My friend has an 88 Camaro SC... he pulled out the L03 and swapped in a ZZ4 engine. He's running the stock 305 TBI on top, or so he says.... and an Edelbrock Performer w/an adapter. And some type of exhaust manifolds, I don't know if they are the 305 TBI ones (I sure as hell hope not). Anyways, with the TBI from the 305 on there, that motor has to be EXTREMELY choked right now. It's still quick, it ran a 14.7 at like 100mph... lots of wheelspin on that run. What can he do as far as TBI mods go? I'm a TPI guy, but this dude needs my help... he paid a lot of money to have the engine swapped into his car, but isn't too sure about how to make it run stronger. I've heard stuff about 454 TBIs... he'd like to get Holley ProJection, but the cost is prohibitive. Any ideas on how we can free up some horses?

------------------
91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

 

ultimate tbi mods will yeild a little more air flow. im still researching boring the 305 tbi to 2". As far as i know now, it would hit two of the vacuum passages and that might effect power brakes, heater controls and cruise control. i should know in a few weeks or so, maybe longer depending on how busy i am when i finally do get one bored out and then on the car. Also, some material is going to need to be added to the rear wall of the tbi, and the bores will come very close to the rear bolt holes, but thats not to big of a problem.

holley's tbi replacement is 290 i think.
if thats to much, tell him to do the ultimate tbi mods that are in the tech section, and damn dude, you dont put exhaust manifolds on a zz4. he needs headers bad

also if he waits till summer, i myself might be producing an even cheaper replacement for the tbi base. the prototype is almost done now. testing should begin by may i hope.

[This message has been edited by snflupigus (edited February 07, 2001).]

 

snuf is right. Your friend needs to get headers ASAP. The stock TB flows under 500cfm and that is..well...250cfm shy of what the zz4 was designed for. His redline is probably WAY below spec. The holley 670cfm TB might help but it would still be the bottle neck (if he got headers). Tell the guy to invest in a 750 carb, take off the adaptor plate and tune the carb. Make sure the guy has open element air filter. What gears does he have in the car? That might also be a problem. The zz4 should be running mid/low 13's so obviously something is wrong. Also what kind of chip does he have, if stock then that is another BIG problem.

------------------
, Jon (91 RS too many mods to list), getting new engine in summer

 

Yes I believe he has the stock 305 TBI programming as well. I told him to get headers a while back, he plans to eventually. He had also planned to swap to a Holley carb, but I am trying to talk him out of it.. I want him to stay EFI, split the cost of PROM burning hardware with me, and learn to burn PROMs. He has a 3.42 posi rear end, and yes he is running a K&N open element filter.

 

Swap to Carb. Thats what the engine was made for. Slap a 750cfm vacumm secondary on there, MSD non-computer controlled Dist. and do the rest of the stuff Jester says in his TBI to Carb Swap in the Tech Articles. Sorry, but there is no sense of wasting a nice engine like that with this injection system.
[Bring on the flames boys]

------------------
Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

There is no doubt that swapping to a carb will get him to where he needs to be power wise but I'd stick with EFI... a 670 2bbl from holley or the 454 unit will be fine for his application... use at least 85# injectors and custom tuning as an absolute requirement. A single plane will only help if he runs TBI... Go with the Weiand Street ram #7525 on that motor (vette heads right?).

------------------
1988 T/A,
9" Ford, 3.50 gears, Auburn posi, 700r4 -w- 2100 converter
350 .060 over with forged 1 pc rms crank, and forged TRW pistons, 9.5:1 cr
Factory GM heads Pocket ported, 2.02/1.60 valves, back cut
Lunati roller 219/227, .479/.480, 112 LSA
Holley 700cfm 4bbl on TBI truck 7747 computer and chip by Howell-EFI
Edelbrock Performer EGR intake, Edelbrock TES and 3" cat

 

i wanted to do this eventually when i graduate from school. but he should go with a holley 670 tb or the one from turbo city. those 454 tb are hard to find but some people on this board have found them cheap. i thought the zz4 comes with an exhaust(looking in camaro peformers magizine pg.87)it comes with new exhaust manifolds nevermind go with some headers. keep us up to date with his mods i want to do this in the future.
Shawn

 

He shouldn't go with a 670cfm because the engine was dynoed with a 750cfm carb. So apparently 750cfm is the recommended carb (thats what GMHTP people recommend too) so why restrict the engine with something like that?

