Kingtal0n

Torque converter IMO is the heart, the most important part of the setup, any auto setup.
I would use a Yank 2800 or 3200stall, be sure to get 9.5" converter not a 10" or 11" unit or anything else. Do not compromise on this.
I also recommend triple disc lockup clutch so you can lockup the converter like a manual transmission and go high torque near WOT situations however you want on the highway with it. I can't stand the unlocking behavior of a high stall on the highway just to make 1/2 throttle passing situations, the engine revs out unnecessarily. Its expensive but triple disc is worth it IMO strongly recommend. Do it once.

The trans... this is where I get LS and 4l80e syndrome from 'been there done that'. Its hard for me to encourage a 700R4L60E rebuild unit for first timers. If you are not DIY the only real option is Probuilt automatics, get Dana to build a unit for you while he still does them. Otherwise, I can't recommend rebuilding it or doing anything with it. I would just honestly and personally jump right to the LS platform and stick a 4l80e and turbocharger and go at that point. The stock LM7 5.3L LS engine is like $250 around here and it will go 200k 300k miles 650rwhp no issues using pump fuel and 4l80e is very simple to rebuild compared to a 700R4... in my mind the simplicity & power output > originalness with the similar economy, literally double the power and half the complexity and twice as easy to DIY everything and tune and maintain... build thread in sig

Bill Chase

He said, and I quote "looking for feedback from the been there done that". Just a cold air induction, free flowing exhaust,1.6 rockers, gears, and higher stall converter it probably wouldn't need a tune to really wake the car up especially coupled with a shift kit and modified governor to change shift points and a single stage nitrous kit. He states he likes the drivability, the car runs good, the things I have stated will totally change the cars character and those things done with the stock tune will help it live, be reliable etc. Pouring a lot of timing into it, leaning it out for drag strip use to make an extra 15-25 hp at the cost of the fail safes built into the factory tune isn't the best thing to do for a car that will see significant street use. After dropping 13 grand into a tpi Vette and spending way more than I had to to achieve the mild goals I had ; my comments are relevant, I probably shouldn't have strayed off topic talking about warranty, emissions etc.

Arctic White 91 RS

Reasonable

Folks have their preferences, I can respect that.

However, your advice goes against what Yank, Precision Industries & RPM Transmission suggested when I discussed getting a triple disc lock up clutch for the street.

All basically said benefits for a triple lock up is in certain situations racing like top end of drag strip for that bit through the traps. All mentioned sometimes triples (regardless of brand) are shutter prone on the street compared to singles when locking and that is typically annoying if it shutters. Likewise, all said they'd only recommend triple lock up if I had a motorsports related reason for wanting it. That was earlier this year. Of course all are happy to provide a triple if that's what the customer wants.

Just wanted to share that side of the triple lock up discussion because one of the main arguments against getting triple lock up for the street isn't cost.

For a top notch 700R4 or 4L60E rebuild, yes probably best left to the experts as mentioned.

LS1Tech automatic-transmission has several 4L60e do it yourself builds that worked out well that maybe worth a look for anyone interested in trying it. Not for me, I'll go RPM Transmission when the time comes. Well built 4L60E's can have the capability of handling ~650+ whp however it's not inexpensive.

Have a stock 4L60E w/263,000 miles. It shifts and drives like a 40,000 mile unit in a car w/326 whp and 3.73 gears. Not willing to drink the everyone needs a 4L80 kool aid. Have a 700R4 that went 389,500 trouble free miles. Frequent fluid and filter changes plus keeping temperature under control being keys to helping increase odds of long a life.

Kingtal0n

There is tuning involved with locking up the converter at various throttle positions, both hydraulic side and software side. The software details allow 1% to 100% range of pressure adjustment for PWM engagement of the solenoid. There is also a time and engine rate based functiond depending on the year of ECU. The Pressure regulator, TCC circuit, boost valve, check ball situation, orifice diameters, etc... control hydraulic component fluid lockup characteristics depending on the transmission as well.

IF the unit has some difficulty, poor behavior, it needs to be tuned properly. And maybe most people do not understand while building their transmission how to do that properly or how to utilize the software properly to that end. Many simply copy and paste their tune file from some other file. Or cookie cutter the hydraulic parts used.

