Dyno run done!

[jeffp]

Thanks Tim, that is correct regarding the flow of the turbo. I will make sure of what the system is doing and if it is operating within good specifications. I have already made arrangements to have an external waste gate installed on the manifold. I am going to try this steup first and see the outcome. Taking the intake and exhaust off the car is a pain in the A** anytime and if I do it now or one try later it really doesn't matter to me. I am also considering a smaller compressor housing, but I need to get some data from this first setup.

You are more then likely correct in that I will need to go with an external unit, but I want to cover all the bases here. This work is not only installing a bigger turbo, but also some R&D for future builds of similar configurations. I have some what of a unique setup and I have not found any real data on what I am doing, so I will approach it in a step by step basis until it is correct, reliable, and accurate. One thing about me is that I am relentless in the persuit of making something do exactly what I want it to do when I build it.

[Lockjaw]

Yeah I was getting confused until you put it into language I can understand.

 

The problem is I am not sure what it would take to properly prep my wife. She doesn't find any humor in my fondness for slapping and/or rubbing her butt.

[Lockjaw]

See now I am confused. A leading Turbo Builder told me that it is at low boost levels that the wastegate has trouble controling boost since it has to bypass so much air to keep the boost low, but as the boost climbs, then the amount of air that needs to bypass the turbine decreases.

 

I mean I can see your point Tim, but now I have a conflicting story.

 

As a side note, Jeff is picking up roughly the ability to force an additional 20 pounds of airper minute by going to the 62. The stage V is a quarter inch larger in exducer then what he had, so the wheel should flow better too. I would think the limiting factor would be what can flow thru the .63 housing, and that would be where his boost creep would come from, and where the big wastegate would benefit him the most.

 

Maybe a combination of the two.

 

Anyway, I would like to see him try it just to see what happens. Since he is at 8 psi, there should be a pretty wide margin of safety before detonation, so if it creeped some, no biggie.

 

Besides, I hate the noise externals make. I would have to plumb it back into my exhaust.

[240Z Turbo]

What, the mighty Lockjaw doesn't understand and 4 out of 5 turbo builders say low boost is harder to control. I thought you had an answer for everything Lockjaw! I can't believe I ever doubted you after seeing you ran 112mph in your turbo car!

As Tim said, the more boost run the more exhaust is generated. There is no R&D necessary to say that after 400hp an external wastegate is advised. Run the biggest baddest Mutha you can get, HKS GT(60mm) and be done with it. After that you can slap on any turbo up to 1200hp and have no worries about the wastegate being too small. If you want, I can get you a good deal on an HKS GT wastegate just because you NEED an external wastegate. If I tell you that my 57trim was having serious creep issues then what the heck is a 62-1 gonna do? Hell, my stock wastegate holes in my two 16Gs were too small causing the boost to get out of control. When the RPM hit 6K the boost would spike to 22psi and that is through two 22-24mm holes. I ended up milling the holes to about 35-37mm or so on both turbo's. This whole thread makes no sense to me. The stock wastegate hole WILL NOT WORK for your 62-1, but you would rather put the setup together and find out for yourself and then tear it right back apart to make the mod you should have done in the 1st place. I will make this offer now to get you a good deal on an external wastegate for your setup. If you use that internal wastegate the deal will be gone. If you wonder why I get pissy it is because you have made this post for others to give input yet you choose to disregard the input. BTW, did you ever retard your cam timing so your motor would pull on the topend? Don't you just love this thread? On a lighter note, I finished welding up my new intercooler today and it looks monstrous! I will post pics soon. Here is a pic of my ported 16G's. Just to let you know, I had boost creep with 2 of these holes and your wastegate hole is the same damn size!

[jeffp]

ok James what do you got? I would also liketo get some info from you on the semi flexable coupler you have on your system in a 1 3/4" OD. I want to be able to make small adjustments in the pipe if I need to.

No I haven't done any further cam work on the car. I was running the cam retarded in the first place and what I was wanting to do is bring it back to 0 and see what it was doing on the dyno. I guess I am going to have to consult my notes some on this one. I thought runnig retarded would bring in the lowend and advancing would bring up the topend.

I have to get a new dampener before I continue with the test. I dont feel comfortable running it with the damaged part, so I am going to wait to get the new part from BHJ and do all the upgrades in that area at once.

Lockjaw, I am already running a stage 5 exhaust turbine wheel in a stock (machined housing) .63 A/R Nissan housing.

[clint78z]

Play nice don't make PeteP give you a Let's have a pint and continue on James and TimZ are right about the analogy for wastegates. LockJaw think of turbo flow this way. you turn your tap on full blast in your sink. As the water goes to the top you try to open the drain. If the drain isn't big enough the sink will overfill. If you barely turn on the tap low flow it will be easier to controll it this way.

 

Sometime a couple of psi boost creep is all right, but at higher boost can be deadly. An external wastegate will allow you to use full potential of the turbo safely.

