everyone complains how a stock ltr tpi craps about 4500?? right?

tell me this? why was my stone stock 85 tpi z28 shifting at 6500 to 6700 rpms
shifting into 2nd at 70mph? the car with new coopercobra gtz's would 0-60 in 5 seconds

still think im bs'in? it took me 3 years of owning the car to start diggin into it, the culprit? good or bad? u tell me!

the car NEVER had an active service engine soon light, which has to mean the ecm is inoperative...turns out the original owner bypassed the ecm, the orange 12v ign wire was wired directly to the fuelpump, and injectors...nothing else!! hell you could pull the ecm out of the car and it still cranked and ran

so what is the REAL problem making power past 4500rpms? maf? runners? nah, i think its restrictions and perameters made by the ecm... any and all criticizm welcome!

ive even thought about running the same setup but with a vacuum advance non ecm controlled distributor

 

I suspect that the biggest problem is that most people complaining about tpi limitations are running 350 motors or bigger. The tpi was designed for a 305 which is what your stock engine is. As long as you don't put a 350 in there, you probably won't have a problem.

 

Issue is not that TPI doesn't make power, it is that is makes it very poorly after a certain rpm (4,000). The runner lengths and diameter prohibit it from flowing enough air to satisfy engines at high rpm's, especially as displacement increases.

TPI can still make power. Here Comp Cam tested several intakes on a 383. First dyno was with stock TPI setup. Engine made 410hp and 500ftlbs. Sounds good right, until you see torque levels drop off dramatically after 4,000rpm and horse power flatlines at 4,000rpm. Engine needed more air than stock TPI could provide.

Further down they test a extrude honed TPI and TPIS bigmouth system. Although they both add horsepower and torque, power flatlines again but at 500rpm higher (4,500). Even though stock is restrictive, it gives you good torque boost at low rpms so car feels strong on street.

http://www.compcams.com/community/ar...?ID=1737510521

Did your car still pull hard after 4,500 rpm?

 

it has u against the sit til it shifts, then it barks the tires at 6500-6700, with only k& ns and flowmaster, i was eating lt1 and even a few svts 96-98, the car was an 85 tpi 305 700r4 with 3:23's, i had a friend with an 88 350tpi with a nice cam and headers.. he couldnt touch my car

 

having the tranny in od, u could stomp it at 60, it would downshift 3 times, into first and hold it to 70, u shoulda seen the look on ppls faces when i passed theM!

 

It doesn't flow enough air above 4500rpm to support high rpm hp numbers. The way the system is designed just doesn't support it. You can turn them 7000rpm, but that doesn't mean it's building any power. When I ran a tpi out at the drag strip, my best numbers were shifting at 4700 rpm or so. Anything higher would slow it down.
And I wouldn't be turning that many rpms on a stock motor anyway.

 

i swapped in a 355 a few years ago, and repaired the wired, and the ecm and chips were all trash, i replaced the 870 ecm and put the 350 corvette chips in the ecm, and it wouldnt pull past 4500, but it had more low end up to 2500, 0-60 wise, the non ecm controlled tpi 305 wouldve eat the new motors ***

 

well, also I don't know how a car would run without the sensor inputs from the motor into the computer....it needs that to determine injector pulse width, timing, fan control, etc. etc. etc.

A stock 305 only runs like a 16 sec 1/4mi, while a lt1 can push high 13's or low 14's, it just it basic hp numbers....

 

intercepter

i ran the car like that for 78k miles, and if it wasnt makin power, why would it outrun faster cars? by the time my friends 96 svt was shifting 3rd in a 5 speed, i was just hitting second... and i was outrunning him, and when i tore the motor down it was all factory, and had xrods on the pistons.. ive seen them in many early 80's 305s

 

well, mustangs didn't make that much power to begin with, they are about the same as hp I believe that a 305 puts out.....235hp on the 305 with 295 ft. lbs, the mustand I think put ot 240 or 250 with less torque...so the cars would be close.

 

theres no way it could run without the ecm ..... Unless the injectors were leaking. I guess it could run maybe because the cold start injector isn't run by the ecm but I highly doubt it alone could provide enough fuel by itself to run even fairly good. There is your critisizm !

 

Is nobody else seing the BS lie this guy is trying to pull off?

He said that the ECU was disconnected and that the fuel pump and injectors were wired to recieve constant 12v power, that means the injectors were all locked open 100% of the time from the time the key was turned on including at idle and part throttle.

He then goes on to say that the car still uses the TPI distributor yet still ran without the ECU in the car.

I had a few hung injectors when I bought my car and it barely ran, he's a lying troll.

