Rematch: '95 Stealth TT vs '91 300ZX TT

[lepimpjuice7290]

@96stealth Never did I say that the Ash ecu didn't change the factory presets. I am not sure where you got that from since altering the presets is the point of an aftermarket tune.

You can't run over 9.5 psi safely. Sure some people get away with it. But that doesn't mean its safe and not doing unnoticed damage.

Perhaps maybe you could stop over sometime to discuss this in person instead of over youtube. If you are allowed...

[summeronthechain]

I think I mentioned a stock turbo Z in the 10s once when we were discussing stock turbo potential, hardly what I would call a common topic.

You most definitely do what you do in part to show off. Whether you realize it or not. You wouldn't post race videos of your car, post unofficial Gtech times, or mods unless you wanted people to wow at your accomplishments

The difference between us is I admit it. Even though I have never had a goal of 1/4 times because drag racing really isn't my thing.

[96stealth]

@summeronthechain You had no goal for the Terminator? You've brought up 300zxs more than once.

[summeronthechain]

@96stealth

Nope. Not in the 1/4 mile. Austin may have, but I didn't care so much. It is just a number from a track. A good car for me is about the feeling and fun of driving it, not some estimated number a gtech flashes once on a backroad in the middle of the night.

Besides, what good is a number from the track when those kind of times aren't replicated in a race? Which is what some people would say is all that matters.

It is about as useful as a dyno number, I'd say.

[summeronthechain]

@96stealth "To safely run higher levels of boost, one must modify these settings to keep from damaging the engine"

Which is what I've been telling you. The article says that anything above 12 psi is unsafe for a stock ECU, it doesn't say that 12, 11, or 10 psi is safe for a stock tune. Because it isn't, in all situations. Bottom line is that if it was safe Nissan would have raised the OEM boost to 12 psi and made another 30 HP safely.

Thanks for doing the footwork to prove my point, though.

[96stealth]

@summeronthechain Unbelievable! I think your just trying to piss me off now at any expense. No one is that stupid. The article isn't benefitting you're arguments in any way, shape or form."The article says that anything above 12 psi is unsafe for a stock ECU" Why put 12 and not 9.5 then? Where does 12 come from?

-insisted the the ash ecu doesn't alter the stock presets = false

-insisting anything above 9.5psi isn't safe w/stock ecu = false

Thanks for being so entertaining.

[summeronthechain]

It is about impressing other people. You don't put 1/4 mile times in signatures for your own knowledge.

There are few people willing to push the boundaries of stock parts because it is unsafe and they just don't care that much about it, me included.

Suffering possible engine damage try to tune it myself just isn't my cup of tea. I'd rather be slower, but not have to worry about my knock count.

[96stealth]

@summeronthechain Well I'm going to pull one of your responses. You wouldn't bring up to me every time a 300zx does something incredible on stock turbos if it wasn't important to you. There's a big difference when you're doing it for other people or yourself. My goal has always been 11's on my own merit. Maybe that will change in the future now that I've achieved that. I accomplished that with my own ability. That's for me not anyone else. I do not seek attention like you do. Not even close.

[96stealth]

This race was done AFTER the Z had SMIC, UD pulley and downpipes.

[summeronthechain]

@96stealth

I thought this race was done with my roomate taping?

[96stealth]

So, this race is from over 3 yrs ago? I think not. It was after your 12.8 track run which means you had every mod you currently have on your car. Your roommate taped a race when my car was still bpu - damn near stock.

[summeronthechain]

@summeronthechain

I realize this now.

[summeronthechain]

If I can remember correctly, this race was done before the SMIC, UD pulley, and downpipes.

Mods would have been ecu, boost controller, and catback at this time.

[justin7803]

stealth looks strong, wish i could run you from a rool to see how we'd match up my !/4 trap speed is pretty close to yours but street tires from a stop you'd walk all over me...

[bigbossrav]

stealth sprays alot of gas with bigger turbos, stealth wins as you can see.

