Bob_H

I wouldn't worry to much as long as the A/F is below ~13 the entire run. If you are too rich up top, it is an air corrector change,(can't remember which way), but I'd leave it for this weekend. To rich down low, mains,(smaller). That is real general. Accelerator, etc.., self explanatory for throttle tip in, etc.. Start to worry if you are seeing above about 13.5:1 as the rpms go up. You can deal with some leanness downlow, but stay away up top. About 12.5:1 for the run is nearly perfect. If you see 9 or 10:1, drop a main jet size. Of course, soldering up 6 jets and redrilling them is way fun I'm sure. I'd leave it fat as a pig if it is rich and order the smaller ones for later. If it is lean, drilling is much eaiser. Again, lean down low, but getting fat up top or staying close to the same, increase main size one tick. Good down low, getting lean up top, I think it is smaller air corrector. And I think going to a bigger air corrector is called for if it gets rich as the rpm's rise. It makes sense, but I'm cya,(well, cma) on this one, I don't know for sure. Get a good printout and I'll swing it by my guy next week to see what he suggests. Get a printout with the A/F graph for the run at the bottom. If you can't get it scanned in, see if the shop can give you a .jpg of the file on disk. Word racer dude, Bob ps- you work too late! you are always at work when I am at home getting ready for bed! edit-by up high and down low, I am refering to RPM. Lean at low rpm, increase main jet, fat at low rpm, decrease main. lean up top, smaller air corrector. the more I think about it, the more i recall that is what we were looking at. the mains are the big one to monkey with. the air corrector helps the higher rpms and fine tunes the a/f up there. think about it, smaller hole, less air and more fuel to mix in the emulsion tube, meaning more fuel available for the main to spit into the carb. yea, lean up top, decrease air corrector. by up top, i would say 4000 rpm +.

oh, one more thing about the carbs frequent need to urinate. Is this when the motor is cold as well? Or is it only when the motor is hot, or has been idling for a while? If the second case is true, you have the same problem I have, too much heat in the rear carbs. Driving is no problem, b/c their is airflow through the engine compartment. However, that is not true when idling or driving slow. I can hardly touch the last carb, but the front carb is not too hot at all. FWIW, bob

So you think you can join me at Summit point Nov 2-3 with NASA? I'll have the Z there, last time on the track before I start the RB swap! Glad to hear you have some dyno time scheduled. AS for the rear carb dumping fuel, it is clearly the float valve/seat, -I assume that is what you mean by needle jet,(valve?). If you have cleaned it well, and it is metal to metal,(vice some are rubber to metal), then think about putting the needle down into the seat, then tapping it lightly with a hammer to form the seat better. It should be a steel,(silver), needle with a brass seat. You might be able to take them both out and see if they are sealing well. Do you have a psi gauge hooked up to see what pressure you are actually running? Something to consider playing with on the dyno as well,(assuming timing is fairly close, you should be looking at about ~36 degrees total). I run 3.5-4 psi. If you run much more than that, you can very easily overpower the float valve. I assume you have some form of pressure regulator? I am running a holley one, and it is almost backed all the way out to get the low psi I need. You have been spoiled with SU's that can have gross jets that seal much better and can deal with more pressure. An option to consider. You can pick up a cheap-o pressure regulator at autozone or similar. Just plumb it in line to the carbs. I put my pressure gauge btw carb #2 and #3. Bought it at Autozone, the holley Fuel pressure regulator I ordered. But ~3.5, max of 4 psi for those carbs. BTW, food for thought on this problem. It pisses out of the carb airhorns when the motor is not running. That means it is likely spilling over into the motor when it is running. I'll bet #5 and #6 spark plugs are running rich.... I would also check the float level...And check to see if the floats still "float". If they are like mine, they can't sink. If they are like weber carbs, they can get a hole in the float and sink...easy fix, drain the fuel in the floats, epoxy the hole, race away. -Bob

