Ok i have been looking around and I have found out that stock '91 350 Z28's run 14.4 et's? Is this right? The main reason i ask is because last summer i took my car to the track for the first time and ran a best 14.8, the other two runs were 14.9's. Is the 14.4 times accurate? Is my engine that tired. It wouldn't suprise me, it had 150,000 miles on it at the time. The only reason i find this hard to believe is because it still runs great Is it time to just compleatly overhaul the engine?

 

I'd start with a complete tune-up and bolt-on's. Then in a year or so when you have exhausted every bolt-on that you wanted to add, move on to the bottom end. BTW, I consider heads and cam to be bolt-on parts. Don't forget to beef up the tranny, rear end, suspension, and fuel system along the way.

 

When I was last at the track I there was two 350 tpi camaro's their, one was running exactly 14.4's and other 14.6. Both cars were stock as could be. I looked under the hood of the 14.4 car and it had fresh plugs, wires and tune up and had 90k on it. I did not have a chance to talk to the guy with the 14.6 car. But I would guess it was not as while maintained as the 14.4 car.

When was your last tune up? With 150,000 you probably have lost some compression. But not enough to make the car run bad, but just enough to start hurting overall performance.

 

Also, what was the mile per hour on those runs. Your high times may related to a traction issue. The mile per hour is a good indication of that problem.

For example: My 88 305 can run a 14.9 (thats with alot of mod's on it). But if I get bad traction on one of the passes it runs a 15.3, or 15.4.

 

trap time was 92-94 mph on all 3 runs

 

my 1991 Z28 350 Ran a 14.3 on the track back in the day stock It still has the same amount miles as it did then

 

according to the 350 owners on here they can run anywhere from low 14s to low 15s. all the ones i raced on the street ran high 14s on a good day. the fastest 350 car i have ever seen ran a 14.8 and it had a shift kit, big runners, and a headers. (here come the flames, sorry guys i just dont think 350s are all they are cracked up to be) every car is different. i think the numbers you ran are jsut fine for a healthy stock 350.

 

I would do as others suggested. My first time at the track was a 14.8@94. (2.77 Posi rear)

The car only had 64,000 miles at the time and I found all this after:


Found out I had two bad wires, the distributor cap/rotor and coil were very old and corroded (Replaced whole ignition system with MSD parts). My injectors were dirty, and 4 of them were so dirty they leaked, causing hard starts (Got them all cleaned and flowmatched). My plugs were black as hell due to the injectors (Replaced them too), and my Tb gasket was torn.


Ive fixed all of that since then and added headers. Can't wait to see the new times

 

Ok i am still a little confused as to how the stock cars can run such different 1/4 mile times. I thought that mine would be on the low side of those times, because i was told that my car had a few more horses because of the dual cat set up that is on there.

 

let me clear it for you


1987-1989 MAF L98s run - mid 14s- high 14s

1990-1992 SD L98s (thats u) low 14s-mid 14s in a 1/4


My 1991 Z28 L98 ran 14.3, Yours with good tune can run the same

 

mine with stall converter and headers/catback, prokit springs and adjustable shocks ran 14.02 at 96 so if it was stock i would guess somewhere around 14.5-14.6ish but if it was slower than that, then i would feel better gaining like .8 seconds with mainly exhaust and stall converter LOL, but whatever i gained, it was good.

oh, my car is 89 Irocz with stock L98 with 140,000 on it. all original as far as i know.

 

My mods for next spring are a 2800 convertor, and some Nitto NT 555R Drag Radials

 

OOOOO can i please have your 305, i'll give you my 350, and maybe i'll throw in a quality 7000r4. Just kidding, but i hope you are talking about stock 350s because what you said is kinda vague, like you'd rather have a 305. Anyway i'm not trying to flame, really, but just giving some of my opinions. I've seen plenty of stock 350 cars run, in good tune they run around 14.4-14.7. Your 91' should be on the fast side, but what were your 60' foot times, they car play a major role in overall times.

 

also..I'm sure there are a few "factory freaks" out there too

 

MAN, you will be so happy with new stall!! 2800rpms is perfect and with drag radials, your launches will be SICK!!! Such a great feeling. Even with my 2.77 gears, the power response from that convertor is great. Feels like whole new car!! I cant wait to put my 3.27's in. LOL I know, i have had those gears laying around for nearly a year now. LOL What was i waitng for I dont know.

