That way, I could keep it in the shed and take my time, get the damn thing ported and polished, maybe some aftermarket pistons/rods or something. Then, the car would have far less downtime, I could learn a HELL of a lot (our engines are not THAT hard to rebuild), and save tons of money.

Does anyone know the best place to obtain a VG30E? I have not checked locally yet. I can get a factory rebuilt for just around $1000, but what's the fun in that?

Thanks,

 

I would just opt for the turbo. Same rebuild procedure. Maybe cheaper if you just use factory new pistons(depending on boost you want to run) some extra cost for the turbo rebuild. In the end you would have a much more powerfull engine.

 

Since I have a Z32 FSM I was able to compare the internals vs my FSM. Basically the crank, rods, pistons, bearings will swap from the VG30DE to the VG30E. I found out that the VG30DETT has the same compression numbers as our VG30E's. Basically all you need is a bottomend from a 300zx and get some OEM or forged aftermarket pistons with your choice of compression. Now I have will have an extra set of heads that I can give you for a good price. Also SGP charges $800 for a 5 angle valve job and porting/polishing. After that you can bolt on that turbo and keep the boost to 7psi (w/o Ic) or 9psi with an IC. When our VG's are tuned on boost we see around a 50-70hp gain with a T3/T4 or equavelent sized turbo. If you want no lag opt for a ball bearing turbo. But really the bottomend is pretty strong stock. Aside from getting the crank balanced and shot peened or cryo treatment there isn't much to go wrong. Its the valve train that limits the power. If you were to tune your VG at 7psi with a 7500rpm rev limiter you could realisticaly see around 240-270hp at the wheels. Also VG30DE valve springs won't work either . BTW you must get a bigger fuel pump and injectors before you start adding boost. Otherwise you can blow a perfectly good engine. Stock Z32 injectors are good till around 320RWHP so they are more than enough for us.

 

How about buying a totalled Max?
maybe fine one with the back end trashed, then you can just haul it to the house and work on it on the car.. (so it'll sitll run and stuff)..

as has been mentioned, the turbo option would also be my suggestion.. you'll have to pul lthe engine to rebuild it, but if you had a spare car lying there, you could drop the engine in and do whatever mods you needed to on the trashed max, THEN move it to your car once it's running..

again, it would save tons of downtime, and you would have a test-dummy to try everything on before you dumped it in your car.

then again, I think just rebuilding the top end on our engines will give you a lot more power.. do something with the valves (more than just a 5 angle job-that's snake oil anyway), intake/exhaust ports, learn how to weld and build you some headers, design and fab a new intake manifold.
the top of ours is fine, but the bottom end is VERY restrictive.

as is kinda obvious, most of this engine is designed for torque. when you start blowing open the intake/exhaust, it's gonna give you more high end HP and you'll lose low end. most of us aren't too worried about that though.

what's your rev limiter now with the JWT ecu? just wondering if it'll make a difference.

 

[QUOTE]Originally posted by Matt93GXE
[I]How about buying a totalled Max?
maybe fine one with the back end trashed, then you can just haul it to the house and work on it on the car.. (so it'll sitll run and stuff)..

So can we use YOUR yard to store the trashed max in??


Learn how to weld and buid some headers?? Matt, I believe it would take him years to 1) learn how to weld good enough and 2) learn enough about header fabrication to even build a half-decent set of headers.

 

IMHO forced induction or NOS is the only way to go. In order for us to make power we have to either rev higher or force more air in. Given our smaller valves and intake manifolds vs the VG30DE, reving higher is the only way to go. Even then it would be hard with stock compression to make power. But reading the FSM on the Z32, I do believe our engines can handle around 10psi (intercooled) with enough fuel with no problems. However without an IC the boost should be kept at 7psi or under. If one had a intake temp gauge or sensor like the 4th gens do you can monitor how hot the temps are. Believe it or not with CAI, Y, full exhaust, UDP, ECU you would gain around 20-35hp at the wheels. After that the effeciency of the stock cams and heads comes into play. We just don't have enough compression to make much power (compared to boost) with bolt ons. You'd be lucky to dyno more than a stock VQ with bolt ons. However with boost you can match what they dyno modded.