Bob, Are you 100% sure you have a LSD? That looks exactly like an open diff to me. Do you have a different shot which shows the clutch packs? My open diff R180 with a 3.54 would leave two beautiful black marks for 100 feet. I have had many people tell me they had LSD's because they spun both tires equally. That doesn't prove you have one. Just trying to find out how you came to that conclusion, since it looks just like my open R-180. What happens when you grab,(hold) the input flange and turn one axle? What about holding one axle and turning the input flange? -Bob H

john c, I'm not so sure it is normal. Eliminate the ring and pinion,(well, hold them) and as john said, we are getting .156 inches of movement internal to the Gleason itself. I guess another way to check would be to hold the ring gear itself and one of the stub shafts and see how much it moves them - i'd bet pretty close to the same. I don't think it is additive, when the R&P itself has .008 backlash, vs. the .156 on the stub. Not sure how the two distances relate ratio wise, but I don't think that the tolerences added are giving me/us this amount of movement John, maybe try holding the ring gear and a stub and see how that changes the mvt at the other stub axle? And haven't had a chance to scour the web yet...will work on that soon. -Bob

I was going to reply to the list, but you have it here, so this is better. You really need to find time to run a dyno with a exhaust analyzer if you can. You want to run the piss out of the car for the weekend and you have no idea what the jetting is like. Remember how far off my jetting was when I first started, and it was "supposedly" from a tuned 3.0L motor. It was so lean, I would have burned several pistons if I drove it hard for any period of time. It idled and pulled fine. And free reving with an analyzer is not the answer either. If you can't get a dyno, get a shop that has an analyzer and rollers to let the car be loaded up. You ran it on the dyno before, find the time so you don't kill the motor this weekend... -Bob Instilling the fear of motor breakage in a town near you...

Ok, I dropped my R-200 off with john,(from this board), to check backlash, etc.. for it felt rather loose. Well, he pulls it apart, everything checks out, .008 backlash. Bearings etc.. were in great shape, no metal floating around. Ok, I have the Gleason-torqlok or something similar last name, bottom line, works like a Torsen, but preceded it and made by Gleason. To quote john's response to me: "but if you hold the ring gear, pinion, and one stub shaft still there is about 1/8-3/16 movement in the other stub shaft." So we are stumped. I don't know if the gleason should have that kinda movement internally. Can anyone point us in the right direction of who to ask? We can't go to Torsen, b/c it is a different design and different company. Looking to find out if there is a way to set the lash internal to the gleason, or if that is normal. -Bob Hanvey

I talked to a guy 4 years ago who was working on putting a RB head on his L6. It involved welding up some of the coolant and oil holes, drilling some others, and custom adapting a setup to drive the camshafts,(DOHC vice SOHC). It was serious custom work. Don't know how he fared. The only interesting note I think I remember was that the actual bore spacing was the same and the head bolt holes were pretty close or in the same spot. But this is all hearsay because I can't find my old e-mails,(we talked back and forth for a while), and it is all memory I am going from. You might be able to bolt it on, but be prepared to do massive custom work to ensure it all works correctly. And I haven't even talked about porting, custom exhaust manifold, etc.. Might as well spend $1500-2k on a well built L6 head from Sunbelt or similar. I don't think you can put adapt the ECU, or rather I don't think it would be worth it. Just my few cents. -Bob

please put in the for sale. I realize you are targeting this audience, but at least say you put it there as well and just wanted to bring it to our attention. -Bob

Eddy, Here is a post that basicly answers some of your turbo swap questions: hybrid post on turbo swap -Bob

as the topic slowly drifts off topic... Netscape! ACK! Loved it when it first came out,(1,2,3), not anymore. It is akin to AOL for me, too bulky and akward. The one thing I do like about Netscape though is the favorites and how they go to another column when you are full top to bottom,(vice having to scroll down when you have tons of links). You saw people in the Navy trying to get all the answers with no work? Where? I NEVER see that! Bob Navy pilot type.

