Tbird

Anyone know what it will take to get a 305 tpi into the 13's, will heads,cam,exhaust do the job, what about fuel and tuning?

TunedPort 335

How about free mods, here's my friend Joe's car..

89 IROC-Z 305 tpi

13.9 @ 97mph is pretty good for a stock 305 TPI if you ask me.

Fix the stuff that GM made crappy from the factory. Do a whole bunch of free mods and I think you'll be happy with the results. With good enough driving you should get good 1/4 times.

Heads, Cam, Exhaust, and Tuning will definitely get you there.... you just gotta match up your parts accordingly so it will all work well together. The TPI chokes our cars at high rpm's...so try some mods to make it breathe better. (Port the plenum, K&N's, Airfoil, etc).

Good luck

PONTIMANIAC 90

I got my 305 into consistent 13.9X runs and a one time best of 13.88. I had all the bolt ons but what did it, I think, was good launches w/4.10 rear and Sportsman Pro tires. I had a heavily siamessed and ported SLP runners and Edlebrock base which propably gave me a little more top end. Although the tires is what put me into 13s more than anything else.

Bort62

There is a Differance between Getting a streetable 305 into the 13.x and Getting a Lb9 powerd Drag car there.

W/ a 3000 Stall, 3.73's, headers, Catback, slicks/DR's, A decent WOT Tune, and some Minor weight reduction, Any Non Peanut Cammed 305 should be Kissing the 13's with ease.

They Key, like pontiac Said, is in the 60'

But who wants to Show up w/ Slicks and Skinnies and Run high 13's ?

Your going to look like a goddamn Fool.


If you want to get your street Tire modestly Geared Daily driveable Lb9 Into the 13's, then You have a slight bit more work ahead of you.


Altho it's still Not that hard.

I havent got the 13.x Slip yet, but ive got a host of excuses a Mile long and I am hoping that my next trip to the 1/4 Will prove me right regardless of my restrictions.

Oh yeah, and if you've got the Peanut Cam - Forget it.

SLP IROC-Z

iTrader: (1)

Im the kid TunedPort335 is talkin about, its pretty easy to hit thirteens

1989 IROC-Z LB9 MK6 Hardtop 3.08 posi

vehicle weight with driver 3350 with a 1/4 tank of fuel

hollowed cat
emissions delete
A/C delete
throttle body coolant bypass
cut the bottoms off the air box
manifold air temperature sensor relocated to the air box cover
160 stat, manual control dual fans
dynomax super turbo exhaust
dynomax headers
headman Y pipe 2.25 to 2.50
ported plenum
ac delco plugs
centerforce dual friction clutch
energy suspension torque arm bushing
energy suspension tranny mount
9 bolt with 3.27 gears (not run at the track yet)
pbr rear calipers and 11.86 rotors

its all about 60 foot and that was with a 2.02 60, with suspension work i hope to get a 1.8 60 and with the new 3.27 rear i got im expecting 13.3-13.5

Bort62

Point.

I don't know about a 13.3 w/ the 3.27 Rear tho, haha. That might be a little overly optomistic.

SLP IROC-Z

iTrader: (1)

doin some math here:

good rule of thumb, every tenth of the 60ft is 2 tenths at the end of the track so lets see 1.8 from a 2.0 thats 2 tenthes, times 2 = 4 tenths, 13.952 - 4 tenthes is 13.592

a lot of people are saying a two tenth reduction in time with the gearing change, 13.592 - 2 =13.392

but like i said 13.3-13.5 seems fesable

ive also proved the theory of the 60 foot tenth rule, i got alll my old slips and changed em to 2.02 60s and they came out around 13.8 and 13.9 just like my 13.9 slip.

Bort62

I agree with you on the 60' - 1/4 Rule, But I don't think your gonna Rip out a 1.8 w/ a manual and Street Tires w/ 3.27's.

Sorry.

I would expect to see along the lines of a 13.6-13.7 from your car w/ the Rear end - definately nothing to shake a stick at.

Bort62

Along the lines of the 60' Rule -

My car Ran a 14.3 On a 2.3 60' That should put me squarely at 13.7 if I can hit even a 2.0 W/O accounting for the 4500 rpm 1-2 shift or letting off to hit 2-3.


Stock Stall Converters are gay.

SLP IROC-Z

iTrader: (1)

im hopin to get 245 50 16 Nitto NT-555r Drag Radials for the back
and regular 245 50 16 Nitto NT-555r radials for the front

one thing ive learned from messin with these cars is how important suspension is and how important the combination of parts is!

i used to open up the magazines and pick out a lot of catalog junk that is totally unnessisary for what i wanted to do, and would have cost me a lot more money and hassle then how i got where i am.