 

670 with single plane should be equivalent to a 750 with dual plane like it was dynoed with. check my efi page. The intake options are interesting

------------------
-Tas
'89 Formula WS-6
[soon to be Torch Red with black hood and headlights =) ]

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

Super GRK_Taz World
EFI & Intake Options
AOL IM: superGRtaz
ICQ 82881207

 

Hmm, neat. We would have to see on a dyno though.

 

Tas that's a good point, hmmm...I wonder if it's all that true though. About the injection system being a waste on that kind of motor. It all depends on the money my friend. TBI is a much better system than a carb. No stall, better gas milage, more reliability, **** power on the whole rpm range. I was wondering...is there any TBI system that flows 750cfm? All I see are ~450, 670, 800+!

------------------
, Jon (91 RS too many mods to list), getting new engine in summer

 

ya Dan W got a Holley 4 barrel TBI. I don't think they sell them without the computer anymore though.

 

91bird305 why are you so stuck on carb? he said above they would like to keep the EFI. i always learn something new like off tas right now. this board is sweet.
Shawn

 

i think mrJ wants him to stay efi for his own selfish needs of splitting the cost of prom burning stuff.

but i think the engine could run great when finally programmed correctly. in my own personal opinion. even though im a diehard tbi guy. thats a beastly power capable motor, and simply so with a carb. if he wants to play with tbi injection. go for it, it doesnt sound like hes in a hurry or anything. since he doesnt even have headers on it. I really think the bigger tbi could do just fine, if like the carb tuned right. it would just take a hell of a lot longer to tune the tbi.

 

You assume too much. I haven't even asked him if he'd be willing to do that first of all. Second, I want him to stay EFI because I detest carbs and think they are backwoods, stone-age era technology that has no place in the 21st century. TBI is a more capable system for a street car when done right. That is why I want him to stay TBI and work the bugs out of the system he has.

------------------
91 Trans Am WS6
Bright White
5.0 TPI auto
Flowmaster 3" 2 chamber catback
Trans Go shiftkit
2000 stall converter

Built on Wednesday

[This message has been edited by MrJ (edited February 08, 2001).]

 

Mrj, the guy HSOULD get a scan tool and check the BLM numbers. These numbers will tell him how overall rich or lean he is when driving. With that displacement change and the 305 PROM, he should be pretty consistantly lean (BLM numbers above 128) across the board and the scan tool can tell you EXACTLY how much. THEN, he can have the PROM base pulse width (BPW) changed to reflect the overall displacement change. This will help IMMENSELY and he should do this ASAP as he may be running very lean in certain areas, especially at WOT and open loop areas...

 

Your so right, Carb is ancient technology. Oh wait, they use it on todays NASCARS, dang, oh wait, they use it on all hotrods and dragsters. Dang, nevermind then, guess it isn't to anicent if it works good enough to power 400-1000hp machines. Hey, I won't recommend carb for an engine that needs to pass emmisions but I will recommend Carb or TPI over TBI anyday. Show me a ZZ4 with a TBI that is faster then another ZZ4 with a Carb on it. Sorry, but some engines just aren't meant for TBI. Our engines run fine and perform fine with TBI on them. But a high performance ZZ4 or 383? No thanks. If you need to pass emmisions I would suggest a TPI swap instead of Carb. Sorry but like I said, find me a ZZ4 with a TBI on it that is faster than another ZZ4 with a Carb on it.
Good luck.

 

ok bird, youre about to do it again.

mrJ, i was just kidding man.

tbi is nor less capable of making power, WHEN TUNED RIGHT. but, it takes a long time to tune any fuel injected motor. because when you are being more precise, things take longer. when you want a quik solution. you go carb. thats why dragsters use carb, they only have what. 4 - 9 seconds to test and decide what adjustments to make. they dont need as much precision as tbi. just something that gets the fuel atomized.

yo

 

They use carbeurators in NASCAR today because that's what they put on the cars from the factory when NASCAR was established. They set up the rules for carbeurators...They still use 'em to keep cost down and to avoid having to make all the changes that would be required with a new induction system. Same with the NHRA. Look at the open wheel cars, they all use EFI, sure they use crazy sequential injection rather than throttle body, but it's fuel injection none-the-less. Throttle body injection gets knocked so much because it's on the middle ground...not as good for power as a sequential/MPFI setup, but not as easy to tune as a carb. The hot rodding world is not big on compromises so everybody goes all one way or the other. I've tossed the idea of swapping over to a carb before, still might do it (not because I'm particularly fond of carbs, just 'cause they're cheaper than a good SFI or MPFI setup...like that kick-*** Ram Jet).