 

why do to all the trouble of building up a na vg30 engine and then turbo it, while he could just as easily rebuild a vg-t engine?? An engine that has a better block(?), better oiling system(piston oil squirters), better oil pump, turbo cams and already has all the manifolds. Whatever machine work just as easily can be done on the Vg-t engine.

 

Wow.. Someone who actually understands what I'm doing! YES!!! Maybe I'm not so crazy afterall. I would go VG-T. Just do what Matt said. He has a pretty good idea of what he's talking about. This is what I'm doing when I find a spare VE for a good price..

 

we DONOT have the same compression ratio as the VG30DETT or VG30DE

dett = 8.5:1
de: = 10:1
e (us) = 9:1

 

Keep the stock VG compression. The higher compression will spool the turbo quicker compared to 8.5:1(not much but its still less lag) and remember that ball bearing turboes are *not* rebuildable. You mess one up, you buy a new one. Just get a reasonable size t3/t4, a nice intercooler and fuel injectors(and pump) and run like 13 psi. You'll be fine and with the mods you currently have you'll be pushing the 275-300 wheel hp mark.

 

I was refering to the compression test numbers. According to the Z32 FSM the VG30DETT should be around 173psi @ 300rpm, min is 128psi and max difference between all cylinders is 14psi. Those are the very same numbers in my FSM for the VG30E. The VG30DE on the other hand has its compression around 186psi @ 300rpm, minimum is 142psi with the difference limit between cylinders being 14psi.

 

Why build a VG30E when you can do the VG30ET? According to the Z31 guy's the stock engine without an IC can handle up to 10psi. Above that you go above the safety margin for the injectors. Not to mention with that engine you would be able to get the JWT 450hp package. Now the only problem with using the VG30ET is the wiring issue. Now I don't have a 3rd gen FSM so I don't know if the ECU pins line up. I do know that I can use a Z31 ECU in my car with little to no rewiring. Also the alternator on the VG30ET sits on the opposite side and its a 70amp unit. You would have to install a maxima 90amp alternator. But then again you could just buy the VG30ET oil pump, oil supply line, injectors, and put them on a VG30E.

 

You still can't get(easily) the cooling feature of the oil squirters on the Vg-t engine. Doesn't the VG-T have a stiffer block?? Any mods for high hp you would have to do on a VG-t, you have to do on a VG30 plus more probably.

 

Can't you change compression with different piston heads? If so, making her 9.5 or 10:1 with a head job would produce at least a moderate HP and torque gain...true? The VQ is 10:1 with the same displacement, look at that HP.
(the VQ IS 10:1 right? I read that somewhere)

-Kaleb

 

I believe your confusing the VG30DETT with the VG30ET. The block for the VG30E and VG30ET are the same. The VG30DETT is the one with oil squirters.

 

might wanna also look back to what I mentioned in my post. (since in mentioned the more air/better breathing= more power subject and it was skipped over)...

you could increase the compression using different pistons yes. I don't know what that will do to your HP/TQ numbers though.
you could also make that puppy breath better by re-working the heads. I dunno if it's possible, but open up the intake and exhaust ports on the head a little, and install larger valves.

Rebuild the lower intake manifold so it'll give more airflow intot he intake on the heads.. the upper manifold may or may not help much.. it looks to have pretty good flow already, but you might want to play with that a little too.

I've got a couple race-engine building books here in the lab.. I'll read over some of what it says in the "adding power" section.. yes, it does have a section on adding power by modifying an existing engine. most of it deals with cams and timing, but I'm sure there's also stuff in there on valves/heads/pistons.

 

Normally aspirated? What fun is that. GET SOME BOOST!!

