Wow, I was going to try to reply to everything that has been said, but the problem is that dumb **** is being posted here faster then I can read it.

Lets make this 100% clear. AJ, we understand the concept that you're trying to describe, and the problem isn't that your math is off, but that your concept is wrong.

Yes, the injectors open 180* apart, each one opens one time per revolution, but at WOT the ECM calls for them to be open about 90% of the time and closed 10% of the time (In real life there is a lag and dwell time and somewhere in that range the injector actually ends up open 100% of the time). It doesn't make one hell of a bit of difference if the plenum is split or not, you end up delivering EXACTLY the same amount of fuel. No more and no less. If the injector is open 100% of the time (not closing), they why would you get more fuel spraying it into half the plenum vs the whole plenum???

The reason that this is different then the airflow is because the cylinders only draw air for a fraction of that time. For example, with a cam with 200* .050" duration the cam is only in a usefull lift range for 200* out of 720*, or approximately 28% duty cycle, as compared to the 90%+ DC of the injectors.

 

Yea, MrDude, I believe that I said that 4 pages ago…

 

I see what you are saying. On a single plane the two injectors are added together for total flow into the cylinder. With a TBI ECM they can both be on at the same time. And are once the PW's/DC/RPM goes up.

So 2 90#/hr injectors will be the same as 1 180#/hr. There is also 2 TBI bores flowing air to match the increased injector size.

With a dual plane the cylinder in question will only receive the fuel flow from one injector. It will also only see air flow from one TBI bore.

The question becomes whether that one TBI bore becomes an air flow limiter. If it does then the fact there is only one injector does not matter as much as if that one TBI bore did not limit the air flow.

An example of this was when I was running the stock 1-11/16" bore 2BBL TBI and the 63#/hr injectors. By 4,800 RPM the intake manifold vacuum had dropped by 3-4 inches Hg and the engine was flat. Didn't matter that the inejctors were too small. Couldn't get enough air in the engine anyway.

My 1/1 = 2/2 = 1 was the ratio of air to fuel delivery, 1 injector:1 bore to 2 injectors:2 bores equals 1.

RBob.

 

eh well... i usually skim over your stuff...



but hey, atleast i wasnt wrong.. thats gotta be worth somthing.

 

And just think... a little over 24 hours ago I was wondering why I didn't read the TBI board... now I'm wondering why I anyone would waste their time...

 

NOW THERE'S AN INTELECT FOR YOU ......

A 1983 CROSSFIRE NOW THERE'S AN AWSOME SETUP...NOT......

 

i donno, but i wouldnt mind taking his brothers ford down the strip....


if you want to be really cool about it, you could poke names at the other names he has listed in his sig too....

like silverback..... where the hell did that name come from?

and dont forget to make fun of his avatar.... "BAD DOG!"




id say im still driving my 82 but i sold it for a much better 91... i mean comon, it was a 82 and i just LOVE this l03... the power diff is amazing!

 

They won't exactly give a ****. Most look at TBI as an ugly middle ground between carbs and "real fuel injection." Even more knowledgeable people don't really even consider the advantages (brutal simplicity/reliability, cooling the intake charge allowing for higher compressions/timing then with port injection, better atomization…).

What would the outcome of their writeup be? Simple, whatever their advertisers tell them it will be. Do you really think anything else controls what they publish (instead of arguing with me do a search here and at CZ28, there were threads about a reply that one of the editors gave to a letter that stated this pretty bluntly, that to stay in business the car enthusiast mags have to cater to their advertisers and their claims)

 

Wow… considering some of the brilliant engineering insights that this board has had in the last day or so… I'm not sure but I'll take that as a complement (assuming that you mean that sarcastically, if you're serious I should probably just go out and shoot myself in the head).

