alright guys. i really want to run a turbo. please don't do the "don't build a hoss-daddy 305 that will hand my 350 it's butt" thing. i want some of what willie has; respect. but i want a turbo instead of a supercharger. ok, so, if i were running the HSR and commander 950 ECM, about what size turbo am i looking at running if i were to want something totally streetable, yet could really lay it down if i need it too. any imput or suggestions welcome. money really isn't an object (keep it in reason though) only cause it's not something that has to be done by tomorrow. i will build a four-bolt 305 (yet again, thanks willie for the inspiration) with h-beams, the works. i will probably have guido or someone like that do my exhaust work. blah, blah, blah. give me some ideas guys.

 

Something in the 60-72mm range would work pretty good for what you are after. Would give you a good kcik in the *** when you stomp the go pedal. LOL

A decent external wastegate woudl work too.

You wouldnt even have to swap out to a stealth ram if you didnt want to. a factory type TPI intake works fairly well with forced induction.

Preston Smith from Boston had a T76 on a 305 and it ran into the 9 second range on a high boost pass. He had trick flow heads, but a factory TPI intake system. Of course the rest of the car had been through the wringer so it was prepped to handle it but goes to show you what is possible with a 305.

 

that is exactly the type of thing i am talking about. well, i want the tunability of the commander ecm. can i run that ecm on the stock intake and stuff. i am currently carbed and don't have a whole lot of knowledge when it comes to these things. i really like the way the HSR looks too, but with some siamesed runners and the holley ECM, with a good lower intake, i could make some power. hmmmm...more, more!

 

That's not your standard configuration of 305 though.

 

what you talkin' 'bout Willis?

no seriously, what do you mean "standard configuration"? if you mean forged rotating assembly, beastly heads, wild induction, bad cam, then i am already thinking this way.

 

Very true. A lot of people hear "305" and think it's a factory 305 or something which is so far from the truth...

MW-he was talking about Preston's motor, not *******.

 

A TE63-1 or a ball bearing T70 would be happy nice eh?

 

sorry, i was quoting "Different Strokes" if you didn't get it, then never mind. i want to know what your talking about though. custom pistons, bushed h-beam rods, forged crank, custom cam, it's all in the works.

 

doh, lol I get it, read it too fast, thought it said ******* not Willis

 

LOL

It was for a long time.

I know he changed it around to an "unconvetional" 305ci LOL which Im SURE works very well but for a long time, it was a factory 305 block.

 

What was the best time with the factory block? I have videos of that car. It leaves the line so quickly it makes me laugh like a maniac.

 

.... it was a factory 305 block.

Are you sure Guido? I've heard otherwise; that it was a 4.00" diameter bore. That means it was a 302 (4.00" bore x 3.00" stroke), bored 30 over, which makes it slightly over 305 cubic inches. I think that's what Robert (RMK) is talking about.

 

Willie,

You are correct. I believe he is now running a Bowtie block 4.025” bore x 3.0” stroke-305 cu/in combo.

Looking forward to seeing your new times with the small bore 305. I wish you luck, and will be in touch soon.

Robert

 

alright. willie, i have already talked to you a couple of times about your motor. i am going to follow in your footsteps, basically. but i want a turbo instead of a procharger. i will try to keep you updated on my plans. i already have a set of h-beams.

i figured you were talking about a big bore 305. that's what i was trying to find out. my motor won't be able to spin near as hard as his(preston). willie, what kinda rpms you pulling. able to make power above 5800?

 

Looking forward to seeing your new times with the small bore 305. I wish you luck, and will be in touch soon.

Thanks. The engine has about 800 miles on it now and the F1 blower was installed last week. Now, to convert to SD and do some serious EPROM burning......


alright. willie, i have already talked to you a couple of times about your motor. i am going to follow in your footsteps, basically.

Cool. What I've learned about all this is to follow in the footsteps of someone who's done it. I myself had a hard time finding someone who's making big boost on a small block Chevy, but finally did. Good luck...


but i want a turbo instead of a procharger.

Cool again. There's more than one way to make power!!


willie, what kinda rpms you pulling. able to make power above 5800?

Before the rebuild, I was shifting at 6,000. The power band for that cam was up to 5,600. Now with a cam that has a power band up to 6,500, I figure I'll be revving slightly higher. Let's put it another way: I installed an AFR Hydra-Rev kit, just as insurance.

