DevilDog7

iTrader: (1)

Ive got an 08 gsr. Looking to upgrade to a bigger turbo, interested in maybe getting the ef4. Ive got the supporting mods along with looking to do cams and springs. Would that turbo get me up to 500 hp or over? Also will the stock block hold up to that along with the transmission, clutch, and everything else? I heard the block could handle up to around 400 tq and heard the rods were a big thing that held it back also? Any input is greatly appreciated.

Robevo RS

iTrader: (16)

No, at least change the rods and the clutch.
When you start pushing hard the stock rods an clutch will go.

In racing you get a regular check ups and maintenance much more often the street car gets.
So you want to have wider safety margin the what we have. Just to be safe with your investments.

Sharkbite2000

iTrader: (21)

LOLOL, it will hold but the question is for how long

DevilDog7

iTrader: (1)

Really im just looking for some numbers that the things can handle because i dont know how much the stock rods, pistons, block, clutch, and tranny can take. I havent heard much on the transmission. How well does it hold up? The clutch i planned on upgrading and was wondering if rods would be a good idea to do when i do cams and springs. Also is 400 tq correct for the block?

DevilDog7

iTrader: (1)

Haha well thats what im asking? Is around 500 hp a pretty good safe number? What should be upgraded so that it is pretty safe. I plan on building it this winter.

SilverEvoX

iTrader: (2)

The EF4 on e-85 or race gas can make 500whp I'm sure, doubtful on pump I'd think though. If you're planning on running 500whp/450-500wtq on that turbo you will probably blow out the tranny at some point and the center diff if you're launching it unless you beef them up. Sheptrans can fix that for you and offers many stages of upgrades.

400wtq is about the "safe" limit of stock rods and even then over time you're playing with fire. A lot of the failures are because of when the torque hits, on smaller frame turbos when it comes on early in the rpm band it goes boom. Even with like 500whp and 350wtq it will probably still grenade without swapping rods/studs.

The stock clutch can hold 400wtq but it won't be happy about it. Some peoples clutches have held 400wtq just fine for extended periods of time (mine and many others) however some people start to have stock clutches going out with as little as 350wtq depending on how hard they drive/launch the car frequently. I'd swap in a 6 puck sprung clutch like the ACT if you're shooting for higher than 400wtq and plan on launching it frequently.

ChrisCarey

iTrader: (38)

500whp on pump has been done It's certainly nearing its upper limits though.

WarmMilk

iTrader: (1)

there have been engine failures on stock turbo and there have been 500+ whp engines that have been running for 20k+ miles. imho at 500 whp its really a gamble with odds being stacked against you...

if you're gonna open up the engine to put in new rods, spend a little more and get piston's too. labor is the bigger cost here. 500 bucks for a set of pistons really isn't that much when you look at how much you're spending on everything else to get to 500 whp.

Inprogress

iTrader: (30)

Wouldn't rod bolts help add safety, that is if building the short block isn't a immediate option?

WarmMilk

iTrader: (1)

The way I see it is if you can do it yourself, sure rod bolts would prolly help. But if you're paying somebody else then it's just a waste of money, just save up to build your engine the right way, no point in paying someone to open up your engine more than once...

Robevo RS

iTrader: (16)

it is not a question, is achievable, the question really is, how long.

if you baby it , can be forever, if you push it hard that is a whole other story.

There is also not a question what gas you are running. The question is the tune and the PSI you will use. For the clutch is how much TQ you will have.
Those are the most important things you have to look out for . If you do the engine the ARP bolts all around is a cheap and great insurance also.


ROb

SudzRA

iTrader: (2)

I would say that the best way to keep everything safe would be to not go very far past 350wtq. To hit 500 whp you'll need to be making in the ballpark of around 375 wtq at 7000 rpms. If you're going to push the engine to 8000 rpms, you'd need 330 wtq at that rpm to hit 500 whp. You'll need to hold ~30psi to produce this kind of torque up top. This will require a turbo producing ~50lbs/min of flow. It can be done on the stock block, but as stated above, you're going to be pretty much at the limit of the block. I wouldn't expect it to last all that long before you have problems.

SilverEvoX

iTrader: (2)

Upgrading rod bolts is only really necessary if you're pushing past 7800rpm. Most of the engine failures relating to rod bolts have been with people pushing 35r or larger setups into the 8500rpm+ range. Any good aftermarket rod will have better bolts so if you're building it, you'd be replacing the rods anyway. Plus just changing rod bolts would be 2k in labor to crack the block etc and install which is redundant when you could spend another $1000-$1500 and have a budget build with forged internals

Fishstix

iTrader: (1)

Overall you'll spend more money if you do not build the motor first.

Also make sure you are going to the right tuner and having your motor built by the right mechanic.

Mr. Move

iTrader: (2)

500whp on low boost is fine but 400-450 wtq is no good keep the torque down.