There is nothing more to a triple disc converter than a triple disc clutch. You can engage a triple disc harshly and cause parts breakage in manual and automatic transmission units.

The big difference is the ability to avoid slipping the triple disc when locked. The single clutch will slip. When it does, the shed paper materials clog trans filter and facilitate an entire transmission rebuild and replace the converter necessary. Thus, they must be unlocked when you step down for torque. So you are cruising on the highway 65mph or 70mph rolling 2400rpm or so, nice and smooth and the engine tone is low and tolerable. Then you decide you want to accelerate to 85 or 95mph quickly, say 65% throttle, the single disc converter must unlock. Now the engine screams to 3200rpm or 3500rpm or whatever for this simple increase of 10 or 15mph. What a waste of energy, loud noise, it makes the vehicle seem like its 'trying hard'. I do not tolerate that kind of behavior. I want the car to cruise like a manual transmission will, you step down and the engine tone barely increases while MPH shoots up rapidly. It is far more intimidating as to the effort of the vehicle vs MPH gained, and easier on the drivetrain, economy, efficiency, friction, etc... the engine will make less heat and noise with the triple disc locked.

If you have two products but one is more difficult to utilize, tune, finesse, etc... you will recommend the easier to use product even when the superior product is superior. I don't think the issue is that the triple disc is inferior lockuo quality I think that they are just more difficult to tune properly and setup properly and the converter company doesn't want a high rate of complaints and questions concerning the behavior of the unit when it wasn't necessary for the application.

Fast355

iTrader: (2)

PWM is only used on some newer computer controlled automatics. A 700r4 uses a simple on-off arrangement.

As for your single disc slipping comment. Almost every GM transmission setup has the converter force locked at some speed. 700r4s typically around 65-70 mph. My 4L60E was force locked at 75 mph. My 4L85E locked up in 2nd gear at full throttle around 60 mph. GM even uses the same 2nd gear WOT lockup behind an 8.1L or Duramax and neither are known for smoking the converter clutch. It was not until GM decided to use PWM to continuously slip the converter in the 4L60E in about the 96 model year that they started having problems with the lockup friction clutch. Some of those setups will continuously slip the clutch 100+ rpm all the time.

SbFormula

I don't really want to sound like an a****le. I don't know how to put it to you without offending or hurting. It's obvious that you don't know anything about tuning.

"A single stage nitrous" and "maybe a 100-150 hp nitrous kit" actually requires some basic tuning. Might also need to beef up the fuel pump for increase flow. Timing and AFR have to be adjusted for nitrous (since timing is inaccurate from the OEM tune anyway - SA Latency table). There is also all the knock retard that could happen with "free flowing exhaust" & "shift kit", it needs to be managed (knock attack/recovery). And tuning AFR at WOT is a no brainer. I don't know how anyone could just throw parts and mods without EVER data logging let alone monitoring AFR. OP is planning on changing the injectors for 24lb/hr. That alone requires modification to the tune (.BIN). Why not getting the fan to come on earlier, would not hurt, specially if new aluminum heads are installed. PE mode can also be tweaked to come on earlier at part throttle acceleration. That gives better throttle response and safer AFR at "close to WOT" hard acceleration. If A.I.R. was removed like OP stated, might no be a bad idea to disable it into the .BIN. That would help the 02 sensor operation. That is just a few examples. I could go on.

Saying "probably wouldn't need a tune" is an uninformed opinion. No one can say until at least a data log is done and AFR is monitored to see what is going on with the engine. After that, maybe one can say it does not need a tune. Otherwise one is just shooting in the dark.

"Pouring a lot of timing into it, leaning it out for drag strip use to make an extra 15-25 hp at the cost of the fail safes built into the factory tune isn't the best thing to do for a car that will see significant street use".

Again this statement shows lack of knowledge in what tuning is all about. You don't pour a lot a timing and lean out. You make timing accurate and appropriate (which requires dyno or track session) and adjust AFR for maximum power. No sense running high 10s AFR when 12.8 is sufficient. Waste of gas. And street use can see a lot and I mean a lot of hard accelerations. Who would not take the extra 25hp?