[96stealth]

stock 300ZX turbos are in between 13g and 15g class and will hold 17psi to redline. 300ZX also has larger injectors stock and a better stock fuel pump. This 300Zx has a chipped ECU, so it doesn't need the same fuel upgrades that the stealth has. The 300ZX in this video ran a 12.8@112 at 16psi. Our stealth ran a 12.4@110 at 12.5psi.

[niz55]

300zx 112 and stealth 110. So why is the stealth pulling from a roll?

Throw away that crappy ecu and get a z1 or jwt with some 550CC nismo and the 300zx will put down 380-400.

[96stealth]

You need to pay more attention to the descriptions of how the cars were set up. In this rematch the Stealth is running 14psi not 12.5 like in the other race. The 300zx trapped 112 on 16psi and he told me he would never run that boost level again, because he doesn't know if it is safe.

[96stealth]

The Stealth also had a 15g class turbo replacing one of the 13g's that blew the seals. It also was on the stock fuel set-up in the 1st race. (550cc's now)

[96stealth]

The 300zx professionally tuned should be able to make 380 - 400 with the stock injectors. You probably won't make those kind of numbers with just a preprogrammed ecu, because all cars tune slightly different. So the ecu's that you buy from any vender is not giving the max potential of the car.

With his mods in my opinion those numbers aren't out of reach. It just would take a dyno tune.

[300ZX06]

You can't make 380 on stock Z injectors. You need 555's to do that. The stock Z injectors are 370's. As a general rule on Z's the injectors will do a little less hp than cc's. 380 would be well beyond max duty cycle.

[96stealth]

It can be done by increased fuel pressure, but I'm positive that it can be done on stock injectors without increasing FP. I'm also talking dynojet #'s not a loaded one.

[300ZX06]

I won't risk my Z with pushing that far on stock injectors.... No reason not to get 555's and call it a day.

[summeronthechain]

@96stealth

Raising the fuel pressure isn't going to be helpful when the injectors are already maxed.

[summeronthechain]

@96stealth

I don't think just a tune would be sufficient for 400 WHP. At around 14-15 psi peak injectors are around 90% duty cycle. So higher levels of boost wouldn't be a good idea. But with the addition of water/meth injection might be able to be raised a bit.

Even with proper personalized tuning I don't think anyone is going to gain 50 whp from fine tuning an already decent tune.

[96stealth]

Your statement is correct, but that is based off of stock fuel pressure. Increasing fp increases the size of your injectors. I don't know the limits that injectors have over their rated CC, but it's a philosophy that is used by Matt Monotte who holds the current record for 3/S. He set the record using 720cc injectors 8.7@165. The car dynoed in the upper 900's. His secret was just turning up the FP. His car was making over 200 more hp than the rated CC. 400 hp is unlikely, but is possible.

[96stealth]

I'm not making any claim of what the 300zx in this video is making. I said it was possible with stock injectors.

[96stealth]

I made a mistake. Boost was only 11.5 not 12.5 the 1st race.

[summeronthechain]

@niz55

Z1 ecu is the same thing as ASH ecu. Ash formerly worked for Z1 and did all of their ECU tunes.

[summeronthechain]

@96stealth

A aftermarket ecu doesn't equal a fuel upgrade.

Basically it is just step in the modifying process that the Stealth doesn't have to get. Boost can safely be raised a level in a BPU Stealth without another tune, whereas the 300ZX needs a different tune for the increased boost.

[96stealth]

I disagree somewhat, because the fuel trims are manipulated. I was never able to run more that 12psi bpu and I don't recommend running the supposed safe 14psi. If Stealths came with bigger turbos they wouldn't be able to increase boost without changing fuel trims either.

[summeronthechain]

@96stealth

The stage III tune doesn't alter fuel trims very much. According to Ash, it expands the fuel maps and increases timing.

Basically the stock air/fuel maps are programmed to accomodate fuel up to 9.5 psi. On a stock tune, if you increase boost over the stock 9.5 psi the computer can no longer effectively control fueling/timing/ignition and so on. The aftermarket tune takes the factory maps and adds programming for up to 15 psi. It basically just adds in the missing data.