 

well i guess it depends on what your big bad 350 runs now doesnt it? no i dont mean to be a hater, and yes i acknowledge that a 350 is a better platform to start with if all out performance is your goal. However, i do think that a 305 is still a very worthy engine if reliability, performance, and street manners are important. now my 305 runs 13.9 with single 2.5 inch muffler and the stock chip, which is not really all that fast, but then again i would guess that 90% of the 350 powered Thirdgens out there cant run in the 13s, let alone all the 350 powered muscle cars and other hotrods out there. (i will admit however that almost no 305 cars can go 13s) I keep hearing people say that the 350 is such a fantastic engine and 305s are junk. I also hear people say that it is just as cheap to build a 350 as it is a 305, and as long as you already have a 350 laying around, it is as cheap to build. what you dont hear is that it is almost as cheap to build a 383 as it is a 350. so where do you draw the line? a 350 is better than a 305, but then a 383 is better than a 350, so where does it all end? the bottom line is, that any small block chevy can be built to run hard, one is not better than the other, every person's situation is different and everyone has a reason why they spent their money on one specific engine over another. i built my 305 because it is what i had, and i wanted to be different. besides, i win more money from the 5.0/4.6 mustang guys that way.

 

I agree with what you are saying. And my 350 really isn't that fast at all, mid 13s. The point some people are making(not necessarily me) is who much did you spend to make your 305 that fast? I have a ZZ4 cam, stock heads, headers, exhaust, as&m runners and port matched base. Thats less that $1500 worth of stuff. Of course a rebuilt trans and nice tires don't hurt either. But I agree the 305 has its place and is not that bad an engine. I also know a guy with a honda faster than 95% of the guys on this board with any engine size, its all about how much you want to spend and how risky you want to be. Also its not all about sheer engine size. Its all about bore/stroke ratio. I'd rather have a chevy 302 than chevy 305, the bore stroke ratio is just better. With that said i'm impressed with the work you have done and time it turns, it is obviously a well matched combo.

 

It all depends on what shape the motor is in. Your car may have some pretty hard miles on it. My car has 131k on it and is consistant in the 14.4 14.3 with a best of 14.1. 60 ft times count a lot. MPH on my runs was 94-95 mph, and 97 on the best. 60's are 2.1-2.2, which is i think the limit on the futuras i run. The car definately has potential for 13's. I just need to lighten her up, and get stickier tires

 

thanks for the compliment, yes i woudl rather have a 302 with an LT1 intake and 4.56 gears!

just for reference. i rebuilt the engine for 500 bux, that includes cam and everything, the heads, rockers, valve job, and porting kit all cost me 700 together. the converter and shift kit were 500, i got the converter used for 400 bux. so 500+700+500= 1700 bux.

 

thats a hell of a price, but what about exhaust, but still i'd love to find nice heads for under $700

 

i found the heads on the classified ads on a C4 corvette website. those heads dont mean squat to those guys so they let them go cheap. i ported them myself and had a valve job done on them which totalled the $700, i actually got the heads and rockers and hardware for $600.

as for exhaust that is the funny thing. i have the edelbrock headers which are $300 or so, but my cat back is stock with just a single 2.5inch flowmaster which i got used for $30. pretty sucky but its what i had and i couldnt afford new pipes, so tahts what i ran.

 

Hey Orr89rocz, ur saying its ok to have that stall for the street or only for the track?

 

2800 is fine for the street.

 

its great for both street and track. Perfect stall combination as my car is daily driven and 2800stall lockup is great. locks up in overdrive at 35mph or so. cruise all day long at 65 and like 1500rpm with 2.77gears. LOL

 

Alright i just got a tune up done, the plugs were all but gone. I think the last time i had those changed was around 50,000 so i guess that not to bad to get 100,000 out of them. The only reason being, i do most of the work on my car myself and the plugs are so hard to get at. I replaced the cap and rotor last year. The guy told me that he tested all my wires and they were all fine. I had been kickin around the idea of a cat back for a while so i ordered the Flowmaster AT cat-back kit for my car, 3" in dual 3.5" out. It sounds great, but i was expecting it to be louder, even after i cut the muffler off I fired it up and it wasnt that loud i guess ill just have to get some hi-flow cats. I would like to get to the track before it closes for the winter but who knows if i will get a chance. I need new tires before i go as well. I was looking at the Pirellie PZero Nero M+S from TireRack.com. I had the BFG KDWS and they lasted like 25,000 i was very dissapointed i thought they would last longer with a tread wear ratting of 400.

 

oh ok cool Thanks,

 

Orr89RocZ, what brand are you running?

 

Edge Racing converters. got the custom Street Edge. Custom configured by them for your application. 554 shipped to my door. LOL 9.5" converter.

 

how much was the converter?

 

525 for it, plus 29 for shipping. Plus free T shirt!!! LOL

not a bad deal!

Oh its built to handle some power, i think 450-500hp and if you decide you need more stall, send it back and they will upgrade it for little more cash!!

 

cool deal, thanks, i didnt realize thats what you meant by 554 in your last post, sorry

 

Is that considered a "tight" or "loose" convertor?

 

not sure, i guess its tight cuz its only 2800 stall. Its more efficient than stock sized converters 12" ones. Loose is lots more stall like 3500-4000+ as far as my understanding goes.

Also the ratio that the stall hits the tires, i think its called the STR ratio, is pretty soft, but hard enough to provide quick launches. Not sure how it all works but more STR, the stall lockup transfers the power to the tires quicker and harder so more snappier acceleration.