Arctic White 91 RS

I'm sure they have a superior understanding of what will work best for the customers and recommend accordingly.

Bigscott

I am looking to do my L98 as well. I have headers, exhaust, CAI, and no smog equipment. I have been debating doing stuff to the car for 3 years! LOL! I hav always wanted a Supercharger for it. But that's a ton of money. I picked up a LF Super ram that I am now thinking of selling. Keep me posted on what you do I am curious. I just sent my 96 Cobra to GTR for the intercooler Pro charger. I want my Firebird running with it

Kingtal0n

Not really. They recommended me a single clutch and I hated it. I didn't realize the fuss the engine would make in my application coming in and out of lockup on the highway just to accelerate a few mph without the disc slipping.

The desire of the owner is not what they will recommend, its just a guess based on what you tell them. That is why I bother to make my post- I'll never buy or recommend a single clutch converter ever again.


Yes and no. The 700R4 has internal fluid circuits which can be modified to the character of a converter lockup. For example the checkball in the end of the input shaft is often removed to increase lockup rate. A simple on/off switch electrically applied to the solenoid- yes. But a simple on/off arrangement internally, NO. It is up to the transmission rebuild how you want the lockup character and take into account such things as triple disc clutch.

IROCThe5.7L

Here is a comparison video I made a long time ago. Concentrate on the tac as I didn't change the speedo gears yet with the new setup.

LT3D

Wow, that is no joke. A different car for sure.

SbFormula

"safes built in" What are they? or is it just something that gets thrown around like a typical myth.

From factory (Camaro 1989 IROC-Z M5, LB9, 21k miles, stock to the core with premium gas, APYS tune). It knocks at mid throttle when engine is cold, audible and recorded on data logger. And no it's not due to the ALDL SA since it is disabled and 10k resistance is removed. It's terrible! Why? Because GM has the knock retard disabled until the engine gets warmer. That is safe all right, isn't it?. The engine knocks without any SA being pulled. Scary but factory. On top, GM adds timing when engine is cold at WOT to an already too high SA... with no knock protection (remember it's disabled)... very very safe! The reality is the factory tunes are mediocre with too much fuel and SA at WOT.

Let's also mention the rev limiter set at 10k rpm by GM... maybe it can be brought down a bit!

At the end of the day, to max out a street L98 and protect it, one needs a tune.

Kingtal0n

Honestly if the engine is knocking cold, then something is up. That is not normal. Sounds like timing is off or some significant carbon buildup due to long periods of inactivity. What is APYS tune? Aftermarket tune? Too much timing or too much compression is the main culprits of cold engine knocking. Also if the engine is 'retuned' the new tune has control over cold advance yadda yadda- sounds like a bad tune, improper timing, or carbon buildup causing knock.

I would never use an OEM ecu on one of these old cars. Use an aftermarket EFI Unit with seq-efi, individual cylinder tuning, injector phase control, if possible.
And also never rely on knock sensors or audible knock. Both are misleading. Knock starts way before human ears can detect it. Knock sensors calibration depends on the engine internal config and other factors nuance. When I tune an engine I use EGT and TORQUE characteristics to find the minimum best timing and work out the 'tuning window' to get an idea of how much safety factor is between the least timing and worst possible situations such as high temps, excess boost, bad gas, whatever might happen. Knock sensors should NEVER be used for tuning. The knock sensors come in after the fact to protect from bad gas and similar random occurrences IF they are capable, which they may not be. Sometimes a part changed inside the engine (did we ever change a part in an engine?) will affect knock sensor frequency calibration making them display knock when there is no knock, and completely silent sensors when there is a ton of knock. Not all ECU allow us adjust knock calibration frequency or knock sensor type, and even for the ones that do I would not want to deliberately test them by forcing the engine to knock.

SbFormula

Kingtal0n

"Sounds like timing is off or some significant carbon buildup due to long periods of inactivity"
Nope, timing right on, SA latency was verified to be accurate. From factory. No build-up.

"What is APYS tune?"
Factory .bin. Bone stock LB9 with 3.08, 5 speed.