Willie

 

awesome, all i gotta do now is decide on the size. would something right at like a t-68(is that even a size) be in order here. want something totally streetable guys. i have a guy in NY that will grind my cam for $150, just need to get him the specs of the motor so he can give me a good grind. my heads will probably be a set of world s/r torquers for a 305. there is a method behind that madness too. going with the smaller valve size makes the heads cheap(that and the fact that they are iron), forced induction is cool, it makes small things work well together. looking for a low 11/high 10sec street car, basically. i will probably go with a set of ROSS Racing pistons, JE just wants to much. $880 for a set of pistons! i don't think so. Ross wants $750, which is still a lot but, a little less. *want spiral locks(reason for going with ross)* any forged 350 crank should work right? i heard something about having it balance for 305 rotating assembly though. thoughts on that? thanks fellas, your a huge help.

 

.... JE just wants to much. $880 for a set of pistons!

I got my JE's for $522 from Flatlander racing. JE's price was almost $700.


.... any forged 350 crank should work right? i heard something about having it balance for 305 rotating assembly though.

Right. I use a forged 4340 "featheredged" crank from Scat. Yes, it will have to be balanced. I had the weights removed from the flexplate and internally balanced to compensate for it. I'm also using an ATI Super Damper balancer with a custom-made inner hub with a big block sized outer radius and seal. You won't need the custom inner hub as I do because you won't have a blower belt!

Willie

 

aren't yours pressed fit pistons though? been through this with you once before. totally lost.....i was under the impression that you used pressed fit....

 

here is my motor as it sits, N/A

 

PRESTONS SETUP. copy and pasted from here http://www.tpi305.com/ to this thread. The site goes up and down So I figured past it here it should be around awhile.

1985 IROC
Vehicle is modified to improve in five areas: Acceleration, Braking, Handling, Ride, and Appearance, while maintaining original Eng. Disc. and 4-speed O.D. transmission with some compromises, while being driven a minimum of 8k miles/year and obtaining 20 MPG.

TECH SPEC’S

ENGINE
BLOCK Bowtie 4.025” bore x 3.0” stroke-305 cu/in.

RODS Crower 6”

PISTONS J.E. 8.25 C.R.

CAM Crower hyd. roller 114° L.S.- .520” lift.

HEADS Trickflow G2 - 2.02” int. (275 CFM) – 1.6” exh. (210 cfm)

INTAKE

LOWER Stock, extrude honed.
RUNNERS A.S.M. TPI
PLENUM Stock, extensively modified.
THROTTLE BODY A.S.M. 58 mm.

INDUCTION
TURBO Innovative GT-76 ball bearing Q-Trim.
INTERCOOLER Spearco air-to-air with 3” Alum. tubing.



FUEL SYSTEM
Fuel Tank 1 LE tank with a 255 liter intank pump. 5/8” pickup line installed connected to aux. pump.

AUX PUMP Weldon 2025A

LINES Both pumps into Y-block inlet, single stock 3/8” line on outlet to stock fuel rails thru Weldon press. reg. to 3/8” return line. Aux. pump activated by 1 PSI Hobbs switch. Flow with fuel reg. set at 80 psi@12V is 105 gal/hr at return line.

INJECTORS Siemens 83 lb inj’s.

E.C.U.

ENGINE Electromotive WinTEC 2

TRANSMISSION TCI T-Com



DRIVETRAIN
CONVERTER Vigilante 9 ½” 2500 rpm stall with a 5 clutch lockup.

TRANSMISSION Upgraded 4L80E with tailshaft housing for torque arm.

DRIVESHAFT Denny’s 3 1/2” matrix alum. with 1350 U-joints.

REAR-END KTRE 12 bolt with Tom’s H.D. Eaton posi and 3.42 gears turning Moser 30 spline axles. 9 ½” alum. brake drums with dual secondary shoes and 1” wheel cyl’s.

RIMS (F) Weld Pro Star XP 16”x 9”x 5 ½ ” B.S.
(R) Weld Pro Star XP 15”x 9”x 5 ½ “ B.S.

CHASSIS
K-MEMBER P.A. tubular.

FRAME CONN. Global West tubular, welded entire length both sides.
Tubular transmission crossmember welded to subframe connectors which moved the instant center back 11”



SUSPENSION
FRONT Morrison coilovers, Koni adjustable shocks with modified stock lower control arms (better ride). Stock 1 7/16” tubular front swaybar with poly-u bushings.

