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but look at the other 90% of guys who are running 15+ second quarter mile times and it kind of gives you an idea of what your up against. It takes a special breed of man to do alot of modifications to tbi

14 sec

 

I would agree, you have to be willing to stick with it. Its not persay hard, once you have put the hours in. but there is a learning curve. I think that all of us who have stuck with it, are glad we did. We learned a TON of information , that transends just TBI. The tuning knowledge I gained. I have used to help other f-body guys, it also has helped with my Audi, and with fellow Audi owners. In fact, one of the guys I work with, was so impressed with tuner-pro, he is using it to modify his AUDI chip. It is just so hard to learn this over the internet, and it really seems like a daunting task. but, with enough time, and effort, it gets easy.

You do have to have an attidude, that is will keep plugging away though. If you are the type of person who needs instant results, you are probably not going to enjoy, or stick with tuning. You have to be willing to take the bad, and chalk it up to a learning experiance. Some of the MOST valuable lessons I learned, were from the mistakes.

either that...or we are all just short a few brain cells...

 

never heard of a AUDI bin? what GM platform was it used in?

 

ummm...its german dude.

 

i a computer nitwit.:doh: :burnout:

 

CamAUDI... what a great idea... DOHC w/ 5V per cyl... haha, j/k thats pretty funny though..

 

I've modified the hell out of mine, and I still don't know jack about chip tuning. G0d bless capitalism.

 

ditto... im a lil far from stock... but ive got friends haha speaking of friends, bill... you gotta show a young grasshopper the ways of datalogging at least... its lookin like i might have a die-grinder soon, so my heads will get worked on, once those get worked and i buy the rockers/springs, im going to be replacing the whole valvetrain... deffinately going to need a new tune...

 

Accidently posted the same thing twice.

 

I decided tonight that I'm getting rid of my TBI. I would much rather get a carb, than change my cam to one with more lobe seperation. I was stupid in getting one with only 109 lobe sep but I like the cam and kinda want a carb anyways so I'm gonna give it a shot. The only bad thing was the wasted money on the high-flow tbi, injectors, and adjustable fuel pressure regulator which is now worthless.

 

My 305 TBI just ran a 13.2 @ 103.98 .
60 ft . 1.921
330 ft . 5.498
1/8 8.478 @ 82.76
1,000 ft . 11.050
1/4 13.221 @ 103.98 .

My mods are headers and cat- back , Edelbrock RPM manifold , NOS nitrous system ( running a 135 shot ) and ET Streets . The chip is a Hyperjunk . I have a friend making a new one now . I'll be going back as soon as it's done to hopefully break into the 12's . I can post my time slip if need be , but I doubt it would show up very well . Heck I have a hard time reading the little print on it .

 

LOL!!! I was about to say "Not without NOS you didn....ohh nevermind "

 

ill be in the mid 13's. no nos with pretty much entirely stock parts... 91Z heads, 95Z cam 93 Caprice bottom end, 91RS TBI/Intake... new 700R4 (stock setup, no shift kits or nothin..) and a 91Z rear

 

You have hit the nail on the head! This is EXACTLY why I DID stick with TBI!

...........because they said it wouldn't work.

 

i know a guy that had a 454ss with headers,cam,heads.carb intake stock chip higher fuel pressure and advanced timing and he ran with a 03 vette up until 100 so i m guessing he was runnign easy 13s

 

One of the things that makes tbi difficult is the ECM. The stock computer wasnt that great and the code is limited in what it can do. Another thing about computers is that there is no coupling like there is with mechanical systems. The spark and fuel can completly change from one moment to the next. This means that there is more parameters to change

An even more important aspect is that the tables you see dont give you a picture of how things really fit together. Like, just tuning via the main timing table in your tbi ecm might not get you what you want because there are other things at work, like the PE adder table, CTS corretion, some MAT correction, changing throttle transient spark, startup spark transition, the biases, teh initial base advance etc. If you have an idea of how all this fits together, its a simpler task of making the changes. we as tbi users should consider ourselves lucky, 98% of everything in that computer is well understood and all the info needed to do whatever you want with it is contained here on TGO.

