Built Block
 

So.. Anyone have one yet? I have a shortblock on order from GTM, (stage 1) and eagerly waiting it's arrival.

On the GTM website, the block says it's rated to 600whp, but when I spoke to Sam, he said that it says 600 because they have to put a number on it, but really the pistons/rods are capable of more. What do you guys think?? How far would you push this block comfortably?

Also, can someone chime in about some differences in driveability with lower a lower compression engine? I chose (with the help of Sam and my shop) to go with 9:1 compression ratio. Will this affect how the engine runs at all? Also, I know that i'll have to boost higher to make the same power, but how will this affect torque numbers?

And last question, for anyone running a stage 2 TT kit. I don't remember what the injectors where running at. From what I understand, they should'nt be running higher than 95% or so, correct?
Thanks guys!

Congrats on the built block, I'm in for the result and review.
Forged performance built a G with a built block running 9:1 compression with a greddy TT kit. It is said that it runs like stock and made 636whp with 93oct.
From GTM's website, you should be running a 600cc injector, if you planing on going higher tune with more boost, bigger injectors won't hurt. Injector Dynamics have 725cc and 850cc which are probably suitable for your application. Altho not sure how well the walbro 255 will do with 6 850cc, might need to look into getting a higher rated pump too.

Thanks for the input, theaudir8fan. I was also thinking I'd need bigger injectors. I was thinking of swapping some 800cc's and a 300lph fuel pump, not sure if that would be sufficient. Also, do you know what turbos that G was using? And on what kind of dyno they made this kind of power? Not sure at what point my gt28s will max out. I get 94 oct here, so hopefully with the new injectors and pump, I'll be able to hit those kinds of numbers as well. *fingers crossed :p

yea its probably rated for more, but a lot of times those hp capable numbers are arbitrary. a stock block is good for 600whp for 1 dyno pull. The question is how long. i think the implication here is that this motor can handle 600whp day in, day out, without issues. Building a motor and beefing up the internals is less about how much peak power it can put down and more about how well the block holds up over time to the rigors of actually putting out that power after thousands of miles. the GT28RS are good for 700+whp on the 300zx (VG30DETT) with the right setup, so i'm sure they are good for at least that much, if not more, with the right setup on the VQ37 with a built block.

You should ask sam about getting 1000cc or larger injectors so you can run an e85 tune :)

BTW, way to go on doing this whole VQ Forced induction thing the right way ;)

Thanks a lot, Jeffblue! Trying to stay away from as many headaches as possible :P

Glad to hear the turbos will hold up. In any case, I don't think I'll be trying to push anymore than 630-640whp on this block, specially not on a regular basis. I'll most likely be sticking around 570-580whp most of the time, with a few exceptions.

As for the E85 tune, I'm not sure how that would benefit me? I'm not the most knowledgeable when it comes to tuning, but wouldn't 800cc injectors be sufficient with a custom tune? Also, I'm assuming with 1000cc injectors, I'd have to run a dual pump, correct?

e85 is much higher octane equivalent than 93 octane pump gas. Think of it like really cheap race gas. Lots of people are running e85 setups right now on modified cars like evo's 300zx's and lots of others. The only trouble is, that it burns about 33%% (i think) faster than normal gasoline. So, as a result, you need to accommodate for that with larger injectors, and typically a dual fuel pump system. But, if your car is e85 ready, you can go to your nearest e85 station and essentially fill up with a full tank of race gas for less than 40 dollars, as opposed to 150 dollars for race gas. Talk to sam about it, i'm sure he knows a lot more about it than i do, and whether or not it would be practical, or doable for your application, as well as how much it'd cost you.

BTW i believe there are some dual pump setups that only run 1 pump most of the time, then have a supplemental pump that comes on when necessary, so you aren't running 2 pumps simultaneously all the time.

Im curious to see what sam says. I think you'd be the first 370z with an e85 setup though :tup:

Phunk (Charles from CJM is) already running E85 with a Greddy TT kit

Edit: Here ya go http://www.the370z.com/forced-induct...views-etc.html

That looks very interesting.. In any case, I don't have any access to E85 here in montreal, just a quick google search crushed my hopes :P

ID makes 1000cc injectors (I have a set) and the Aeromotive makes a 310 lbs/hr pump (I have that also) that CJ Motorsport (Phunk's shop) makes an in-tank kit for. Just saying........check out Phunk's setup and you can't go wrong, if that is what you are after!

Baker Tuning finished a TT with built block a few weeks ago.
They are still breaking in the motor and waiting on some other parts before final tune. Goal is easy 8-9PSI (what it currently runs) and then a 15PSI map for fun.

Do you know what compression ratio they went with? If they went with 9:1, wouldn't they be making similar power at 11psi on a stock block or around 15psi with a lower compression engine?

well if your target is 630-640whp, i think a set of 725cc injectors should be good for your goals. So if you don't want to spent too much just yet, you can just get a set of injectors. If you want more room for more power in the future, 850cc and a bigger fuel pump should be enough. Do note that the bigger injectors you put in, the more fuel consuming it will be.
This is the link to the forged performance build.
Forged Performance: 636whp G37 Coupe!!! - MyG37
The dyno is done on dyno dynamics, so not the feel good once like dynojet.
As for turbo, it's the greddy G20 kit, so it will be which ever turbo that came with it. Should be similar to the GT28.
Also they used 725cc injectors, so if your power goals is similar, it should be enough.