 

the car ran respectable, the temp never got over 160 even in the summer, it was getting around 24 on the highway, the only problem i had mechanically was with the ac on, the car would run about 190 and the engine would dentonate if u hammered on it, probly due to the ditributor not having a ecm signal to advance it or retard it, i never got it to a dyno or a track, i had solid 0-60 times and i topped it out around 140( i had swapped in a 145 speedo

 

I know, just like to break down people's BS on here so they know that we know they are full of it......and hopefully will only post good stuff in future.

 

u guys say what u want, im not feedin u a line, im not after braggin rights to $h!T.
im mentrioning this bc, i wanna know if anyone else has ran a tpi as a sensorless injection system and had similar results, the car was by no means a badass, i just never understood why someone would have bypassed the ecm on the car! mebe tryin to cheap out on buying a ecm and prom?

 

interceptor

do u have any numbers on ur stealthram yet? i have a similar setup in my 86, jw how well it runs

 

as i said gentlemen: criticism welcome

 

The injectors are grounded through the ecm to open. So by wiring 12 volts to them which isnt necessary anyways since when the key is on 12 volts is fed to them. So if he removed the ecm and still had his 12 volts, there is no way the injectors could open .... This could be the guy that bought that TPI system and added a carb to the top of the plenum and that explains why it runs with no ecm (don't know if you guys remember that TPI system on ebay)

 

Well my stealth is ported and port matched, so it flows better than from factory, but it has power through the entire power band, and tons up on the top end.

 

tpi with a carb? wtf! i only found the fp and injectors wired to the ignition, i didnt look any further, when i replaced the motor and fixed the wiring, i got a new 870 ecm, prom and calpack, and it ran ok, didnt twist the rpms...but it had a lot better throttle reponse

 

i see your running procomp heads, i went with the rhs proaction 200cc, they came with 7/16 studs, didnt really want em, but i ran with em, my hsr hasnt been ported, runnin the same bbk tb, i went with longtubes on mine (what a PITA!) had to pull the motor 3 times, but there in, gonna run dual 2.5 and dump in front on the wheels no mufflers or cats required in this state:P

 

You cant run a computerized system like that sensorless. Your post makes no sense. Either you're lying or you're mistaken.

The ECM doesnt hold anything back either. It's the runner length. The system is tuned, via the intake manifold's actual components, to make power up to 4000-4500 RPM and make gobs of torque. The computer cant just automagically make it flow more air even by being disconnected.

The ECM controls the spark timing, the fuel amounts, etc, but one thing the ecm does NOT control is when the transmission shifts. The ECM has NO effect on shift points.

 

i think the stock tpi setup works well..but much more on the 305, i just have trouble on dynos seein more than 325hp out of them even on a 350, it was a toss up between the hsr and the miniram III, but damn start comparing prices....the hsr's more bang for the buck

 

then what would have caused the tranny to hold each gear so long? weights on the governor? i was taking off with the shifter in drive

 

Throttle valve (TV) cable is set incorrectly. The throttle valve cable adjsuts shift points and clutch pressures. If it's shifting that late I'd be worried about how much damage you've been doing to the clutches in there.

 

how do u post images that are on your computer?

 

the tranny lasted til 208k, had the fluid changed in may 01 at a quicklube, they put type f in it, the next day before i made it to town, it was slippin at anything over half throttle

 

i just took a cpl pics of the harness where it was spliced back together

 

No ECM means no pulsing of the injectors. You can't just bypass the ECM and "feed 12V" to the injectors like that. This guy needs to study the electrical diagrams in his car and better yet, just take the whole electrical system apart, all sensors, wires, dash, etc. like I had to do in order to get my car to run when I first bought it. After 3 weeks of checking everything and learning about FI from the fine folks in these forums, I found out that the problem was the ignition switch on the column was broke and only sent partial positive current to some accesories, except the ECM. I had ignition, spark, fuel pump, and good fuel pressure in the rail, all except FUEL INJECTORS!!!!! Hello?????

 

It's not the ECMless of the car that he's BS about it's the performance.
Why regress to ECM control and lose all that performance?
Anyone on this forum who doesn't take his car to a shop for anything other than machine work knows that permanently grounding the injectors will burn them out, and if they're not shorted to ground they won't fire at all (as has been stated) not to mention that it would immediately flood and hydrolock any cylinder with an intake valve partially open if the ignition is left on without starting the engine.
The distributor will work it just won't advance as he has graciously admitted.

This is how I'd do it, not saying this is how it was done:
Cooling can be reverted to a clutch fan, as well as spark/timing using a non CC electronic Dizzy. Then there's mechanical fuel injection which has been around for years.