With the later systems, sound tuning seems to gradually give way to wild speculation and conjecture. Im currently trying to work through the later tbi pcm, and I was looking for info on how the force motor is handled (electronic equivelent of the TV cable). On the fourth gen site all the people seemed to be fixated on making changes to the two tables that define the desired current vs desired line pressure vs temp., and yet it seems like theres alot more to it then just whats in the tables on the code side. To me it seems like just working with the tables is only half the story, which is probably why all of us have trouble some times with tuning. Teh computer is out of view and sometimes working the strings in ways we dont know about.

 

Very true.. The advantage with the later PCM's is that you can see, via good datalogging software like datamaster, EXACTLY what is going on.. You can see how much timing it is giving, you can see flags change when it goes into PE, or AE, or sync/async etc etc ..
They may be more complicated, but you have so much more feedback available. It aids tuning tremendously and does remove some of the guessing.

 

from what i read we have speed density system. while i dont know exactly what that means i will guess it means the fueling A/F(include AE the bi@#h and PE ) is not metered like a carb which is metered in part by air flow over jets. maybe a carb could be considered as similar in function to MAF EFI cept MAF i believe is air flow over a sensor? in each more flow more gas. am i close on this? before i went to a modded engine i had no idea the challenge ahead in tuning. but it is just that, a challenge, and it gets better as i tune and begin to understand what needs to be done. since it is not a daily driver i work on it as i find time. if i needed to get it perfect in thirty days i would be totally frustrated. call it a hobby.

 

I cant wait to finish with it. With all that extra speed, hardware and space/time from removing all the e-trans code (never use another automatic again after the TC debacle) it should be real nice.

Ron, with a SD system, the computer uses the ambient air temperature as an inticator of air density, the volume of the cylinder, the engines volumetric efficency, and some fudge factors in the tbi computers, to estimate the mass of air in the cylinder. Using this along with the injectors mass flowrate per second, a time based result, namely the pulsewidth, is obtained.

 

thanks. i have no IAT sensor currently(7747) and neither did my original cross fire ECU.

 

Its not used much in teh tbi cals. Pretty much mostly for the knock handling in the f-bod ecms.

 

In your cals maybe... or stock . RBob gave a patch for the IAT and it works really well. It's in the xdf file I gave out. Obviously if you haven't patched the bin it won't work and the table will look all messed up but you'll get the idea of what kind of resolution and tuning can be done with the IAT on a stock ecm. I found it to be a huge help. My BLM's would swing all over the place and I was chasing my tail with the open element and a warm engine in the winter. Infact I almost gave up with tuning part throttle until his patch. It make a noticable difference in the stability of the BLM/INT's. Very much needed and appreciated.

 

The stock cals it wasnt. In my romless SD setup I had RBobs blended IAT/CTS. Seemed to work well.

 

i was going to say something about your factory freak


my car is going to be just a tenth faster than whatever he is running no matter what he does


hey dave look what site i found

 

I personally see no problem with the 305 TBI Engine set up, I just bought a 91 RS last week and since then I have been taking the car out for drives everyday.

It's the perfect first sports car. It may not have a lot of HP but the torque is more than enough and the car can get you in and out of trouble whenever and wherever.


Its faster off the line acceleration then most cars out on the road today (of course if a kid in a Supra pulls up next to me I'll whimper away) I'll be doing everything I can to get atleast 205hp at the wheels and maybe 230hp at the base engine. I am not really concerned with top speed or anything I love clocking my zero to sixty time.

The 305 TBI engine is a good durable engine, its very sturdy.

 

Catch me if you can Jim !!

 

i ran 11.67 in the quarter at 122mph... i think, was about a year ago after i finished my build on my "305" but since then my motor has gone down hill a lil bit and now ive got a few things to replace as usual... but dont have the money or time due to my lawn service and bills... also have a GMC 1500 w/ a 350 and it runs 13's but im more into my thirdgen!

 

The only way I could see you running a 11.67 on a LO3 would be that the motor is built to run 12's (HUGE cam and HOURS of tuning, unless it's a carb), slicks, and 150 shot or bigger.