"Too much timing or too much compression is the main culprits of cold engine knocking"
I guess!! Compression is stock, so it's gotta to be timing, too much on stock tune (that's the point here)

"I would never use an OEM ecu on one of these old cars"
I wish I could but it's a collector's car. All original. I'm just tuning it with piggy back chip so it can be returned to factory if need be... but why would ya?

"And also never rely on knock sensors or audible knock"
An audible knock caught my attention one day on this bone stock car. So I datalogged and confirmed it with major knock count with no SA being pulled. Knock retard not activated under 104Deg. F CT. Again all factory. Timing was way too advance at 38*.. Again all factory (that's the point here)

Kingtal0n

Maybe 38 is too much, Maybe not. At 50% VE you can get away with 48* of timing some of those old engines. Highway cruise for example 30-40% VE 44 to 50* of timing even in a modern LS engine.
I would say if the engine is original then the issue is simply carbon buildup, or a noise coming from something that sounds like knock but isn't. I had a 305 TBI that sounded alot like knock but it was the tensioner for the belt at a specific RPM.

I would de-carbon the engine and see what happens. Could take a while if diy
Hard to knock a cold engine in an natural aspiration application with 93 octane fuel at less than 10:1 compression. I mean REALLY hard to cause that.

SbFormula

Definitely not a "noise like knock" type. Once SA retard is activated, ECM pulls timing and noise goes away. This MAF system does not have VE and MAP. Knocking occurs at mid throttle when engine under load at 3000 rpm going up hill cold. Those TPI are quite efficient at that RPM range. At around 70g/sec of air (LV8 =112) we are at around 70%-80% VE. I can't get 93 around here, I'm on 91. Again, I am surprised too, but I highly doubt the engine is carboned fouled based on overall conditions. Plugs looked really good.

Kingtal0n

When an engine sits for extended periods the carbon coating inside combustion chamber becomes hard diamond-like and raises compression and facilitates hot spots.
It is on the piston, valves, head, deck.
So for example you run the engine every 6 months for 30 minutes, that would create multiple layers of hard diamond-like coating.
Especially when the engine isn't fully warmed up by driving for 1hour + to raise oil temps to 212-220*F before shutting down.

This is typical for old cars with low miles. I would try de-carbon solutions.

Tom 400 CFI

Does the carbon change it's volume (and thus, the compression) as it's sitting/"hardening"?

How does it get on the deck (of the block??) when there is an gasket there, smashed between the head and the deck?

Do you know what "wash" is?

SbFormula

Let me get my hands on a borescope and I'll report back. Not saying it's going to be done right away but it'll be done.

Kingtal0n

There is two parts to this answer, theory and experience.
First, theory
Fuel and oil are made of carbon. There is also carbon in air, Pollen and fungus contain carbon (life constituents), bacteria, dust, skin cells, etc... some always passes the air filter especially < 2uM size particulate
Carbon behavior
The difference behaviors between carbon containing substances as charcoal, graphite, diamond, life compounds, etc.. isn't the carbon atoms individual molar mass or number of atoms,
it is their respective different bond angles of formation, electronegativity of nearby atoms, number of bonds, electric field probability, electron placement, energy of bonds, twisting, jostling, bouncing, and other details. For example Diamond have wide bond angles and graphite has numerically low bond angles, same carbon atoms.