Fair enough if it were broken. However, it worked for me. Before I typed that message, I tried the search to make sure the topics he was asking about were there. Before I shoot of my mouth, I usually check and double check what I am saying. They are, over 200 results for turbo alone in this forum. However, to search all the forums, I have never had luck with that, long before the problem was reported. If he had searched, it would be easy to rebuff me and make me really look like an ass by saying that the person tried the search and it wasn't working,(and would have garnered a quick apology from me). People have posted that way before, i.e. hey, tried to do the search, but its not working. gotta question... Besides, you don't need the search to go back a few pages and see what has been posted for the last month or two. The only topic not really covered well by the search or looking back some pages is the NOS question. That is why I answered it. Not everyone likes my method, but take it as akin to James, (240z turbo - he may not like the comparison ). Bottom line, I am usually nice the first time, but put it stronger the second time. -Bob

So Terry, how much vibration/feedback did you gain by removing the coupler? I have a urathane one right now, but... I know yours spends many hours in the grarage being fabricated upon.... Sorry. Just wondering on the vibration, etc.. -Bob

Alright, time for me to turn into the ass, since you haven't been listening. There is a really cool button at the top of the page. It is right between register and FAQ. It is called: SEARCH! And I quote: That has been covered, on average, about once a week for the last year - every single detail you could possibly think of, even water injection and blow off valves. You really don't even have to do a search, but scroll back a few pages. All of us here take time from our day to ask and answer questions. We're not going to sit here and give you all the details when it has been done several times over. It is a waste of yours and our time. Look at what other people, who have already done it, have said and posted. Then, come back and ask more specific questions. I'm raggin on you because I already said it once before, but your questions show you haven't even touched the search. My standard comment, eat more wheaties if I am hurting your feelings, it is nothing personal. Next, you talk about wanting to run 13's,(now revised to low 13's), but want a daily driver? We told you turbo is the way to go. To run 13's NA,(Norm has, I have, and a very few others), you will spend a fair amount of money, lots of time, and will break things. I am on my third transmission, and I don't go to the dragstrip all the time! You can spend a lot of money building up the internals of your motor to handle the naws,(flips Fast and furious hat off) or similar, but why? It is a huge expenditure of money for a very small return. If you really like wasting money, I can give you my account number and you can send a few thousand my way. It is the same effect. I quoth again: Again, already been answered. And to back up the last question, you can't run a dry system with carbs. It must be wet unless you have some magical way to make the carbs dump more fuel into the motor. And Norm, gotta address that last comment on webers. You never raced me! Actually, yours is faster, but it would be interesting to see you drive mine as if it were yours to see what it would run. I feel sure I am putting more power to the ground. But I expect with my 2.1 second 60 foot times to run in the low 13's when I get back on the track. I ran 13.7/13.8 with the open 3.54 and crappy street tires. Now it has good tires and the 3.9 with a gleason and the better ratio's of the T5. But 95%+ of weber carb'd L6 motors are NOT tuned to their potential, so that comment was misleading. I have driven several that sounded fast, but most certianly were not any faster than a 2.4 with SU's. And I am refering to 2.8's.... Now stick your motor with a good set of well tuned webers, now that would be a good comparison! Bob The Search Nazi