 

There is so much misinformation about turbos, but the information here as a whole is very accurate.

[Lockjaw]

I don't think I ever said Tim or James were wrong, and I understand the theory of what they said, which I have already said.

 

I can see how both theories would apply, and I can see how what the guy told me could be flawed as well. Your example makes it a clearer, and it sure is a lot easier to digest considering you are being nice about it.

 

Anyway, I am just ready to see the results of the bigger turbo, and a balancer that will hold together. Wish I could be there to watch too.

[R0N]

I love this forum and I'm learning a lot, especially with this post. Sounds like the situation is squashed. Lets keep it that way. I would hate to see 2 very good technical Z dudes not get along.

 

Jeff, I would first try with the internal wastegate since everything would be a direct bolt on or close. Then do the modifications if it doesn't work. I'm sure it would cost anything to try the internal first. Although clint78z example makes it sound like it's not going to work.

 

I'm curious of the results using internal with a bigger setup because I'm a cheap bastard and don't wont' to pay for the mods when going to a bigger turbo plus my technical skills suck!!!! I currently have a hybrid turbo, had the wastegate hole enlargen and put a bigger wastegate flap no problems yet.

 

If it doesn't work then at least it's been proven on this forum and others like me won't make that mistake when going to a bigger turbo.

[D83ZXT]

Jeff,

 

I'm curious....

 

What is your CFM target and at what PSI do you expect your turbo to reach that CFM and at what compressor efficiency level of % ?

 

Donna

[Lockjaw]

Originally posted by 240Z Turbo:

What, the mighty Lockjaw doesn't understand and 4 out of 5 turbo builders say low boost is harder to control. I thought you had an answer for everything Lockjaw! I can't believe I ever doubted you after seeing you ran 112mph in your turbo car!

 

Well since I have read the intro to the forums I am not going to go off on you like I should, and just leave it like this. Maybe you should head back out there and read them.

 

Just because you think you know everything, doesn't mean you do. If a man who builds turbo's on a daily basis, and has turbo's that continue to set records every time there is a shootout says something, I tend to believe that.

 

The second thing is this. I have a bigger turbo than your 57 trim was, and so does Jeff. Neither of us had boost creep issue's. Both of us are internally gated, so what does that mean?

 

You know, if you have a problem with me, send me an email privately. Otherwise I would appreciate you keeping smart alec condescending comments off the forum.

[Lockjaw]

The 62 flows 70 lbs per minute, the 60 trim he currently has flows 50. I would have to hunt to convert to cfm, but I believe the 62 flows 10 percent more than a 60-1 and the 60 flows about 900 cfm.

 

The problem with cfm is turbonetics lists all its compressor maps in pounds.

[Mikelly]

....If you guys keep policing yourselves so well, Pete, and the rest of us moderators will be out of a job!

 

Good job bringing it back into civility. This is GOOD information, so lets not lose site of THAT!

 

Mike

[jeffp]

Hi Donna, I did the calculation but dont remember the exact numbers, napkin calculation LOL I need a PR of about 3.3 to get to the hp I want. I will have to go back to my notes and get the numbers. Basically, I need to build about another 100Hp and increase the flow rate of my turbo. This at the same time try to keep the spool up at a reasonable rpm range and that is the real trick. My first turbo spooled at 2500 rpm and it ran 15-16 psi, this turbo spools at 3000 rpm and it runs 23-25psi I am shooting for about 30psi and that should take me into the numbers I want. I am shooting for the 600hp and stop there. I dont think the car can handle any more then that, and really I need to take it easy turning on the power. I will need to ease into the power and not idle to 600hp off the line. The transmission is the real weak part of the drive train, so if I dont watch it a little I will make a junk transmission. I have talked to a number of people and they cant believe I am putting the torque throught it right now and it did not break.

I did the calculation of the compression, I have to check it out and make sure I did the math right, but I am looking at about 300psi compression to get to 600hp.

[jeffp]

Hi lockjaw, you are correct about what turbonetics does with the pounds per minute figure, a pain in the butt. I used my engine math handbook to do the CFM calculation and it was in the 1000 CFM area, just about right for your calculation also. I also looked a corky bells formulas, but they were not to helpful with the conversion. He uses CFM in his book, but I was able to use one of his formulas to get the PR I would need in order to get the cylinder filled with the correct amount of air to produce 600Hp. Then I was able to calculate the cylinder pressure and I cant remember the psi exactly, but it was up into 300psi @ TDC with my current static compression ratio. I dont think I would try this on stock head bolts, Studs are a must, and a steel head gasket, or orings. We will see how it works out, I was thinking about bigger studs, but I would have to go through another set of formulas to convert the compression to pounds per Sq inch of pressure on the cylinder head, and the beat goes on.

A number of things to consider and all of them need some head way in my opinion to have a reliable setup. I like building overkill it has helped me so many times when it comes to improvements and upgrades.

