how bad is this supposed to be, because when i step on the gass it kinda slow at first for like 2 seconds then it builds up?

is this what i should expect?...


Mods:
intercooler
2.5 inch piping
rest is stock

 

This is pretty vague. Some more info is needed. Is it the stock turbo for the motor? Have you checked for exhaust leaks? It being an old motor did you check the manifold for cracks? Is the turbo rebuilt or the original unit? Did you check for vacuum leaks? Are any of the pipes heat wrapped?

 

no heat wrapped pipes, the turbo is stock as the motor, 300zx turbo year 88, no exaust leaks as of yet as well with the manifold cracks, no vaccum leaks.


well tell me waht your cars turbo lag is like, been in an eclipse turbo before and its nothing like that until the turbo kicks in 2 seconds later..

 

Seems normal to me. You're not going to start building boost until around 2500rpm's depending on setup of exhuast, presence of underdrive pulley or lightweight flywheel, etc.

 

What kind of manifold setup are you running? How about exhaust? I'd run at least a 3" exhaust, that'll help out a bit. If you're running a modified manifold like running the turbo off of the crossover pipe, that design can make a huge difference as well (for instance, I didn't have the two cylinder banks separate in mine which caused slow spooling).

 

ok well 2500 sounds about right

the setup is stock 300zx turbo

 

If my Z ran correctly I could tell exactly when it should spool.

I would think it would be a little sooner than that being that the turbo is so small... but you are running an aftercooler so that could slow it down a little bit. If I were you... I'd actually put in your stock Maxima engine with all of the boost goodies and you'll notice a huge improvement. The 9:1 blocks can definitely take some boost so you don't have to worry about that.

Are you using a 7.8:1 or 8.3:1 Z engine?

 

As Mtcookson said... the older engines are not as spunky due to the lower compression. The stock turbo size on that engine is small which won't pull real hard either.

My setup is the stock engine with a Buick GN turbo (TA 49) which flows 800CFM and supports 550hp. (I don't make that much power) But anyway it's well into boost by 2500rpm.

My stock engine (VG) Now has 231,000miles with the last 50,000 being boosted at 12psi.

Keep working with it! you'll get it,
Scott~

Ps... How's it goin Mt?

 

Not bad. Maxima has rusted apart pretty much so I decided it wasn't safe to drive on the road. No worries though, I found a pretty nice Infiniti M30, which really resembles the Maxima. I'm going to put the Maxima's turbo stuff on it. VG30E-T + RWD... its gonna be fun.

 

i always wanted to do that to an m30 would like to know how it comes out, about the gran national turbo, could i put that babby on with the stock z components like a turbo swap or would there be come custom work or welding required?

working with it, but it isint low compression either, its got a w (it came out of a 92 maxima, and all of the pistons have w's marked on them, with snaprings to hold the pistons to the rods) block vg30 (pistons, block and crankshaft,with 300zx turbo heads) so that should answer the question about the z engine...

here is a pic of the engine code stamped on it..

 

Yeah, I think it should be spooling a bit quicker with a 9:1 engine and if I'm reading it right, you're using a turbocharger from an 88 model, correct? If so... it should most definitely spool quicker as those are T25's. So you're running a completely stock Z31 exhaust setup? If so, you might check for some exhaust leaks pre-turbo (I know you mentioned earlier you didn't notice any but I would definitely check the exhaust studs as they tend to be weak on these engines). Wastegate... stock internal? ECU, are you tuning it or using a Z turbo ECU? Sorry for all of the questions, just trying to get to the bottom of this.

 

not complete on the exaust setup had to make a custom downpipe, as for tuning standard z turbo and ecu with standard injectors, as for the studs i went and bought about 50 dollars worth of them and replaced all of the broken ones (6-7 IIRC) the wastegate is stock internal, but the turbo is from an 84 but if an 88 spools quicker then ill get one of those, dont worry bout the questions theyre fine, i need the help...

 

I would stick with your 84 turbo. They're T3's so slightly larger, basically they'll allow you to get a little more power than the later T25's... unless you're wanting low power with quick spool (nothing wrong with that at all).

On your down pipe, are there any extreme bends to get it in the right place or are they pretty smooth (I think I mentioned above, I'd upgrade to a 3" as that should allow more power and quicker spool).

What is your timing at idle set at?

Are you using a boost controller? If so, manual or electronic? Most electronic boost controllers can actually be set hold the wastegate shut longer which will help make it spool quicker as well.

Last thing I can think of at the moment is your blow off valve and intake. Make sure neither of those are leaking as that can make spool seem longer and can also cause the car to run a little richer. It looks like you have everything t-bolted so intake leaks shouldn't be a problem, I would double check the bov though (shouldn't be a problem, but always worth double checking).

 

no boost controller yet scamming e-bay as we speak to get one of those with a turbo timer, the timing is set at stock 15 deg TDC, as fot the 3 ingh ill go to that after the smog test im told that all i need now is a new cat so i dont wanna mess anything up so as soon as i pass ill be open to more options...








sorry but cali is a byiotch on smog regulations, i took it to one shop and he told me thaat he wouldnt touch it and said that they would induct my car! i left asap!!!

 

ok so i took out the turbo and replaced the compressor housing gasket (the one the size of a CD), played with the timing, and adjusted the throttle cable and tps.....
and skibbidie hot damn. this **** got launch, you can hear the turbo sucking the air in from the passenger side as well as hear ing the WIZZZZZZ high pitched wistling noise, onlu tried on the streets around my house but i can get to like 60 in like 6 seconds now which is way better than the n/a 8 sec time, and it pulls too, hard and all that in an auto.....

i think i need to go to 5 speed!

 

Ahh, yeah... didn't notice you were in California. The downpipe looks pretty decent though. Sounds like you got it working out better now though. The 5-speed is definitely fun but you have to be careful once you start making more power as they like to break quite a bit. I don't know about the 2nd gens but I'm sure they're pretty similar to the 3rd's. Good luck with everything!

 

thanks for the help but now i got a noise, after driving it a bit yesterday at about 2500 prm and up i get a noise like a mini maching gun being let off in a aluminum can, i think its the turbo because it only does it during boost could it make that noise with bad shaft play?


thanks in advance!

 

If the shaft play is bad enough the wheel can contact the housing which might make some bad noises. If you can move the wheel enough that it does touch the housing I wouldn't use that turbo much longer if at all, don't want any metal shavings in your engine.

 

ok i got a vid listen to it and tell me what you think...

 

Hmm... yeah, that's really weird. Kind of sounds like an exhaust leak as well. I'd check the turbo for excessive play but I'd also check around your exhaust for some leaks as well. Other than those two I'm not sure what else I would check at the moment.

 

ok thanks i think it is shaft play as well, going to the yard today so ill pick up a better one and see if it goes away

 

it was play to tha max.. got a donor turbo but impaitence got to the best of me (5 broken bolts) luckily my turbo was exercised with heat because i used it and the bolts came out easily, after i get the bolts out ill rebuild the other turbo as well and slang it on ebay... the donor turbo and a lot of different parts, or should i say fewer parts which makes it easier to rebuild





also wondering why did one turbine come with 3 notches and the other didnt?