I'm calling your bluff here. Some of these assumptions are way off. But first, I would love to have that motor in my car. Period. I have the previous version in my M coupe and it is incredible. But I digress. Sodium filled valves are really for one purpose. To help the exhaust valve withstand more heat. It helps keep the valve cooler by transfering heat away from the end of the valve and into the head. Under high heat, the sodium becomes a liquid and splashes up and down inside the hollow valve stem. If this is what you were refering to by splash effect, ok, but I have never heard it called that before. So in that respect, it does have better cooling, but it is a far cry from "far more efficient". The only time the valve head could transfer heat was when it was on the seat. Now, think about that liquid sodium when you extend the valve, it rushes up to the top of the valve stem, with all its heat, and lets it transfer its heat out then. Next, as the valve closes, it rushes back down to the valve head where it can transfer heat out to the valve seat. It is not just transfering it out, but absorbing the heat as well. Next, it has nothing at all to do with high rpm limits. If anything, in really,(over 10k) high rpm motors they won't use sodium filled valves, since you are introducing a liquid that is moving up and down, often in the opposite direction of the valve. It may not be much weight, but take that at 9-10,000 rpm and it starts to become significant. They are used in race motors and exotics,(ferrari, etc..), but there is a limit to what they can take, and they are not really used to gain a higher rpm limit. The exhaust valve is usually the hottest part in the combustion chamber, hence the need to cool it a little better than the other stuff. Sodium filled valves are lighter than a conventional valve, and that is why you often see them in high powered, higher rpm motors. It is really a mid to high rpm design. It is not really a high rpm motorcycle type design. Think about this, VW motors use those valves, Air cooled, gets kinda hot.... I once saw a reference to VW motors that went like this: What a VW motors sounds like at idle: putt, putt, putt. What it sounds like at Redline: putt, putt, putt. Sorry, good side humor. And the reference to making the air more dense, remember, we are talking about the exhaust flow, not intake. The idea is to keep heat from the valve seat and transfer it up to the cylinder head. I seriously doubt it is a noticable or measurable difference in the temp of the outgoing air charge with a sodium filled valve vs. the other. Not picking on you in particular, but just wanted to clear some of this up. They actually started this with NaCl, or table salt in the valves, and eventually got to the metal sodium. -Bob

Steven, I just finished reading about that ECM. Facinating that they use a base Delco ECM. Although the software is over my head for immediate understanding, mostly because of the use of abbreviations for many functions. Just as a contrast, I donwloaded the AEM software and it is more straightforward to read. I can't compare how well they work compared to each other. So you are using this unit on your RB30 motor? My only thought is how much harder it is to tune with a turbo motor with that ECM. Part throttle response/driveability is a big issue for me when I do the swap. There are numerous times when you are steadily increasing the throttle and boost is in a transient stage. It is that area that I am tailoring my search for. And I have dictated that I want data logging. SDS would be a cheap way to get started,(w/o data logging), b/c Clint already has some maps for the RB26dett. I think in the end I will go with a system that has someone running the same type of motor. That way, I at least have a starting point for tuning, vice doing everything from scratch. So right now, the search is: ECM with a program for a mostly stock RB26dett, with intake/exhaust and upgraded intercooler. I may play with larger injectors later as Clint did, but for a baseline to get started that is what I am looking at. AEM doesn't have their race setup going yet, SDS doesn't data log, Tec III is mainly a US thing, so there are no RB programs that I know of,(same goes for Wolf 3d and 4). Motec is more than I want to spend.. So Autronic and Haltech are up front for now. We'll see what I can continue to turn up. I have debated running the stock RB computer with the AEM, but ultimately, that limits me, and with the multiple throttle bodies, can prove troublesome... -Bob

Clint, Actually we just all wanna be like you! You and Cuong. It is becoming more and more official. I just sold the harness bar and 4 point system from my BMW and have put the Ground Control suspension up for sale. It is sad to start to see these things go.... But at least I have the Datsun. -Bob

Jason, Did you get an e-mail that I sent you and Brad about a week ago? I have been having probs with my account, and I don't show that it went out, but Brad got it. -Bob