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

 

Hey, I am just saying, its just a little odd that u never see hotrods on the street or other High Performance engines with TBI labeled on the side of the car for them to show off. If you want to put TBI on a ZZ4, go ahead and do it. Then go time the car and see what u run.

------------------
Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

i have never seen a hot rod that had carb on the side of it either have you?smart guy?
If i do put tbi on top of a zz4 i'll be sure to look you and your carb up but i'll probably just buy a new camaro when i graduate.



[This message has been edited by pimpintheRS (edited February 08, 2001).]

 

There is nothing wrong with TBI. It gets knocked because it was only used on 305's and truck engines. It's a cheaper system that from the factory sucked. Why does it suck so bad? Because it only flows 460 CFM and has a low end computer system.

 

TPIs will choke any engine bigger than 305. if you wana spend a small fortune on it for bigger engines go ahead. Single plane EFI intake is only $255 and will do the same as a $900-$1200 Mini Ram that most TPI owners drool over.

 

I highly doubt that Tas. Kevin91Z's dyno numbers (TBI vs. TPI) showed that TPI was a lot better than the TBI injection system at ALL RPM ranges. 20 more hp and 70 more lbs of torque. Can't argue with those numbers. So how is a TPI gonna choke any bigger engines? I didn't get what u meant. Like a stock TPI? Like the one Kevin dynoed with the stock TBI?
PimpintheRS, put a TBI on that ZZ4 and u look me up ok? But don't tell me how fast it is, give me a time slip.

 

Ok I'm gettin in of this now. A stock TPI doesn't flow that good for the higher rpm ranges. It's becaues of the long runners, they are geared more for low end than high end. There are plenty of TPI products in the aftermarket and TPI modificatoins to satisfy the ZZ4 though, but it's gets expensive.

 

isnt he going to cause more headaches trying to switch from tbi to carb? so what kevins numbers i dont really care the big numbers i care about is the all mighty $$$$... if it costs that much to get 20 hp and 70 tq i doubt its worth it its simple numbers. money is money and the swap is expensive.
IF I DO switch i'll look for you dont doubt me cause if i do it'll be soon. i am all the way in Arizona. if i end up doing it i'll post time slips.91bird305 its cool we all got our own opinions.
Shawn

 

Actually, go on Ebay and look for TPI setups. Usually there pretty darn cheap. 300 bucks usually for almost everything. Hell its 300 bucks for a Holley 670cfm tb unit new. Doesn't sound that expensive to me.

 

He isn't going TPI. He is staying TBI. Any more ideas from you guys?

 

I know, i was just saying that from pimpinthers's comment about money on swapping to TPI for more power. That guy in the ZZ4 can do whatever he wants with TBI. I don't really care anymore. I gave my input several posts above.

 

I want you all to study this what is in this link. http://sallee-chevrolet.com/ChevySma...er_Deluxe.html
It's about the 330hp engine that got a heavy compcam which boasted hp from 330 to 380 and torque up an extra 25 ft-lbs. Now look at the carb used. Yes it's a demon but look at the cfm. Yeah, you read right, it's only 625 and that cam is more radical than a zz4. Only thing I see different is the compression ratio (difference between zz4 and HO engine). Who was saying the 670 holley wasn't good for a zz4?..who was it..?

------------------
, Jon (91 RS too many mods to list), getting new engine in summer

 

http://sallee-chevrolet.com/ChevySmallBlockV8s/325.html
Is talking about using an edelbrock 1406 carb which is only 600cfm. So...

------------------
, Jon (91 RS too many mods to list), getting new engine in summer

 

My cavalier has TBI, my mom's crown vic has TBI, I think some imports have TBI. it's a good system, just a little dated with the advent of mutiport, I still like TBI it better.

 

You guys drop a ZZ4 in your cars with TBI, and when it runs 13.25 @ 107 MPH, dynos 285 HP and 380 TQ, *and* passes smog, come talk to me. I'll be impressed.

Dont hate me, dont hate me...