Bort62

Goddamn, you're not an Idiot - Im not sure how to respond, lol.

W/ the DR's you might be able to get the 60's down - We shall see

SLP IROC-Z

iTrader: (1)

new87

With 2.73 posi and BFG drag radials I pull 1.99x all the time. The hook up mods have been my best. Now I have a 3.70 posi to try and hook. 14.0@96 with a 2.73 gear.

SLP IROC-Z

iTrader: (1)

the stock tpi unit will do just fine for the 305 for now, the only thing id do is port the plenum, there is an EGR casting wall behind the throttle body ports that is a bit of a restriction. the injectors are sufficient (my car actually runs rich) tuning is a great place to start so is basic mods, free mods, keep it cheap. suspension is also up there with the first things to do, gotta get the power to the ground before u can go tryin to make more of it. with headers, ported plenum, exhaust, free mods, ull see about 15-20whp gain.

is ur car automatic or manual, id suggest changing to a manual tranny or atleast getting rid of the peanut cam for the larger l98 cam or even a stock LT1 cam, the cam is one of the main reasons the automatic version of the 305 is slower then the manuals. there is big restrictions on these cars, thats why free mods are so important, most of these fix the restrictions, some not so free things are the headers, and exhaust, porting the plenum is cheap and easy, it can be free if u already have the tools.

bjankuski

With stock heads and cam and bolt on's I was able to run a best of 13.85 at 99 MPH. With the Vortec heads and ZZ-4 cam I ran 13.53 at 101 MPH.

Bort62

And I ran 14.3 @ 99 MPH no wheelspin. - I really can't wait to get on the track with the T5 so I can cut a decent 60' and watch my ET plummet

bigals87z28

you som'bitches with the 5spd dont have to worry about TC's! This summer, im putting on SR heads, ZZ4 cam, 1.5 rr's, ported runners/plenum/base, and full exhaust.... what do you think ill run? with the stock TC and 2.73's i think i wont get the full potential out of the car, but thats gunna have to wait till next year when i can get the trans rebuild and have a new posi with gears put in. i was hoping for that set up somwhere in the mid 14's if i can hook. best time so far is a 15.32@89mph with a 2.1 60' time...

new87

Or the PEANUT CAM! That was onw of the best thign I ever did, was to put in a LT1 cam even if it was a little LT1 now I have a bigger LT1 and a lot better gear.

Tbird

how big of difference would u feel putting a 222/222 @ .050 with .447/.447 lift 114 lobe seperation? 20-30 hp?


in an automatic of course

TunedPort 335

That cam has too much duration for stock TPI. Try to find something less on duration, and has a little more lift.

For instance my cam is 210/220 with stock TPI (I do have Airfoil, K&N's, Descreened MAF, but thats it).

Good luck

BORLAZ06

where u from Bort?

i remember u saying that you saw my car a while back.

looks like this is a lil' off topic.

ttt

Tbird

dang i already have the cam what will it do to my car

SLP IROC-Z

iTrader: (1)

back on top

TunedPort 335

Well this is what I would do if I was stuck with that cam..

1. Port the plenum (ridges behind the throttle body)
2. Get high flow runners if your budget allows.
3. Get a custom PROM chip.

Those should make the car run pretty good. I may be wrong...I'm no expert, but from what I know those would be your best options.

wyclefsirocz

its not so much of having the parts its weather they will all work good together.

about the cam has anybody ever thought of using the ram jet cam, cause thats what i'm planning on getting.

Duration @ 0.050 (I/E): 196/206
Lift, (I/E): .431"/.451"
Lobe Separation: 109
RPM Range: 800-4500
Type: Hydraulic Roller

but i plan on putting 1.6 rockers on
which should bring lift into the
.460/.481. which give a nice power band with a 305tpi. along w/ world torquer heads ,ported intake, full exhaust.
some spohn lca's and sfc's
a set of 3.43's and 2200-2500 stall converter, and good tires should bring u right into the 13's

redtail2624

I have a 305 tpi 88 transam and last summer i put on some sr torquer ported heads and a comp cam 210/220 .480/.480 lift and that cam seems to work very nice for me.It put out about 275 horse with untouched intake.I have not run it at the track but i do beat all stock lt1 auto and stick cars.My car is an auto by the way but not for long.If you want to move with any 305 get a stick.I have an lt1 intake all ready to go on i will let everyone know how it runs before and after intake swaps.That ram jet cam seems a little small on both duration and lift.

