thewhitestripes

So I'm in the the middle of doing a 305 to 350 swap an everyone says I definatley need a 350 prom but my friend just did the exact same swap in his Chevy truck and he just ran it with the 305 computer for like 3 days, disconnected the battery and reconnected it one morning and it ran fine. Is it worth even trying this? And if not has anyone ever heard of fastchip.com? Looks like they have what I may be looking for, I'm just trying to save a few hundred bucks.

Orr89RocZ

iTrader: (20)

Depending on which bin is in the 305 prom it may run a 350 ok, if its a stock 350. The MAF cars can tolerate some basic changes like that and still run ok. I've had mostly stock 350 bins run 383's and 400s a big cam heads 360" motor. A 305 should handle a stock 350 ok. Just wont be optimal. YOu can keep your ecm and just order a chip for a 350. That would work ok but you may want to also get a new knock sensor for a 350... I know there are 2 different part numbers for them for TPI cars

Or you can shop around here on the classifieds... I'm sure someone has a stock prom for a 350 car. TPI right? MAF sensor?

thewhitestripes

Yea but I'm keeping the t5 and all tpi350 had an auto trans. Will it make a difference?

Chevy86 IROC-Z

iTrader: (17)

Might I make a suggestion.. This guy right here did a few tunes for my 86 Camaro. He burned a few EPROM's for me with various settings. Some things that where changed was the EGR Error Delete, lowered coolant fan turn-on, and removal of the VATS settings. So now Im able to run a 89 TPI 350 bin that had VATS on my 86 TPI 350 Camaro...
fd5f6b82.jpg?t=1341362055

Orr89RocZ

iTrader: (20)

It should still run ok if using 305 manual bin. Even if using 350 auto bin i would expect it to run ok but may not be optimal. I know my buddy uses an auto bin for his manual swap.

If you could do your own bins there are vette 350's with manuals. Similar to arap bins but configured for manuals. Could have a chip made for that

Chevy86 IROC-Z

iTrader: (17)

Let me get a friend into this. Perhaps he can help out.

Tuned Performance

iTrader: (92)

arar and arap will work well even thought the timing table have more advance than aujn or similar bcc. A automatic bcc will work fine with a manual trans but when switching bins you may need to pay attention to the coolant n/o n/c selection and vats selection when going to $6E. I would not run a 305 memcal on a 350 the lv8 tables are not the same and expected injector size is not correct for long term fuel trim correction.

Davidgou

iTrader: (2)

I don't mean to hack someone else's thread but I just did a 305 to 350 swap and installed the entire original tpi setup (including the stock injectors, computer and prom). The 350 is a stock '92 LO5 off a ZZ4 Silverado Truck. I also have an extra prom for a 350 but what's the difference between the 2 proms?

Six_Shooter

iTrader: (2)

All I'm going to say is that even a stock engine with a matching MEMCAL/PROM can benefit from a properly tuned bin loaded to the MEMCAL/PROM (or adapter with EEPROM).

Chevy86 IROC-Z

iTrader: (17)

http://tpiparts.net/305_tpi_to_350_tpi_conversion

Chevy86 IROC-Z

iTrader: (17)

The memcals have different programmed settings. 305 is programmed for 19 lb injectors while the 350 MemCal is programmed for 21 lb injectors and to recognize the difference in frequency between a 305 engine knock and a 350 engine knock. I believe there are other factors, but those are the major differnces between the 2. Do a search in the search field up above. Your question has been answered many many many times. You must search to find what you are looking for.

Davidgou

iTrader: (2)

Thanks! Very useful information.

Street Lethal

iTrader: (16)

If you pull the 305 in favor for a 350, you either need a new chip burned for the stock 19-lb injectors to compensate for the increased displacement, or simply run the stock chip but install 22-lb injectors. If you don't you will run incredibly lean because O2 correction isn't that broad on the early ECM's...

Chevy86 IROC-Z

iTrader: (17)

Even if you put 21 lb injectors, not 22 lb, you'll still need to reprogram the single fire and double fire rate to 21 lb within the bin file. If your gonna go that route, the. You might as well drop the the coolant fan turn on at 192* and off @ 182* and install a 180* thermostat just to keep the engine cool vs the factory setting of 220*. If you choose to remove the egr valve, you can do that too so that you won't get the ses light on (egr setting programmed as maxed out). If the vehicle has vats, that can be disabled too. Now you have 2 routes of getting your hands on the proper MemCal. You can buy a Moates G1 socket, piggyback the current 305 MemCal, and have someone burn you a EPROM with a 350 bin. Or you can buy a 350 OEM MemCal. If your interested in getting a custom MemCal, I got a friend who has several ready to ship MemCals. Let me know and I'll have my buddy contact you.

Chevy86 IROC-Z

iTrader: (17)

Here is what my friend had to say about keeping the 305 MemCal with a 22 lb injector set......