 

Matt,

Yes your idea about reworking the upper or lower intake collector/manifolds WOULD produce desired results. However, I'm afraid something like that would be out of my price range. I did have an idea, however, of using the VG30DE (Z32) lower manifold. Those ports are freaking huge (and oval)! But I'd have to research to see whether or not it would bolt up. I'm gonna look into some stuff tonight (like valve diameters, compression, fuel pressure, etc) for the VG30ET vs. the VG30E.

My concern with the VG30ET is this: I don't want to "rig" the car that much. I don't want to fool with extensive wiring problems, alternator relocation, oil filter relocation, and I like they way our engine looks better than the Z31, so I'd want to use my intake manifold (gotta look into that issue). I need to find a salvage yard around here with the engine, or look in the shop to see if we have a Z31 Turbo out there.

My thoughts are that I could use the VG30ET long block, but using my intake manifold and have some custom intake piping to my manifold. I still want to use the CAI. And since it is in two big pieces it just might work. If it goes turbo, it's getting upgraded internals, maybe like they're doing on overboost.com.

If I go NA, I'll simply use another Maxima VG30E, raise the compression combined with a head job, and pray for 30HP. I will talk to a few people to see what they think.

Let's keep talking about this guys, it's a great benefit. I especially value Nismo87's comments, as he's done more research on this than all of us.

 

But honestly though you don't need to upgrade the bottomend if your aiming for less than 280hp at the wheels. You would have to have the tranny upgraded to support more than that. This is when things get expensive. But I do believe that you can use 3rd gen intake and heads on the VG30ET. All you have to do is check the head gaskets while your at work. I today when I dropped off my heads to get them worked on I got to look at several VG30DE's including the one Kyle broke. Man the damage is huge, the gridel is broken, a rod is torn in half the block is scared. The oil pan has that huge hole in it. Also the block it self doesn't look any bigger than a VG30E. Matter of fact it almost looked like the heads would swap over. But the VG30DE heads are way to freakin wide! Hmmm I wonder what VG30DETT manifolds would do for a VE? Remember though that the auto is the weak link. All you would need is an intercooler with 12 psi on a T3/T4 turbo, run a hotter cam designed for the VG30ET. Then upgrade the valve springs, retainers, keepers that way you can rev to 7200rpm safely. Once your able to rev higher then you can start tuning your car to make power from 4000-6800 vs 3300-6000 of stock cams. Also Kaleb you can get JWT to reprogram your ECU with a turbo program too. But before you do that you need to decide if your going to run the turbo before or after the MAF. Don't forget bigger injectors and fuel pump then watch those EGT's too.

 

VG30DE heads are 5 bolt, VG30E heads are 4 bolt. They won't swap..

 

Arixonxi (that's right isn't it?),

Yeah if I do turbo I'd do it right (EGT guage, Boost guage, Oil Pressure, etc). From your conversations with SGP and Kyle, what can we expect in HP/Torque gain from a head job on a non-turbo?

Also, what does the computer need to know to effectively run a turbo without blowing the engine? Like, doesn't it need to know something in addition to stuff a NA would already know? Damn, now I have a turbo bug :0). How must PSI I would run depends on the additional cost of an intercooler. I could use one from a Mercury Starion or whatever Overboost.com used, the duct work is what worrys me.

My main concern right now is the electronics. What's the word on what the ECU needs to know?

-Kaleb

 

thats why I came around here. much better than standard flame wars. & I gotta post or always be a lurker.

 

Maxima VG30E Block:
11000-85E00 which is the same as 11000-85E80

300ZX VG30(T) Block 07/1983 to 09/1985:
11010-V5280 which is the same as 11010-V5282
This block is used in both the Turbo and Non-turbo

300ZX VG30(T) Block 09/1985 to 03/1987:
11010-V5281 Turbo and Non-turbo

300ZX VG30(T) Block 03/1987 to 08/1988:
11010-21V80 which is the same as 11000-21V00
This block is used in both the Turbo and Non-turbo

300ZX VG30-T Block 08/1988 to 09/1990:
11010-21V80 which is the same as 11000-21V00
The Non-turbo was not produced in this time period

300ZX VG30 Block 08/1988 to 09/1990:
11010-85E80 same as Maxima VG30E
This is the Non-turbo only engine

300ZX VG30-T Block 09/1990 and up:
11000-21V00 which is the same as 11010-21V80
Turbo only engine, wierd because 09/1990 and up was not
a Z31, it was a Z32.

