Duke

Does the 670 really make much of a difference on L03 engines? A friend of mine bought one, but I'm not sure if it's such a good idea for a bone stock 1990 L03. I have a 670 on my 327, but that thing needed one, I'm not so sure what to expect on a stock 305, I think that would be overkill.
Any advice?

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1992 RS
327, Modded TBI, Rebuilt WC T-5 5-speed, PRO 4 15" rims, Nitto's, 3.73's, SLP 1 5/8" headers, and a few other things.

Scott C

It is certain overkill for a stock LO3. I had a 670 on my last LO3 with heavy mods and it still ran rich! Way too much fuel for a stock 305. Spend the money elsewhere.

A stock LO3 barely knows what to do with the stock TBI! A 670 should be used only when approaching 250+hp. Stock is nowhere near that.

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'92 RS, ZZ4 10:1 350, Edelbrock 6085 heads, Crane 208/214 467/482 cam, GM/LT4 1.6 true roller rockers, Holley Projection TBI intake, Holley 670 TBI, SLP/Jet-Hot 1-5/8" headers, Catco 3" cat, Flowmaster 3" catback, Hughes 2500 stall converter, stock 700R4, Auburn Pro posi w/3.42, 17x9" SS rims w/BFG tires, Medium Quasar Blue w/white SS stripes, 48,000 miles....

[This message has been edited by Scott C (edited November 30, 2000).]

Pablo

iTrader: (1)

well the throttle body wont make you run rich, the injectors in the TB will and your chip. The purpose of the larger tb is to basically let more air into the motor. Will it make a difference in a stock L03? Nope

a modded one? sure

I had a stock TB on a single plane on my modded 305 and it was CHOKING the motor big time, 2" of vacuum by 5500 rpm

went to the bigger TB and of course had to retune for it but it made a huge difference, and no more vacuum at wot

id start with other bolt ons like headers and exhaust, gears, etc you wont really need the tb till you get rid of the pathetic cam anyways

91Bird305

I thought that if u get to much air in your engine that you will run lean. Wouldn't 670cfm on a stock LO3 be a little to much air?

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Eric Natzke
91 Firebird 305 TBI (ZZ5 summer of "01")
ASCD Ram Air Hood-3" custom exaust-Flowmaster 80 Series-No Cat-Edelbrock TES Headers (coated)-March Pulleys-TBI Spacer-K&N Open ELement-TransGo Shift Kit-B&M Supercooler 28,000 GVW-Hypertech Thermomaster-160 Stat-3:42 GM Gears-Auburn Posi Unit-Edlebrock Strut Tower Brace-MSD Superconducters-MSD Cap & Rotor-MSD Blaster Coil-Rapidfire Plugs-265/50/R15 Tires-Emmison's all Gone
http://members.aol.com/j007golden/91firebird.html

[This message has been edited by 91Bird305 (edited November 30, 2000).]

snflupigus

hey guess what, i have a 454 tbi on my stock l03 and my a/f is fine. Not lean at wot and not rich at idle. no problems. i did boost the fuel pressure though. One problem. hesitation then boom. it creates something like turbo lag, and as i understand it. It is because the motor goes lean when the larger blades are opened quikly and then you get a shot of fuel miliseconds later. and boom your off. id say increased torque and a slightly throatier exhaust tone, other than that, dont spend the money till you need it.

FastBroker

Snuf, any news, yet, on getting me a 2" Rochester TBI from your dealership???

JoB

To eliminate the hesitation, you need to program a larger pump shot in your chip to compensate for more air.

snflupigus

Fastbroker. I know for a fact that it would be much more than you are willing to pay, you told me that you wanted one for under 150. im sure its over 250. sorry, i thought i told you that already.

snflupigus

o, and i have no chip programmer. wana do that for me.

Duke

Well, we put it on his car today, even though I told him it was a waste of time. We replaced the intake manifold with a single plane Edelbrock (don't remember which one) and I sold him one of my spare turbo city adapters (grinding these things to fit the 2" butterflies sucks). We got it all put on and fired it up. It wouldn't idle for ****, then I relized I forgot to hook up the IAC, then it idled ok. I think it needs some tuning, but it did wake the engine up quite a bit and it's not running rich at all. I think that the manifold greatly helped it though, the stock manifold is pathetic. BTW, we had to remove the EGR system, that worked out ok too. If anyone is really interested on how we did it, I could type up a tech article, and I have some pics I could use.

Later

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1992 RS
327, Modded TBI, Rebuilt WC T-5 5-speed, PRO 4 15" rims, Nitto's, 3.73's, SLP 1 5/8" headers, and a few other things.

snflupigus

article for every possible thing is my ultimate goal now. Do it. neway,
the manifold replacement with the stock tbi would have awaked the beast. the tbi unit probably helped aid the manifold. When i originially did mine, i had to make a new throttle linkage, did you? also my tps and iac plugs were different, and i didnt solder em at first, just used t tabs. and it wouldnt idle to well, i think i was gettin a voltage drop across the t-tabs. soldered em and no problems since.(about 4 months now i think)

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IM: snflupigus | ICQ: 96787192

Open Element Tech Article

ENGINE SPECS:
305 TBI,Open Element,K&N 14x3,Hypertech Stage I,160 Deg. Thermostat,454 GM TBI

STEREO SPECS:
JVC Kalmeleon kdlx3,Infinity Kappa 2way 6x9's,PPI 4x6 Coaxials,PPI PC2400 AMP @ 2ohm
DEI Studio 12" 4ohm DVC,Custom Box:Exactly 1 Cubic Foot