Carbon formation on parts within an engine combustion chamber
Some Carbon enters combustion chamber and adheres to engine parts, piston, deck, head, valves, etc... Gasket coverage is not perfect. Most head gaskets leave spaces, and especially in the quench or distance between head and deck, and the exposed surface of the head, valves, piston, all converge carbon byproducts.
Carbon as gasoline and engine oil dissolves carbon, it can solvate carbon. In other words oil can dissolve gasoline and gasoline can dissolve pollen and other carbon products. The difference is, again, in their chains, bond angles, properties associated with electronegativity and so forth, Not necessarily the number of carbon atoms which is not a factor in carbon deposition. Many carbon atoms come and go but only the few which can form conglomerates and properties which adhere at high temperature and pressure to engine parts form deposits, this must involve carbon cation and radical formation, un-reacted byproducts of combustion. No engine is perfectly efficient at reacting carbon chains, there is always some partially reacted products which adhere to each other and engine parts.
Auto manufacturers are aware of carbon cycling and deal with it by providing specialized regions, carbon pads, designated for harmless carbon deposition. Particularly portions of a piston and valves are able to contain smooth unbroken carbon deposits which will not interfere with normal operation when kept cycling endlessly by incoming fresh carbon (gasoline and oil) in the presence of heat and pressure while the engine is fully up to peak operating temperature, they take a little bit, deposit a little bit, and reach equilibrium in operation which prevent excess carbon buildup.
However, there are many issues which may arise which upsets the balance of carbon cycling within the engine,
First, non-optimal temperature, cold pistons, cold valves, cold air, cold fuel, all will reduce combustion efficiency and lead to excess un-reacted carbon byproduct formation which results with carbon deposits, carbon conglomerate formation, excess blow-by containing carbon radicals and carbon cations which enter engine oil and circulate, all manner of contamination within an engine ensues when the temperature of various combustion components is not optimal. Auto manufacturers go to great lengths to bring engine parts up to ideal operating temps as quickly as possible to limit the excess carbon buildup and deposition. It may come as a shock that IDEAL IAT for part throttle and cruise/idle situations is much higher than ambient temperature, it must be kept warm to equalize cylinder distribution, maximize velocity at low mass flow rates, and the higher temp helps to vaporize fuel which is injected as a liquid. Thus, 'cold air intake' can increase carbon deposits, disturbed cylinder distribution, interferes with vaporization of fuel, at idle/cruise/part throttle conditions where warm air is desirable and cold air is not needed for the sake of performance at such low engine HP output conditional.
Next, long periods of inactivation, e.g when the engine is left sitting *off* for extended periods, causes light carbon chains from within existing deposits to leave, which strengthens the bonds of heavy carbon chains found in substrate. Thus, carbon gradually loses mass and becomes more hard, brittle, diamond-like over time. Then, when the engine is run again, a new light layer of carbon will deposit over the old-hardened layer and compression ratio will be increased each time a hard layer is left behind from periods of inactivity. Sometimes because of the brittle nature a piece will break off leaving a sharp corner which creates hot spot and this causes detonation unexpectedly.

Experience,
I've examined around 1000 perhaps 1200 to 1500 engines imported from Japan produced between 1988 to 2002, such as 2jz-gte, sr20det, rb26dett, 4g63, K20A, and similar. Mostly turbocharged. I formed such a large sample population and over time came to recognize trends, for example engines with aftermarket air filters tend to have excess wear and tear, sand blasted throttle valves, chipped compressor wheels, pitted head and deck metal materials. Engines with disabled PCV systems have dark filthy crankcase & deposits, failing oil systems & oil inclusion debris, stuck piston rings 'glue' with carbon slime, reduced turbo lifespan, poor drainback. And finally, engines which sat for many years and those very old with low miles tend to have stuck or sticking valves & excess carbon buildup. We would remove the head and spray carbon cleaning spray (solvent from Toyota) to remove the old carbon glue and that would bring the engine back to life, restore compression, free the valves, etc...

Tom 400 CFI

Oh my god....The amount of dogshit! Wow.



.

Arctic White 91 RS

Sounds like a failing on your part to properly communicate what was desired.

I've had excellent experience with Yank products to date and with RPM Transmission. Haven't purchased from Precision Industries yet.

Fast355

iTrader: (2)

thDefinitely thinks he knows more than he does about how things work.

My favorite laugh is how he thinks a K&N air filter makes an engine burn oil.

Tom 400 CFI

I hadn't read that one from him...yikes. If it weren't affecting the unwitting, it'd be entertaining? Maybe?

Kingtal0n

there are many published papers and (GM) engineers discuss these things. I merely break it down for laymans terms so you can stop repeating the same mistakes as copy and paste from everybody else.
Not everything they sell for you to buy is good for you or your vehicle.
If you read hundreds of thesis papers you would know these as well.
As a scientist, doctor of engineering, background MS bioengineering, chemistry, mathematics, biological science, I assure you my credibility in this subject are true modern theory developed and derived for combustion engines.
Furthermore I just happen to have built and tuned hundreds of vehicles over the last 25 years where I learn many things before becoming a doctor and completing so many coursework and readings.

