Whats the deal with my 305 TBI i have edelbrock headers, gutted cat, flowmaster 80-serious, open element, and a chip and my car stands no chance against all my freinds 5.0 mustangs withe just exhaust not even headers. they are runnin low 14's hight 13's and doin barely nuthin. I don't think i could get my 305 to run 13's without nitrous and heads. Does anyone have any suggestions on what i can do to hang with them? I was thinkin about getting a holley 670cfm unit and the holley tbi manifold with a comp cams compucam and a better chip then wut i got and puttin 3.73 gears in my 9-bolt posi disc rear after some suspension mods so i hook up. does anyone know a way i can get into liek 13.9-14.2 range with out heads or nitrous. and also what do u think i will run with all them mods. its a 5spd by the way. Thanks

 

my friend has an 88GT. I use to smoke him through first but now I'm toast. You need lots of top end HP. Get a single plane intake, gears, try LT1 or better cam, gears.... But I don't think you're getting 13s without heads or Nos. sorry.

 

hey that was post 4000 :lala:

 

Hehe...

Tas, you're a bum :P

 

one definite fall back is the gutted cat, your losing back pressure on your exhaust valves, you actaully lose power, i have not seen any sufficent evidence that a gutted cat makes more power then a good free flow performance cat on the dyno, i'd say swap it with a DynoMax superflow cat ,or Random Tech, just to name a couple, beef up your ignition MSD is the way to go, Cams and a good valvetrain beef up always help, take a look at my signature,im smoking 302' no prob


mike

 

keep the gutted cat but maybe put a pipe through the center of it. Just having it gutted probably causes a lot of turbulance.I'm not going to get started on the "you need backpresure" misnomer as it has been described better than I could on the exaust board already.

 

Such is the nature of things.

The 5.0 Mustangs had a little advantage from the get-go. The stock 302 heads are WAY better than stock 305 heads. They had factory headers and H-pipe. The Mustang also feels like a much smaller car.

HA...look at them now. They cut corners so bad that their '99 Cobra was slower than the GT.

 

V8Astro said it all. The main problem with the LO3 (besides the small bore) is the fact that they don't breath right. Heads are about the only thing that are gonna help put you in that same range as those ponies. If you go the Vortech route you'll have to have them milled while World SR Torquers will bolt right up with no loss in compression. Something like an LT1 cam would help you make the most of new heads, but that's a pretty rough undertaking. 3.73s will make a huge difference too.

 

see this is the case i am 16 and don't get my license till august so i have some time to work on my car. i have already done alot of work on it and money is def a factor. i am trying to figure out if it would be cheaper to mod the **** out of my 305 tbi till i run around 13.9 witch from wut i hear will be amazing for this engine or build a 350 and do just about nuthin and run 13.9. then theres always that little voice inside sayin buy a mustang but i really don't wunt a peice of **** lol. what do u guys think? wut will be cheapest? if u guys are runnin good numbers with the 5.0 tbi let me know your combo. thanks so much

 

plain and simple!!!
you want 13's, you need a LT1 cam, edelbrock intake, ultimate tbi mods w/afpr, drop front sway, posi wiht 3.73's, and a custom chip. some good tires woudl help but aren't completely necessary.
13's are easy with a 305, just do this stuff and shift around 5600 with the cam and you will run big time on a lot of stangs.
half the battle is hook and gearing. most of the stangs everyone seems to be in fear of are stick cars, taht means unless they are a really good driver you have them on hte hook and on the shifts right off the bat. give it the right gear and these simple mods and you can match the power, that menas you win!!!!

later
tim

 

would the holley projection manifold with the holley projection 670 cfm tbi be better then the edelbrock with the free mods? also i was planning on buying the crane cams- compu cam witch has a adv.duration of 272/284 and a gross lift of 454/480. does that sound as good as a lt1 cam ? also were could i buy one of these cams new? thanks

