My engine is on it's last leg, and instead of redoin a 305 I want to go ahead and do a 350. I can get a 350 for $350, and I want to retain the factor TPI intake. I think I need new injectors (22lb for the 350), but what about the computer? Is there a chip I can get or do I need a 350 computer? Thanx
Wes 87 IROC-Z 305 TPI

 

You will need a new Memcal (aka chip) a knock sensor and 22lb injectors for the 350. You will NOT need a new computer, they are the same for the 86-89 MAF cars.

 

What's the best place to get a Memcal (or chip) and how much is it?

 

Also where can I get 22lb injectors? All I found are 21 and 24lb injectors. I looked at Summit and Jegs.
Wes 87 IROC-Z 305 TPI

 

I am not disagreeing with LSI his advice is good but you can get away with the stock chip, computer and probably the injectors especially if the motor is gonna be mostly stock.

I did a swap a couple years back and had every intention of getting a new chip. I put in 24lb injectors and left the rest stock. I did a 355 with AFR 190's and Superram. H3eaders/gears etc. And the car ran great. I probably would have been better off with a custom chip but I ran out of cash.

If you stay basically stock I would say to stay with your stock computer chip/injectors. Get a custom chip if you have any drivabilty problems/hard starts/ or bad idle.

 

i'd say go with the 21's and slap an adjustable fuel pressure regulator on if the injectors are a good price....

 

Just remember, if you have 24# injectors w/ a stock PROM, the computer thinks you have 19# Injectors, and your going to Run Mucho Rich.

Depending on the combo, It may just happen that the extra fuel deliverd by the 24# injectors is pretty close to the extra amount of fuel needed by the more agressive combo, But thats real hit and miss and Not a great way to do things.

A Mild 350 should run ok on the stock 305 Stuff ( other than KS )

 

Just slap them in as jeff said

ha
Aj

 

No it won't run rich, thats what the O2 sensor and computer are for. If it starts to run rich the computer will narrow the pulse width for the injectors and if the condition lasts for a while (15 seconds or so I think) it will "learn" the new pulse width and use it from the get go. Learning computers are wonderful.

~M~

 

Wrong.

During initial start and warmup...ECM is in open loop mode and not learning/adjusting anything...as well as WOT where it's also not sampling the O2 sensor or making adjustments.

Also be aware the ECM has limits to how much it can "learn". When it dials down the Block Learn Multiplier to 108, that's as far as it goes. You'll run pig rich.

So, if you don't mind fouling up your cat conv, O2 sensor, plugs, etc, go ahead and use 24# injectors with software set to 19#.

 

Learning computers is wonderfull, maybe you should do it

 

By the way, best spot probably for the memcal/knock sensor is gmpartsdirect.com

 

well just switch the 05 in 305 and you get 350...leave the TPI part alone and you got it

 

I know I m going to catch heat for this but look I know many of people who have done this swap, and couldn't get the car to run right, there something about the computer, You have to go to a 350 computer. I don't know what it is about it, but they even tried just swapping in a 350 prom from chevy, into the 305 computer and it wouldn't run right. In fact it ran when they ran it with the 305 computer not good, but ran and then put in a computer from a 350 and all the problems were sloved. I have seen this on two different swaps for TPI and TBI. both were 305 to 350

 

Getting a lot of mileage on the flag today. I'm running an ECM from an '89 Beretta V6 pulling 13.5 @ 105 in the 1/4mile. Before that I was running an ECM from an '87 Pontiac Trans Am that had a 305, pulling 13.2 @ 102. And I suck at shifting.

If swapping ECMs cleared the problem, it was either a defective ECM or a poor connection.

 

I did the swap from a 305 to 355 TPI and when I first did it I used the 305 knock sensor, 24# injectors, and the stock 305 computer chip. I was running my fuel pressure at 36psi and was getting 20mpg as well as very nice performance. Then I decided to buy a aftermarket 350 chip from Ed Wright. I replaced the chip, changed to a 350 knock sensor. Now I'm running 40psi and still pulling down only 20mpg and roughly the same performance but I had to retard the timing due to too much timing in the Ed Wright chip. I need to burn my own chip, but that's another topic all together. Basically from what I've noticed, when switching from a 305 to a 350 and keeping the engine "basically" stock you could definitely use the 305 knock sensor and the 305 chip. My setup is not what I would consider "basically stock" and I noticed very minimal difference going to the 350 knock sensor and the 350 chip. I've even used my AutoXray with both setups and not noticed much difference in those readings either.

