Robert56

iTrader: (2)

Just wondering who actually uses EGTs or Wide Bands per cylinder for tuning their DP Wet hits? I think I know of two guys that have done it but neither was a DP Wet. If so, please post what size hit you begin to do this on.
Robert

Mike@HSW

iTrader: (6)

I seriously doubt you are going to get a lot of "yes" on this one. Since most people dont have the money or resources to perform a test like this why I always recommend a dry direct port. I am also a fan of wet direct ports since i dont like filling my gas tank with C116 and would rather run a standalone. BUT when it comes down to it a dry direct port is the more efficient of the two right out of the box. If variations in cylinder temps occur as a result of flawed intake design then why inject fuel through them which would increase the inefficiency? It would not surprise me to see less variations in EGT's with a dry direct port over a wet.

Hennytime

iTrader: (33)

doesnt bs3 have a function or add on that can support individual egt sensors per cylinder? im just spitballing, but thats the only way ive heard of doing that, and im not even sure if its real

BCNUL8R

iTrader: (2)

Can you give a brief explanation of how a dry direct port works? How do you get the correct amount of additional fuel while spraying? If your running a large enough shot to justify a direct port if your going dry wouldn't you have to have huge injectors to keep up with the fuel demands?

My only current nitrous experience is with a wet plate, but would like to learn about all the possibilities in case sometime in the future I want to do something different.

Thanks

Mike@HSW

iTrader: (6)

You need an external controller like The Interface or an engine management system like BS3 to run a direct port dry shot. And Yes you would have to run larger injectors to compensate. A 60 or 79 lb injector will cover you up to some pretty high power numbers, which may be more expensive but you can also consider that on a Dry DP you have two less solenoids, 8 less lines and fittings and a cheaper nozzle.

What robert is talking about here is running a set of exhaust temperature probes on each cylinder. EGT's have a direct correlation with the A/F ratio of each cylinder. What you want to do (mostly on high horsepower applications) is to get the EGT's of each cylinder as close as possible to one another. When you add an intake with various runner lengths and designs, add manifold porting and head porting into the mix you can see some variations in EGT's as a result of every runner not being identical to the other and also the design of the manifold itself. Even a set of flow matched fuel injectors can slightly vary from one another. now, one way to correct this would be to make slight fuel adjustments in a Wet DP to compensate for a slight lean/rich condition in each cylinder. It is virtually impossible to get the A/F perfect on all cylinders, but we'll ignore that for now. But, changing fuel jet sizes would be one way of achieving it.

Now, the question, why cant this be done on a dry direct port? For some reason people around here think it cant be done unless you are running something like the BS3 where you are able to make adjustments on each cylinder. In my opinion this is not true and it can be done on a stock computer. Again, i dont know why anyone running a stock computer would be doing this test, but we'll ignore that as well. Injector flow rate can be changed if you order a specific set. With variances in flow rates for injectors you can match them up to specific cylinders. So, that is one way of compensating varying EGT's per cylinder on a dry shot.

BCNUL8R

iTrader: (2)

I can definately see the benefits of that kind of setup. I was just curious how to control it...thanks for the info!

Robert56

iTrader: (2)

With FAST you can also control individual cylinders and specifically for the very big dry guys and couple guys doing this. I might add, this is much easier than messing around with all the fuel jets. Adding fuel through the injectors is much more efficiant compared to fuel jets. Though, like Mike said, we will never get every cylinder exactly the same, just to many variables.
Robert

860 Performance

iTrader: (1)

I don't do it on my car, but my buddy with a 555 does. The information is great, and I'd like to set mine up, but there always seems to be something more urgent to spend money on.

The biggest suprise to me when we first set it up was how the EGT's varied NA. There was a pretty big spread. He then used the DP to help even things out. This is on a carburated motor, I'd love to see how an LS motor does with the plastic manifold in comparison.
Also, once he had a fuel jet clog, and saw it immediatly after the run, which was a bonus.

After working with his car, I'm a firm beliver in logging all 8 EGT's. Hopefully I'll get to it this year.
Vinny

Mike@HSW

iTrader: (6)

Vinny, you are absolutley right, it is a fantastic tool to use, but not all of us can afford it . This is exactly what we were talking about. You clearly saw the inefficiency in the in the intake which are a result of many factors. Now, if you add fuel to that equation via a wet DP, you going to make "something bad, even worse". Obviously the need for individual cylinder tuning on a wet is because of the way fuel is delivered unevenly by the fuel system in the DP wet hit itself. If EGT's are uneven NA, then they are going to be even more out of whack on a wet DP

I think what is important here are the people who DON'T do individual cylinder tuning via EGT's or Widebands. How are they supposed to tune out lean/rich conditions per cylinder. Do they go with a wet dp that can often make those lean/rich conditions worse. OR do they go with a dry DP which i gaurantee will have more even EGT's right out of the box over a wet DP. If I were a consumer and had no access to an 8 EGT setup, i would be all over the dry shot for its consistency and efficiency in delivering AIR (not air AND fuel). Lets think about this, WHY is an injector located in the position it is? Because that is the most efficient location for it, otherwise it would be somewhere else. Would it make sense to have an injector half way up the intake runner???? no it wouldnt make any sense so why do it with a wet dp.