BTW, are you getting 94 from husky? i thought about going on a higher tune, but after reading up on the amount of ethanol they use to boost oct number, i ended up sticking with shell 91 and take the decrease in power. Also i noticed that 94 from husky returns less mileage per tank then shell 91, have you had that experience? I'm in Calgary by the way, so no chevron like Vancouver :(

I get 94 oct from petro Canada here in Montreal. I've only ever used 94 with my Z, so I wouldn't be able to give any kind of comparison :(

Anyone know what kind of a pump I would need to run 800 or 725cc injectors? I'm hoping a 300lph would be enough? Or maybe even the Waldo I have in there already? (255lph)

Also, I noticed that the G had driveshaft shop level 5 axles on the parts list. Is this a must?

Thanks for all your help guys!

larger injectors don't use any more gas than smaller injectors. they just have the capability to flow more fuel than smaller ones. If they were truly flowing more fuel than they were supposed to then the car would be running very rich

yep^^^ tune will dictate the output of the injectors, largers ones just have the capability for a larger output.

OP I'm assuming you already have an F.I. kit or are you going to run the built block without F.I. and then add the kit shortly thereafter.

Yeah, currently running GTM stage 2 turbo kit.

Ok, I must admit that i was wrong on saying that bigger injectors will use more fuel, since the tune does determine everything. I think i meant to say that it has the potential to be more fuel consuming.

To OP, i think you should call forged performance to ask what fuel pump they are running. I think a 255 should be fine with 6 725cc, but it is probably pushing the 255 to max, 300 should be enough for 850cc. As for the drive shaft, i don't think it is a must, again talk to either forged performance or GTM about this. Most likely, the car is fine without it.

i think they did use the 300 on that but dont hold me to it

I am out of town, but I will ask when I get back to Houston.
The other concern is they have built this on a 7AT and are waiting to do transmission upgrades before more boost.

I personally wouldn't want to run anything more than 85% duty cycles on the injectors.

Back to the OP's original question, you will likely have less tq down low with the lower compression pistons. If you can spool the turbos fast enough, that may not matter. The nice part about the FI kits on top of the stock motor is that you mostly maintain the down low power (even though this car is pretty weak torque-wise). Can't wait to see the results though. I'm sure you will make some monster power.

I agree, trying to figure out which injectors will be around that number at 630-640whp.

There is a formula that you can use to get in the ballpark. If I can find it, I'll post or link it for you.

Thanks for the info. Just got word that the block will be shipping out in 2 weeks. Also, I opted for all the coating services available from GTM.

I'm excited to see the numbers as well! Also, I had a couple other questions. As far as the block goes, I know that I'd be safer keeping it at around 600whp. My question is, does it matter how much psi it takes to get there? What I mean is, if the car is only making 560whp at 17 psi (just an example) would it matter if i crank it up to 21psi to go hit 600whp?

Here is a link to an Injector calculator. Based on your goals of ~580, I put in what the crank hp is (since that is what you would be using for the formula) once you factor in the generally assumed 15% drivetrain loss (puts you just shy of 670hp), I came out with an estimate of an injector size of 733cc with an 80% duty cycle. I would be willing to say that either 750cc or 800cc injectors would give you a comfortable overhead without being way to big.
--edit--
I should also say that if you go to 85% duty cycles, you could possibly run a 700cc injector.

Awesome, thanks Skeeterbop!! Is there any way to tell what my walbro 255 can handle? Probably gonna go for 750cc or 800cc injectors, you think i'll have to upgrade my fuel pump?

I don't have an answer to that. I just know how to find formulas :tup: But if I had to guess, I would say that you might be able to take the injector flow rate at w/e pressure you will be running and add them up. Then find a pump that will supply the total flow at your desired pressure. That is just me making assumptions though so take this with about 10 pounds of salt.

A few articles about sizing the fuel pump:
Stealth 316 - Fuel Pump Upgrade Guide
Calculating Your Engine's Fuel Requirements from Fuel-Pumps.net
Fuel Pumps and Horsepower|Aeromotive

That third one is IMO (after reading them) the clearest.

Thanks, skeeterbop, that was very helpful.

So no E85? I went with the larger FP and injectors so that I could have room to grow as necessary, but how much boost are you looking to run?

Not sure how much boost I will run. Whatever boost it takes to get to 620-630whp I guess :P

Update* spoke to my mechanic and got my hands on some 1000cc injector dynamics injectors and a 340lph aeromotive stealth fuel pump. Should do the trick!
Also, the block is being installed right now, so should be done within a couple weeks!

Awesome.................I'm in for updates!

Nice work in for updates also.

Pics of the block???

This is all i got for now, but I'll have more/better pics incoming soon :)

I'm taking notes. Keep it coming!

Sent via Tapatalk 2 on my T-Mobile G-Slate

Just ordered the 3" downpipe kit with external wastegates from GTM, going a little more aggressive ;)

looks good, what stage is this? did you order a brand new block?