stock LG4 still doesn't sound any where close to believe able to me. Maybe 40hp but not 65 hp

 

You don't have to believe it, but it's true. They took a stock 145 hp LG4, put it on the dyno, added long tube headers and dual flowmastef mufflers along with some timing and then proceeded to dyno at 199 flywheel hp IIRC. Take it as you wish, but keep in mind these are FLYWHEEL #'s, not rwhp.

 

Guess its something I would have to be there to believe. I got a question should I be shifting when Torque and Horsepower cross or at the end of the horsepower peak??

 

You should shift when the gear you shift into will be just below (like 200 RPM below) the torque peak. Usually this will occur if you shift just below peak HP RPM in the gear you're already in.

 

Thanks all try it out, shifting at about 4100-4200RPMs. Again does anybody no if the L69 air cleaner is the dual snorkle.

 

Here is something that might help you out. BTW, I dropped .5 seconds in the 1/4 by shifting at 5000 rpm versus 4400 in my bone stock L03, which everyone else says is no good at all after 4500. HMMM.

http://www.bgsoflex.com/shifter.html

 

Yes. The L69 air cleaner is the dual-snorkel cold-air setup.

 

What car at a junkyard do I need to find to get a L69 setup.

 

I suppose it would help if I could post the damn article scans that I had instead of just vaguely mentioning it, but it was a dyno flog bolt on test on a LG4 all the way up to cam/heads swaps, not some advertisement numbers... Very useful for 305 bolt on numbers. Magazine racing is one thing but this was a multiple dyno run test on a LG4. Can't get much more relevent...

Are your cam specs 206/206 @.050, .500/.500 lift? Should be pretty good, 220-225ish hp at the crank still seems way low. You say new springs and not to insult but are they good stuff recommended by compcams to handle the .500" lift? I'm assuming they are just trying to cover the bases... Don't suppose you have a scan of your dyno graph, and did you get air fuel ratio readings while on the dyno? What did they do to tune in the 7 hp/20 ft-lbs?

 

I don't believe that magazine, but thats beside the point(I would have to be there myself).

I got to find out from the speed shop the exact cam numbers and what valve spring set they put in, I can't remember(I got the invoice but its got the speedshops own part numbers on it, not the manufactures ).

Already mentioned in this thread was the fact that I don't have a scanner.

The dyno tune consisted of timing, changing spark plugs, carb jets and other minor stuff the shop spends up to 8 hours dyno tuning the car its a $300 package I got it for free. Sorry no fuel ratios.

What I have down so far has gained 60hp and 70tq at the flywheel and I'm fine with that. Other people who have 305s and moded them said that I had less power then the 210hp rearwheel I thought I had before the dyno.

 

Here's that 305 build up from Car Craft.

 

83-84 L69 Z28s (HO cars)

 

The ram air L69 air filter was standard on '83-'86 L69 Z-28's. That assembly is still avalable new from GM. The part numbers are: air cleaner 25043641, Left duct 14070917, right duct 14070918, left hose 14073299, right hose 14083990.

 

I have not been able to find those part numbers available from anywhere. GMpartsdirect, ACDelco, Classic Industries, etc.

phil

 

may be your only choice.

Sorry, but it's no one's fault here that GM doesn't make them any more. There's not much we can do about it. Watch the classifieds on this site perhaps, they show up there from time to time. Unfortunately the proces tend to be a bit predatory; but that's the way these things work in this hobby. The good stuff usually isn't the cheap stuff.

 

I made 265ftlbs and 235hp at the wheels with my 305 in my 86 firebird.

It was a 183,000 miles on it too-

had a compucam 2030, edlebrock performer intake, holley 670 carb, edlebrock tes shortie headers, and STOCK, i repeat STOCK rebuild (better springs) LG4 305 heads (the smaller valves- 186 intake or something)

all that translate to about 275hp, and 310ftlbs at the flwheel- best time for the car was 13.8 @ 103mph... it was fast enough to give a solid lt1 bolt on car a run for its money...

here's the chart-

http://pages.cthome.net/ssoares/webfolder/dynochart.jpg

 

I hope its just my ignition that is holding me back. All this money spent and very minamal results.