Im new to my evo x. i was curious what the weak point is on the stock 4b11t? Some ppl blow these up at 450ish where others have pushed them to the 600s...and then blow up. is it the bolts? rods? pistons?

 

You should talk to ttp about this. Awhile back someone there had an interesting theory about this.

 

Rods seem to be the common weak point. There is no magic number for how much hp your car can handle. A good tune can go a long ways but even with a good tune some bad gas can spell an end. From everything I have gathered over the last year it looks like anything over 450 WHP really needs a built engine for piece of mind. Of course some lucky bastard will run around at 600 hp for a couple years and brag on the internet how all cars will be fine at the 600 level. In the end if you are replacing your stock turbo with anything bigger I would be prepared to eventually build your engine as you just never know. Just ask Murlo, lol. On the bright side if you do pop your engine it is a good excuse to make your car really fast. If you look at my sig you will see I am running around at 445 whp. But I am not to worried as my TQ is fairly low and I have no worries about making it a year before I build my block I and turn up the power.

 

rods

400tq seems to be the limit

that means you can make upto 600hp @ 8k

but it also means that stock turbo + E85 can get close to that @ 3500rpm

 

I ran over 400wtq on the stocker on E85 for quite a while with no problems, the Red killed the motor though.

I'd say rods are for sure the weakpoint. If you plan to make power, just man up and do some drop in's and get new rods/rod bolts and pistons.

Some people think rod bolts will solve their problems, i doubt it.

 

lol...i'm that lucky bastard on the x that ran 600+ for about a year before building. Mine lasting probably had more to do with my mild driving habits and a solid tune more than anything else.

TTP thinks its the #4 cylinder wall according to the old post. I don't think there have been enough malfunctions (which is a good thing) for people to truly know what the week point is yet.

 

It seems to be a lot of torque at low RPMs or revving out the motor that does in the rods. The medium-sized turbos (Red, BBX) on a hot E85 tune is too much. I suspect you could run anything short of a moose turbo on pump and be fine.

 

Agree with Lomker, the bigger the turbo the safer it seems, but that is a theory.

I think Tephra's 400wtq level is a little low, i'd say 415-420 should be alright.

Here is my car running only 28ish psi and not quite running right before I turned it up to 33psi



So 400wtq is safe for sure.

 

^^^ not so sure on that since every dyno reads different and knowing that dynojets read really high you are prob around 315 tq on the dyno I was on since my stocker read 205 awhp and 215 awtq.

 

I can assure you my car wasn't at 315wtq, lol.

That was on 28ish psi, i normally ran my car at 33psi when it broke. I hit 390wtq on a DD dyno which reads lower than any other properly running dyno...