Sad day, just posted today at my350z forum, blown motor with APS TT and Turbonetics ST. Seems the kits are not at fault here. Like most are saying, seems our VQ's cannot handle all this power. Since both are Turbo's, maybe our VQ's cannot handle so much Torque ( +1 for Randy ). So if your planning going FI ( Turbo ), maybe consider building-up your motor first.

APS : http://www.my350z.com/forum/showthread.php?t=130374

Tnetics: http://www.my350z.com/forum/showthread.php?t=130354

 

Yes I read the Turbonetic's thread . Was reading the other , but didnt see that it indeed had blown

 

huh?from what i read here,that's not the 1st blown APS.
http://www.my350z.com/forum/showthre...highlight=poll

 

I just came from my350z. The APS isn't the cause of the engine failure as GXCLUSIV and I seem to think.

Ccartwright had posted:
It was a coolant leak, caused from a misaligned gasket on the LHS waterpipe going into the side of the motor.

There was heat, but it wasn't pegged, and I never got about 2000-2500 rps on the short drive home, and was certainly not under boost.

The one other APS "failure" that was posted that I am aware of was some guy using his friends account and said the APS blew. That was confirmed by the poster several weeks later.......no engine failure due to APS. However, no matter how strong your engine, if it's not being cooled properly then kiss it goodbye.



Hopefully more information will surface on the Turbonetics ST case. Two months and no diagnosis on why it failed? Something's not kosher.



I wouldn't put too much credence in the poll if the persons aren't listing themselves as having blown their engines and what the exact reason for the failure was. At this time there are 17 posts, a bunch of which are by the same people, yet there are 19 engine failures listed. No blown engines due to PE and none from ATI? Not accurate.

The single hardest factor to pin down is what's causing the failure. I've read a couple of threads recently where guys have killed their engines. No tunes, just installed, to me that doesn't mean the VQ is a weak engine, it means that if you don't tune your engine after you FI it, don't be surprised if it goes boom.

 

there is more to the story of the turbonetics blown motor than what is posted.

 

GZire..thanks for your explanation.
i argree.that poll is not accurate due to the fact that it doesn't show who posted it so you coundn't tell if that person infact own the kit.also on PE and ATI kits,you and i both know that they failed too but no one post it up.
bottom line.doesn't matter which kit you have,there ALWAYS a "**** happen factor".you can do your best to reduce that percentage by have someone know exactly what he doing to work on and tune your car and also spending more money to upgrade other components to works with the kit.

 

It sounds like he may have skimped on the tuning/engine management for the Turbonetics. It's hard to tell on that one if it was user error or a faulty kit, but I would lean towards user error.

 

I still stand by my belief that the VQ35 is not a boost friendly motor. It can't push near the boost nor power as the VQ30 can, plus the VQ35's rods and rod bolts are terribly weak. There's a good reason why Nissan is going with a TT VQ32 in the Skyline and not a VQ35.

Going with aftermarket forced induction expotently increases your chances of a major failure. To think any of these kits are "reliable" is quite the understatement. You're boosting a rather high strung motor that is designed to run as NA. Boost creates a lot of stress and if the engine wasn't designed for it, things tend to break.

If these guys thought that heat is such an issue, maybe they shouldn't be running OEM radiators. It's a fact that as you increase HP, engine temps increase dramatically and you need to upgrade the cooling system. Unfrotunately, most people that go with boost are more concerned about power and how big of a bling intercooler they can cram in front of the that OEM radiator.

 

DaveB I completely agree with you that the VQ35DE isn't way overdesigned like some other engines out there. It really doesn't need to be for the application it was designed for.

I'm going to be taking that leap to FI (hopefully in the near future), so everytime I read something about this or that happening to the VQ it freaks me out.



FYI the issue of blown motors has spawned it's own thread/poll over on my350z, here's a link to the thread.
http://www.my350z.com/forum/showthread.php?t=130375

 

with these issues of heat, i was wondering if it would be a good idea to go with some sort of hood that has vents or a hood spacer. i have read that these things decrease engine bay temps a lot! if this makes no sense, sorry in advance, i am a FI newb.

 

The vents would help a bit, but nothing like going with a larger radiator.


Well, you could always swap in the VQ30 lower block. There are quite a few 95-99 Maximas running VQ35 blocks with VQ30 heads. I believe you could also run the VQ30 block with VQ35 heads. There are quite a few 95-99 Maximas pushing 400-450whp with no issues what so ever. There are even a couple that have done over 500whp on a completely stock VQ30......and injectors!!!!!!

 

Totally agree with DaveB. If you are going FI, consider getting a larger radiator. In addition, consider both oil and water temperature gauges.

Dave

 

are there any larger radiators out for our car yet? i havnt seen any if someone could post a link?

 

SOCALTED has a racing radiator added to his ride. Maybe he'll chime in and share his info with us.

 

as of right now nobody make radiator for G yet.except Griffin made prototype for sedan (no coupe) and also you can get Royo radiator for the Z and with a minor change on the bracket,they will fits on the coupes.