Okay everyone, I'm sorry if I came across like the Turbo Grinch, the fun killer, the safety ****, etc. Really.....if I wasn't into some good ole foot stompin', butt-kickin' fun, I wouldn't be supercharging my car. My concerns arise from what I have seen too much of in the past. Until recently, I was the organizer and promoter of a major aftermarket car event. I have seen too many people who have NO FREAKIN' CLUE what they are doing to their cars. Many of these people are enthusiastic kids who are scraping and scrounging every penny to put into their cars. The looks on their faces when something serious goes wrong is almost heartbreaking. People should just know what they are getting into, that all. And by the way....I will be grinning ear to ear when I smoke some unsuspecting victim at the next light!!!

 

The path to safe and successful FI is a set of forged rods and pistons, and a really really good engine builder.

If you can't afford forged internals, you can't really afford to run a boosted VQ. End of story.

 

Well I recently came to a big decision about my Z. I purchased the Vortech kit on the assumption that it would be CARB approved soon, safe, and reliable. I would install the kit and be done with the Z. Well basically none of those things look they will be a reality. After reading post after post of blown motors I am a firm believer that FI on the Z requires a built motor, no matter what kit you get, even the HKS kit. Our stock internals just plain suck. The rods in a B16 Honda motor are beefier for gods sake. So next I was looking at building the motor. But I would still not be CARB legal and I would basically be throwing my warranty out the door. Not to mention all the money I would have to spend to upgrade everything properly. In the end I decided that I am selling the Z and all the stuff in my sig. For the same price of my car, SC kit, and a motor build I could buy a better car with more power and allot more potential. So thats what I'm doing. The Z was fun for the 2 years I owned it, but I always thought it was a bit slow. As for what I will be getting. Its still a Z but with an 06 at the end.

 

Ah, the secret's out! I knew it wouldn't be long before you went out and told everyone.

 

I agree with Speedracer about the selective use of power with forced induction, but have a slightly different way of looking at it. I had a Mitsubishi Eclipse running twice the factory boost and had no problems with reliability (for over 4 years of racing) compared to several people I knew that had reliability problems with the same car, modifications, and boost pressure. When I raced, which was a lot, I ran the car as hard as it could be run – dropped the clutch (aftermarket) at 5000 rpms on the launch and shifted each gear WOT and at redline. BUT, after a run, I’d always go back to the pits, lift the hood and let the car cool down a good while before the next run. (At test and tune days you can run as often as you want all day at the track.) When on the street, sometimes out on country roads, I ran the car just as hard in mock qtr mile races and through the curves and twisties, BUT after several trips through the gears at WOT and redline shifts, I’d cruise along fairly easily for a while and give the car a breather and let it cool down a bit. A good example of the other way is one guy I knew that had the same car, mods, and boost I was running – and the mods were performed by the same mechanic at the same shop – would street drag race his car. He would hot lap his car – run a hard qtr. mile and immediately come back and run another and another something like 10 or 12 times back to back with no cool down time in between. He eventually had reliability problems to no one’s surprise. And I knew a good many guys who ran like him and had problems as a result. I also applied overkill to my maintenance for reliability sake. I changed the oil and filter every 2000 miles, always ran a clean air filter, etc., etc., etc., etc. So when I ran, I ran HARD. And often. But I also would frequently give the car a break for a spell instead of ringing its neck continuously. And I used quality heavy duty parts, precise tuning, and overkill on the maintenance – whether the car needed it or not. Anyway, I have been driving high performance, modified cars of all setups, including FI, for over 30 years and have had great “luck”, that I do not consider luck, with reliability. Just my 2 cents.

 

(My Eclipse was AWD, hence the high rpm launch.) In any case, I am leaning toward the HKS kit because I feel they have heavy duty parts and precise tuning (I ran them on my Eclipse as well). I know I will sacrifice a little power compared to other kits, but I think this power level is a good compromise with an emphasis on reliability. And by the way I shamelessly LOVE my 350Z!! She is a real sweet heart.

 

By the way, the 2005 Track and Anniversary Z's will probably ship with stronger con rods. So a reliable ~400whp (a sweet spot for most of us) for under $10K could be reasonable on the Z, soon.

 

Speedracer, do you have the HKS kit on yet? i'd love to read a review

 

Thanks for the info! It seem the consensus of opinion is that needing stronger con rods is at least one of the main reliability issues standing between us and the high power with FI. And 400 whp is a real sweet spot with me as well. That is the power level that I had with my HKS Eclipse and that power would make my and our 350Zs very fast for a street car. Good for mid to low 12 sec qtr. miles and serious giggles. That feel of that type of acceleration is the second best feeling I've ever had, ha. Please keep us informed about this issue early and often as you hear more about it. With the current VQ, I think I'll try for about 400 engine hp. With a stronger engine, I'd love to go for 400 whp with reliability. Which is really where I prefer to be. If I hadn’t already bought my 04 350Z, I’d consider waiting. I think I can be happy with the HKS power levels for this car and plan to go for More Power in my next Z if the engine strengthening happens. (Or rebuild the engine stronger eventually, hmmmmm.) I read something in the current issue of Sport Z magazine that they are going to start putting a stroked version of our VQ engine good for 4.0 L in the Pathfinder. Might a 4.0 L as well as a stronger built VQ engine be in Z future for our cars. Anyway, your news makes my day and keeps the dreams alive! Good post and thanks again.