Details please.

 

when i was 19 i got lucky and won 7,777 dollars with a lucky bingo 7... so i figured what better way to spend my money then on my car... got the block bored(.030 to keep it safe) bored the TB and edelbrock intake to 2" had the swirlports machined to make them otherwise usefull with zz4 cam 10:5 CPR, 1.5 rockers on the intake and 1.6 on the exhaust, hooker 2460's that run to true duals and 50 series flowmaster... and no nos or slicks... at the time i just had a soft suspension in the rear with two twenty pound sand bags and 189 lbs of audio equipment weighing down 275 50, 15's... as for the chip tuning, it was done by my buddie that went into the army and is in germany... sad thing is that was two years ago and i cant just throw money around like i use to... other than that, yea man its possiable...

 

Choate, I'd love to believe you but I'm afriad I can't. Something about having a punched out 305 with ported swirl ports, a zz4 cam, and no slicks running n/a trapping 122mph in a thirdgen f-body and then getting into the 11's without slicks... it's just not adding up. Heck, it's not even multiplying up! Is the thirdgen 2200lbs? Either that or you're telling me you're making about 450hp or more (depending on weight). It's very hard to believe. Infact, you would be the first person, if you decide to do this, to prove that swirl ports in an f-body can be very fast on all motor.
I would really encourage you to provide as much proof as possible to avoid further criticism. Like the name of the head porter, the fuel pressure, fuel pump, injectors, vehicle weight.
Then there's the hole running on 3.08 rear gears that again brings more doubt to your claims. It's just so hard to believe!

 

........do I really need to say anything else. Keep in mind buddy this is the most knowledgable TBI information source on the net. Your not going to be able to throw numbers like that around.

 

WHATTTTTTTTTT!!!!!20

 

Damn, I stepped in a big pile of here.

11 sec. tbi. Now that's funny. Has ANY TBI gone 11's yet?

 

I think someone did with help from nitrous.... NA, no one is close.

 

I have a buddy running TBI on a 383 he ran a low 12 but hes not getting enough fuel around 4000+ RPM. We checked his fuel pressure and hes only getting about 15 so he has to fix that. Wouldn't be surprised if he did a 11. Considering its NA....imagine if it was nitrous.

Also I am sure a 334 Stroker TBI could get into the 11s.

 

OK, first off I'm going to step in here BEFORE I need to step in. I can see this thread going down hill from here and I'm gonna make sure it stays above the belt. Consider This Your Official Warning!

That aside, I do wanna say one thing. Although I'm not yet conviced, I will say that there are some freak-of-nature L03's on the roads. For example, I know I've got a couple of 'non-believers' that my sled made a 15.3 pass with nothing but an aftermarket muffler. But, even saying that, it IS still a 15.3, not an 11.67. People that are spraying to get into the 12's need slicks just to keep traction, so the hp/tq needed to get you into the 11's would be quite substantial, and a pair of stockers with weak suspension would have left you the entire way down the track. If that was the case, slicks would concivebly(sp?) get you into the 10 second bracket. NO N/A 305 (even a bored .30 over one) will get you there. So when it comes down to it, I really would like to know how the dynamics of getting that 4,000lb sled going that fast that quick work...

 

I agree sticking with TBI is a bit of a pain in the ***. The 305 with swirlports just isn't fast, period. LS1 cars with full exhaust, intake, suspension are hitting 12's easily while we're struggling to get into the 14's with that, just makes it seem pointless no? I'd say the only thing good about buying a TBI car for my first car was the fact that it wasn't fast enough to kill myself with . The first time I ran at the track I put down a 17.3, 18.3 and 17.1, hardly fast at all, but it's been fun breaking into the 16's, then the 15's, then the 14's and hitting 13's (next weekend) should be just as satisfying because not many people can shank 4 seconds off of their 1/4 mile time without changing throttle body or heads (granted nitrous helps...a lot). But basically this car has been great to learn on and I've definitely learned a lot. At first prom burning can seem daunting, but I guarentee it's cake if you have the right tools. My Wideband lets me know my exact AFR vs. RPM, Load (MAP), and Throttle position which takes all the guesswork out. I can't say enough about the prominator, it's amazing, all I have to do is plug my laptop in and click upload, no pulling chips, reflashing BS. Throw money at these cars and they'll respond, but it's not a good platform to start with if you want to go 11's or even 12's, it is a great platform to learn on so you don't nuke a real race car.