[96stealth]

This isn't entirely true. All cars from the factory come with a rich tune as a precaution. This means you can can turn the boost up to a point dependent on how much fuel is available. I'm not sure how high. Probably 11-12psi for 300zx's. You can effectively control A/F with just boost even with the factory settings/maps. By turning up the boost you car will began to lean out. The ecu upgrade allows you to safely run 15psi by adding fuel. If it didn't the car would be running dangerously lean.

[summeronthechain]

@96stealth

While a stock tune surely has some fuel safety margin, I don't think anyone would agree that adding nearly 30% more boost than factory would be a good idea on a 300ZX.

I disagree that you can effectively lean out a car by just increasing boost. You can probably make the car run lean, but I don't think it will be as effective of a tune. Obviously the ECU does adjust a lot more than just fuel and they are all critical to engine performance/longevity.

[summeronthechain]

@96stealth

The aftermarket ecu is not just simply adding fuel for increased boost. It is expanding the "maps" the computer has available so it can correctly adjust fuel, spark, timing and so on. It also must correct the VG's variable cam timing.

I think this is one of the downfalls of your ARC2 is that it is essentially only adjusting fuel and that is why people tend to go with AEM because it allows more tuning possibilities.

[96stealth]

Downfalls? The ARC-2 is the most proven fuel controller on the 3/S platform. It holds virtually every 1/4 mile record because it has been used by probably the best tuner of 3/S's being Matt M. of Dynamic Racing. This debate has been going on for awhile now and it's his opinion that a piggy-back set up can be just as effective as a stand alone. It's also a much more simplified process which helps reduce error in the tune. Fuel and timing are the 2 most important aspects of a tune.

[summeronthechain]

@96stealth

I'm not saying it can't be effective. What I am saying is that because of the nature of the ARC2 the computer can't adjust other aspects of the tune as effectively as it could with a stock like tune.

Thats why when the temp changes, a stock car ecu can make all the adjustments necessary to run a safe tune. With the ARC2 you have to adjust knobs every time there is a decent change in temp because the ecu no long has complete control over all aspects of the tune.

[96stealth]

That is not true. Why do you think there is compensation from the factory? Temp changes is one of those reasons. The reason I have to change my settings is because I'm running as much boost as I can. I could easily set the car up with a safe tune in all temperature conditions.

[summeronthechain]

@96stealth

Right I agree. But, for example, the 300ZX is running as much boost as it can, but yet doesn't have to change any settings when the temp or other variables changes because the ECU is capable of making all the required adjustments.

Yet it is not losing much, if any, horsepower in the area of the tune department over using a piggyback.

This would be known as a drawback.

[96stealth]

Opinions opinions. It's my opinion that the factory tune is a draw back, because it is not an optimal tune it is a rich tune. This means hp is being left on the table. I will agree for everyday driving a stock tune is best, but I have no regrets buying the piggy.

[summeronthechain]

@96stealth

I don't think you are understanding what I am saying. When I say a stock-like tune I mean a tune without a piggyback or AEM, like the tune that people buy for 300ZXs, or Cobras, or LS1s, or GTPS. That is usually seen in cars with easily burnable ROMS in the ECU which no one has really been able to do with the 3s. I don't mean the OEM from the factory tune.

Everything has pros and cons.

[summeronthechain]

@96stealth

Also keep in mind that Matt Monett is a business man first and foremost and makes money off of selling ARC2 controllers.

Not saying he lies about it, or that the ARC2 is incapable, but he has more incentive to put forth effort into getting a product he sells to work good versus getting a product he doesn't sell to work good.

[summeronthechain]

@96stealth

That could also be why the Stealth's tune was off on the dyno because the load/operating conditions were different than the car was tuned for on the street and the ECU can no longer compensate correctly as it would normally do. Just an idea.