 

I said it would choke an engine bigger than a 305. Kevin's dads car is a 305. I think its perfect for 305 but for anything bigger you'll need to spend a lot on it. a ZZ4 with a TPI is a L98. 245hp. if you want more HP break out the check book. If you want a torque monster TPI should suit you fine. Many even argue its the TPIs toruqe that makes it a good system since some of our cars can be optioned close to 4000lbs.

 

A ZZ4 with TPI is only rated at 245hp? WOw, let me go look at Jim Pace's dyno charts :looking: Hmm, well they say that its at 355hp and 405lbs of torque. Are u saying that by adding TPI we loose 110hp on that engine?

And J, I said to use a 750cfm something with the ZZ4 because that is what they dynoed the engine with. If someone dynos the engine to create the most horsepower and torque with a 750cfm carb then that is what I would use on it. Nothing below 750cfm cause u might be robbing power from it.



------------------
Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

the L98 is rated at 245 net horsepower because it is in a car. the ZZ4 is gross horsepower because it isn't. Also the ZZ4 has a better cam. I doubt you'd loose 110HP with TPI. Maybe around 50hp since thats how much HP GM got when they put the short runner intake on the LT1.

 

You guys need to figure some stuff out. Use the calculators, look at actual engine dyno charts and do some research. A holley 670cfm is a great product to make hp on 5.7L engines. Did anybody see the post about the 325hp engine with a 600cfm carb? I'd say that's darn good for only 600cfm. So why would the 670cfm be worse?
Another thing, about TPI, TPI was designed for the 305. It was put on a 350 (the l98) to offer more power. If you swap on a carb onto the stock l98 I bet you'd be able to get a little power. The TPI was designed to make lots of torque with the 305 and not the 350. It just so happened that it worked well with the 350. If you put in too big of a cam or better heads the TPI is going to be the bottle neck big time. That's why it costs an arm and a leg to change stuff. Like injectors, TB, runners, and intake manifold. TBI is great, we can use any carb intake with an adaptor plate for $43. Our 670cfm holley isn't even too bad at $300. It comes with everything you need (injectors). I guess that I'm getting at is that ever induction system can be used on any system and get LOTS of power...BUT it depends on how deep your pockets are.

------------------
, Jon (91 RS too many mods to list), getting new engine in summer

 

i think i like this new moderator.. Thats kind of what i was trying to say but some guy on this board swears that tbi cant make power for nothing. i dont want to call out names...
Shawn
STIcK WITH tbi it can make power like any other system


[This message has been edited by pimpintheRS (edited February 09, 2001).]

 

Shane B had a Vortec 350 running mid/low 13s with his TBI. Seems like TBI can make some power worth something What are those specs?: 250 net HP in trucks, 330HP gross for 350 H.O. crate engine? Seems just like the ZZ4/L98, don't it? so your ZZ4 TBI can run 13 just fine if not better that fine.

 

Of note: a 350 ci motor running a 100% VE will use 608 cfm at 6000 rpm. A more realistic estimate for this motor would probably be 90% VE and 5500 rpm... thats and airflow requirement of 501 cfm. A 670 cfm 2bbl will feed this motor nicely... even with a dual plane. Dont forget the 85# injectors and custom tuning.

Here is a good link to help those interested in the calculations. Motors with dual plane intakes like carbs 10-20% larger than the numbers that you calculate on that page.
http://www.prestage.com/carmath/calc_carbsize.asp

It looks like you can still get the 4bbls.
I found these numbers on holleys web page.
http://www.holley.com/HiOctn/ProdLin...IA/Access.html

The last two have IAC provision.

P/N 500-8 TBI Assembly - (900 CFM)
4-bbl Pro-Jection, P/N 504-1

P/N 500-15 TBI Assembly - (700 CFM)
4-bbl Pro-Jection, P/N 504-2

P/N 500-16S TBI Assembly - (900 CFM)
4-bbl Pro-Jection, P/Ns 504-11, 504-21

P/N 500-17S TBI Assembly - (700 CFM)
4-bbl Pro-Jection, P/Ns 504-12, 504-22

On a personal note, I'd choose a 2bbl unless absolutly required to run a 4bbl. Depending on the motor, 2bbls can support a maximum of 350 - 400+ hp.