Not sure what you were asking about Norms car. First, Norm has been drag racing for years. He has changed the internal ratios of his transmission,(mixed and matched to get what he wanted), he runs open headers, high compression,(10.6:1 currently, but has been up over 11:1 before), and EXTENSIVE tuning of his SU's. I said it would require lots of time and money to get into the 13's. He has spent all kinds of time to get his car to that point. To give you an idea, I could go out in Norms car, and likely turn a 13.5-.8 in the exact same configuration he ran the 12.9 in. He knows what he is doing, and that is the extreme end of the spectrum. Did you take a look at what kind of head work he did to his N42? Serious stuff. Next, stock with no shaving of the N-42. You will cause more problems trying to run that kind of compression. 10.5:1 is really too high for the street. 10:1 is really the practical limit for a street driven car since you can't always count on getting perfect 93 octane gas at each fillup. Lockjaw put it best: You can't put it much better than that. And really, to run the compression you want, the P series are a much better design. However, they require some not insignificant mods/work to work after shaving to get that CR. Are you willing to do that or pay someone to set your valvetrain and cam timing back up? It all gets back to time and money. And for the record, I have only been talking about a 240. To get the heavier 280 into the 13's is the same as trying to get a 280zx into the 13's w/o a turbo. Their weight is very close to each other. You are dead set on that high compression ratio. Let it go, it will cause more problems than you care to deal with. If you chose to ignore those of us who have done it, expect it to break just like Norm's did. Remember, this is NOT a honda or a toyota. The cylinder head design just does not support that CR w/o race gas. Don't shave the N-42 if you use it. Run it stock with a good aftermarket cam. I recommend somewhere in the neighborhood of .490 lift and 290 duration or larger,(but not larger than the other one I mentioned). Next, the difference in .1 of C.R. is worth a hp or two at best. I think,(recalling from memory here), that every full point increase in C.R., i.e. 9:1 to 10:1 is worth about 10-15 hp. So you might get 2-3 hp from the .2 point increase.

I shall point you in the right direction.... It is called the SEARCH function! Learn it, use it. It has been asked and answered many times over. It can be bolted in your platform. Research some more and you will find the approx prices and such. -Bob PS - drop the all caps please. It is hard to look at and is like you are shouting I never understood why some people post in all caps...

You don't have to go to full blown racing classes to get time on track with good instruction. Many clubs offer weekend courses where you can get 2+ hours of on track time with an instructor. The typical cost is in the $200-400 per weekend. For that price, you get two days at a track, with usually 4 20-25 min sessions on track. Compared to an autocross or anything else, it is a lot of time on track learning you and your car. Groups like the BMW club, the Porsche club, Audi/miata,etc... And there are dedicated groups for instructing like Tracktime, Car Guys, etc.. Do a google search for High Performance Drivers Education and you will be surprised what you find. I instruct with NASA. It is a group that combines the HPDE's with racing groups. it is great to go to a race and watch American Iron, Honda Challenge, spec racers on the same day you are on the track. E-mail if you have specific questions,(I tend to forget where I posted and don't check the threads..). -Bob

Alright, don't make me do a reply like I did in the weber cylinder head thread. But you asked for it. I guess some people just don't know what they are talking about.....(stolen from your earlier post) First, know what you are comparing. Let me take you back to school. I refer you to this page for the figures for a "stock" 280zx hp and torque ratings: Z and ZX specs page Next, I refer you to this page to covert the NM torque to LB-FT torque (for an apples to apples comparison): Unit Conversion Page You will notice that 274 nm of torque converts to 202 lb-ft of torque vice the stock rating of the 280zx of 203 lb-ft of torque. So in 100% stock form, the zx turbo motor puts out more torque,(yea, 1 lb-ft), but more importantly, at a much lower rpm of 2800 vice 4800. That says a lot about driveability. If I am mistaken in reading what you wrote, by all means tell me. But the fun stuff was just beginning. You told us absolutely nothing. I know nothing about your car, no specs, no figures, no numbers, so saying it is nice off the line tells us the reader, Nothing. You are a fan of the SR20det. No problem. Mike is trying to make an informed decision about which motor to put in. You were dead on in your comments about parts availablility. But don't bring in the other comments, for they only degrade the discussion. And Len168, you aren't helping either. Your discussions don't address the differences in tuning, hp, setup, etc.. of the cars you compared. I'm not going to get into that right now, but will if you want. Bottom line, w/o car weight, gearing, tires, state of tune, turbo setup, boost, etc.., saying a SR20det was beat by a v8, but ran over xx car tells us nothing. There are SR20 motors with 5-600 hp and will stomp nearly everything on the road. And? There are RB motors that will do the same. W/o specifics, it does nothing for us. And a comparison of RB to SR motors is only really valid with the RB20det vs the SR20det. With identical displacement, there is minimal advantage with the RB motor. You save weight with the SR motor, but likely can rev the RB higher,(stock vs. stock). Both are great motors, and the SR20 is eaiser to get parts for. However, as soon as you start looking at larger displacement motors such as the RB25/26/30, all that goes out the window. You now have more displacement, so a comparision is not fair or valid. Keep to the facts, and state your opinions as such. -Bob (grumpy right now)