[96stealth]

@summeronthechain I was just rereading your arguments on tuning. Ignition & cam timing is fine tuning. In some cases it doesn't even need changing. Since there are increase's in ignition timing with the Ash ecu means there is plenty of fuel available to take advantage of that. You said the fuel trims aren't altered very much. I guarantee the fuel is being altered more than any other aspect of the tune. Also raising the boost will effectively lean out the a/f if you can accurately monitor it.

[summeronthechain]

@96stealth

Fuel trims are altered by the ecu itself, not the tune. The aftermarket tune does not increase fuel, at this level. It simply adds fuel maps for the addition 5ish psi that a car like mine has.

Think of it like this: The ECU uses input data from the boost sensor and MAF to determine fuel/ignition and so on. The stock tune has data for up to 9.5 psi of boost. If the MAF/boost sensor report more than 9.5 psi of boost the ECU doesn't know what to do and therefore the car runs lean.

[96stealth]

@summeronthechain Have you ever seen a fuel map & know what it means? I don't think you know what it means. More boost means more fuel is needed at high loads. If the fuel map is set to run an a/f of 11:5 from say 5-7500rpm. It will do what is necessary to achieve that with it's presets. To make fuel available to run 15psi @WOT additional fuel is added. In other words the idc % is increased so the trims stay ideal. Additional mapping is for the rev limit increase. Not for the additional boost.

[summeronthechain]

@96stealth

While you are partially correct. The Nissan ECU doesn't set AFs based on engine RPM alone. Among other sensors it uses boost/maf/temp/and so on.

So while there are cells added to the data for increased engine RPM, there are also for increased engine load(boost) as well.

Without the additional boost(air) maps the ecu is only guessing as to how to adjust fuel to get it to be its desired AF at increased boost. Which might be fine for some people, but not for others, me included.

[96stealth]

@summeronthechain You are taking what I said out of context. You basically just repeated what I said with out explaining. The ecu is not guessing if the maps and fuel are not changed for additional boost. The ecu will max out its presets and if it isn't enough it will go into a safety mode & decrease timing from knock. If no knock is sensed, then it's a roll of the dice.

[summeronthechain]

@96stealth

The ECU isn't guessing because in an aftermarket ECU such as ASH's the maps are expanded to cover the extra 5+psi of boost, among other things.

This provides stock-like reliability and drive ability without the hassle of piggy-back setups.

You can do whatever you want without as long as there is no knock. But you can't do much before it starts knocking.

[summeronthechain]

@96stealth The modified tune provides data for up to 15 psi, where there wasn't any before. It doesn't necessarily alter the previous data, just adds to it.

An increase in boost pressure, provided it is less than the 15 psi or so, on a stock-like tune(no piggyback) car like the 300ZX will not lean out the AF because the ecu will correct it and maintain the AF it was tuned for.

If you increase boost past 15 psi, where the ECU no longer has fuel maps for, then yes it will lean out the tune.

[96stealth]

@summeronthechain Providing data would be altering the previous data. The stock fuel setting will max out to what ever it's set at. If it's programmed to use only 75% of the injector at WOT, it will use no more. To my knowledge 11-12 psi for a stock Z is maxing out the stock setting for safe fuel even though fuel is available. If the boost is increased beyond that it will lean out.

The aftermarket ecu's raise the fuel % for WOT & alters the maps to balance out the extra boost.

[summeronthechain]

@96stealth

Adding data is not altering the previous data. If you download two new songs from iTunes, does it alter the music you previously had? No. It is just expanding your library.

Increasing boost past the 9.5 stock level without a different ECU is not safe and there have been instances of it ruining engines. Although it might work for some, it isn't considered to be a good idea because it removes the safety buffer that the stock tune provides.

An aftermarket tune maintains that safety

[96stealth]

@summeronthechain Um, yes it is & a song is not software. Values are being changed in order to achieve ideal results. The ecu does not have a boost limit. You can do whatever you want as long as there no knock & the egts are within a safe range. By simply putting race gas in a 100% stock car you could probably run 18-20psi peak boost & not hurt a thing. All you need are gauges to know you're in safe ranges. I'm pretty sure the map is leaned out across the board & fuel is increased with Ash ecu's

[summeronthechain]

@96stealth

Values are not necessarily being changed, values are being added. Nissan's ECU does have a boost "limit." It is only programmed to manage the engine properly up to 9.5 psi. Thats what the additional cells of data that are installed do. I understand you think you know everything about every car ever made, but you are wrong.