Mike@HSW

iTrader: (6)

can we make this poll public, or at least can the people who are voting yes post up your experiences so the board may learn from them. No sense in clicking yes and not having any input.

Nitro Dave's Nitrous Outlet

iTrader: (25)

I voted YES on this little poll. Let me explain to you why and then dont expect me back in here.. I dont have time to argue with all you internet know it alls.

The purpose of a directport is even cylinder distribution and individual cylinder tunibility.

Wet or Dry a directport can be a awesome tunning tool when used properly.

With a wet Directport you have the ability to maintain a even HP distribution to each cylinder and adjust airfuel to each cylinder by adjusting the fuel jet to add or take away fuel.

With a dry directport with aftermarket computer system you will have the same benifits as with a wet directport just a different method. You will adjust the airfuel by taking away or adding fuel to that cylinder through the computer software.

With a dry directport that you can not adjust the fuel delivery to each cylinder through tunning software your tuning choices are just not as great as the two above.Assuming you have a dependable way to add fuel when the nitrous is activated. The only way you can adjust airfuel is to upsize or downsize the nitrous jet. Doing this will clean up that cylinder to running right. You will no longer have even distribution to each cylinder but it will work. the small difference should not really be to big of a deal. Just not my favorite option. I dont see how anyone that truly understands things can argue that this option is better than the two above...

As far as the question of who really individually tunes each cylinder. The answer is simple...
Anyone who is really throwing a large amount of dope at there motor and wants it to live should be individually watching each cylinder while tunning. Yes having a high dollar EGT system is nice but simply knowing how to read spark plugs is you need.

You guys have a good day and argue away.

Dave

Robert56

iTrader: (2)

Yea I have been wanting to for some time also. The $$ is my biggest hold back, but do have a single EGT to play with, lol. I know Al had a setup some time back and he posted the results. actually what he found was the temps to be not to far off for the LSx, IIRC.
Robert

Robert56

iTrader: (2)

I thought it was? Maybe I don't understand how to do this, or really what it does?




As usual, there seems to be only one "Internet Know It All" (as you state) in this thread. Of course no one else could possibly have any insight or knowledge besides your self, lol. When you get some actual Dry DP experiance then you'll see the difference.

Robert

ATVracr

iTrader: (5)

I bought a FAST computer to tune my DRY DP this year.

I learned alot over the past year so We are going to try and Creep up on it and hope it lives.

383LQ4SS

iTrader: (33)

I have tuned per cylinder with a wet direct port. Although not much was needed.

I used the Alltronics Red Alert. You can get it from Jegs or Summit for a lil over $900. Very very nice unit.

You dont need an EGT setup to do per cylinder tuning if you are very good at plug reading and take incremental steps in HP.

You can do that with wet or dry.

Mike....you said you could get different flowing injectors to adjust Af on a DP dry. Why not just reduce the size of the nitrous pill on that cylinder? Whatever your using to fuel it, such as the Interface or some other tuning option, can still deliver a "flat" amount of fuel...and just tune the nitrous pill around the fuel.


One other observation. Mike...i noticed you said that if you had some hot cylinders NA...that it would be worse on spray. That really is speculation. In my experiance....with a wet kit...be it DP or plate or simple nozzle...many times the leanest cylinder may not be the leanest while spraying. In some instances...that leanest cylinder would become the most...or second most RICH cylinder halfway down the track. And some of the richer cylinders NA would become some of the leaner ones as well.


Also as Vinny said...when running NA those damn EGTs can be all over the map as well. Something like a FASt or BS3 with individual tuning per cylinder would be AWESOME all motor as well to really get max HP.

Anyways...Im not even sure what the damn arguemnt is about in this thread....lol.

This is just my experiance.

