anesthes

iTrader: (12)

The fact is, TPIS does not drive your car, scan it, program, drive and scan, program, and so on until its done right. We (the owners and burners of our cars) do!. So its not a guess, its a mathimatical fact that analysis is more accurate than guessing (which is what THEY are doing).

A PROM is a set of instructions and values that the car runs on. THey must be matched to the car. TPIS doesn't have any special magic routines that make the car run better. THey just guess. I don't like guessing.

-- Joe

REDZ28

So I guess the wideband Dyno and Diacom Info they sent them didnt give them any info? Not to mention info about engine, trans and rearend! I guess all this isnt important information when making a chip. If TPIS was guessing, why would they ask for all this info? Sounds more like your guessing on how they determine programing for a given vehicles prom!!

lykan

He's not saying the TPIS chip doesn't do a Decent job.

What he is saying is that to squeeze the last bit out of programming, and do it right, you need have access to the car, and real world logs.

Not saying that a dyno isn't real world, it gives a great starting point to base a chip from. But it doesn't give you the reactions the car has when you're on the street.

Tha being said.

All cars react different. With a mail in log, and a dyno sheet, you can see what the car is lacking, where it is rich or lean etc.

However you can not see how the car reacts to your changes. Ok so it's rich here, lean here. Add a little fuel here, remove some here. We're all done.

Not necesarily. What if you've added to much here, or not enough there. Time for a new burn.

The only way I can see getting a prom right mail order. is sending the logs, and the prom. Making the changes, sending it back.. logging again and see how those changes affected the car, and re-burn accordingly.

Once again im not saying the chip doesn't perform better than stock, or really good, it's just IMO not as good as it could be.

BTW thanks for the reply, looks like your doing pretty well with the stock prom.

REDZ28

Well he said they were just guessing, I dont think he ment they were decent at all! But we will see what my Stock Prom does with my speed density with my 383 in a few months. Ill see if I can feed the Prom burning fire some more Anyway thanks for the compliment. Good luck!

Grim Reaper

No, I am not impressed with TPIS eproms whatsoever. I've seen more than I care to admit to, and I haven't seen ONE that impresses me. In fact, I've seen too many that are really a rip off IMO.

There is a lot more to tuning than just a couple of WB readings and a Diacom file. This seldom does anything for part throttle (they rely on the O2 sensor to keep them onside - but it doesn't mean it's the best for the eninge or driveability). Definitely doesn't invoke Highway Mode and optimizes it to improve your gas mileage by anywhere from 10-20% If a person gets into eprom burning, they quickly find there is a lot of other things that can be controlled that none of the "custom eprom burners" will invoke. They just don't have the time to do that.

I just demystify all the mubble jumble that TPIS and other "custom eprom burners" would have you believe is involved in eprom burning. Do you really think people like TPIS would like you to know how simple it REALLY is and that it's a cheaper to burn your own than pay TPIS $500?

If you like spending $500 - fill your boat. I have better things to do with my money.

ski_dwn_it

I did not read the entire post and all the entries, but I got my 350 into the 12s with my 165 ECM.

With my new setup, well you can see my sig.

Not sure if you meant stock prom'd by stock programmed ECM, no added programming just mods. Or of you meant non-DFI etc type ECMs. I suspect it the first of the two.

I firmly believe that the most you will see if all else is right in your system is ~.5 sec ET gain on the strip. HOWEVER, that only looks at 1 small portion of your driving experience.

Lets say you have a stock l98, and you do the following: SR/219 cam/24# svo inj/58mm TB.

Without the tuning at WOT you will see a huge difference in power. Mostly because your Redline will be moved from about 4600 RPM to about 5500RPM. I truely believe you could run this way forever with little ill effects. Since the ECM is programmed for smaller injector, you will just be running much richer. Here is a graph that depicts why this is possible:



There is really little difference in power when the mixture is already rich. Conversely if your lean, then you will see a huge power swing. In the nutshell this is telling you DO NOT look for huge gains in power from different AFRs, like some would like you to believe. I have tested this theory out many times on the dyno this past summer. Most changes were only 10-15 HP. Not much when dealing with over 400 HP to the rear wheels.