"The duty cycle is at 85% with 19 lb fuel injectors with a 305 bin file. You can get them to flow more with higher fuel pressure but can risk a engine fire and the injector life. No real way to compensate for a small injector."

Regal105

a friend of mine done a 305-350 swap a couple years ago he swapped in a 350 swirl port long block with all the 305 intake all he changed was the knock sensor.... runs great

Street Lethal

iTrader: (16)

I can appreciate what your friend has to say, but your friend is wrong. First of all, the original poster needs it to run, he did not say that he wanted to maximize performance through VE and SA tables, he just needs it to drive after the swap. Second, the ECM doesn't know what size engine you are working with, it only knows how much fuel to release at a given point in time, and what the O2 reading is reading as the byproduct. From the O2 reading, the INT is either raised, or lowered to attain a 128 BLM reading. The stock chip is burned for 305 cubic inches of displacement and 19-lb injectors, and when swapping to a 350 (a swap in which the computer could care less about knowing, it only knows O2 readings), you need to install an injector that will help bring the air/fuel ratio as close to a 128 BLM reading as possible. Ask your friend how much of a percentage in air is being increased when swapping to a 350 from a 305, then ask your friend how much of a percentage in fuel is being increased when swapping from 19-lb to 22-lb injectors. The stock chip will do fine with the right injectors. I once burned and ran 24-lb injectors on my 305, swapped in a 350 with 28-lb injectors while I rebuilt the 305 and touched nothing in the prom, and guess what, maintained a 128-BLM...

Chevy86 IROC-Z

iTrader: (17)

I will not argue with you at all. You can go ahead and pitch all the wrong info which will allow to run a car, but not as efficient as it can. I'm here to help the correct way. Although I can give advice on the correct procedure to remove the egr system, I always suggest not to remove due to consequences. But go ahead and continue. I will not participate or engage in an argument that is contaminated with bad info. Have a good day.

Chevy86 IROC-Z

iTrader: (17)

Not an argument, but just a bit of my personal experience. Back in 2002, when I got my 86 IROC, I knew I had a 305. So I drove her until she threw a rod. It sat for a little over 7 years. When I finally yanked out the engine, I ran the casting number and it ended up being a 350 block. I was drivin a 350 with a 305 memcal, and it was fine. I had minor issues but nothing out of the ordinary. So yes, you can drive a 305 memcal on a 350. But you can still cause damage to your engine by means of detonation or ping. If you have a 350 block, with a 305 memcal, and a 350 knock sensor, the 305 memcal is programmed to sense the knock frequency of a 305 block. So if the 350 block is knocking, the 305 memcal is not gonna recognize the frequency of the 350 knock. So then the spark will not get retarded and engine damage can occur. Now I could be wrong about the 305 memcal not recognizing a knock from a 350, but until I'm proven otherwise, then I'll retract my opinion about the knocking.
One more question Street Lethal, explain how Whitestripes can maximize his performance through the VE and SA tables. I'm curious.

DJP87Z28

When I swapped my 305 TPI to a 350 TPI using everything that could from the 305.
The excecptions were 22 # FI, Knock sensor and a stock GM 350 TPI mecal for the RCM. I used the stock chip to get everthing up in running without some unknown variable. Everything worked, then I changed over to a new one from Fastchip and that was over 10yrs ago. The car is still running strong and I have NOT had any tuning problems over the years.

Chevy86 IROC-Z

iTrader: (17)

To make a long story short, 305 is fine, but performance will suffer.

Davidgou

iTrader: (2)

Nice looking engine you got there man!

CaliChevyLover

is prom the same thing as the computer? I'm confused

Chevy86 IROC-Z

iTrader: (17)

It's all good. Here we go:
1. PROM-Programmable Read Only Memory. The chip can get programmed only once.

2. EPROM-Erasable Programmable Read Only Memory. Can be programmed and erased many times.

3. ECM (computer)- Electronic Computer Module

4. MemCal (Memory/CalPack)- little blue rectangular box that houses the EPROM and CalPac chips. Sits inside the ECM.

People often refer to the PROM as the MemCal.

Chevy86 IROC-Z

iTrader: (17)

And the UV PROM sits inside the MemCal.

CaliChevyLover

So if I need to the change the prom, do I get a new computer? or is the computer physically separate?

Davidgou

iTrader: (2)

The PROM is installed inside the ECM. There's an access plate with 2 small screws that when you take it off you can take the prom off easily.

Chevy86 IROC-Z

iTrader: (17)

Wrong. The PROM is inside the MemCal. The MemCal is inside the ECM.

Chevy86 IROC-Z

iTrader: (17)

MemCal= http://www.lt1swap.com/pictures/memcal_before.jpg

PROM/EPROM= http://www.mcmelectronics.com/conten...s/s4/EPROM.jpg

ECM with exposed MemCal= http://support.moates.net/wp-content...move-cover.jpg

CaliChevyLover

Thanks!!!!