Important fact, the stock exhaust pipe was cut at a 90 degree angle and extended out near the edge of the bumper as I mentioned in my first post. As soon as you start changing ANYTHING with the exhaust tip, that goes out the window. I have all new seals in the back of my car, and the rear hatch has contact all the way around,(good contact). I had the smell/fumes pretty bad at about 45 mph. While I haven't changed my exhuast from the 45 degree tip cut I have on it right now,(vain bastard) we did try something. Borrowed a 90 degree cut pipe,(not a bend, but a flat surface) to go over my tip, about the same overall distance, i.e. just behind the bumper as you look straight down. Significant difference in how much "smell/fumes" came in the cabin at the speed mentioned above. The best is to angle it down. Angling it up as Scott has is the worst possible combination for the exhaust. It should be fairly apparent that the area right behind the tail lights is a dead spot airflow wise. He is dumping his exhaust right into that spot. So if there is any reverse flow up the side of the car,(common on bodies at slower speeds), he will smell the fumes, sealed hatch and seals or not. While there is no denying the cool factor of the rear diffuser, I don't think it addresses the problem. It may help, but I think he will still find some fumes present. It is a quick simple check to turn it upside down and see what it does. If the muffler is welded in place, then purchasing a cheap-o 90 degree bend for each tip at the local auto parts store,(that puts them 45 degrees down vice 45 up). It may mean he has to get rid of the cool muffler he currently has, or modify the tip if he finds the above suggestion works. I was saying it gently the first time. This time I will say it a little more clearly. Scott, your exhaust tip is a major factor in your smelling fumes. And having the rear spoiler only makes that dead spot more prominent. Go for the rear difusser if you want, but I don't think it will solve the exhaust probs,(but it will look awesome!) -Bob

Ok, so I have seen the 11 psi w/stock injectors, the 11 psi with 680cc injectors and the 15 psi chart. Do you have any of the above with the torque curve as well? If you don't, and ask your dyno person to print you out one, ask them to make the scales the same for the hp and torque,(start at the same point and same gradient), otherwise it puts the crossover at a different point visually than 5252 rpm. Trying to get an idea of what torque you are producing for the hp you are getting. Do you have the plot with RPM as the x-axis vice mph? Thanks man, your the coolest. -Bob-o

Hey, no taking my comment out of context! That comment was in reference to getting a 1900 lb 240z. You sure as heck aren't going to get a 1900 lb zx or a later z. And I quoth: I was refering directly to that. I in no way said the 240 was the only way to go or that it was the only way to get to 1900 lbs,(but as far as Z's go, it is the only way to get to that weight w/o chopping off the entire front end). My reference to track driving was for ME track driving MY 240Z on the track and the motor reference. Bottom line, I think you misunderstood the sentence. Would it be eaiser to understand if I said: You have to start with a 2000 lb 240z to get down to 1900 lbs with the SR20det (italics added to the original sentence). -Bob