My opinion to you would be to just swap the engine and slap in whatever injectors you want, and adjustable fuel pressure regulator and just leave it at that. For that matter, I know several people that are running 19# injectors with their 350s and not maxing them out.

 

Kevinc,
well like I said that's what I've seen from 3 swaps, from 305 to 350, so if you disagree thats cool, and I knew I would catch for but it doesn't hurt my feelings
Well anyway good luck with your swap

and this one is for you Kevinc:hail:

 

I don't disagree with you, the documented facts do. I just pointed it out.

 

I just did this swap and am still running the 305 knock sensor. Also the 350 and 305 computers were the same in my year, just the PROM is different, and I'm still running the 305 PROM, things run just fine.

~M~

 

What are your BLM and knock counts?

 

Considering how cheap and easy it is to burn a custom PROM i don't even pretend to give people advice on how to do swaps by hacking and kludging.

If you want to do **** the wrong way thats your prerogative, but please don't advocate it as a 'correct' solution. We know so much more than we did just a few years ago that no matter what might 'run' the car, there is a definitive correct answer...and that is, if you want to get into modding an injected thirdgen you just can't ignore the chip and kludge your way to it working. Thats how we did it 5 years ago, back when TPI was the TBI of the performance world. Now that we know more there are a lot of great cars out there putting down great power.

the only engine swap you can do without a chip change is if you have a MAF car and you keep your stock injectors. The MAF computer does not know engine size, just airflow and injector size. So if you are using stock size injectors, use the corresponding stock chip.

Every other engine swap it should be considered mandatory to burn a chip for. If you change injectors on a MAF car without changing chips, your fueling will be way off. If you change engine size OR injector size in a speed density car your fueling will also be way off.

Occasionally with dumb luck and the alignment of the stars in your favor you can get away with using other tuning tools, but honestly it's just plain stupid to waste your time with that when a little more money to do it the right way. If you're trying to make power on the cheap, get a carb. If you want to make power with fuel injection, consider prom burning and a scanner the cost of admittance. It does not cost that much money, and it makes everything about it that much easier. If you 'ran out of money' after buying heads/cam/etc then you had your priorities out of whack. I'd rather have a properly tuned car with less go fast parts then a hacked together tune on great go fast parts....

edit...thought i'd add, the 305 and 350 TPI cars all used the same computer in any given year. Any problems fixed by swapping from one to the other HAD to have been a defect in the ECM(s) in question, PERIOD. 5 years ago we might have thought you were on to something. Today there are a lot of us running non-stock ECMs, in fact most PROM guys in the know are running or have spare ECMs from V6 cars that shared ECMs with us. For example, I am also currently running off a 730 from an 89 V6 car as kevin is. An ECM is an ECM, there are no differences that make them specific to engine, or else they would be different part numbers.

 

Just for clarification purposes. I said nothing about what I said in my previous post as being the "correct way". I just simply stated what you "could" do and it will work just fine. Some of us just aren't as rich as the rest of the people on this board and yes, $150 to start prom burning is ALOT of money to some of us. I don't know how many times I've tried explaining that but I guess all the rich guys are too thick headed to understand. Just my .02. I'll get off the soap box now.

 

I don't know what to tell you 86 except that i'm sorry you wasted a bunch of money on an ed wright chip and now you can't afford the burning stuff. Or that you thought 24 lb injectors (or the AFPR and prolly a bunch of other detail stuff) were more important than having the set-up as least close to right from the start.

You don't have to be rich to do things the right way. You just have to think them through. And it's hard to get things straight when you have people offering bad advice like "My opinion to you would be to just swap the engine and slap in whatever injectors you want, and adjustable fuel pressure regulator and just leave it at that. " - Everything about that sentence makes me cringe. Unless they are lucky or already know what they are doing they stand to lose a helluva lot by taking that advice. FI being off is not like having the wrong jets in a carb. You can easily have WAY too much or too little fuel to the point where immediate and permanent engine damage could result, and thats not even mentioning non-optimal power and efficiency.