 

I think mileage also plays a huge factor. I didn't know a rod change was slated for 2k5 models, but more power to those owners. My engine already has almost 55k miles on it, and I wouldnt even consider turbo'ing it without rebuilding it first.

 

Kit is about 80% installed. I had hoped by today, but XXtuning also had to spend time this week preparing for drags which are happening today for them. Believe me, I will post TONS of info as soon as I get the car back. They have also been taking quite a few pictures of the install. While you don't need to pull the engine or rip the car apart, it is not, by any means "bolt-on".

By the way...my pre-install dyno gave 242whp and 222lb-ft wheel torque. This was with a Nismo catback only. Everything else (engine-wise) was completely stock.
Air temp was 75 degrees, 58% humidity, 93 octane fuel.

 

I will eat my left shoe if Nissan installs forged conrods on the track version. It would add way too much manufactuering cost, and the raw performance again will be nil. They might strengthen them using some using other methods, but they will most likely still be weaker than optimal for F/I.

 

They certainly won't be low compression or as strong as the Pauter rods. They won't be able to handle the enormous amount of boost that you'll soon be running.

But they certainly won't be the paper clips that we currently call OEM rods . They should be good for ~400whp, which is where a TT @ ~7.5psi should be at. That's a sweet spot for a lot of people considering FI.

By the way, I am basing my prediction on the assumption that the changes to the 2005 track/anniversary engine are coming from the NISMO S1 engine. Read some of my posts in the numerous "2005 Z Changes" threads for justification

Shiva

 

Care to explain why there are guys running WELL over 400whp (ravaz, phunk, skidazzle just to name a few) on completely stock motors daily without any problems at all....yet there are some guys running well under 400whp that have blown up?

This doesn't sound like a motor strength problem to me at all. Some of you guys know what I'm getting at here. Sure you can go and say that there are VQ's with "weaker" rods than others out there..but I find it very hard to believe that some stock VQ rods will barely handle 100 extra whp while others can handle near 250 extra whp. That's WAY too much of a difference to blame on "production variations".

I came from the nissan maxima community in which the VQ30DE was hailed as a VERY strong motor which could handle substantial amounts of boost (14-15psi) with no internal modification. I find it really hard to believe that nissan would stick WEAKER engine components in the VQ35DE motor.

 

seems weird to me too.. you don't see any of this with the 2k+ maxima's that have gone turbo and you would think it's the same internals to a point?

i was 200whp over stick.. no internal work, how can the vq30 be that much better?

 

The VQ35DE most definitely has weaker internal components than the VQ30DE. This was done on purpose (gasp, the horror!) to significantly reduce reciprocating mass (the most undesirable mass in an engine). When you increase bore size significantly (like when you bump up to 3.5L from 3.0L), the pistons are a lot larger and carry a lot more mass. In order to counter this increase in reciprocating mass, they lightened every component. Nissan went to great lengths to do failure analysis and computer aided design to create rods that are strong enough for NA use but significantly lighter than what they were previously using.

All of this makes sense for a company trying to make a great NA motor. They weren't thinking about boost, and it's more than obvious from looking at the engine design.. but even if you don't want to believe that, have a look at the SAE papers Nissan published about the 2nd and 3rd gen VQ engines. They clearly spell out their design goals and the methods they used to accomplish them, including what I have described here.

 

Very good question. I am also running 9psi daily...and just crossing my fingers that I dont blow something up at 415whp or so.

I cant explain it entirely. But keep in mind that metal will fatigue over time, and nobody knows when a motor will fail. All I know is it doesnt seem entirely boost related...since three failures were in the sub 7psi range, and it may not have anything to do with tuning...since Gurgen's car was perfectlyi tuned, and he even ran a J&S as a double safeguard. The only consistent pattern here, is that everyone with the TT's has bent, snapped, or otherwise broken their rods...at varying levels of boost.

So based on these user experiences......the likely suspect is a weak/defective/underspec rod. Sure, tuning, of course...plays a big role, but again, I'd refer you to two cases..Gurgen...and Bini2...both PERFECTLY tuned..that still snapped rods.

 

Lighter does not always mean weaker.

 

While some of the cars that failed may have been "perfectly tuned" they were all still running piggybacks. I think that the 350Z's ecu is the component that could possibly be making motors puke. The ecu in the Z does some really weird stuff when it has a piggyback on it. What's to say it wouldn't change something like timing for a few split seconds creating detonation stresses in an otherwise "perfectly" tuned car.

 

<--- 3500 miles now at 9.5 psi or more. dynoed 467 at 9, you do the math. im just under 500rwhp. over 13,000 since boosting the motor. around 6,000 miles i think is when i went to 416rwhp, then like 2 weeks or so later went to 435rwhp. never do i turn the boost down, i am always running what i am tuned for.

my rev limiter is at 7000 RPM and there are several witness' to the abuse i put on this car. Not only am I known to race 5-6 cars every day from rolls up to or over 140mph, taking each gear to 7000 and what not... but **** i floor it in 1st and 2nd and typically im just banging the rev limiter at 7000 with full boost... sometimes i miss a gear (like i did today) and bang the hell out of it.... i do burnouts with the peddle to the floor with the tach just banging 7000RPM.

i purely abuse the car.

i might be jinxing myself... but i really dont see a problem with these rods yet... if they hold up to the next weeks of abuse before i pull the motor out, then I am gonna be convinced that the rods are just fine.