How much boost pressure can a built VQ37VHR withstand?
 

Hey guys,

So I'm in the final stage of planning out my 370z twin-turbo kit, but I was wondering about tuning and labor cost.

1. Is there an estimtae on how much will it take for a shop to install a twin turbo kit, a rebuilt engine, and oil coolers? I am currently viewing the Fast Intentions Twin-Turbo kit, but AAM Comp. just came out with their own.

2. How much pressure will a modified engine be able to withstand? Current mod list:
CSF Competition Radiator
Methanol Injection
EcuTek/Uprev Tune
Greddy High-Capacity Oil pan
ARP L19 Head Studs
Cosworth Head Gaskets
Wiseco pistons
Carillo/Eagle rods
ID/Bosch injectors
CJM Fuel pump
Fuel system
Return fuel system
Valve body upgrades
New spring and retainers
Fuel pump voltage stablizer

Thanks!
--Nuc370z

What do you mean by Carillo/eagle rods , Wisco pistons and billet crankshaft when a brian crower stroker kit is in your list already?! Do you know what BC kit includes ?!!!

Kinda skeptical here , sorry :)

i am on an unsleeved block with wiseco pistons/eagle rods and stock crank
i was told by my builder that the combo will be good for 600rwhp easy

i guest my question is at what point do you need to go sleeved ?

im not building a drag car just a strong street car and for me 600-650rwhp will get me 10's at the track and kill most cars on the road.

Sorry about that. My mistake. The parts list for the slash ("/") marks is still undecided/unordered, just trying to figure out which ones and I accidentally uploaded an old parts list. Taking out the BC kit.

You don't need a built engine to make 600-650. My F.I. twins make 604 on 100 octane with 14lbs of boost and an E85 car makes 620.

This is true. But for how long? We don't have the data yet. But his built engine at 600 will no doubt last longer than stock.

When I was running my 350z at 430whp...every time I got on her hard I prayed she would hold together..lol..

Built engines offer a piece of mind and allow you to have more fun vs. riding the ragged edge.

But at the same time opening up the engine can bring about a whole new set of issues.
I would say this car, if taken well of can survive quite well at 550-600whp on e85. A prime example of that is Phunk, he has 50-60k miles with his greddy TT kit making over 550 (if not 600) on e85.

In terms of boost pressure, the highest I have seen currently it John's 370z TT: John’s 370Z TT+ |
They hit about 25PSI though it seems and 800whp & 700TQ.

:iagree:

yea now it makes sense here ..
its ok, all the best.

But really how much does a new engine cost vs all the built money? I understand building for 700 or 800 hp but at 600-650 I would rather just put the money in the bank and buy a new engine if something blew up. They really aren't that expensive.

^^baller

How much is an OEM engine?

6-8k I believe.

I can get a built one installed for that same $8k. I'll gladly go built just so I know it can handle the power.

How much is it going to cost you for build parts and install?

eBay, 3k

Boost your stock engine first. Get it tuned well and stop at 550-600rwhp. Done right, it will last. If doesn't last, its very likely that whoever did it wasn't going to have better results from a built engine either. Except you would have spent twice as much and not had your car for 3 times as long just to end up with an empty roller and boxes of parts. Yes there are exceptions to every word I say, but we all know not to plan on being an exception.

Use the boosted stock engine as your "feeler" before you dive into the deep end. Your experience through this will help you make better decisions on your full build if *IF* you still think you need more power.

The 370z is no GT-R... past 600rwhp starts to get a little pointless unless you are going to make commitments towards traction that take away from why you purchased a Z-car rather than a Mustang to begin with.

CSF Competition Radiator - OK
Methanol Injection - Go E85 if you can
EcuTek/Uprev Tune - OK, not like you have any other options. The real decision is "whos gonna tune it?"
Greddy High-Capacity Oil pan - OK
ARP Head Studs - L19 only or dont bother, standard ARP studs torque limit is too low
Cosworth Head Gaskets - OK, i didnt even know they had HR/VHR gaskets
Darton sleves - Never do this to a VQ, it only introduces room for error to fix a problem nobody has
Wiseco pistons - OK
Carillo/Eagle rods - Carillo OK, Eagle probably OK but scarey
ID/Bosch injectors - OK
Brian Crower Stroker Kit - Pointless
CJM Fuel pump - OK, so long as its large enough for your power
Fuel system - OK
Return fuel system - OK
Valve body upgrades - I pretend the 7AT doesnt exist so I have no opinion what to do with it.
Billet crankshaft - Waste of money
New spring and retainers - Consult JWT what to do with the VVEL heads based on your goals
Fuel pump voltage stablizer - I assume you mean upgraded wiring to the pump? If so, that is good and should be done for anything larger than a 255.

Exactly. Why bother with another stock if you can build for same?

Phunk dropping knowledge FTW!

Because stock is stock. Tried, true, tested with tens of thousands of cars and millions upon millions in R&D. Sorry but bolting on something is one thing. You open the engine up and you could be headed for disaster.

Like I said, it would be one thing if you wanted to push the car past 650 in to the 700s but it seems like a silly thing to do for a power level that has proven to run just fine. Why not just replace the engine with something that comes stock at 650hp? Put a GT-R engine in it. I think it is safer than building.

My 2 cents.

A new VQ37VHR is $6000 from Courtesy Nissan (Complete). A short block is $3600.

I dont think I would bother putting a new stock one in if I blew the engine, but I also would not build an engine until attempting to exceed the power the stock is capable of.

GT-R engine swap is out of the question as far as realistically... its much too expensive, nothing bolts up including the transmission, its a lot taller and might not even clear the hood... definitely not the coveted strut tower bar, LOL. The GT-R engine tends to have rods fail before 700awhp anyway, making it almost pointless unless doing a full build on it before shoe-horning it in.