 

My WS6 TA still holds the fastest MPH out of all of our cars… though we may have something interesting done with a '91 Lincoln Town car by late next summer… If that works out it should be able to put the LTD and the project festering in my garage at this instant to shame (well, I'm assuming that you've seen the "freightliner" parts that are being added to my formula on some of the other boards )

All I want is a banana…

RRRRrrrrrr! WOOF!

heh, my '83 is dead… the t-tops are sitting lower then the dash (6' in diameter oak fell on it during Isabel), current projects are the Formula, WS6, LTD, possibly the Town Car, the 66 Lemans (with the 500ci caddie engine) and a few other surprises.

 

NAH dude crossfire is just fine......

I'm just tired of hearing about this one intake manifold......

I got a TBI injected AMC running 9.60's< That is now under going a $40,000 restoration/build up ....

after that is completed it will be running 9.20's and still streetable.

I'm also builDing a 91 GTA with a 406ci TBI v-8 that will run low 12's high 11's so as fare as TBI being a performer I prooved that with the S/S AMX....... the 91GTA was just the nestalga of it .....

Big bad 4bbl 6.6L sept it's a 6.8l Dual 2bbl but you get the idea....

 

i havent noticed any "freightliner" parts mentioned... what board?

 

The S/S AMX and the 91 GTA were built to prove it could be done....

you can make TBI's out perform TPI it just takes more thought and planing then a gear swap and and intake swap with a shnazzy chip...........

I'm not ripping on TPI's I Had 335TPI that ran 15.20's

and a Junk L-98 running 16.11's TPI can go fine.....

too many people have said " TBI has no PERFORMANCE "so I built 2 TBI car's that blow away:
LB-9'S,L-98'S LT-1's,LT-4'S,LT-5'S,LS-1'S,LS-6'S...........

lS-6 IS THE FAST ONE RUNNING MID12'S.....

the AMC390 in my AMX is almost stock well 90% stock....

only mod's i did was..... swap the stock 12.5:1C/R for a 12.75C/R.
swapped thw 2.5" sidepipes for 3.5",and swapped the 2- 650 carb's for 2-900cfm TBI's. swapped the 29x10r15 ploy glass slick's for 28x12r15 DOT slick's and whiz bang 9.60's all day long......

other wise before them nod's it was running 10.80's.......

all i did was shaved a measly 1.2second'd off the stock E/T'S but then again my AMX is a 69 HURST S/S AMX SO IT CAME SETUP FOR DRAG RACING....

the preditced E/T's for the 91GTA is 12.10's to 11.80's.....

DYNO: claim's

540hp@6500rpm.

620ftlb torque@5,000rpm.

at the fly wheel on my 406 TBI but i think the torque reading is a bit high...
i think it's more like 520-560TQ it's only flowing 1340CFm with a 10.5:1C/R with a 292*Dur.575Lift cam dart iron eagal head's .

Dyno could be right on who knows i'll find out after the Rwhp & RwTQ are checked...

We Will see when it's all done and wheel Dynoed then fine tuned and ran down the drag strip....

 

I've rebuilt a few turbos off of some freightliner wreckers and larger over the road semis… decided to keep one for the formula (sold the rest off) one for myself, polished it up…. It's too small for what I really want for that car (it's an H1E/HX40, probably top out in the high 700's to 800hp or so), so it'll probably eventually be moved over to my TBI K1500, but of course, we all know that TBI isn't worth anything…

 

oh of course... afterall it doesnt matter if the right amount of fuel is there or not.... all that matters is where in the induction you spray the fuel... if its not directly before the port aimed squarely at the back of the valve, its junk.


and you just gave me a idea... theres a semi truck junkyard not far from here, i wonder what they have as far as intercoolers......

 

No really there 83 crossfire My TBI car is only worth $60,000......
most sell for $80,000 -$120,000........... But i swapped my carb's for TBI so my was appraised at $60,000 but i could prolly get $70,000 for it Now and prolly only $90,000 After I finsh my Rebuild moddify Repaint....

pocket change Yup TBI car's are worth less.......