But, if we stick with the present - injectors need electronic control, and therein lies the rub.

I personally don't believe it.

 

Maybe the poster means running "open loop" as oposed to ecm less. Most ecm's run open loop at full throttle anyways. Could be there was a wiring problem so the original owner McGyvered some wiring but left most (some?) connected so the ecm was still controlling at least the injectors and reading the TPS. Since the ecm fires the injectors by grounding them, running +12v to the injectors would make no difference. I am assuming the 12v was controlled by the ignition key or the continuously running fuel pump would require a very good battery.

Probably repairing the wiring and or the tachometer driver circuitry caused the tach to start reading normally when the 305 was swapped out.

"the car NEVER had an active service engine soon light" When I first started modifying my TPI car I took the bulb out instead of the ECM to get rid of that annoying light.

Performance is very subjective. My first "fast" car was a 1983 302 Capri. I did some work to it and me and my friends thought it was a fast car until one day on the highway a carload of beer drinkers in an old stock 383 Mopar pulled up beside us, waved and pulled away like we were standing still.

But this thread has got me thinking. Maybe I went the wrong direction in buying an aftermarket Dart block. Perhaps a lighter 305 block and some weight saving by chucking the ECM and the harness is the way to go. A stock tpi intake could make the stock block 2 bolt mains and cast crank more durable than an aftermarket splayed 4 bolt with a forged crank allowing for a higher redline.

 

haha redvette thats hilarious!! i didnt modify the car, i just drove it and fixed the wiring f*ck ups it was what it was!

the engine blew a headgasket on number 7 back in 01, the guy had the electric fan wired up to run n e time the key was on, the electric fan burnt up and summer heat took its toll in traffic i still have the harness, and posted this thread to get some ideas on why sumone would bypass the comp, and mebe get an idea of how it ran and why it ran better than stock, trust me, when the engine blew, i went with a nice balanced and blueprinted 350, if i thot the 305 was made of gold i wouldve rebuilt it,lol

 

I was surprised to notice nobody saw where he stated that he was able to hold 1st gear to 70MPH without blowing his engine

hotrod85, your just a troll trying to get a shock factor. The second your tranny downshifted into 1st at 70MPH there would be a loud explosion and all your connecting rods would be lodged in the fenders of both the car to your left and to your right.

 

I think hotrod85z has sniffed a little too much unleaded fumes. Here's what I think,
Let me tell you what happened to my 86 TPI MPFI IROC-Z when I forgot to reconnect the power lead for the ECM (meaning there was no power) ..... ABSOLUTELY NOTHING. It just cranked and cranked and cranked. I can see the lies coming out of your tail pipe, and I know your tail pipe is factory, not aftermarket. hotrod85z you are for wasting messageboard space. Go try to lie to some Mustang owner. Ohhhh, and have a TRUTHFUL New Year. Peace to all my honest 3rd Gen owners.

 

that's funny, let's see, 26 inch tire, 2.73 gears, 3.08 first gear ratio, even with no convertor slip, that's 8000rpm on a tpi, I don't know if I could do that on purpose. too cool for me

 

I was thinking the same thing. The ECM controls too many things for the car to run right if at all without it. If the injectors were locked open, then of course the car might run as the throttle assembly is mechanical. My money says that the car won't run worth a crap, and your gas mileage will go into the toilet. The car might also stall after a short period of time. If it started at all.

Too true. I tried to fire up my 1985 car which didn't run when I got it. (Still doesn't.) And too my surprise, the ECM was removed from the car. I had the same exact experience that you did.

 

also, doesn't the ignition control module also run through ecm, as well as the est..........so no timing or spark either, and running injectors at 100 percent duty, burn them out. Also the fuel pump wouldn't energize either. I think everyone knows......and I'm throwin' a flag

 

Hotrod85z just needed to fix his tachometer.

 

And his speedo, along with whatever he used to get that 5.0 second 0-60.

 

LOL! Is he really banned? Cause that'd be hilarious.

 

Yes it does. A regular ICM has 4 prongs, our TPI's has a 7 prong ICM. The 3 extra prongs are 1. for ground 2 & 3 connect right into the 4 prong wiring harness that goes to the ECM.

 

Nope. He is not banned. But I think he with his P.O.S. 3rd Gen.. Man I feel bad calling his 3rd Gen. a P.O.S. because we all own one. I retract my statement. But I think we made him feel like he is no longer welcome. I guess he started his New Year with a bang huh.