I'm quite aware of what can be gotten away with on a stock chip, like i said, thats where we were over 5 years ago. Nowadays it is so cheap and easy, if you can afford to buy injectors or a cam you can afford the PROM stuff. Would you buy a bad *** roller cam and use el-cheapo springs. Would you build a 450hp engine and run junkyard special tires? Then why would you buy go fast parts or a hot engine and then try to run it by kludging your fuel delivery? PROM stuff should not be looked at as unnecessary and extra, it is not just something for 'rich people', it is a FUNDAMENATAL part of modding fuel injection. Like i said, if you want bang for the buck, run a carb and be done with it.

 

Well, unfortunately, I didn't know about the importance of prom burning prior to the $3000 (income tax money) worth of work I put into my engine. Now I'm stuck and dealing with it the best way I can. That's not anyone else's fault but my own I guess.

 

Got a timeslip?

 

$150 to start PROM burning versus how much for an Ed Wright or other chip? (hint: slightly more than $150)

I don't know how many times people have tried explaining that but I guess all the #$%&@ are too thick-headed to understand.

 

$149 for the fastchip when I bought it. Same price. Get your facts straight before you open your mouth and make yourself look like a jack@ss.

 

So...that extra $1 makes people who burn chips "rich guys"?

Someday when you graduate from middle school this will all make sense.

 

You obviously enjoy this and I'm not going to waste anymore of my time on you. You're probably one of those B!tch boys anyhow that had mommy and daddy buy your car. You're all alike.

 

nope, engine just turned the magic 500 miles for break in and there are no drag tracks here. Also, WTF is so *** all mighty impressive about a time slip? I didn't build my car to be a 1/4 mile monster, I'd rather have a car that can easily go 140+ MPH than one that can run the quarter in 11.5 at 120 MPH and be topped out in speed there.
My engine runs fine, gets 20+ MPG, sounds good, and will plant your butt in the seat from a stop light without kicking a code. I'll leave the 1320 to people like John Force.

Over or under fueling? Not really possible with a properly functioning O2 sensor system. Scanner? No thanks, I have done without one for the 17 years I've been playing with and modding this car, don't think I'll need one now unless I do decide I need a custom burned chip, then it would be something more useful like Diacom's software or something as good.

Sorry if this comes off as snide but I have owned and worked on TPI since it was first avialable in my '85 IROC and have heard everyone from dealerships to shadetree mechanics say that you can't repair or mod TPI without a scanner and I know from expierance differently.

~M~

 

Wrong again, I have 24# injectors in my 350 running a 305 chip and it does not run rich at idle or WOT. Because it CAN does not lead to it WILL

~M~

 

Typical, someone disagrees and it turns to insults.

~M~

 

you were incorrect.

 

No-one is saying you can't work on a tpi without a scanner, but we are saying that it isn't a very good idea. It's kind of like building an engine and without a torque wrench and guessing how tight you have the bolts. You might get lucky, but do you really want to take that chance.

How do you know that you aren't running rich if you aren't using a scanner? Yes under or over fueling is possible with a properly functioning o2 sensor owing to the limitations of that sensor. Don't attempt to justify your own ignorance by simply referencing a running car. GM did their best to make these cars idiot proof, and it looks like they did a good job.

When changing from a 305 to a 350,with regard to the knock sensor, you need to use a scanner, and here's why: The 305 and the 350 knock at different frequencies. The crytal inside their respective knock sensors is calibrated detect knock at their respective frequencies. You could, very possibly, pick up false knock readings when using the wrong sensor. Furthermore, knock sensors are installation depth sensitive. If not installed at the right depth, the readings will be off. The only way to check for knock is to use a scanner.

 

And more insults, how mature.

 

wow. settle down guys....you're still a thirdgen'er no matter who bought your cars,lol i paid for mine and i dont care if someone else had their daddy's buy them for them. if thats how they got it then thats that, happens all the time aroundn me, i used to bitch, now i dont give a **** cuz mine will be faster than the daddy bougth mobiles,lol

 

kevinc, and tpi_roc

Sorry guys, I was wrong my bad fellows

 

Since this thread is starting to lack technical content I think im going to let it sink to the bottom.


Sorry wes