------------------
1988 T/A,
9" Ford, 3.50 gears, Auburn posi, 700r4 -w- 2100 converter
350 .060 over with forged 1 pc rms crank, and forged TRW pistons, 9.5:1 cr
Factory GM heads Pocket ported, 2.02/1.60 valves, back cut
Lunati roller 219/227, .479/.480, 112 LSA
Holley 700cfm 4bbl on TBI truck 7747 computer and chip by Howell-EFI
Edelbrock Performer EGR intake, Edelbrock TES and 3" cat

 

Actually? Didn't Shawn B switch to carb in the end? I can't remember why though, does anyone remember? Did he ever time his Carbed 355 with his TBI 355?

------------------
Eric Natzke
91 Firebird 305 TBI
"It Ain't Stock"
http://members.aol.com/j007golden/91firebird.html
For info on certain parts or mods go to the site below
http://members.aol.com/j007golden/modeval.html

 

Damnit I'm actually gonna have to post. :-)

First off, we know carbs can make power.. no argument there... The issues are efficiency and emissions. Why do you think they started going to EFI in the first place? Do you really think it was because they thought it would make more power? Hell no.

I think the 670cfm unit would be plenty for that application. Even without a different chip, I think you would see some pretty good numbers. You would need to play with your fuel pressure, but the holley unit comes with a AFPR anyway. Guages are around $15 from summit.

My car went low 13's on stock 305 chip, 670cfm tbi unit, vortec heads, 214/224 442/465 cam. That's stock converter, stock tranny, normal ****ty street tires with a 400 treadwear rating. The dyno #'s worked out to over 320HP at the crank when I had it dynoed.

After that I got the blower and the 4bbl tbi unit. I never even drove the car with this setup because it would not run right. I could not figure out why. I went out and bought a carb just to see if the computer was what was killing me...

As it turned out I had a huge vacuum leak on the intake. When i discovered that I had already pulled the TBI unit, stock distrib, etc, and was running a 750 holley with a Accel HEI. I sold the TBI stuff and never tried hooking it up. Why? I dunno.. It was stupid on my part.

Anyway now i've sold the supercharger, and i'm running the setup with a 800 double pumper. I would do anything to have my 670cfm tbi setup back. The mileage sucks, the driveability isn't as good, etc. It still makes a lot of power, but so can tbi.

Since then i got a new tranny, a continental converter from pro-built, bigger cam. Have not taken it to the track since then.

Anyway, my point is i've had identical setups with carb and tbi, and I liked the TBI better. As for which is faster I'm not sure. Need to get out to the track or dyno with the carb. It's definitely close enough that it's not worth losing the emissions/fuel economy.

Shane

------------------
Shane Buss 92 Firebird 355, Holley 800 Double Pumper Carb, Vortec 1.94/1.50 Heads (Ported,Polished,Milled .025), 10:1 Comp Ratio, Cam Specs 224/234 498/520, 1.6 Roller Rockers, Hooker Headers, Flowmaster, !Cat, 3.73 Posi, Msd 6A Ignition Cyb. Speedo box, Single Plane Intake
http://users.ev1.net/~sdbuss/index.html

Note all girls on web page are x's, and will be removed when i get more time

WEIAND SUPERCHARGER REMOVED

 

There it is ladies and gentlemen.

Take that Eric. Carb King boy with tbi.

[This message has been edited by snflupigus (edited February 11, 2001).]

 

Hey, I was just looking for a case like his. He did it. I am glad someone finally responded with some info like Shanes. Clears things up. Thanks Shane.

 

I get no thanks?

[This message has been edited by Tas (edited February 10, 2001).]

 

What a great reply. Thanks Shane, you cleared a lot of things up. Good to hear from you, it's been a long time.

------------------
, Jon (91 RS too many mods to list), getting new engine in summer

 

something i like to hear tbi will work. now i want to do the zz4 with 670 tbi unit. made my night!
Shawn

 

now thats tbi tech talk.

 

I think I can try and clear some things up this spring. I'll use my car as the test piece. I'll have the 670 on it and run it with that, then I'll swap on a 650 holley double pumper that my friend uses on his 327. We'll run that and see which makes more power. How does that sound? It'll be on the 350HO 330hp. This summer I'll be doing a cam swap and a upgrading the torque converter. I'll do the same thing then and we should have our numbers to play with and think about.

------------------
, Jon (91 RS too many mods to list), getting new engine in summer