 

Huh, so you're telling me that you know of an engine that has the injector pointing right at the back of the valve??? For that matter, what exactly is the advantage of that?

(I believe that you spent some time arguing with me about how badly TBI sucks about 2 years ago...)

 

should i edit my post to include [sarcasm] [/sarcasm] tags?





hehe, without going back into that again,

the concept of TBI is solid.

IMO GMs execution of it sucks...
(and if you're heavily modifying it, its not really GMs execution is it?)

 

I just got back from some errands to finish these letters and I was wondering who got up and smeared monkey s**t all over this thread?

What a waste.

 

Hey Guy i hear that this thread has gone all to Crap man this is interesting but oh wel is just running my posts Number's up nice and fast there tho......

 

I only bee registerd on here sence december 2003 and I;m allready yup 156 posts But i Have gotten some good info and some interesting BS too so it's been worth it .........

Well anywho yeah caprice i do have to agree with you there.......

....:hail:................ :hail:................. :hail: ..................:hail:....

 

Yes please

You should know damned well by now that a lot of the "problems" with GM's execution can be fixed with very minor tweaking. If that wasn't the case how do you think that I get cars to run "incredible" times with what all stock or close to stock parts? I'll still stand by what I said a while back, that there is no good reason for any of the 3rd or 4th gen v8 powered f-bodies to run slower then 13's without anything more then a decent exhaust on them, and for the most part, a stock 4th gen exhaust is all you really need (with minor bracket changes it will bolt right into 3rd gens)

 

with ONLY exaust being done, i see very few thirdgens in the 13's the peanut cammed TPI cars, and TBI cars were really doomed with the crappy cam they got. now a l98 cam (like the hot 305 TPI cars we hear about) then yes, they all should be able to run 13's consistantly.

 

4th gen's run low 14's high 13's out of the box.............

so did most 1st gen's.........................

the second gens and the third gen's where the heavy turd's......

 

double post.

 

Ok Dyd this is cool and all but the l-98 is a wase of space there choked off threw the inrake's and exhaust's......

my L-98 only has 120,000miles on it.

MODS:
1. M-A-F delete swapped for MAP.

2. 3" single Exhuast with dual tip's you the retarded carppy sound ing one's....

3. open element Cone filter.

Best of 2 run's was;

16.11@88.9mph yeah i'mma Fan there of that Mad performance....

Yet my L-98 in my 91 GTA belw up ay 35,000niles..

si it git a worn beaten 350TBI tryck engine with 190,000 miles on it and it ripped off an:
ran a 15.66@90.2mph with 3.42's......

then i got it run a 14.86@95.78mph

all i did was was throw on some P295/50R16's and some 3.73's and give it a tune up ........

 

Peanut cammed LB9's are hard but not impossible to get into the 13's with minimal mods. With the 5 speed and 3.42 gears the're actually easy to run 13's in.

The cars that are difficult to run 13's in without some more serious work are the ones that got factory 2.73's.

WRT to 4th gens I said "at least." I've run a 13.003@106.9 in my LT1 WS6 with nothing but 4.10 gears… With some slicks it should be a 12second car…

 

FWIW, 1st and 3rd gens are light, typically under 3500#, 2nd and 4th gens can be heavy with all the options. My '97 WS6 TA has weighed well over 4000# at the track with me in it, of course, to run sub 1.8 60's I usually went with a full tank of gas.

 

1.8 60's bit slow off the line huh......

I run 9.63@143mph with 1.3? 60's......

you must need some gear's and good tires...

But then agian you got the 4th gen ........Nevermind......

 

if your Running a 4th Gen the what in the Hell are you doing on a third gen site in a TBI forum ???

Must be a lack of grey matter.........

 

Off the bat this thread had quite a bit of very informative info in it, but now that it's winding down it's going nowhere but circles. For what should be perdy obvious reasons:

Bruce (90RS305)