Wilwood 12.19” rotors – billet Dynalite calipers – alum. hubs.

REAR Boxed stock torque arm (no poly-u bushing and no pinion adj.) Tubular lower control arms. Tubular panhard and upper panhard brace, stock swaybar with Koni adj. shocks.



OTHER 180A Alternater.Rear mounted drycell battery.
130W Alpine sound system with two 12” woofers. on hinged rear panel.
Power steering
Power brakes
Power windows
Cruise control
Dupont Bright Red metallic, clearcoated finish.

 

aren't yours pressed fit pistons though? been through this with you once before. totally lost.....i was under the impression that you used pressed fit....

Yes, I recall going thru this before. I'll tell you what I was told by JE when I inquired about my pistons. They are not shown under their small block Chevy listings. They had to go to "Boat Applications" (or something like that). They are APBA (American Power Boat Association) forged 305 pistons. I was told they can be installed either as pressed or full floating. The P/N can be seen in the pic. You may want to call them on this issue.

Willie

 

.

 

:hail: wow, that is pretty much the exact setup i want, only with a HSR. man....

Willie, i will contact JE soon to find out exactly what the deal is. what kind of comp. ratio you running with those?

 

The pistons are -12cc dish. With 55cc AFR's, 0 deck and the following head gaskets:

Cometic Multi-Layered Steel
4.165" Bore (true round)
0.078" Thickness

My C.R. is 8.4 to 1.

Willie

 

alright guys, it's late at night and i am feeling a little frisky. wonder what a pair of Garret T-3's with log style headers would do, or are those too small, maybe t-4's? i've seen these on ebay for almost no money, and the log style headers, well, i could throw those together myself.(i already have a set of old 1.5 primary sbc headers laying around, i could steal the flanges off of them.) what do ya think? streetable? probably... kick butt 305? heck yeah! give me some imput fellas on what you think of this idea.

 

Would it work OK… yes. With a 305 I’d shoot for T3’s with .48A/R hot sides.

Streetable… depends on your definition. Yes, it would be very driveable, but I don’t think that I would consider 99% of the twin turbo setups that I’ve seen on f-bodies streetable. You’re just forced to make too many compromises in packaging, and I’ve never seen a setup that I would trust on a long trip or as your only daily driver.

 

well, if you build it well (ie forged bottom end with correct comp ratio) and really low boost, i don't see how it would matter on the street. crank the boost up and add some timing, 100octane gas and blast outta the hole at the track! car would get everything from whatever hellacious tranny i decide (either a probuilt 700r4 or equivilant, or a beefed up t-56) and a 12bolt out back.

edit: i don't wanna run low 8's high 7's with this car, it just costs too much. i wouldn't mind, however, dipping into the low 10's occasionally. it's totally ment to be a ***** to the wall. i think that with log headers and some decent used t-3's i could have something work well with a lot less money. (yeah, the money thing kinda hit me just a little bit ago) i will see if i can't get a decent used tpi setup for cheap.

 

You make it all sound so easy to hit low 10's with a 305. Congratulations to you if you do it, and I'd love to see someone on here do that, but it's a serriously high goal to reach with a factory bore/stroke 305 motor. Good luck to you though.

 

Low 10's on ANY car isn't gonna be cheap...

 

Low 10's on ANY car isn't gonna be cheap...

 

Interesting thng I noticed about that turbo motor TPI383 posted...he's running a DIS ignition system...cool DIS gooooooooooooooooood

 

alright, i see your point, i guess i was getting a little too enthusiastic about it. it would be cool though. just gotta get some more money...

 

You're missing my point... I'm not questioning engine durablility (hell, mustang guys do it all the time with blocks that are reliable to a little more then half of what sbc's are), hell, if you're on a road trip no reason to actually USE the boost, but packaging, boiling brake fluid, melting wiring, melting everything...

there is room to do it in a 3rd gen, but not room to actually route everything out of the way unless you want to spend $$$ on the setup. Hell, look at Andris's setup, much less cobbled then most of these things end up and he's spent time fixing melted 'stuff' even though most of the optional stuff is gone on that car...

 

things i hadn't thought about. good point. i will look into that.

