i was talking to porky and bennie today and porky was telling me that TPI is like cave man injection, were the 4 injectors on each side of the block fire at once, unlike sequential injection where each different cylinder gets a squirt in an order at different times. somone explain this **** to me, i logically first thought that the engine would be rocking from side to side like all the cylinders were firing at the same time (obviously not, but the way bennie described it made it seem as if it were that way)

i will be waitng for bennie and eric to chime in here about this, as well as anyone else who can explain this.

 

what the hell.........okay dude, come over again tomorrow for more tech talk. Bring your pencil and paper to take notes. Just to stir your mind a little more....on a carbureted engine, all cylinder get their fuel delivered at the same time..hmmmmmmmm.....now what

 

Correct me if I am wrong, don't ls1/lt1 sequential fire have a batch fire mod for full throttle?

 

haha. good stuff.

I don't know about "cave man" injection, I would consider TBI/CFI more along those lines.

I'm not sure what you're asking man, but it sounds like you kinda got the idea already.
The main difference between TPI vs SFI is this to me:

TPI - Has 2 firing circuits in the ECM, one for the front of the the cylinder and one for the back. When you fire it up, the front injectors spray at the same time to their intake valve.

SFI - Still 1 injector for 1 cylinder, but each fuel injector has 1 firing circuit, which can open just before the intake valve for its cylinder opens, making it a quicker response for this type of system, better emissions, power, etc.

So, what's up with your GTA?

 

His engine is rocking from side to side, time to sell the car.

 

Del, your TPI injector explanation made no sense to even me. What the hell is the front and back of the cylinder?

 

my wrenching knowledge is limited i know... but i agree with with trav *scratches head*

 

Well mine is even more limited I'm sure, I guess I'm more of a book knowledge kinda guy, maybe I coulda worded that better. hmm.

 

Basically, the ECM isn't smart enough to fire each injector individually, so it fires 4 at a time, and the fuel waits above the intake valve until it opens and the rush of air pulls the fuel into the compustion chamber. Its called batch firing, a batch of injectors fire at once. Because only 2 intake valves are open at a time, and at least 4 others arn't going to open up right away, so it is possible for the others to be fed fuel and wait until the respective valves open. Sequential is just the opposite, as was explained before, each injector fires at the opening of the intake valve, it provides better atomization of fuel, better efficiency, etc. Batch firing is not the most effecient system, but it does work. Does that make sense? Or is further explanation required?

 

I understand how it works, one bank fires, then the other, left side, right side. I have heard that even newer vehicles are having the injector spray on while the intake is closed, so the fuel burns on the back of the intake valve and makes a better vapor.

 

isnt that just valve overlap?


no its not never mind haha

 

yeah, atc3434 your explanation makes sense, but wouldn't there be problems if there is gas sitting on top of the valve waiting to be let in?

i went to bennies shop to run a diagnostic on the bird. we tested the injectors: 4 were 17 plus, one was 9, two were 7, and one was five, therefore i am ordering a set of new ford injectors.

another question, can i put 30 lb/hr injectors into my stock car (with stock computer)? will it not run right, some people say that the computer will think it is 22 lb/hr injectors and run rich/lean, and others say that by just bumping up the fuel pressure that it will be fine,

and the reason why i am asking is becuase thorugh eric it will cost me $320 for 24 lb/hr ford injectors, but through hawks( which i am ordering other parts from them soon) i can get bosch 300 lb/hr injectors for $290, and yes i want to save that $30 if possible.

 

It will not run properly at all without tuning and 30lb'rs.
Even with 24's it would not be optimal without minor ECM adjustment.

What're you ordering from Hawks?

I just bought a set of 24# blue top Ford Injectors for $230 off eBay.

My current set are perfectly fine Five-o Motorsport 22lbrs if you're interested.
I'll probably sell them for $100. Save yourself $200, you don't need bigger injectors.

 

If you are stuck on fords, summit sells the 24's for 290

Ford Racing High Flow Fuel Injectors: FMS-M-9593-A302 - summitracing.com

 

Damn, I'm looking to buy a set of Ford 24# Blue Tops but I wanna pay much less than that. Like, $120

 

I'm sure you can find 1/2 a working set for that price, heh.

Looks like I've got some interest in my injectors from a couple parties, so those 24# blue tops might be going on mine sooner than later.