 

i was thinkin about getting a stang but after driving my dads 95 GT i just dont like it even that model takes turns terribly compared to my camaro with all the original suspension (102k on it) the 95s are slow and i think my car will hang with his if not destroy it because hes got an auto to...his hooks up pretty good with 17's on it. stangs do feel TINY compared to the camaro plus you ride way higher and you gotta watch your *** in a mustang because youll loose it easy around turns the 302 is a great motor tho but complicated as hell compared to the TBI motors...trust me on this one ive been messing with his and its not easy plus IMO the 3rd gen camaros (taking yours isnt a POS) look so much better than a stang unless its got a better wing, hood, ect. and no 5 speed stang ive ever seen/driven hooks up well at all just spins like mad sorry for the long post

 

too bad my stang isnt stock and the firebird is or I could be of some more help now. Instead Ill keep posting what iM doing to the firebird and the results. from the track and on the street. so far its slow as **** like 17.3 and we got beat by a cavalier which may or may not have been a Z24 (had a big *** sticker in the rear window). give me a lil while I dont even know if the plugs are in descent shape.

Im planning shortly: Tbi mods and a non drop aircleaner, a performer intake (4bbl style w/adapter) and an lt1 cam. Then a different rear and some exhaust as money is available.

 

personally i like th eholley intake a little better for top end performance because it has a larger volume in the plenum area. for some year not all the ports will line up the way they did stock though. the 670 unit is always a good idea, get the one with the 350 injectors and you will have plenty of gas for all your mods.
as far as the cam goes, that is a really big exhaust lobe. i don't know what the actual overlap on the cam is, but with that size exhaust lift you are not gonna see as much cyl pressure as you would with the LT1 or LT4 cam prolly. there is no need to buy an LT1 cam new either, they are roller lifter, which means the only way they get wrecked is if there is a massive lifter failure.

later
tim

 

My plans if I had my stock Lo3 would be to get a 350, like I did.
If you can't do that and afford the $2800 for the swap then think about cam, intake, exhaust, gears and N2o. The problem with the Lo3 is everything EXCEPT the bottom end. The flat top pistons are decent but the heads are crap. They're probably one of the worst designs I've seen. Good for making LESS power but it's just so restrictive it makes me sick. I looked down the intake ports and I honestly, I'm glad I GAVE it away.
Sorry, I just had to get some of that off my chest. I just never liked GM and their super low output engines.
The exhaust manifolds on the Lo3 are smaller than the TPI versions. It's a joke, the Lo3 got the smallest of everything except for the intake.
The intake is the same thing used on the Lo5, the 350 equiv so it isn't terrible, just slightly better than the heads.
If I was going to do mods on my Lo3 I would do gears, exhaust (headers), ultimate TBI mods (including AFPR), Lt1 cam, and 75-125hp shot of N2o. If you blow up a Lo3 you can get another one from the junkyard for like $50 .
With what I just said, you'll be high 12's if you do the major suspension upgrades like LCA relocation brackets, boxed and poly bushing LCA and panhard. Poly tranny and torque arm mounts are always good. SFC are a must on all thirdgens, more so on t-tops but every unibody needs to simulate a full frame if you want to be fast.
I have to disagree with Tim on the fact that using the stock heads and just a Lt1 cam will get you into the 13's. That's REALLY hard to do. You'd get like a 13.999 on a perfect day with crazy suspension mods and a 3000lb f-body. You gotta remember that he probably doesn't have all the suspension work done, doesn't have the gears, doesn't have the weight reduction like you.
Hell, you ran a 14.2 with those heads, you think if you had the stock heads and just an Lt1 cam you'd be in the 13's? I don't think it's possible. Your heads are giving you like 60+hp and weight savings. Stock heads are just worthless. Only way to go fast for cheap is what camaroracer1992 did with the shot of N2o. He was running 13.2's with stock cam and heads. Basically he took the fact that his heads flowed like crap, said, hmm...gotta get more O2 in there but have that little port...N2o is perfect.
It's the replacement for heads, not displacement!
The velocity theory is nice for a street car to run 14's but not 13's. You just need more ballz than what the stock heads can dish out.
I can't wait until you do the mods to that 305 you just picked up (Tim). You had BETTER dyno each mod or at least go to the track and run it a bunch of times before doing something else.
I'm thinking I'll bet money you can't get a stock head Lo3, Lt1 cam with ANY intake (n/a) into the 13's!