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Depends on fueling. It is always more the torque than HP that drives block failures, and I think bad tunes/bad fueling that cause more than torque. I am running 550HP/500TQ on 93 octane on a stock 80k block. Running E85 it is not uncommon to see the 370zs running mid 600s HP and probably 550-600 TQ on a stock block. If you have a 7AT it seems 400 TQ is about what you want to stay below. 6MT has been shown to handle pretty much anything people have thrown at it, minus the occasional synchro issues with 5th that happen to non forced induction cars as well.
300 tq limit for the 7 AT as that is all the re7r01a is rated for. At minimum, you need a 25 row cooler and that will buy you time. Gears 5-6-7 have a very high chance of breaking when under boost. 1-4 is where you can rip.
7 AT should upgrade the clutch packs, cooler, maybe TQ converter. That will give you enough beef to throw down 500 without too much worry.
I'm in the same boat and have opted for the Stillen supercharger kit with a higher boost pulley. I'm leaving the internals alone but will most likely have the transmission (5AT) looked at/beefed up. As RMB said, torque is what murders our transmissions, and being that I have an X model, I need to be extra careful of torque spikes and keeping an eye on things.
Well lets assume my transmission has been built and I am running e85 but my motor has not been built. Then do you think the stock block could handle more than 650hp and 600lbs of torque?
Well lets assume my transmission has been built and I am running e85 but my motor has not been built. Then do you think the stock block could handle more than 650hp and 600lbs of torque?
TLDR: If you care about your stock rods, limit the HP to under 550HP and limit the TQ to be under 400. Otherwise, build the motor.
The VQ37 blocks have proven to take 800+ whp, but it's highly recommended to upgrade internals once you get past 550 whp if you want reliability.
Remember though that for these motors/drivetrains, its not so much the HP but the TQ to plan ahead for. Echoing what everyone said above, for a daily/streetable car, I wouldn't feel comfortable pushing anything over 400 wtq without doing basic internals. You could get away with 550whp/380-400 wtq but I would be sketched when pushing it, especially in any gear over 5th.
I cannot stress enough the importance of a proper install/tune and quality parts though. Usually when motors around here go boom, it's ultimately traced back to shoddy tunes or improper installs. Fueling is also huge here too, fuel starvation at higher numbers has claimed a fair amount of internal components.
There was a member on The370z that had 679whp for about 20 miles (on stock internals). He bent four connecting rods causing piston skirts to contact crankshaft counter weights. I would say anything over 600whp isn't going to last without cracking your motor open.
Hmmm.... But is it not true that tuning has a lot to do with it? Ive heard poeple they ran 600+hp for years without issues and other that did not have such great luck. And as for fueling wouldnt bigger injectors and a walbro fuel pump be ok? What would be the cost to build the motor though?
Hmmm.... But is it not true that tuning has a lot to do with it? Ive heard poeple they ran 600+hp for years without issues and other that did not have such great luck. And as for fueling wouldnt bigger injectors and a walbro fuel pump be ok? What would be the cost to build the motor though?
There are too many variables to take into account, and I would stray away from thinking in absolutes and strictly anecdotal evidence here. Sure, there are people who have run 600 whp on a stock block, but things like mileage, driving styles, location, fuel quality, etc. etc. come into play as contributing factors here.
An upgraded pump and better flowing injectors are absolutely key in the longevity department, but don't forget about the added utility of an oil cooler or meth kit here either.
As for costs, that's another realm of variables too. Whether you bought everything separately or as a package, the boring/honing, decking/squaring, pistons, connecting rods, engine bearings, studs, and the eventual balance and rotation of your block could be anywhere from $4-7k before labor and tuning.
Going FI isn't cheap, and going FI with a build meant for longevity is even less so. At the end of the day, it's your money.
Personally, if I was going TT I would build for long term reliability. I'm not sure if you've ever ridden in a car with 650whp, but I've owned a few and can promise you it's absolutely too much to be remotely practical in an everyday setting. Honestly, anything over 550 whp on the street is overkill. At least with a built motor, you'd be able to enjoy the benefits of being able to experience every range of the spectrum without worrying about popping your motor. Just food for thought.
Gonna echo WNE here. 550 whp and keeping tq numbers under 350 is the key for the block to live with stock guts. You might here guys saying they've driven with FI for years but what makes up that year? 2k miles? 5k? 20k? It's a vague statement to go on. When I inquired about a single snail setup to my local shop, they said 400-450 whp is what they recommend for the car to retain its DD reliability. They stated they hadn't done a 3.7 yet but from what they've seen working on boosted G35s, 400-450 is the magic number for the block.
Agreeing again with WNE regarding 'usable' HP. After 450whp, I can almost guarantee the everyday guy is not capable of handling it. I remember taking my cousin's GTO for a spin when I was 16 and wow. The highlight reels of Cars and Coffee is evidence of that. It's worth noting, you better beef up the brakes and suspension components as well...gotta stop eventually.
FYI this is what I've gathered through my research and contacting Fast Intentions. Labor rate was a guess so that could vary. The hours should be accurate though. If you add a built motor to this it adds up even more. This is not a perfect estimate but should be fairly close and wanted to share.
This will easily put you at 500+whp/375+wtq, definitely could be more or less depending on the tune and how much boost you are running.
^I remember you sharing this in another thread but it's essentially dead nuts on. Obviously, you can save a few thousand here and there with a different kit but it's accurate.
02-01-2018, 09:40 AM