 

why didnt you have bennie put on those injectors when he did your heads??

 

Why didn't I bang more girls when I was 19 and single?

Hindsight is 20/20 son, just how it goes sometimes.


edit: Got the part # for Bennie's diz gear, it's on the way to him. (owe me about ~$15 off my tab next time)

 

Del . No problem on the $15 off you tab.
When are you bringing the Silver Bullet for the mod. How bout the BIG air pump that flows more than 1000cfm, is it going in also?

 

Del grab another unit?

 

Haha, I wish.

I want to pick up that Racetronix high-pressure Walbro pump with the easy-install plug/play harness first.
I'd like to knock out both fuel items at the same time.

Sucks to have to take the intake off again, but I think the 24's are must-do.

 

Why or who told you that you need to replace the injectors again? Have you checked the duty cycle of your injector at full thottle or at least calculate it?

 

I don't really need to replace them, they are sufficient for the power I'm making now.

You know me though, I like to plan ahead for the future.
Even if I never use nitrous/blower in the future, only minor adjustments need to be made in the tune to have the ECM accept the 24's.

Yeah I calc'c the approx DC now.
[22 x 8 x 90%] / 0.50 = 317 Hp (flywheel)

Which is probably just perfect for where I'm at, now.
24's would actually be working too hard if I were to use a blower, but still do-able.

 

If I can get jeremy to read his PM's over at 3go, I am trying to set up a date to pickup his umm.."BIG air pump".

 

Did he finally give in to sell that thing? $2000?
It's the older p600b, but I'm sure it will do the job for you.

 

Ya I got the confirmation about a week ago. 2k And its mine, I will have the change for that within 2 weeks. He just needs to read my dang pm's LOL. I want to get it in my hands so I know for sure how to rework my engine build for it.

 

A**HOLE TRAVIS!

 

Sorry steve! I love you.

 

I figured that'd be the only way you'd get one.

Steve was trying to get his last year, but the guy was too indecisive.

I sold my P600B for $2300, so that's a fair price. What does it include?

 

n/m on what it includes, i found an old post.
9 & 12psi pulleys and 2-core intercooler, same as mine was.

 

Except you sold yours!

 

Everything happens for a reason.

I'm going to have to strap on Bennie's nitrous and magical chip to keep up with you youngstas, hahaha.

 

You keep that kind of tone, and I am going to start calling you pops.

 

 

Theif, you hotlinked that!

 

 

It's ok, I steal them from 3go all the time.

 

 

 

Koolctk- You probably don't need anymore unasked for advise, so just skip reading here if it dosn't reply. I purchased a set of the Ford injectors and at the same time ordered my prom chip from PROMSforLess.com. (this is for my 88 IROC L98 engine).
I have yet to install the new injectors but the chip went in about 3 months ago and made such a sweet difference even though it thinks I've got the bigger injectors running; the smoothness, the power, the increased fuel mileage, the better midrange and shifting points, wow!!!

It sounds like money is tight for you, and we all know that the factory injectors have a limited life span- just think about the cheap Prom chip while you're working through the project.
Hope that wasn't a waste of your time, Nitro

 

thanks for the info , nitro. since you got the chip, tell me what exactly it did for your iroc (your mods), cost, and if they could incorporate somthing for nitrous in there?

do you have a shift kit?, i just ordered mine but dont know if i really want it, especially if it said that you got better shifts anyways because it changed the shift points.

 

Unfortunately, I'm really over busy for the next couple days and don't have time to give your question justice. What I'd suggest is to go to the PROMforLESS web site and 'pretend' that you are ordering an new PROM. What that will give you is access to their web page questionairre that goes through a huge list of potential areas you want to change or 'improve'.

I spent a great deal of initial time just taking my 88 IROC from a mechanically neglected (but not abused) ride into just getting it to run consistantly, smoothly, and all the worn out parts replaced.

Initially I spent time diagnosing what turned out to be that typical '9th' injector (cold start injector) issue, gave it a thorough tune-up, took the TPI intake completely apart to clean all the black grunge build-up off of it, set the throttle position trick, basic fluid leaks etc. Since I pulled the 9th injector I had to get a new PROM anyway for winter/cold driving.

