Hi,
Ive been trying to piece together a rear mount turbo (he351cw) on the stock 2.25"ish piping with the piping ceramic coated with a UTEC or Haltech but on stock internals...and now Im at the point where I have to order the turbocharger and UTEC

My questions are ( I searched, found some of the questions previously asked but I didnt find the answers):
Can I use only forged rods and slightly lower compression to push 500whp on the stock internals on 94 octane?

Cometic makes custom sized gaskets... I was thinking a 2-3mm gasket with the strongest studs I could find. The timing belt has a tensioner so this should work right?

Would you know the limit of the vq35de if forged rods are used along with a slightly lower compression, like 9.7:1?

What are the common components to cause engine failure at high boost? rods...then the high compression knock issue and then?

TBH building a forged vq35de seems like a waste of money when I can trade it in put the same money on top and easily get a 370z, G37, 1994 R33 GTR (RHD, high on insurance), 1993 Supra TT (RHD)


ALSO, I looked up the vq32de, destroked version of the vq35 using vq30 internals...so I was thinking if using forged vq30 rods would be able to support the vq35de at like, say.... 18psi??
Im guessing I would lose roughly (.3/3.5)x 274ft.lbs = 23.4ft.lbs of torque? but a faster and higher revving engine....i always thought the vq revs slow...except the rev match on the 370z
Theres a 500whp+ (560 i think) vq35de on stock internals but on 116 octane.

you can indeed, hal from dynosty actually runs cp pistons and eagle rods on his personal 744 rwhp(i think its 800 now) z, you can probably even use stock pistons i havnt seen anyone break them yet although might need meth due to the compression, the weak point in the engine is honestly just the rods. you can try the cometic route but its going to be pricey i would highly recommend just use a meth kit if you need it, but wait until after your tuned and see what you can do on stock compression because i know there are cars who did your goal on stock pistons and rods temporarily without det. also no need for the strongest studs....... your going to pay a ton for l19 head studs around 400-500 bucks, a better route if you go with the stock pistons is to use a HR gasket with HR bolts, no one has actually found the limit to de bolts but its just accepted the hr's are stronger plus the hr head gasket enables better cooling but it does need a little grinding done on the block.

as far as limits i wouldnt try for much past 500, when you start going beyond that your going to need alot more money invested, 9.0:1 or lower compression depending what you want to run on pump(or even stock compression if you have access to e85) cp or equivalent, larger clearanced bearings, arp main studs, billet girdle, fluidamper or ati pulley(HIGHLY recommended anyway though even lower then 500), l19 head studs, hks or dynosty headgaskets(cometic honestly arnt as good as the magazines make them out to be), larger turbo or turbos(now sure what the he351cw will put out not familar with it but i can tell you that you arnt going to be happy with the spool characteristics since its aimed at a diesel.), bigger fuel system, headers(stock become a restriction about 500 to the wheels) and more i know im forgetting atm. expect to spend around 10k for a well performing single turbo to around 500-550 to the wheels, expect about 16-20k for above that where the clutchs alone needed are 2-3k by themselves.

for common failure points rods, rods and rods, no one has pushed stock components to failure yet we dont even know the limit of stock sleeves, xkr on another forum ovaled his cylinders at something like 890 wheel horsepower(couldnt even tell till tear down car ran fine and made power) but hal runs 744 to the wheels no issues. people have ran 500 on stock compression no issues some have meth some dont depends on your area. bearings have spun alot on various power levels i attribute this to shops who have no clue what they are doing that "specialize" in the vq or nissan in general trying to use factory like clearances on high power build. the vq has bearings larger then a small block chevy and lsx and almost as large as a big block chevy, it needs large clearances especially so it can use thicker oil for higher power. i recommend 30 to 35 thous for over 550 to the wheels and 15w40 oil, almost double factory clearances.

you can try to trade in for one of those cars but after trade in the cost of a 370 is going to be 3 to 4 times the cost leaving you less money to mod, it still only holds about 500 to the wheels stock block like a hr 350z, for bigger power you have to swap to 350z hr heads because the vvel heads are a pain in the a**, all the parts are just as expensive, if doing stock block power they have overheating issues due to the vvel, and overall your taking a step backward when budget is concerned. if your looking at a r33 or supra im not sure if your in the states or not but you will be looking at around 30-50k for a federal legal one, for the supra your looking at 20-30k, both platforms have there own host of issues dont be fooled by the "it will hold 700 stock block!" hype, sure but again just like anything else its a time bomb, you will notice even for both those cars people start building the engines around 600-700 whp and again they have there own issues. not to mention the fact a 800 whp r33 will be utterly unstreetable due to the smaller displacement but the vq35 is right at home with it, and both platforms are just as expensive as a 350z to modify. the supra especially needs major headwork to flow what the vq35 does stock, the rb requires major headwork to flow good as well but it wont hit vq35 numbers due to its smaller displacement. both engines where great for there time but the vq35 is a superior engine its only major downfall is the rods.