 

So there has been no 11 second n/a pass made w/ TBI. Regardless of cubic inches?
People try and justify that TBI isn't all that bad, but raw numbers tells me otherwise. When a group of people can't get ONE single combo that is a consistant 11 sec. motor, then something is wrong. I don't care if someone did run 12.0-230x in a row, it's not a consistant 11 second n/a motor.

 

Yes there is something wrong......TBI is fuel limited to about 450 HP. Thats it, thats the big secret. Untill some one finds injectors that are bigger than the 90 pph units, or some one designs an injector pod that will take 90 psi, TBI won't make any more power. TBI is just a form of fuel injection. If you don't give an engine enough fuel or air it won't make power, no matter where you inject your fuel.

 

I think that 11's could be achieved quite easily.. Problem is that it costs money and a lot of the guys who drive TBI Camaros are students, or don't have a lot of disposable income to throw at the car.. Guys who do have enough spare cash to build a motor capable of pushing the car into the 11's would usually spend up on the induction also, so the TBI gets the boot...

As BMmonteSS said, they are fuel limited on two injectors, but it wouldn't be all that hard to use a pair of TBI's on a dual quad manifold, have an extra pair of injector drivers, and even turn 2 injectors off at idle if the pulse widths are too short..

I'm putting a 406 together now that will make 50% more power than the 12.4sec TBI 383 I have now, but I have no intention of running TBI on it. Not because I don't think I can do it, just because PFI is a better system..

 

BEN:

i assume that is going in the Vette?

if so what intake manifold will you run with PFI?

will it fit under the Vette hood?

GM components?

 

Then show me somone who has done it. I assume when you say "quite easily" that it's common practice and can be done by any laymen given a list of good parts. Or does "quite easily" mean starting off w/ 400+ cubic inches in a fiberglass car? In that case, I'll agree w/ ya.

 

Now thats not completely true. Yeah, we don't have any 305 cars here that make consistant 11 second passes, but I know a guy down here in AZ with an 87 IROC with a 454TBI shoved under the hood, n/a, that was running low 11's/high 10's on every pass. Sure, not exactly a common configuration, but it shows that a throttle body is capable of delivering.

 

lets compare apples to apples.

 

Not what you were comparing originally

 

So there's one guy in AZ w/ a big block in a 3rdgen who's gone 11's? I guess I just don't see the point. If you know you can go faster, why bother?

 

Hi Ronny,

No it probably won't go in the vette, it will be too much for the tranny and rear end. I will probably buy a 1st gen camaro for it sometime next year. Manifold is a Super Victor I will convert to PFI. Basic recipe is 406, half fill of hard-blok, splayed caps, Winberg crank, Scat H beams, SRP forged pistons, Dart Pro-1 230cc heads, Crane solid roller, 252/260 @ .050, 670 lift ect ect... I have most of the parts, just need some machining and time! Oh, and a car to put it in!

 

No one said its common practice, you know that yourself...

You missed my point..

Most of the guys who have these cars are on a budget, and its not an 11 second budget..


The parts (heads, roller cams and lifters, headers, manifolds etc etc...) needed to push the limits of the TBI induction system cost money.. I could count the number of TBI guys here with good aftermarket heads on one hand!

You could quite easily spend the value of the car on motor parts alone. For most people with these cars, this is out of their reach, or just plain economic stupidity!

Apologies to anyone who feels I am stereotyping TBI 3rd Gen owners...

 

So free bird, why exactly are you on here poking around???? You have 1400 post and you don't know what TBI is capable of?? I find that hard to believe.

 

What exactly are you trying to get at here man? So far I'm absolutely on the edge of my seat waiting for you to ask the same question for the 10th time.