In conclusion, the Turbo block is not the same as our block (3rd Gen at least, I haven't checked 2nd). I know this from experience, because I remember a guy who brought in his VG30E engine on his pickup truck bed because it was mated with a VG30T block from a 300ZX and the Oil Filter mount was different and he was having problems or something like that. These are the things I'm worried about.

The head gaskets are the same.
The intake and exhaust valves are the same.
The cylinder heads are not the same.
Intake manifold is not the same.

Then there's the problem of routing the exhaust system and actually FITTING the turbo up there with the fans.

 

Why don't you buy yourself a turbo magazine and look for the AD that sells used japanese engines. I totally forgot the number, I called them last time and they said that a 89 engine would cost about $350 to $400, that's prety darn good for an engine that has only about 70k miles on it, that was a long time ago, not sure if they have engines with miles so low, good luck.

 

Basically the ECU in the Z31 is calibrated for the boosted engine. For example our NA ECU knows to inject "x" amount of fuel for Y amount of MAF reading. Now if you ran the turbo output to the MAF then you wouldn't have to worry. Because the more compressed air that comes for the turbo will be read by the MAF. The bad thing is that you can push your injectors over the 80% duty cycle (safety margin). Also I believe the ECU for a VG-T runs a less agressive ignition timing map too. But that can be taken care of with a boost timing retard manager. As for the fuel curve that can also be fine tuned with the APEXI S-AFC. The main reason you want bigger injectors is in case your wastegate sticks/fails or you have too high a boost spike. This could cause you to run lean just enough to blow a head gasket. If you went with stock VG30DETT injectors your engine will be safe till around 300hp at the wheels. Which is way more than our auto can handle without a rebuild. With an upgrade in injectors you need a stronger fuel pump too, you can either get a Z32 fuel pump or an aftermarket one.

 

Kaleb do you have any idea what the other numbers and letters mean??? or does it just seem like a random assignment of #'s??? I'm thinking there has to be differences between the engines (minor upgrades??) Have you looked at the part numbers for the quest/villager, pathfinder and trucks, infinity m30, and xterra to see if any of the part #'s are similar?? Thiks is a lot of work so i realy don't expect you to do it, but it would be interesting.


I totaly agree with your comment on the intake manifold cover. I do like the look of ours, expicaly when it is polished.

 

You can always go from a 2 10" fans to a single 16" fan setup. Also looking at the 3rd gen intake, its gonna be difficult to use VG-T manifolds because of the way your intake is. Where as on my car they would bolt up with no problem. But if you were to get a new intake plumbing made that ran from the TB to the turbo it would be easier to mount the turbo. As for running an IC good luck, there is no room in my car and barely room in a 3rd gen if any. Now if you have an aftermarket front end then its possible but you have to rig the IC pluming too. Another alternative is just use a VG30ET engine and just install the wire harness/ECU. You might want to contact Mark at SGP and ask him for more info on turbo conversion for maxima's.

 

You could always do someinthing like the stock IC's on the TT z's and put the ics in front of the wheel wells. Not the greates solution, but there is room for them back there. The other option is to go with a front mount, but this would probably require some sort of hacking of the front bumper....

 

Done yet?........

 

someone is bored today mad old schizool yo!!!

 

hahahaaha


should have known it would have been Jeffy's "Done yet?"

 

If you're going to go with custom pistons why not get a set that lowers compression down to about 8.5:1 so that you'll be able to crank the boost up to 14+ (even higher with a good computer) psi. Throw a A2A intercooler in for 1/4 miles or A2W intercooler for road racing. And if you've got the heads off and having work done on them they can solve your valve train problems then too. Stay away from 5 angle valve jobs unless you make your living racing. They don't last near as long as a good three angle job and the difference in power is negligible.

 

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