What are some of the best 1/4 et's that anyone has seen or heard a modded tpi 305 do?

My bone stock 90 305 IROC ran a mid 15's @ around
91-92 MPH. It was a cool spring day in 1990.
The car had less 1000 miles on it and I only did maybe
5-6 runs with it. I don't have the timeslips anymore.

I only remember because it was about 1 sec slower then
my 87 350 IROC which consistantly ran mid 14's around 95 MPH. It was completely stock as well.

13.1 with mods in sig.

ive heard them getting as low as mid to low 14's, but have ran mine just a day ago and it ran a mid 15 (15.5). its almost all stock.

16.2 only performance mod SLP CAI

"Modded" TPI 305? 9.93 ¼ with an auto trans.

WOW Vader! I see the blower but what all was done to this engine? Great Pic!

My times are in my sig,

Approx. 1/4 mile times are 14.3 with no juice and 12.90 with a 125hp shot.

That's not mine, so I'm not sure what was done. I would expect at least a decent set of rods, good balancing, and a fast-closing cam a little better suited to a turbo. I'm thinking that some traction issues may have been resolved, too.

Is that Mikey305 or Willy's car?

Jonarotz, most others here posted NA times. Your 13.1 is very good, off the bottle I suspect it runs 14.50s??

Vader, I believe the car pictured in your post belongs to Preston Smith, and while it is technically a 305, it has a 4" bore unlike our 305s with a 3.73 bore. It is a pretty serious combination, not a heads and cam 305 like some of us have. This car used to run in the 9s with a blower a few years ago. Last I heard he was still working the bugs out of his turbo. There are more pics of Preston's car around here if you do a search.

I think the quickest TPI 305 on here that I know of is Tuned Port 335, but obviously he has a stroked 305. From memory I believe he has ran 13.4 @ 98mph. Tim Burgess reportedly had run an 11.9 or something with a stickshift car but I have never heard or seen any proof. My 305 is somewhere in the mix, maybe even 2nd quickest and the fastest barring Tim Burgess. There are faster 305s like mw66nova but they are not TPI cars. My times and mods are in my sig. with a better launch I have the power to match TunedPort335s ETs. There may be faster TPI 305s around here but they are either slipping my memory or I am unaware of them. Anybody in the mid to low 13s with an NA LB9????

You are correct - That's Smitty's car. Technically, the post asked about "modded" TPI 305s. That one qualifies.

14.7 @ (i think 93) bone stock.
and 14.2 with the 373s in the back.

a TPI 305 with fresh bottom end, and trick flow's new 175cc runner heads ported out with a matching big cam and full aftermarket TPI should damn well go low 13's if not high 12's well driven with a stick car and 3.70-4.10 gears

theres lots to be had but no one really builds 305s. its cheaper and faster to do a 350.

Actually that is my goal. I want to develop around 350hp at the crank, be able to tickle the high 12s and still get 28mpg highway and 20-24mpg mixed. Heck I don't have a custom tune or even have a roller cam in mine right now! I think with the big LTR intake parts, a new roller cam, massage my heads a tad more, up the compression, and throw in a custom tune, I think I can make 350 hp and go 12s while not hurting my mileage any with a small 305. I think it is kind of a fun challenge actually.

.... Tim Burgess reportedly had run an 11.9 or something with a stickshift car but I have never heard or seen any proof....

Just contacted Tim. He ran it at Firebird (Phoenix, AZ) a couple of years ago. I'm sure he'll be chiming in within a couple of days with all the details...

As for me, just one word, "Soon."

Willie

Yup, Firebird......back when I still had the stk T5 & 10 bolt rear.....

What are you up to ? Is this the same car that had the twin AtI intercoolers on it ?

Yes. Retained the IC's but no more supercharger. Also replaced water/alky injection with progressive methanol injection.

Willie

wille that shot of under your hood with the twin turbos is the coolest ever!!

Tim Burgess, details please? I am hungry for info. I see your sig now says 11.69?! Was this NA? If you are doing this on the motor I want details! Same goes for your Berlie. 13.50 is strong. Maybe I should do a search and see if you posted any info at the time of the build..........