 

If it is a 700r4 than you can adjust the shift points with the tv cable. It doesn't matter whether you have 1hp or 600hp. You can adjust it to your liking. Adjusted mine and it breaks the tires loose shifting into all gears. Engine has many mods though. I am guessing that his tv cable is out of adjustment. That would make it shift very late. Mine will go into second at about 60-65 with the pedal to the floor. I have to let off to stop the tires from spinnin. Mine is slightly over 400hp and a carbed 350 though.

 

I do think the whole tpi without an ecm is bs though. He just doesn't know what he has. He also said that he welcomes criticism which means he wants to learn. I believe that he spanked those cars. It is more about the driver than the car when it comes down to it.

 

Well his last post was on the 26 of Dec so Im sure that we got the best of him. Honostly, he should of came clean. I think hotrod85z just threw out junk onto the board to see if it would be possible before he went out and try the so called mod.

 

Well I was trying to be charitable. Of course a car with injectors will not run without the ecm controlling the injectors (except for a mechanical fuel injection system), but you can still get it to run open loop with a lot of the wires missing. You could wire 12 volts full time to the injectors and fuel pump and the car would still run ok, just the battery would die. You could set the base timing to 36 degrees and leave the B wire disconnected from the HEI module and run the car like it was a locked distributor.

A common fault with tachometers is reading too high, explaining the high rpm's.

To me the real question would be if you had a 305 that ran that great McGyvered, why wouldn't you run the 355 McGyvered as well. It would probably go 0 to 60 in 4 seconds and shift at 8000 rpm.

On another forum I have come accross people who say they run their injectors at 100% duty cycle at WOT with no problems and regular stock rods and cranks to 7000 rpm regularly as well. So some of what he was saying is, as MythBusters would say, plausible, just not all of it all together.

 

no one gets the best of me:P ive been finishin up my 86 hardtop, so i havent been online much.
i said criticism welcome bc i drove the car for a few years and didnt know what was wrong til i blew a head gasket and pulled the motor down, when i went to put the chips in the ecm for the new engine i found a bunch of $hit bypassed, mechanically speaking, i dont understand why anyone would go to the trouble to cut n hack wires! its so hard to find one of these cars that hasnt been hacked up or stripped down for a carb setup
i have 5 thirdgens in the yard including my totaled 85z, and only one is in excellent original shape, an 88 350 maroon iroc, HELL, the purple 92 rallysport belonged to the local village idiot, he ripped the complete harness out under the hood, and had HOUSE 110v electrical wiring ran for his starter and alternator!!!

instead of swapping the sending unit out for a carbed one, he cut the carpet, the sheetmetal, AND ripped the sending unit out, he had 3/8 rubber fuel line ziptied under the car up to the engine, dont light a cigarette inside, BOOM! the gastank is open inside the car! oh well at least the body is straight as a pen...

 

lotsa good points redvette, i honestly dont trust stock rods, even pm rods, past 6500
as far as the 'McGyvered' 355?

i did run it for a lil bit, and it twisted tight too, but u could tell it wasnt running right, not enough low end and too damn rich! i corrected the cut n spliced wires and got a new ecm, and a 85 vette calpack and prom, the car didnt twist as high, but DAMN! it had ALOT more lowend nuts and shifted around 5k on its own. when ur used to a 305 tpi and u drive a 350 tpi, damn u just never want a 305 again!

 

First thing first, after blowing a head gasket, if you decide to get the motor out, it's usually called "pulling the motor out," not pulling the motor down. Usually when somebody buys a car, there is the common vehicle inspection. Obviously the local village idiot who sold you the car made you look like an idiot here in this board (70 mph in 2nd). What a joke . Sounds like a few of us got the best of you.

 

first off in this state we have no inspection, no emission testing and i gave him a 100 bux for the car, no emissions: no smog, no mufflers, hell open exhaust if you want, and u can think what u want, i just stated what the car was doing when i had it, and the fluke i found in the ecm and wiring, u can all say bs if you want, cause i dont have the 'McGyvered' wiring on the car and if i had even been on this site at the time i would have took pics and videos, yes the stock guages are known for being a lil off, i was 17 and in highschool at the time, i kept it clean and tuned it up, the only mods i ever did were k & n's a flowmaster, and gutted the airbox.
i appreciated the INTELLEGENT comments and criticism, after joining this site a few years ago, i talked to ppl like traxion, and quite a few others who KNOW what they are talking about and finally understood how the tpi system works,

when i have a question: this is the first site i search or create a thread on,because most of the 3rd gen owners on this site are very helpful

Kudos to them!! to anyone who badmouths another member...

know what your talkin about before you blurt out "thats BS!"

i have no reason to lie just to impress any of you, theres lots of sick@$$ fast cars on here, if you didnt know how to work on your cars, when they break down youd all be drivin new mustangs,lol were all on here to post, learn and share info gentlemen