 

hey fellas,
I recently looked into many options to make my 92 rs pull a little harder on the road, and decided to go turbo. my 92 has a stock 305 setup right now, and i know there will have to be a lot done. But what bothers me is all i see are carbed and tpi set ups here... Does anyone run a turbo off a tbi setup?? I dont know if i want to do a tpi swap and dont really want to strap on a carb. Also, what else besides pistons and the crank will have to be replaced on the block? Sorry about the general qustions... im a noob to turbos.
thanks
mitch

 

also, im looking at a moser 12 bolt posi with 3.42 gears in it from thunder racing. I think it costs about 1900 big ones. I know this will have to be done eventuallty if i want to ever make power... and handle it. DO you think thats a good price, or can you offer up some more advice?

mitch

 

moser makes good stuff. honestly bro, if your going to spend the money on a turbo setup, swap the tbi out. it's not really worth trying to shove more air down a tbi setup that already has huge restrictions. can be done? sure. it's been done with an ati procharger at LEAST once before....

 

what will have to be done in terms of the cars computer to make it accept the tpi? or will nothing have to be done?

 

a TPI computer/ecm

 

I scanned the boards for a bit and found this for sale:

"This is everything you would need to run tpi on your v8. Wiring harness, ecu, mas-air, distributor, coil, intake, plenum, runners, fuel rails, injectors, throttle body, rubber and plastic ducting and all the sensors you'll need. Came from an 89 Iroc-z $325 email for pics "

Hows that sound for a price? is there anything else i would need? The parts will be installed on a 92 lo3. I was looking at prices from summit and other places, a new tpi set up is rediculously expensive. But would it be bad to buy used if im going to used forced induction?

mitch

 

So what exactly is wrong with turbocharging through a TBI setup?

 

Stick with street tires and your 10 bolt will last a considerable amount of time (behind an automatic tranmission).

 

Doesn't a stock TBI only flow like 400cfm of air? Thatwould be a massive restriction even under boost. Now if he used a holley TBI or something that actually flowed air there wouldn't be any reason not to do it.

BTW there are several ppl with roots type blowers and TBI. Not one I have seen uses a GM TB.

 

That actually raises an only slightly related question… I’ve never messed with the TB off of an LO3, but I have with a number of LO5’s (350 TBI’s in the full size trucks) and crossfire setups. I was under the impression that the TB used on the 4.3, 5.0 and 5.7L all used the same body/machining and the 454’s used a casting machined with slightly larger bores. If the TB used on the 5.0 (305) is the same as the one on the 5.7 (350) then it will flow just under 600 cfm (usually in the 570 range), which is actually sufficient not to be a big restriction till over 400hp NA. You’ll gain some by messing with it before then , and I’ve successfully bored them to 54mm (works out to be enough for just short of 900cfm).

The crappy intake and heads used with them is more of a problem then the actual TBI, somewhat like how the crappy heads used with a TPI are a bigger problem then the somewhat restrictive TPI intake.

Forcing air thought it you can move much more air, depending on the density ratio.

In real life, injecting the fuel further from the valve allows for better atomization which leads to slightly better MPG and emissions part throttle, and under boost should give a slight intercooling effect since the gas will have a longer period of time to evaporate and cool the air.

 

so in reality, the turbo will not be on the engine for quite a while ( next summer maybe ) what would be the first step to making the car perfrom a bit better? Heads ( ive heard bad stuff about stock 305 heads from GM ) intake manifold, tpi setup ( new or used ? ). My Rs is a stick so a new clutch looks like its on the way. I wouldnt want to put money into a new cam yet would I? I would have to change it again for the turbo right?

 

In my opinion, most of the traditional small block heads that GM made after the mid 80's (87 and up definitely, ’85 and up in most cases) are terrible with the exception of the vortec heads, so you can safely assume that the heads suck. The early to mind 80’s LG4 and L69 305 heads are actually fairly decent as far as oem heads go, and with minor work could be made as good as the vortecs, but with smaller chambers.

 

would any 305 head i buy be able to be transferend to a 350 later on or will they not flow well on the 350?

 

look for some 416 casting heads (you will need a different intake though). they flow really good numbers from chevy and even better when ported. alot of people are running these on 305's as well as many 350 guys.

 

what style intake are you guys running? Im guessin a dual plane.

 

Also im not very familiar with the 416's. Can you give me a little more info about them? Like are they 180cc or 195cc? more/less?