Truth is stranger than fiction.
From the highest point , everything you think you know is wrong

Tom 400 CFI

More BFS rhetoric with a bit of "conspiracy" mixed in for a hook.

All the supposed degrees don't mean squat...once you start typing junk for the unwitting. It's forum "pollution".

SbFormula

1)Quote:
Originally Posted by Kingtal0n View Post
When an engine sits for extended periods the carbon coating inside combustion chamber becomes hard diamond-like and raises compression and facilitates hot spots.
It is on the piston, valves, head, deck.
So for example you run the engine every 6 months for 30 minutes, that would create multiple layers of hard diamond-like coating.
Especially when the engine isn't fully warmed up by driving for 1hour + to raise oil temps to 212-220*F before shutting down.

This is typical for old cars with low miles. I would try de-carbon solutions.
Let me get my hands on a borescope and I'll report back. Not saying it's going to be done right away but it'll be done.


2)No carbon deposit what so ever in combustion chambers. I could not access the valve train with bore scope, but I don't think it'll be necessary.

Like I said, too much timing from factory with ESC disabled at low CT. To Max out OP's L98, he needs a tune with proper timing for his set-up.

Fast355

iTrader: (2)

You do realize MOST engines not just GM have zero knock protection until they warm up some. If the knock sensor was enabled early it would pick up the piston slap from the pistons that have not yet expanded in the bores and retard the timing.

My 7730 as it was tuned from GM did not enable the EST spark advance until ~120F. It ran on the base timing plus module limp home timing when it was cold.

Many stock engine management systems also have a forced knock test. As the engine is warming up and the vehicle is being driven under load, they purposely advance the timing until the point the engine detonates to test the knock sensor. Some GM systems do this 3 times and add as much as 20* of timing over what the lookup tables are providing for final spark advance. My P01 and P59 LS controllers do a force knock test the first time the engine is driven more than 50% throttle with the engine warm. I can see it in a datalog merging onto the highway at heavy part-throttle, PCM increases the timing until it spark knocks, the knock retard value spikes to 4-6*, then it returns to normal. It also does an AFR variance test to test the cats that you can feel at idle. It will lean out a full point, then richen up a full point at idle to test the rear 02 monitoring. Only an dummy would find 10* of timing added to WOT on a stone cold engine a problem because only a dummy would hammer on an engine that is not up to operating temperature. Yes 3,000 rpm acceleration is beating on a cold engine.

SbFormula

Yes. I modified my .BIN ($6E) to have ESC come one earlier as knock was present (audible and datalog) at CT 95Deg.F. GM had pulled timing using table (0x10F) in that CT range from 32 to 128 LV8 which is not WOT but idle to light load. Looks like GM was aware of potential knock. Past 128 LV8 all the way to WOT they actually add timing in that CT range. Knock was present between 80-144 LV8, far from WOT in the 3000 rpm range. Knock was also present after engine was fully warmed up but more in the range of 128 LV8 to WOT. ESC is not enable until CT is over 104Deg.F (0x1BB). There is also a delta CT from cold CT start enabler (0x1BC). Not sure if it has priority over 0x1BB. If yes, that would enable ESC earlier in case of real cold start.

In my $8D (7730) ESC is enable over 104Deg.F (0x20C) with same Delta CT enabler (0x20D). However, EST is enable all the time. It does not run on base timing plus "module limp home". It runs the regular parameters (SA Main, SA CT, SA PE, SA close TPS, etc..). That's based on hundreds of hours of data logging.

On my $6E, the knock test comes on only if CT over 193 Deg.F. (0x237) on mid-heavy load over 144 LV8 (0x238). Maximum Spark adder is 25*.

And yes ALDL Spark Adder (0x23) is zeroed-out. Knocking happens with or without ALDL cable plugged in.

I think we should stop here and continue this on another thread because we are definitely hacking this thread. If one reads the whole thread, it's obvious we are off topic. The point was to recommend to OP a tune for his potentially modified L98 as the OEM tune won't cut it.