if your looking for a budget vehicle sorry to say but you would be best looking into a honda or dsm and even then dont expect past 500, something the magazines dont tell you when they show off these 600,700,800+ hp beasts is just what it costs for the vehicle to be somewhat streetable and reliable dosnt matter if its a 350,370, gtr, supra, evo, sti anything even lsx swaps have a good amount of money invested to hit these power goals


oh yah almost forgot if you do built the vq35 do at least a revup pump, iirc the hr pump should fit also but requires modifying a locating dowel on the engine

Thanks for the reply...

Im in Ontario, Canada.... over here you can import a JDM car as long as its 15 years or older... so there are quite a few R32 GTR's and R33 GTR's here for $9k-$18k... sounds too good to be true... it kind of is,
On a RHD car here, very very very few companies would agree to insure you at at least 3-4 times the cost of LHD insurance. Also it would get you pulled over quite often as most of the local population does not know that RHD cars legally exist on the roads here...but yea here you can get a R32 GTR w/140kms for around $10k

I was looking at the he351cw due to maxima and DSM owners preferring them over the HX-35 and HX-40 due to their quicker spool and similar flow limit. People say HX-35's flow similar to GT35r's...

Plus you can find them at a reasonable cost due to powerstroke engine owners upgrading to bigger turbos...he351cw, hy35, hx35, hx40 seem to be very well sized for the vq35de...They are also journal bearing, making them very easy to rebuild when buying used ones...

The head gasket route to me seemed cheaper than anything else due to the fact that I do not have to take apart the block...if it could get me lower compression I may be able to push higher boost on stock internals...

HR BOLTS and gasket!! got it...TY

My 350z is my DD.

Im planning to run pump fuel at 93-94 octane...from what I have read, with the stock intake manifold and with stock cams ill be limited to around 360-390whp...unless I can drop the compression and run higher boost on pump fuel...

I dont see why it should cost me near $10k if I piece the kit together myself...
The stock 2.25-2.5" exhaust piping is there....
All I have to do is get a turbo flange/manifold welded to the end of the stock midpipe, and then mount the turbo, oil lines and can, IC & piping, fuel pump & injectors, UTEC and dyno tuning...

Plus if my kit starts smoking, I can just jackup the rear of the car and work on it opposed to a mid mount of underhood FI kit

Im going to take your advice and switch to thicker oil either way... Nissan doesnt recommend synthetic. I switched to synthetic and started burning oil, I switched back to non-synthetic and it has not burned any oil at all...
Its funny how a big chunk of 350z and g35 owners stick to synthetic, complain about burning oil and never pay attention to the fact that synthetic was not recommended for the early vq's at the least...theories say that synthetic oil slips past the vq35de's piston rings and burns...which makes sense cuz I had blue smoke when I was burning oil on synthetic...
Other forum theories state that synthetic can make the gunk around piston rings swell up, and can cause the rings to stick...causing an oil burning engine with lower compression...


I dont know which size turbo to go with out of the following (the numbers are to give a comparison between the turbos and not potential for the vq35de):
HE351CW : spools early like the hy35 but provides almost as much flow on the exhaust side as the hx35...probably 390whp @10psi
HY-35: spools faster than the hx-35 but its flow was 57 vs the 60 or 61 for the hx35....probably 350whp midrange before power drop
HX-35: according to DSM people it spools faster than the GT35 and provides almost as much flow for 400hp+...maxima owners have had success with this one
HX-40: Few different versions with different spools...from what I have read, for vq35's, they will probably spool around 3k rpm opposed to 2.2-2.5k rpm of the he351 or hy35...But they can break the 400whp barrier at low boost at the top end....but very laggy in comparison to the hy35


So, If I cant break 400whp reliably (500hp est.) on pump gas and stock internals there is no point in going for the hx-40...Unless I can run high boost

FYI: I found this, cometic 0.140" vq35 headgasket...
I didnt find the 0.140" ones last year for some reason
http://www.shopengineparts.com/productd ... ype=engine


The stock vq35 stroke is 81.4mm, increasing the cylinder head height by 3.554 mm would get us a compression ratio about 0.445 less,
being... 9.75:1..it should allow running 12 psi at 249 feet elevation if the gasket can hold...
I should be losing 4hp due to the 9.75:1 but gaining room to boost...

