I was looking on the board and noticed the topic of DUAL TBI systems... Im courious(sp) as to how this works and what the PROS/CONS are compared to the one TBI. Wasn't even sure if its that different than having just two injectors as opposed to the 1 I have now.. Thanks... I figured it's better to ask than to not know at all... Thanks

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92 Camaro 305 TBI Automatic. 2.5 high flow cat and 2.5 pipes into3.5in tip, shift kit.

Future mods. Spark plug wires and plugs, tint. Headers, O.E., any other advise on getting to 300+ HP would be appreciated. Thanks

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System = Sony explode CD/MD receiver, Rockford 6x9 Fanatics, 4x6 Clarion in the front, 2 12" Hx2's(Rockford) in custom box(black carpet) 1 farad cap, 800x2= 932 total watts Rockford Amp 4gauge wire kit.

 

92,

You should also already have 2 injectors. The TBI 220 unit that should be installed on your 305 has two throttle plates/bores and two injectors.

What I was referring to was installing a second TBI unit, to effectively make a quad unit. You would need a dual-quad carburetor intake manifold, two TBI/carb adapters, some fuel line plumbing, an extra injector wiring harness, custom throttle linkages, and some custom PROM programming.

You can disable the TPS and IAC on the second TBI unit since the ECM is designed to operate the engine at low RPMs with one of each already. The second TBI would be used only for fuel and air. The TPS would still be linear but would confuse the ECM since the MAP signal would rise too quickly with a second set of throttles opening (thus the custom programming).

I'm thinking it would be a cheap and dirty way to get some really serious intake flow from a TBI setup. Some of the dual-quad carb intakes are made for serious flow at higher RPMs - just what a TBI is good at compared to the TPI. I've been wanting to try it but have been mired in my ECM projects and normal stuff around the house.

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Vader,
I know that you probably know this already, but try www.tubocity.com . They have a setup like that. Maybe you can pursuade them to help you because your an important part of this website. (Allow me to wipe the stink off my nose ) I've read about them telling people what they recommend. They also custom burn chips for the application that each person is using. It's worth a try. Plus I'm curious about how well it would work.

 

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Thanks ws6formula89, LOL!!!!! I guess I was thinking of the website that fat guys like me go to!!!! LOL LOL!!!!!!!
Glad you saw it, cause I sure didn't.

Thanks,

Love, Tubo!!!

 

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ws6formula, whats up with the mph on your 1/4mi data? Isn't that a little fast for a 14.9 sec. run? Did you change speedo gears on your trany when you installed the 4.10s? Just wondering!

Steve

 

Steve, that was exactly what I was thinking. You beat me to the post though. That is a really high mph for that 1/4. I'm thinking you jumped to start the time and stalled, then had N20 to get that kind fo mph . Only other explination is the speedo gear change.
As for dual TBI. Great idea but a PITA to figure everything out. For the price of an aftermarket efi system and dry flow, I don't think it's worth doing dual TBI. Maybe if the electronic parts were easier to make but until then...

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, Jon (350 TBI!)
91 Red My website

 

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Now that we're all chit chatting.. What would be the advantage in putting on DUAL TBI untis... Thanks for correcting me(I do have 2 injectors).. And if it does increase the flow wouldn't that cause damage to the engine? Thx

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92 Camaro 305 TBI Automatic. 2.5 high flow cat and 2.5 pipes into3.5in tip, shift kit.

Future mods. Spark plug wires and plugs, tint. Headers, O.E., any other advise on getting to 300+ HP would be appreciated. Thanks

---------
System = Sony explode CD/MD receiver, Rockford 6x9 Fanatics, 4x6 Clarion in the front, 2 12" Hx2's(Rockford) in custom box(black carpet) 1 farad cap, 800x2= 932 total watts Rockford Amp 4gauge wire kit.

 

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Would it cause the same pita trying to use a 4 injector 900 holley with the GM TBI computer controlling it. Just curious for future mods. I love TBI but would like to make it run some serious HP with a 15psi ATI procharger and blower moded 350 but I don't think the 454 TBI and injectors is going to be enough. TPI is so blasted expensive to upgrade on. I know turbocity can bore a 454 TBI to 2.125" but I don't know how much horsepower 454 injectors can keep supplied.

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91 Camaro RS 5.0L Black Convertible 700R4
** Added so far **
*GM Wonderbar
*Alston SFC's
*Turbo City Inj Spacer
*Dual Snorker Air Filter
*March Performance Pulleys
*GM 3.42 Gears with OEM Zexel
*Edelbrock headers
*3" High Flow Cat
*3" Dynomax Exhaust
*Walbro 255 lph Fuel Pump

 

It would probably take twice as much tuning as either of the afore mentioned options (dual TBI or supercharger), but why not get the best of both worlds...



Just a thought.

-Mark W.
'88 SC Camaor w/ 305 TBI

 

Lets see if I got this right.. I dont think I did... Are you(ws6formula89) saying it would be better to just add a supercharger(Money wise) instead of Dual TBI units? even if I did add a SC wouldn't I still need something to deliver the fuel/air... Or would the single TBI be just as good...?

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92 Camaro 305 TBI Automatic. 2.5 high flow cat and 2.5 pipes into3.5in tip, shift kit.

Future mods. Spark plug wires and plugs, tint. Headers, O.E., any other advise on getting to 300+ HP would be appreciated. Thanks

---------
System = Sony explode CD/MD receiver, Rockford 6x9 Fanatics, 4x6 Clarion in the front, 2 12" Hx2's(Rockford) in custom box(black carpet) 1 farad cap, 800x2= 932 total watts Rockford Amp 4gauge wire kit.

 

N/M

[This message has been edited by 92Camaro305TBI (edited June 20, 2001).]