With that being said, here is what tuning does get you. Throttle response, no bogs, cleaner running engine, smoother/less hunting idles, overall better running motors. I would like to also say longer living ones also, but I have no, nor does anyone else, have proof to that claim.

At the end of the day, I guess it boils down to the fact that if your willing to spend 4k on performance part, why wouldn't you spend the extra on a chip that is taylored to your setup? Whether its done by yourself for someone else.

It would be like building a motor that can make 1000 HP with a 1000 CFM carb, but since you have the old 650 CFM carb laying around, you just decide to run that. Sure it will run, but not to its potential. Seems kinda silly doesn't it?

As for the aftermarket chips, I know quite a few guys running anything from 350s to 440 CI motors, that run VERY VERY good with bought proms. I do my own because I like the tinkering, but for someone that doesn't have the time/knowledge/ambition, its gonna be closer than the stock prom with 22# injectors outlined and 36#er actually being run.

Just my .02

REDZ28

Ski Rules

ski_dwn_it

I will also add a friend of mine, running a large CI motor in a vette runs mid 10s pulling 1.3 60' times, all with a bought chip.

Kinda hard to argue with this:

REDZ28

camarojoe

To all the guys who think and know the TPIS chips are crap, what about 11sec91z's car who runs this chip in a 383 and traps 123mph?? I'm not saying the tune is good at all, but I think a car can still run good with one.

Ski, are you just stuck on yourself or what? you think you know everything. j/k.

TPIgirl

Please don't lock this post because I like it and I'm learning a lot. I've been reading tons over on the DIYPROM section too.


Right now my car has a Hypertech chip but I really want to program my own chips soon. Nobody I know likes the mail order chips at all.

ski_dwn_it

As I say the proof is in the pudding, my friend.

I just think all too often the "tune" of a car is blamed for other shortcomings. I see tons of people putting together mismatched setups that are doomed from the start. 95% of us here have a limited budget, why not make the most out of what you have and put together a proven setup. Here is a fine list of guys that have done just that. 80% of them run mailorder chips. Its sorta hard to argue with them and their repeated sucess.
http://temp.corvetteforum.net/c4/bea...nSet-ups.shtml

The key is well balanced setups and they WILL make power. I played with all sorts of parameters on my car this summer on dynos and at the track. Timing/fuel etc. The least it EVER made on the dyno was about 20 hp less at peak. This is going from 13.9 A/F all the way down to 10.0 A/F ratio.

The 13.9 AFR yielded the best HP across the boards, but was a little to lean for my liking when I can run a 12.5-.8 AFR and only make a few less ponies.

I have all the dyno graphs, spreadsheets etc here is anyone needs to see proof.

The name of the game is air flow. The more you can put into the engine the more power you can make. Pistons/blocks/connecting rods are not the primary contributer to building good power. The cam/Heads/intake are. But countless time you see guys on nearly every board build shortblocks that could hold up to 1500 HP, heavy ol' forged cranks, etc. They will spend 5-6 thousand on the shortblock, then when it gets to the heads they put on a set of heads that flow 220 CFM. Then a good intake with a mismatched cam. It doesn't take a rocket scientist to figure out which people did their homework, and which didn't.

At the end of the day if your setup is VERY well matched you should be able to run the following formula to see what your restriction is and it should be your heads. For my setup.

AFR 190s CFM at .500" lift => 262 CFM

Potential HP = CFM x .257 x 8 cylinders = ~540 HP

On the dyno I made 437.5rwhp uncorrected. @ ~20% loss thru my tranny puts me at ~525 fwHP. Correcting them for DA you would see a very close 540 fwhp that the heads are able to make.

Put a set of crappy heads on the car that flow 220 CFM = ~450 fwHp. Then they blame the tune that they are not running as fast as someone else with "nearly" the same setup.

.2-.5 max is the most you will get out of a tune, unless things are GROSSLY messed up before you start the process. That is my firm belief based on my own testing and others.

anesthes

iTrader: (12)

Ski just likes to dissagree with everyone. Though he has a fast vette, so I guess its ok.