860 Performance

iTrader: (1)

Thats when you can click on the poll results and see who voted for what.
btw, I voted for 'Robert get to work'

Mike@HSW

iTrader: (6)

Al,

Thanks for your input, I appreciate it. There is no argument here, just a technical conversation. But I guess they aren’t allowed anymore since people disagree with others

changing the nitrous jets is also another option but i feel it’s not an easy one. It is always going to be easier to match the fuel to the flow rather than the flow to the fuel. If you have one cylinder running slightly rich because of the inefficiencies of that runner, yes you can adjust it by going with a slightly larger nitrous jet. The problem is you are trying to make up a lack of airflow with nitrous which is much denser and has a lot of pressure behind it. So, to make any kind of slight adjustments you would need nitrous jets machined accurately to the .0001, which is difficult. You have to consider the pressure behind the nitrous and the fact that is extremely denser then air. Basically a little can go a long way. As someone stated earlier, you are creating uneven distribution by doing this. Well you are and you aren’t. If you didn’t consider the incoming air in anyway, then yes you would have an uneven distribution. BUT when you have varying amounts of air coming to each runner and you correct it by adjusting nitrous jets, then you are in fact balancing out the airflow to each runner and creating a uniform distribution. This would probably take a very long time to perfect, but could be done.

You are right; it is only speculation that adding a wet dp would make the problem worse. If one cylinder has poor airflow characteristics then adding fuel to that runner would only increase the inefficiency to that cylinder, leading up to more variations in A/F ratios. We could get into the science behind everything, but I don’t have test information to back it up and I’m not arrogant enough to just think I am right all the time like other people do.

My point out of that was leaning more towards the guys with stock computers using the interface whether they can read a plug or not. I believe you would see fewer variations in A/F ratios per cylinder by using a dry dp over a wet dp.

I bolded one comment you made cause i appreciate that. These are your experiences and its great to share them. How would anyone learn if
we didnt. Also, what kind of manifold setup were you running and i assume all the numbers were after you made fuel adjustments.

383LQ4SS

iTrader: (33)

I was using a FAST 90 when I had the EGt setup. I was in the process of making a sheetmetal...but never finished.

On the screen shot above was actually just an NA run with no juice. I never saved a screen shot of a nitrous run. If you note...even on that screen shot above on the NA run...some cylinders swap during the run. Note the red line that moves up and down. Thats the RPM line. You can see a few revs and then launch. Then each gear shift. If you note certain lines during that run...they swap places during the run. Not even just within a gear...but during a run. Certain cylinders where cool at idle or no load...but once they got a load they sometimes became one of the richer cylinders. Note the purple line. Its at 1372 at the sample rpm...which is the highest. But during idle, rev up and laucng and first gear it was one of the leaner/cooler cylinders. Pretty enlightening. It just goes to show that you are just going to have to shoot for good averages throughout a run.....not jst one dyno pull through the rpm range in one gear.

Mike@HSW

iTrader: (6)

While you obviously do see some variations (which are natural) every cylinder is within <2% of the average. Those seem like some pretty damn good results to me and i probably wouldnt consider any adjustments. At most i would swap the 4 and 6 cylinder injectors just to see if i could get those two close to the average. Did you successfully tune any of the cylinders with or without an improvement in mph? Did you pull the plugs after this run? it wouldnt surprise me to see virtually no difference in any of them. Its pretty much impossible to compensate, but even the conditions in temperature and humidity the next day could vary these results one way or the other.

these results tell me one big thing, more then likely a dry direct port would work perfectly on this motor without additional per cylinder tuning.

Robert56

iTrader: (2)

Damn I love this stuff. running the EGTs would seem to benifit not just tuning for n2o, but also n/a if needed. What would we consider needed, is there a base line % that the pro tuners go by for deciding on adjustments. Seems if the cylinders are only 2% off, any variation in barametric pressure, or humidity and/or other pararameters could change this % to the better, or worse? So how would we determine when adjustments are needed?

Al, I know you said you didn't save any sprayed EGT screen shots, but I swear I saw a dry EGT posting from you sometime back? there is one other site member who saved, IIRC, some DP Dry EGT findings and they were all within 50°. I think the LSx platform seems to have fairly close temps from the get go, compared to other motors, like the SBC that Vinny talked about with the carb.

Anyone have their EGTs recorded and plug readins per cylinder to see a comparason? this would be excellant information for my plug tuning write up that we are working on. Side by side would really be a valuable tool for those of us seeking to go EGT and reading plugs.

I know I plan on getting a full setup, what a great addition to the tuning tool chest.
Oh by the way, I don't think there is any argument here, just some great debating and technical facts, with some speculation which always comes with cutting edge technology. So, I do contend, that the DP Dry would/will be closer with the EGTs (from testing/tuning front inlet dry hits), than a Wet DP setup, who agrees with this speculation? Soon I hope to prove this, and will post any results, good bad or ugly.

Robert