The weak point in the system is the waste gate, no question about that, but if I can get to where I want to go without to much trouble on this one then that is what I will do. What Tim and James mentioned is very possible when you stop to consider this new compressor will be putting out 1 1/3 to 1 1/2 times the volume it is now. I love this stuff LOL, mo money jeff give me mo money LOL.

[Lockjaw]

Yeah, Corky's book breaks stuff down, and I did my calculations based upon his book, and then got happy when my turbonetics catalog in and it was not in CFM. So I had to recalculate it. I was a little miffed.

 

I know how you can get 600HP real easy, NOS. HAHA

 

I have one word of caution about the head studs. There is a guy here in town who had what probably amounts to the fastest Z car with an L6 in it in Alabama , and he or his engine builder cracked his block installing the studs. I guess they bottomed out or something. Anyway, he had the worst time keeping head gaskets sealed up until he found out about the crack. I don't know if he has ever put it back together though.

 

He had a big topend turbo cam that he said wouldn't idle below 1200 rpms, ported head, big valves, a tech II and it was a 3 liter too. HE kept breaking tranny's so he ended up getting some sort of adapter plate and running a turbo 350. If I recall correctly, he was running low 7's thru the 1/8th on the 5 speed. I don't know that he ever took it to a quartermile track.

 

If I recall correctly, I think there is a company in Japan that makes a bellhousing to adapt the 300ZXTT tranny to the L series engine. I think Clark told me about that. I am thinking of a turbo 700 or 4L60 or something like that, with a nice converter. Or the Starion auto. Turbo 700 would probably be cheaper, and I have a pal that knows how to put one together that will stay together.

 

I think you should stud the bottom end too. Probably pitch the crank and all 7 main caps thru the oil pan. (There is 7 right?)Might be cool to watch, but not cool to fix.

 

May be time for some strut tower braces and a roll cage, if you don't have them already.

[Lockjaw]

Sounds like she is ok to me.

 

I think there is no doubt you can spend some outrageous money on a Z engine. The guy who did my machine work told me I needed to get carillo rods if I wanted to run over about 5 or 6 psi. I was like they run more than that from the factory. No wonder his shop is no longer in business.

 

I guess the scat crank would probably eliminate the crank resonance issue's with the factory crank, right?

 

I have always wanted to try the 240 crank in a 280 block and bore it out to 89mm and see what that runs like. I don't know why, just do. I bet it would turn up some rpms though.

[jeffp]

well I had a buddy in high school that built a dstroke 400 and installed that in a chevy II that car hauled butt. That engine sounded like it was already up to rpm's and just went down to idle, really cool build. This was a guy that pulled 11 second quarter miles out of a 307 in a vega.

[jeffp]

I did do the studs on the main caps also already. That kind of stuff was a given for me. I was a little concerned about the rod bolts also, but when I talked to Brian Crower about the bolts they wereusing on their rods he informed me that they were a better quailty stud then the ARP parts I was thinking of installing, so I went with their stuff.

The best you can get are the rods and bolts David at malvern sells the Corrello rods and bolts, but at 265.00 each, that was a little more money then I wanted to spend. The bolts alone ran 35.00 each.

I guess if I really wanted to spend some serious cash I would have gone with the Corrello rod assemblies, and a skat custom crank forthe bottom end.

I have entertained of doing a 84mm stroke crank setup on another engine, but that is just a thought at this point.

When I first started thinking of building the engine I looked at some places for various parts and it all totaled about 10K for the parts I wanted to setup just forthe bottom end and a head, but I had to be a little realistic about it.

I think my wife would have killed me over that one, and I almost got it over the seats LOL, but she cant say to much about it. I haven't used a dime of her money doing all this stuff and I like that allot. So I dont complain about the phone bill and she doesn't complain about how I spend my money, good deal I think.

[240Z Turbo]

Just divide the lb/hr by .07 and it gives you a round-about on cfm. So, 50lbs/min is 50/.07=714cfm. To get the hp you can achieve with this turbo divide by 1.6. So, 714/1.6=446hp that can be achieved with 50lbs/min of flow.

This is gives you an idea of what you can expect it to make on an L6 motor with a given turbo. So, with a T66 turbo you can expect to make

(72lbs/min)/.07=1029cfm

1029cfm/1.6=643hp

Jeff, as far as the external wastegate goes, if you should decide you should get the best since you like spending money on fancy things. The HKS 60mm is the way to go, but packaging may be an issue unless you can come up with fancy install. It is easily doable if you run an on-center t4 housing as TimZ and Joel have done. The flex section was 2" as I could not find that accordian style in 1.75". I modded it to work with 1.75" pipe and it is all SS. I would be willing to sell it to you for $50 shipped. It cost me $52, but then I had to mod and weld it to go to 1.75". It also has SS clamps as back up.

[jeffp]

That sounds about what I calculated. I think my figures were about 1032 CFM I used another formula and not theturbo application formula and they seem to match up just about right.