[96stealth]

@summeronthechain Explain to me how it has a boost limit. Your telling me there is no way you can run more than 9.5psi safely?

[summeronthechain]

@96stealth I'm telling you that with a stock ECU there is no way you can run more than 9.5 psi on a 300ZX, without some ECU altering device like a piggyback. Just like the ECU my car currently has has a boost safety limit of 15 psi.

Some of the aspects of the stock tune are retained in a simple ECU upgrade like I have. I never said anything about multiple maps being switched out.

[96stealth]

@summeronthechain A simple manual boost controller will allow you to run more boost. If there was a boost limiter how did you accidentally have 20psi spikes when you were learning how to use the BC? How were you running 17psi at the track?

Just because it's a different platform doesn't mean nature of the ecu will be different. You're saying the ecu won't allow you to run more boost with a manual BC and race gas or even without race gas?

[summeronthechain]

@96stealth Wow ok that must have been over your head. The ecu boost "limit" we were talking about is not a limit on the amount of boost the turbos can make. It is the limit on the amount of boost the ecu can accurately adjust and manage for the engine.

An OEM tune has a limit of 9.5 psi safely. The tune I have is 15psi safely, and so on.

[96stealth]

@summeronthechain "An OEM tune has a limit of 9.5 psi safely. The tune I have is 15psi safely, and so on. " is a ridiculous statement. Any good tuner will be able to run more boost. It may not be the norm, but there is room for improvement on either tune. I'm willing to bet a 300zx could trap 118+ in the 1/4 on stock fuel.

[summeronthechain]

@96stealth Probably. But is it safe? I don't know. I'm not going to risk my engine trying to push the limits of the fuel to trap 118 mph to impress some rednecks at a dragstrip. It just isn't worth it for me.

Of course there is room for improvement on a mail-order tune. Anytime there is something generic, that isn't car specific it won't be 100% optimal.

But you have to a pretty knowledgeable tuner to see improvements over an Ashley Powers or Jim Wolf ECU.

[96stealth]

@summeronthechain It's not about impressing other people. It's about showing what a platform is capable of with stock parts. If it's impressive it's impressive. If not it's not.

In order to push any platform custom tuning is needed. Most people don't go that far. Your agument was there is a boost limit, because fuel mapping is available. That simply is not true. No car is safe when being pushed no matter what knock, a/f's, boost etc. There few people willing to push the boundaries.

[summeronthechain]

@96stealth @96stealth It is a vacuum line, its hard to hook it up wrong. How many other cars dynoed that day use the exact same setup without problem?

A spliced vacuum line, regardless of where it is hooked up to, will not affect vacuum pressure. Therefore the vacuum the FPR sees with or without a spliced line will be the same. Thus the line will be indistinguishable to the FPR.

I don't really care to formulate a theory about why it performed poorly on the dyno. It is irrelevant.

[96stealth]

@summeronthechain If you can't back up what your saying just admit it. So all the boosted cars that were dynoed had there fpr sliced into? They use the most accessible vacuum line. Which would be the one for the fpr on a Stealth. I do agree connecting to this line shouldn't be a problem, but there is no other explanation to why I wasn't getting fuel.

[96stealth]

@summeronthechain I also do not claim to know everything about every car ever made. We are arguing about stock vs modified ecu's and tuning. You have no real world tuning knowledge other than what you've read & have been told. All I can take from your arguments is there are multiple maps that switch in & out as needed. You also are claiming the stock tune is retained & being used with an upgraded ecu. Both of these claims are not true. You don't know what you're talking about.

[summeronthechain]

@96stealth

You are right, I have very little "real world" experience in tuning. And if I did, I wouldn't take what I learned about one car, and apply it to a completely different platform.