I love all sweet power adders you guys with fat wallets are running on 305s. I must say my personal interest in this tread (besides seeing and learning about badass 305s) is who is the quickest and fastest NA TPI 305 because I am poor and can not afford big air pumps like you guys, and I kind of want to see where I am in the mix of guys with NA LB9s. (some credit must go to Willie because he advised me to use the heads I have)

Willie your car was awesome already, now it is just beyond description. Same for Preston Smith's car, really sweet ride.

i know of this guy because he has a turbo cavalier that runs 12s i might add lol

but we're on the same site. hes on here too

Twin Turbo 89 IROC-Z

granted its stock 350 but its real nice

PM me your email address & I'll send you my mods list.

11.69 is with 150 hp nitrous. My best NA time is in the high 12's.

I've been working on my Z for 14 years now, so there is some $ in it, but over quite a long duration of time......

A few years back, I personally watched Tim Burgess run at Famoso raceway in Bakersfield Ca. The car is as fast as he claims... No B.S. from him.


Jason

Tim is really a modest guy and rarely toots his own horn.... one of the best friends I've ever had too. I, on the other hand, will tend to brag once in a blue moon. So I've taken the liberty (sorry Tim) to post some pics of his car. The burnout was at Famoso.... He also hasn't told you that back in 1998, we dynoed our cars. With no nitrous, he pulled slightly over 300 rwhp. Not shabby for a 305....

Willie

300rwhp? Good grief that is roughly 425hp at the crank assuming 20% loss from his Richmond. That manual trans may not be costing him that much power but that is still easily over 400hp. That really is stout, here I thought I was something because I am one of few guys trapping 100mph or over. Guess it's back to the drawing board!

Actually, for 20% loss, it would be 300 / 0.8 = 375. I was using the stk T5 @ the time, so I figured about 15% loss, which would be on the order of
300 / 0.85 = 353 hp - still not to shabby for the tiny mouse N/A.......

i always thought a 305 was underated motor. good power can be brought out of those motors with the right parts and tuning. i'd love to try and build up a TPI 305...whenever i have the time and funds for 2 cars

this is exactly what im trying to do with my 87' IROC hardtop. its a 305TPI 5speed G92 car. see sig for current times. my basic setup will include:

- stock short block
- Trickflows 175cc small bore heads
- CompCams XFI 218/224 grind w 1.5 rockers
- 1 5/8" longtubes into 2.5" true duals with Xpipe
- of course all the mandatory suspention, tire, and chassis mods along w weight reduction

hopefully this will net me mid - high 12s with a trap speed somewhere around 105 - 110mph. then i hope to be dipping into the 11s with spray at 115 - 120mph

I love my 305 and always respected them for what they are. But reading about a few guys with monster 305's then actually seeing Willie's TT 305 car in person this last weekend, all I can say is what's 45 fewer cubic inches when your car can make that much power and look that damn good.

305 baby!!!

To those that care, I blew my motor back in Feb and had it rebuilt. Yes, you read right, I had my 305 rebuilt to the exact same specs as before and actually reused my stock L98 cam. Now that is loyalty to the 305.

My '87 5 spd LB9 tpi ran a 14.9 with headers, airfoil, pullies, afpr, cold air intake, 1.6 rr's, smog delete, no cat and flows. No internal engine mods, aftermarket heads, or porting of any sort.

And no, I wouldn't go back to a 305.

i consider my little TPI 305 to be pretty quick for the lack thereof real mods that it has... im in the process of adding headers which im hoping should put me into the 13's.... then over the winter i should be adding a cam and porting my heads, then some drag radials and im shooting for low 13's

Back in my 305 days running a Comp 210/220 grind, stock untouched vette aluminum heads, stock semi ported TPI, SLP Tri-Y headers, 3" exhaust, 3.73 gears, and with stock T5 she went 13.6x at 101mph. On an 80hp shot of nitrous, she went 12.81 at 109.5. Full weight on 17" wheels. I loved telling people it was just a 305!!

when I had a 305 in my car I went 11.87 @112 w/a 1.56 60ft. Mods were ported s/r torquers, lpe 211 cam, 1.6 rr's, TPIS big mouth base, edelbrock runners, Edelbrock headers, ported plenum, stock tb, 2800 stall, 3.73's w/Auburn, 150 shot. The car also weighed 3600lbs

Yes Tim I did my math wrong. I think I inadvertently used a 30% correction factor instead of a 20% or 18% one. 350-375hp is much more realistic at least. I guess I'll get my 305 right the second time around.