bigals87z28

Redtail.. sounds like you got a good set up... do you have exhaust to help out that cam and heads? 275 sounds a little high... but hey if thats what you got... im glad.. it would be nice to have that after this summer. hoping to run 13's with all that and shift kit and a 2400-2600

wyclefsirocz

the ram jet will work nicely in my iroc, cause it has the power band that i want, plus it is 135, so two thumbs up, i don't want power over 5000rpm. cause i don't wanna get an aftermarket base, maybe just slp runners.

redtail2624

I have about 275 -285 at the crank not the wheels and yes a full exhaust slp headers 15/8 with high flow randon tech cat and a flowmaster catback.Also have 21lb accel injectors with afpr set at 42.the ramjet cam will give a goodsetup with the stock heads.

Bort62

I am from Morgan Hill.

Let's not turn this into a retardly modded and slow 305 Post.

tazmision89

I recently ran a 13.84 with nothing more then 4.10 gears, elderbrock headers, k&n filter, draglites 15x3.5 and ET streets in the rear, & MSD ignition. No weight reduction (i.e A/C)

I cut a 1.87 60' on that run.

BORLAZ06

next wednesday i will find out if i can tack a high 13...'bone stock' motor

IROC315

iTrader: (9)

With stock Tpi? Mine was gasping for air with the 4:10s. I am putting some 3:42s in.

SLP IROC-Z

iTrader: (1)

4.10s! 3.42s at the most with a 5spd

new87

I'm running 3.70's with an A4. Thing pulls till it shifts. On my 26 in tires I'll go through the traps at 115mph max. But, with the 28 ET streets I'm good till 124mph. But 115 will be pleanty for now. Should have Dyno number after rebuild so I dont leak oil on the dyno. I'll see if my car pulls as well as I think it does.

xanax

i have a ZZ4 takeout cam with zero milage if any 305 guy is looking to replace their cam. pm me if you want it.

tazmision89

My intake has very little porting and the heads were ported as well.

Here is my run:

http://www.tristategm.com/video/MOV00082.MPG

FyreLance

What's everyone's opinion? Is this a good cam for a 1991 305 TPI?

wyclefsirocz

thats a mean cam for a 305, but w/ a strong motor along w/ headers and ecm reburning it should be realy nice.

bigals87z28

i cant wait to get my cam and heads on the car... im looking foward to see what the improvments are for my car

IROC315

iTrader: (9)

That's impressive. I am switching to 3:42's since I am putting a 350 in and I will be running Nitrous. I got kinda tired of the 4:10s during daily driving . They sure do make the car pull hard though.

wyclefsirocz

very nice run, i ;like it i hope to have one like that

D's89IROCZ

SDPC told me to get the 3.73's with that cam ( ZZ4) for a 5 speed .....3.42's for an auto



PS how's that 305 running Joe

f-crazy

iTrader: (-1)

when i bought my 91 G92 LB9 from my uncle it was 95% factory..only thing that wasnt original was the ram clutch...
took it to the strip and ran a 14.8 on a 2.2 60 foot...after about 6 runs or so and a couple air pressure adjustments i was cutting 2.0x and running mid 14.4's...

during the next week i put a flowmaster muffler on it a k&n and ground down the EGR walls and took it back....

best the car ran was a 14.1 on a 1.96 60 ft.....it started to spin a rod bearing so i yanked the LB9 out of it...now its got a carbed LT4...

89TA383M5

There is some pretty different E/T's with some near stock 305's. I got a 383c.i. all built and going in this week because I didnt think my 305 was worth building. My 89 TA T-5 with 3.08 posi, the small headers, no cat with flowmaster, no smog stuff, throttle body bypass, 160 thermo, open element air filter, and JET stage 2 chip ran a 14.79 @ 94.67mph with a 2.17 60' time. I got a gay launch. 100K on the speado and I don't think the 305 had rings. Change the oil and a week later the oil smelled like gas pretty bad. Sounded like it had a lifter tick that got louder and louder after about 1,000 miles after an oil change so I changed it every 1,500. It took out a bunch of 5.0 mustangs and a 03 Gt (barely) on the street but I couldnt hook even with my 305 so after I have enough money I'll do some rear suspention stuff and make it hook and go after the rich kids with there LS1's and the kid with the 03 Cobra. I'm telling them I have a cam in my 305. I loved that engine though. Tuff little guy. My buddy is taking the 305, rebuilding it and were dropping it in a S-10 with a carb.

bigals87z28

MUST GET 3.42's!!! Also, i need a 2600 stall...