So if you had your choice for the same money between a stock bottom end or forged bottom end you would pick stock?

Thanks phunk! :tiphat: Sadly, I can't find any E85 stations in Washington, the highest octane we have here is 93-95 octane for "premium" fuel.

Why is everyone going with E85? Why not just get C16?

So people actually got the GTR manifold upgrade on our cars? Can we buy the hardware now? Or was this a one time offer only?

I'm more interested in that GTR manifold! Someone please shed some light on this!

E85 is less than $3 a gallon and available at gas stations in many areas in the USA. What is c16 pulling these days? 12+ a gallon? As far as ease of availability and cost, c16 doesn't make it into the same conversation as e85. Here in the Chicago burbs, an e85 pump is never more than 15-20 min away. You can very realistically run e85 full time... And I have for 3 years, nothing but e85 in my Z.

That cars gtr manifold conversion was done by gtm. Either a prototype or final cast piece, I doubt anyone knows for sure. Call them up and ask if they will sell you one.

cost me $8700.00 to have my motor built and installed.
i call it as said before peace of mind i can beat the hell out of it all day with out that please dont blow in the back of my mind. but i drive like an old lady going to church most of the time

As long as you can keep pre-detonation from occurring, you can boost an engine as much as you want. That's not nearly as easy as it sounds though.

Charles while I fully respect your knowledge I must argue your statement that anything less than L19s are sub par. There has been NO proven evidence that the torque on the head studs is insufficient to prevent head lift and in most cases it was caused because people don't know how to properly use the ARP lube and/or use oil instead. I HAVE however read where the L19s(durning long term usage ie non race/drag motors that are frequently torn apart) are causing corrosion issues in aluminum blocks due to the material they are made of!

it goes way back. it was a major problem with DE's and effected all the early builds. Guys were chasing all kinds of non-existent issues like boiling coolant etc trying to figure out why it was happening. Some were even going so far as replacing the coolant plugs in the head with giant allen bolts and torquing them down to create pressure on the headgaskets between the cylinders (LOL). Eventually everyone went to 1/2" headstuds, boom, problem solved. Until the L19s came out which allowed getting real torque on the head studs without drilling and tapping the block.

I forget, what is the torque spec on the standard ARP? 65-75lb ft? Thats not going to cut it. At least, it didnt on my 350z. Made it about 5-6 blocks from the dyno. Then I swapped the block for one that was drilled and tapped for 1/2" studs, and now we are about 10 years since that engine went in the car and its still doing great! So, I like to get about 90-95ft lb on the headstuds (with moly lube).

Other than being an expensive unicorn and handling so far 26psi of boost. I would wait for Charles, specialty Z or someone else to make a worthy intake that is proven to make power. I have no before or after dyno so I cant tell u if it helped me make power or the opposite. I do know that I had to have custom billet fuel rails made to accomadate the intake conversion as well as repipe my charge piping. Save your money and wait. Plus I doubt anyone will ever see another one come out. I may be wrong and for me rarity is better. Waiting will provide proven results and more bang for your buck IMO. But who knows when that will be...

Thanks for the info! I'm curious as to when your saying worth intake. Is something wrong with the gtr intake manifold? I figure going from plastic to whatever material the gtr material is, it would be much better.

So how did you get that conversion made? I'm very interested! Please do share!

I just finished installing mine here about 4 days ago and they call for 3 equal steps to 85ft-lbs. I didn't feel that was too bad I could most definitely understand concern if it were only 65ft-lb though! God yes. Iirc the ones I installed are indeed half inch now ill look into that though to make sure I'm not just blowing smoke out my @ss to you!

On topic; OP I must agree with my man Charles though approach boosting your factory block. Hell I would still be on my factory block had I had a competent tune done. After having rebuild both my DE and VHR blocks now I can tell you there are several stout improvements in our block. I can assure you technology in both the bottom and top end of the block in our car has definitely been improved.

85ft lbs should be good to go. Perhaps they raised the torque specs or changed material of their standard studs to allow more torque? Because I am pretty sure that the stud threads and length and everything are the same as the DE arent they? Its been many years, its just burned into my brain that all the 2003-2004 DE builds were blowing headgaskets with the normal ones and then it became a non-issue when we all went to 1/2" threads.

My built engine was a big investment, but siting at nearly 600whp at 13lbs boost on 91 octagon fuel is very nice. It makes me comfortable I can beat on the engine on hot hot days without worry.
When I upgrade my fuel system to deal with any starvation I will push her higher to 18ish. 650-700whp should be fun.

One of the reasons people build their engines is to drop compression to a decent enough level for boost. The OEM compression ratio is too high for pump fuel.

You also need to keep in mind that traction is a major issue on our cars, and the increased torque makes breaking parts in your drivetrain much easier. If you're building a dyno queen you'll be fine but anything you plan to race requires serious consideration in terms of traction and strength.

What would you recommend upgrading for the drivetrain? Eg. Clutch (which brand is best suited for high torque spikes), driveshaft, differential (I plan on an OS giken, but any suggestions?), gearbox, etc.

Thanks!

But see he's a 7AT, where are you going ro get the valvebody to help your tanny hold all that torque??? As far as I've read through here our 7At tranny can only hold up to 400 torque and that's pushing it if it was on a good tune? Unless I missed something please elaborate as I too plan on going boosted...Btw between ID's and Bosch injectors whoch would you go with and what about Deatschwerks??? I plan on going with 1000cc for E85..

I am running 13PSI peak (settles in around 12.5 under most scenarios). I had to upgrade to the CJM return fuel system to be able to support fueling at that boost (the stock system would drop ~15psi under boost). Car has been running great. Nissan did right with these engines in my book.