My stock 87 TPI 305 has good torque and power for daily commute... OHHH... it also has 270,000 ORIGINAL MILES!!!! and still running strong. Not a peep of smoke on start up and my oil control is still pretty good...(no fouled plugs).

THANKS TO CASTROL GTX 10w-30 every 3,500 miles.

yeah theres no reason a good running 305 combo cant make 1.2 hp per cube. 350 hp should be well within reach.

what i really want to do is build a solid all forged 302...destroked 350 block.. with good heads and miniram/stealth ram and smaller solid roller. high compression and rev it to 7000rpms plus or so. just like a modern day version of the old dz302 z28 motor

i ran a 13.94 at 98mph in my 89 305 tpi formula i have an slp cold air box mac headers no cat no a.i.r and a descreend maf its a 5spd with 3.45 gears ina 9 bolt

I have enjoyed reading this post. Some cool a$$ 305's. Can you guys give me any idea of were my car should be in the quarter mile?
'87 iroc 305 TPI with RV cam, full tube headers, no smog, 3" Y-pipe w/ flowmaster muffler 2.5in outlets, cool blue filters w/gutted housing. Auto tranny that seems to shift a little soon......like a little over 4K rpms.
That is all I have detected. Any guesses?
I am hopefully going to the track on the 23rd. You guys have any free mods I should make sure I got done?
Thanks, Nick.

MAF sensor screens

Im probably somewhere in the mix, even though its not a 305 anymore... i dont think it would go much slower with a stock crank in it.

13.413 is my best time so far. That was with a 8.371 1/8th time (typically a high 12 second run) but the stock TPI and heads kill it when it hits 3rd gear. As it sits, the car runs 13.7s @ 98mph pedaling out of the hole.

i probably won't drag race much more though, time to make the car handle.

ahh i see ur goin to the handling side. its fun. but just throw a set of slicks on a extra set of rims and u'll still beable to launch great and run good times.

13.90 n/a 305

Got this tonite. w/ a story...because 12's are coming next week


Well I actually did get to run this time....Last time I wanted to run at KK the car started puking oil all over and I had to sit out on drag day....b*tch'

Tonite, I actually got to run the car! Bad thing is that I have a flipping boost leak now. Before when into it, it would jump to 7psi and pull hard to 15psi. Today it would only build about 7psi and it didnt build that till half way down the track. all I could get was 3 13.6's @ 105, 104, 104.....So apart comes the blue b*tch starting tomorrow and next thursday I'll make my second attempt to run on the full 15psi....hoping for a good 12 second street tire run...I hope!
I guess 13.6 at 105 on a 155,000 mile 305 w/7psi isn't to hateful but I know it has a shatload more in it. hell, my methanol injection never even got to turn on...
__________________

thats sucks man, hopefully It will work out the next run

I don't know what my car would do in the quarter but only mods I have now is

1986 Camaro Iroc
LB9 305 TPI A4

- Edelbrock Hi-flo Intake / runners - ported
- TPIS airfoil
- custom stainless 3in /2.5in exhaust
- 700r4 w/ shift kit/ trans cooler
- 3:23 rear

During the Fbody vs Foxbody shootout the best time i ran was
16.2 @ 82 mph

All smog equipment and EGR is hooked up and running, along with the A/C.

You guys that are running 15 second quarter miles, do all you have numerically higher gears than 2.73? My car has nice launch but its just not fast in the 1/4 with the auto and the steep 2nd gear. On the highway it can really move after it gets to 3rd gear.
Those with 3.23 and auto's, how is the cruising in your cars? Going 70mph my car is right at about 2000RPM, and its just purring along.

I have 3.23's and auto.........2500rpms @ 75 mph. I cross the 1/4 mile mark at about 4500 rpms in 3rd gear. This is going by the factory tach, but it seems to be accurate. I am running stock 16 inch rims with stock tire sizes too. -Nick.

I've run a 15.03 @ 91 mph with my mildly modded 91 GTA. I'm hoping for 14s in 2007. See my sig for my list of mods.

Thats pretty good, thanks for the info.

Andy
Im thinking with headers and a better Y-pipe you could break into the 14's...

Nick
Thanks for the info, debating whether to slap some 3.08's or just rebuild the rear end and put 3.23's.