Even after doing the full 3 inch exhaust, the TPI airfoil, intake cleaning, fuel presure regulator, some sensors, full trans cleaning and service, top grade tune-up parts, it still ran really inconsistant. It would do the 1/4 mile in a full 2 second varience and I was pissed and frustrated. Once I plugged in that PROM it idled way-way smoother, my shift points were clean, crisp, and consistant, and my horsepower was suddenly not varying. That's about all I can share with you for the moment because I've got to run and break up a family fight!!!! I'll try and share more later. Best of Luck, Nitro

 

Well I'm back at home finally- It's been one of those months when everybody else has an emergency and they all want you to solve it for them????!!!

I certainly don't need a shift kit in my tranny now that it's runnning so consistantly. My trans is probably near the end of it's life cycle with 150k on the odometer. Oh, that reminds me; one of the things I did at the same time I got my new PROM in the mail was have my 'TV' cable adjusted correctly- THAT made a significant difference also. It's something that is in our repair manual so we can do it ourselves, which I did do, but it's usually something that a proffesional should adjust as if it isn't correct, it can really destroy the 700R4 tranny's quick.

When I got my IROC I couldn't even burn out on wet asphalt. The car passed California Smog with flying colors, but it sure ran rough and lifeless.

I'm having a proffesional NASCAR Truck engine guy put together a new mild (340-360 hp) small block for me. I'm slowly replacing the entire brake system and suspension, seats, etc. My goal is to make something that will fly across country with comfort rather than a stop light bandit.

I did hand port the factory plenum, but this month I bought a new edelbrock intake, SLP runners and sent the plenum & runners off to Mike @corvetteplenum for his magna porting services. Supposedly, it will move as much air as the Accel intake, while still appearing factory and not alarming the smog ****'s.

My ride came with the Borg 9-bolt rear end with 2.77 gears. There are a couple people who are running the tall freeway gears and still running into the low 13 seconds in the 1/4. I'm not going to change them till I put in the new engine. I want to be sure I can launch out of the corners sideways along the ocean back-roads, so I don't want to mess with it until I have a better baseline understanding of how the new drivetrain harnesses all the fresh torque.

My last car was a Lexus SC400 V-8. I'm attempting to duplicate it as best I can with the Camaro. Although the SC was a really sweet and sophisticated ride, it was limited to 200 horsepower and no one has a supercharger designed for bolting up yet.

So that's what I doing for the long term plan. If you have ANY more questions I can answer just let me know. Most of the guys on the West Coast board, such as Travis, are great people and a hella' lot more knowledgable about the Camaro platform than I'll probably ever will be. Definitely go to that PROM site and read through the questionaire; I think it does deal with the Nitrous issue there. If I can get this Beaver Black Bitch Bomber dialed in by next season's drags, I'll head up to the Sacto raceway and meet some of you in person. I'm only about 45 minutes away from the Infinion Raceway which probably is close to the time it would take to just drive up to Sacramento.

Keep the Radar Detector fired up and the stereo hidden;
Nitro

 

Don't know who this ^ guy is, but he's OK in my book.

I like a good thorough post.

Sounds like your ride was really out of whack and needed a good baseline tune.

Hopefully you can make it up to Sac next racing season.

 

Sac is an awesome track. And I am glad you know what the hell you are doing Neagen, that is the most important.
btw, (nice sig)

 

Hey Travis, You recognized the sig, eh!!! It's not like I 'copied' yours as the basic format 6 months ago! Do you remember the old Jeep/GM/Buick dealership that was East of the Stancil's Toyota dealership?? I got a job there selling cars so I could be near my girlfriend. The owner was such a dishonest cheat that I eventually took a bunch of documents to the DMV investigators and helped start the process of shutting the place down. They were rolling back speedometers and all kinds of crazy crap. Of course, being so ethically minded, I didn't turn out to be such a great car salesman but did learn an awful lot about how to buy 'em for much cheaper than list price.

It was close to the time I finally descided to never own another Camaro ever again unless I didn't have to drive/depend on it; they were ALWAYS breaking down and GM wouldn't honor basic warrenty work. I sure miss living near there- always wanted to buy a house outside of Pollok Pines (sp?) where the snow line stayed somewhat friendly... What part of Placerville are you in? Nitro

 

I am right down town, off a side street of main street. Near marshall hospital.

That's awesome you put the owner in his place! Stancils is not around as well anymore.

 

Hummm so you're getting a blower... I was going to do that changing my plans again muhahaha