The timing chain tensioner im guessing could adapt to +3.554mm. The chain cover and valvecover and stuff wont line up
Would it need longer bolts?


if I replace the rods with shorter ones, for lower compression....Would I have to get the crank assembly rebalanced?

Someone has very sorely misinformed you, in order to change the hg's your need to pull the engine about 70% apart, the front cover bolts to Tue heads and seals with rtv so you can't just slide them in place.

Since this is your dd just stop you need a second car any time you build for power, another thing magazines don't tell you is the maintence cost and time cars spend down at high power, "reliability" in the performance world is just nothing major giving you will spend a lot of time checking things and replacing small parts regardless of platform. Whoever gave you the power estimates is someone you need to ignore people run 500+ easy on stock intake and cams, I run over 600 on stock cams and a modified revup lower plenum. Cams don't make power they just alter where it is made. People also run over 500 on stock compression you just need a very good tune. Your list isn't even close to reality yet, a turbo won't fit on the stock midpipe I run a midmount kit andn the turbo needs to be placed just perfect to fit under the car without smashing it to bits on speedbumps, this means all custom piping, if its under the car you need a oil return pump because it can't drain back to the pan(there isn't pressure post turbo it gravity drains) our not counting a fuel return system or internal parts to make it work in the tank so you can use both sides of the tank. Its not a "replace stock pump and go" ordeal. Utec is the worst system you can get you need osiris or the old haltech utecs own manufacturer spent even support it anymore. What about a clutch, wheels tires? Guages? Flanges arnt cheap either you will spend 20 bucks a flange or 40 for vbands, silicone couplers, t bolts? Tons of people have tried to do it for under and no one is successful, a dude tried a eBay kit and has had nothing but problems, not even half my power and three times the issues. That cometic gasket is uncompressed I've spoken with them myself all their vs35 gaskets compress to the same thickness as stock. You will not find a hg from anyone that actually lowers compression but again 12 psi on stock compression is absolutely fine I ran 10 psi on 92 octane. For the rods again it dosnt work that way, no one makes shorter rods and you will be looking at 2k or more custom. Then your looking at quench changes, your short rods and hg idea might make 4 less hp on theory but it didn't factor in quench so figure about 20-30 hp loss in reality then even a rod change is going to make such a huge change in compression the engine won't run. As I said your chosen platforms are the most expensive there is for every day tuners the only cars period more expensive are r35, vipers lambos and the such. If you want budget you need a 1 or 2g dsm, civic or 240sx.

You need to remember static compression ratio is of very minor consequence it really didn't matter and is nothing more then a very rough starting point. Dynamic compression is what matters and why you can run more boost on stock pistons its just a time bomb due to the vq having weak rods. Also take everything you have read on dsms and throw it out the window, the only thing comparable to the vq is the 2jz and even that's a estimate when it comes to turbos.

I saw this:
http://www.floridastreetscene.net/showt ... hp?t=56041
so I assumed it would not be too tough to change a head gasket without taking out the engine....
I was still kind of confused on how to put everything back together in that setup without removing the radiator....

I read about 2 s2000 running 2mm gaskets for boost and they run fine and then I read up a similar build in another form where the new thicker head gasket blew under boost

Yea... When I wake up, I think I should keep it NA for a DD
when Im about to sleep, I think I should turbo it...

I agree... I should get another car but that wont be anytime soon, until then Ill try to collect FI parts

I meant bolting the turbo after the midpipe, around where the muffler is...
Something like the STS but with the exhaust going straight to the turbo instead of around it...if the turbocharger can be clocked such to allow

For the rods I was looking at the vq30de rods. Vq30's seem to be able to push more power on boost with stock internals...their rods I hear are thicker and probably a little stronger. Although I have not seen forged vq30de rods on ebay but I have heard of forged built vq30de's. Thinking about the quench area and rough idle I may have with vq30de rods, I think I'll stick to stock vq35 rods and stay under 400whp on max boost.

I appreciate the info Jerry.... Dynamic compression, got it...
Ill keep an eye out for parts and will start collecting them along with a welder

Yah you need to take at least the fans out to get the crank pulley off. Don't need to take the engine out but gotta pull the lower oil pan the entire front of the engine just to get the heads apart. Vq30 rods are about equal to vq35hr rods and good to roughly 500 they are stronger but still minimal. For rear mount you have to remember they will spool like s***. Seemytailsblink on another forum talks it up and trys to deny it but the fact of the matter is his gt67(about equal to my old precision 6765) with a .64 t4 ar spoiled 1000 rpm after my .96 t4. Yah dynamic compression takes cams and stuff into account, like my 8.0 static compression is equal to about 7.2 dynamic on stock cams. It really sounds like a ls swap might be what your looking for for 400, its more expensive for 500-900ish but its more reliable for up to 500ish