For the record, I don't think someone whose car occasionally dies at stoplights and can't hold itself together for one dyno run is in any way qualified to criticize someone elses knowledge on tuning.

[96stealth]

@summeronthechain One theory to it dying at stop lights is the light weight flywheel which will be replace with a stock one when the clutch is changed. My other car never had this problem. I'm not going to explain why since your so smart. Reason it went ape shit on the dyno was because they hooked up their boost gauge to my fpr. I watched them splice it in my self & didn't think it was something to worry about. I can replicate exactly what happened on the dyno by disconnecting that vacuum line.

[summeronthechain]

@96stealth Disconnecting the line is not the same as plugging a boost gauge into it. When the line is disconnected from the FPR there will be a vacuum leak which can mess up the fuel pressure. T'ing a boost gauge into the vacuum line doesn't create a vacuum leak or alter vacuum in any way.

I have no idea why you would think hooking up a boost gauge is equivalent to creating a vacuum leak. Simply disconnecting a vacuum line is not the same thing as connecting a boost gauge.

[96stealth]

@summeronthechain It doesn't matter what you think. That's what happened. The line was tampered with. I drive the car to dyno & it's fine. On the dyno I was running dangerously lean. Driving home it was fine. At first I thought it was me, but having the high setting turned down doesn't replicate what happened on the dyno. Instead it bucks & doesn't accelerate at all. If the line is disconnected it will run lean, but still accelerates.

[summeronthechain]

@96stealth I'm sorry that your theory is flawed as to why it was running poorly. But you really can't sit there and say that a vacuum line being disconnected is the same as having a boost gauge t'd into it. Because we both know it isn't.

I realize that you don't want to admit that something else was wrong, and that is ok. But everybody else can see that there was.

[96stealth]

@summeronthechain What's your theory then? Enlighten me. What an arc 2 piggy can't be dyno tuned properly? Sufficient fuel pressure wasn't there on the dyno. I can prove this all day long. On the last pull I cranked the the high setting all the way yet I got no increase in fuel. The only way that's possible is if fuel isn't available. The FP was down approx 20psi. It was one problem. Lack of fuel. I tampered with line just as they did & got identical results.

[summeronthechain]

@96stealth You didn't tamper with the line just as they did. A more accurate reproduction of what happened on the dyno would be to tap your mechanical boost gauge in the same place that they did and then see what effect it has.

The effect will be 0 because there will be no change in vacuum to the FPR.

[96stealth]

@summeronthechain This is assuming they hooked it up correctly and/or had no leaks on their end. Also how do you know that the vacuum line on a aftermarket fpr can be spliced into with out effecting fuel pressure? Please come up with another theory other than trying to disprove mine. Why was I not getting fuel despite maxing out my settings?

[96stealth]

@summeronthechain The aftermarket chip is needed because the stock ecu cannot be written to. The chip provides altered presets/parameters so boost can be increased more safely. The car is then running off these presets and no longer the stock ones. The only presets that are not altered for fuel is idle & cruise. It is using an altered fuel map. The only other alteration that I know of is the ignition timing is increased 2 degrees. There is a possibility cam timing ect also have minor tweaks.

[summeronthechain]

@96stealth

Well you are half correct. Anyways this is stupid and if you would like to have a discussion about it you know where to find me.

[96stealth]

@summeronthechain Google - Due to interest in our Z1 Motorsports ECU upgrades. Read the pdf. It verifies everything I just said. End of discussion.

[summeronthechain]

@96stealth

Another difference here in communications is when I reference boost I am referring to peak boost, whether the peak is a split second or all the way to redline.

When you refer to boost you are referring to what the car holds at redline.

So in effect, comparing boost levels on the two different cars in not a very effective way of measuring, since I could very rarely get the apexi to hold 15 or whatever psi I was running consistently.

[gman426]

stealth has bigger turbos and bigger injectors... I don't think thats too fare on the stealth's part. Need another rematch!!...lol

[b00mface]

damn that stealth looks heavy