Good job porting that plenum. I'm curious what the flow differences are now.

-- Joe

ski_dwn_it

Call me the devil's advocate.

That pays attention to other quick cars.

formul8!!

Every little detail counts when building a fast car! Any idiot with enough cash and a car can open the Summit Racing catalog and order a buncg of go fast parts. Wht happens is they order the wrong combo before doing research.

Details for a EFI car are critical. Remember, the factory EPROM's are a compramise of emissions, EPA gas mileage, longevity, with ultimate performance being last on the list.

With a TPI car being the first application of EFI on the SBC engine, every littl thing counts. Right down to the air foil and removing screens on the stock MAF.

This is where custom PROM tuning has its advantages. As many of the DIY PROM guys have figured out, a bone stock car can pick up huge gains just in the computer.

I am just suprised that only in the last few years has TPI motors been having some pretty big advancements in development in the aftermarket!

TPIgirl

Glenn my friend says he knows you and that you really know your stuff about TPI computers. From what I've read so far that appears to be very true and hopefully you can give me some very good advice here soon.

Ski I would have liked to build a 406 but I couldn't find a good 400 block. My dad found me a 350 block though and a friend of mine will give me a good 400 crank so I'll be building a 383 this winter. I'm hoping to start doing some PROM burning this coming month. If I didn't have anyone to help me I might consider getting a mail order chip but I prefer to do things myself and learn how it all works.

Please keep the useful information coming!

REDZ28

Right on Ski!!!!!!!!

OMINOUS_87

Well here is some interesting reading for those who think that they will be able to run well on a stock tune.

https://www.thirdgen.org/techbb2/sho...56#post1506556

quickL98

iTrader: (2)

[QUOTE]Originally posted by ski_dwn_it
[B] As I say the proof is in the pudding, my friend.


The key is well balanced setups and they WILL make power.
The name of the game is air flow. The more you can put into the engine the more power you can make. Pistons/blocks/connecting rods are not the primary contributer to building good power. The cam/Heads/intake are. But countless time you see guys on nearly every board build shortblocks that could hold up to 1500 HP, heavy ol' forged cranks, etc. They will spend 5-6 thousand on the shortblock, then when it gets to the heads they put on a set of heads that flow 220 CFM. Then a good intake with a mismatched cam. It doesn't take a rocket scientist to figure out which people did their homework, and which didn't.


amen brother... a good friend of mine had a 2 bolt 355 with stock rods and nothing special forged pistons, but he did have methodicialy thoughtout top end which pushed his '79 Z to 7.30's before spray.

quickL98

iTrader: (2)

that was about 5yrs ago and it still together.

ski_dwn_it

Ominous_87,

let me first say before we draw a conclusion that the car is going to gain anything with tuning we must know the rest of the setup.

Furthermore, I hate to be the one to break the news to the guys, but there is something GROSSLY wrong with that setup. 421CI motor, should be putting out 390+ rwhp without even trying, and 400+ ft-lb, in its sleep.

Either the build is bad on that motor or he has totally mismatched parts. First thing I see are the heads are not the greatest thing around. I looked at their website and the 200cc heads don't even flow as much as a 190 AFR head. They are crap. Then you stick them on a larger CI motor, and expect them to make decent power. Not going to happen.

Its takes me back to my original statement. Well balanced setups. I if he get that thing over over 425 rwhp, which it clearly should do with a motor like that, and the right parts. But if he gets that thing over those numbers with TUNING alone, I will kiss his *** at 5th and main, and give him a day to gather an audience.

I mean on the dyno that thing was struggling to barely weep out 4500RPM. Something is seriously a-miss.

REDZ28

http://vette383.tripod.com/ Go to His 1987 Vette link it tells you what all the motor has. It ran 11.39 with the stock chip N/A. He sold the car to Hole Shot on the Corvette forum. I know Ski has seen his car in posts. Since the new owner has had it the best he has ran was 11.87 if I remember right and that is still with the stock chip N/A.