Chevy86 IROC-Z

iTrader: (17)

Yup.

Chevy86 IROC-Z

iTrader: (17)

Street Lethal, explain how Whitestripes can maximize his performance through the VE and SA tables. I'm curious.

92 RS Invader

iTrader: (1)

Looks like street lethal has gone AWOL.

Ronny

iTrader: (1)

Lots of good info here on why and how to tune for max perf

https://www.thirdgen.org/forums/diy-...uide-book.html

Above link is in stickies in DIY-Prom and also check out "free tune" on this TBI board. Lots of Q and A there.

Street Lethal

iTrader: (16)

Street Lethal has gone AWOL? Hmm, 4 posts of yours to my 5000 plus...?

A quick search would show you that Street Lethal has been posting in other threads, and doesn't wish to waste his time with a member who is not only parroting what someone else is saying, but parroting words that would have most scratching their heads in confusion. I will answer his "white stripes" question, but first let him invite whoever it is that he is consulting into this conversation as I will not waste my time with middle man antics...

dabird07

iTrader: (10)

lol this thread help me realize something

92 RS Invader

iTrader: (1)

I asked for an explaination. Not a timeline of what "Street Lethal" was doing.

EPIC FAIL.

Street Lethal

iTrader: (16)

I am not here to teach "you" lmao. You want an explanation (one "I") than do your own research like most of us did back during the beginning of the century. This thread was about a 305 prom being used with a 350 engine, and I said that it will work fine so long as the injectors are upped/matched for the increase in air. The ECM does not care what engine is in the engine bay, nor does it even know for that matter, IT IS BLIND, all it knows is BLM, and it knows this through O2 readings and it will correct accordingly. Example, if you install an engine that ingests 30% more air than the 305, and you add 30% more fuel with larger injectors, then the stock chip will work just fine. Mind you, it is not maximized for performance, but that isn't what the original poster was after. He just wanted it to run...

92 RS Invader

iTrader: (1)

Why are you getting so mad? I did investigate. But I couldn't find anything on VE. It was a simple question. But you made it such a big deal. I apologize if I made you uppity. But it's not a big deal.

92 RS Invader

iTrader: (1)

Hey Street Lethal, I found something out. You mentioned in an earlier post that the thread starter wanted to get his Camaro on the road right? Then you said that the poster did not wanna maximize performance through the VE and SA tables. Then explain how Whitestripes can mess with the VE and SA tables if he has an 88 Camaro? The 88 is MAF, not SD. VE and SA are on Speed Density only. Can you say FAIL?

92 RS Invader

iTrader: (1)

Correction. 88 MAF has SA and lv8, not VE.

87Iroc5.0

iTrader: (4)

Ok guys I have a question and the above posts helped out a lot but I wanted to make sure..I am swapping out the 305 TPI in my 87' Iroc and dropping in a 87'-91' corvette L98.. I was informed that I will need the ECM #1227165..the knock sensor for the 350, a ESC module for a 350,..22lb injectors. My question is about the Prom..what needs to be done with this?? and anything else I need to know that was left out?? thanks!

RBob

iTrader: (1)

Your '87 already has the '7165 ECM. Swap the knock sensor while the engine is out of the vehicle (much easier). Need one from a '88-'89 L98 engine f or y body car.

The ESC module you can swap at any later time.

Yes to the 22#/hr injectors. Will need a PROM that is set up for the injectors along with different SA tables due to the aluminum heads.

RBob.

87Iroc5.0

iTrader: (4)

Ok thanks RBob...is there a part number or anything for this specific Prom I will be needing?? and different SA tables???

Chevy86 IROC-Z

iTrader: (17)

Right here dude. On the very right side of the chart is the "F" for f-body (Camaro's and firebirds etc) and "Y" for Y-body (corvettes).

http://www.chevythunder.com/prom_bcc_1987.htm

You have a few different options to converting your Memcal/PROM to a 350. I would recommend you to pm a member that goes by "TunedPerformanc". He is extremely knowledgeable on MAF systems and programming. He has done multiple EPROM programming for me and the whole car club that I'm in. Everyone that had engine conversions to constant ses lights now are very pleased with TunedPerformanc's services. Good luck man.

87Iroc5.0

iTrader: (4)

Thanks for the info bro!...will do!

Chevy86 IROC-Z

iTrader: (17)

Glad to help out man.

Davidgou

iTrader: (2)

AMEN to that. He reprogramed mine and I'm SUPER satisfied with his work and his ethics. He deleted the VATS (which was my main problem), EGR code 32, lowered the fan on/off temps, and put a '89 Corvette tune in there so my car runs smoother and its just 100% better!!! I highly recommend Brian.

Tuned Performance

iTrader: (92)

Thank you guys for the kinda words and support

xch3no2

Just wrong period.

So are full page ads by your customers, lets someone have a talk with that fella.