 

Looks like a Weiand 6-71. Holley webiste for Pn and Jeg's/Summit to purchase.

Now THAT would be a cool dual TBI!!!!!!!!!! Eddie likey!!! Clsoed-loop, too! Gotta get better mpg than a carb...

 

If I went this way... would it replace my TBI unit I have now..?

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92 Camaro 305 TBI Automatic. 2.5 high flow cat and 2.5 pipes into3.5in tip, shift kit. Tinted windows(legal)...

Future mods. Spark plug wires and plugs, Headers, O.E., any other advise on getting to 300+ HP would be appreciated. Thanks

---------
System = Sony explode CD/MD receiver, Rockford 6x9 Fanatics, 4x6 Clarion in the front, 2 12" Hx2's(Rockford) in custom box(black carpet) 1 farad cap, 800x2= 932 total watts Rockford Amp 4gauge wire kit.

 

.

 

Don't do it unless you have the H.P. and the engine for it. I put Turbo cities on my 305 and it was a dog. Too much Fuel. Now when I stroked it it begged for more so it worked out fine.

 

Two words for you power guys: Custom eprom!
You could install 3 TBI units with the right electronics and a custom eprom. Supercharger = new eprom for sure. It's just like N2o, you'll need more fuel becuase your engine will take in more air. Best way to do that is to get into eprom burning after you get the setup matched (right sized injectors for the horsepower, cfm, fuel pump etc).

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, Jon (350 TBI!)
91 Red My website

 

I dont think I want a supercharger for street use.. However.. I do want to get to 300 HP on just the engine... Upgrading the TBI unit(What type, brands are good?) would help me out right.(and it;s not worth the money to get a Duel TBI setup).. but before I get that, what do I need to do...

Fuel pump
custom eprom
O.E.


What else..??

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92 Camaro 305 TBI Automatic. 2.5 high flow cat and 2.5 pipes into3.5in tip, shift kit. Tinted windows(legal)...

Future mods. Spark plug wires and plugs, Headers, O.E., any other advise on getting to 300+ HP would be appreciated. Thanks
---------
System = Sony explode CD/MD receiver, Rockford 6x9 Fanatics, 4x6 Clarion in the front, 2 12" Hx2's(Rockford) in custom box(black carpet) 1 farad cap, 800x2= 932 total watts Rockford Amp 4gauge wire kit.

[This message has been edited by 92Camaro305TBI (edited June 21, 2001).]

 

I have the same goal. A very nice 300+hp that is extremely streetable. I want it to be as reliable and managable as a 2000 Camaro SS but keep the nice looks of my thirdgen. Since my current 305 runs flawlessly I have started by getting the car prepared for the change. I put Sub frame connectors to stiffen the body so that it won't twist with extra hp. I replaced the entire exhaust system from the engine block back. I ordered the parts for a TPI car so I could get the 3" exhaust. I replaced all bearings and seals in the rear and changed that pitiful 2.73 gear that comes in RS automatics with a 3.42 GM gear and SLP's OEM Zexel Posi. Made a huge difference in car. Completely rebuilt the brake system. Added new Lower Control arms and panhard rod to help this car withstand the shock of having twice the horsepower as the stock engine. I also put a Walbro 255 LPH fuel pump in while I had the rearend and exhaust out and could easily get to the tank. I intend to let Probuilt build me a new automatic trans for this car at about the same time I order new GM crate motor so I can put them in together.

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91 Camaro RS 5.0L Black Convertible 700R4
** Added so far **
*GM Wonderbar
*Alston SFC's
*Turbo City Inj Spacer
*Dual Snorker Air Filter
*March Performance Pulleys
*GM 3.42 Gears with OEM Zexel
*Edelbrock headers
*3" High Flow Cat
*3" Dynomax Exhaust
*Walbro 255 lph Fuel Pump

[This message has been edited by brharris27370 (edited June 21, 2001).]

 

Thanks... brharris27370 what's your HP now ??


[This message has been edited by 92Camaro305TBI (edited June 21, 2001).]

 

I know we've had this discussion before, but there is a roots-type blower made especially for TBI. It's made by Weiand/Holley, and I think it's the 144 size. Made for a single TBI unit, and is supposed to fit under a stock truck's hood (low-profile type). Check it out on Holley's website. Pretty expensive, though.

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No guts, no glory.

 

Since I have not gone into the motor and don't intend to on that engine. Its probably to low to speak out loud from laughter. My wifes 98 Maxima still kicks my butt. I don't see any point in messing with the engines internals since it has over 100k miles. Just going to put that money aside towards new motor. I would really like the new gm crate 383 vortec 325hp/410 lbs.torq and change the cam to a zz4 or similar cam. The 383 vortec was designed for trucks so it has a peanut cam in it but has plenty of potential. At $2600 with cam change it should eat a zz4 for less money. Might anyway with all that torq. I might have to settle for the 330hp Vortec 350 for $2000 and change its cam to a nicer roller cam. Don't know yet. Will have to see what the future holds. I would like to have a NEW crate motor and not a rebuilt engine. Never had great luck with rebuilds lasting like the original.

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91 Camaro RS 5.0L Black Convertible 700R4
** Added so far **
*GM Wonderbar
*Alston SFC's
*Turbo City Inj Spacer
*Dual Snorkel Air Filter
*March Performance Pulleys
*GM 3.42 Gears with OEM Zexel
*Edelbrock headers
*3" High Flow Cat
*3" Dynomax Exhaust
*Walbro 255 lph Fuel Pump

 

How does a maxima whip you??? they only have 200HP at max i thought...? If thats the case... I better get me an import.....

[This message has been edited by 92Camaro305TBI (edited June 22, 2001).]