Hey guys I just got my evo ix mr flashed by Mellon, and all i can say is wow, what a difference! The only mods i have done to my car are TBE (no cat), HKS RS intake, and a hallman pro rx mbc. my new rev limit is 8021rpm and i wanted to know if it is ok to bring my rpms up near 8k on the stock block. btw i am running 23psi. One of my friends who is also on evom, told me to get head studs. do i need head studs? is it dangerous to rev to 8k without them? i hit 8021rpm for the first time tonight in 4th gear on the freeway and apparently i shot a 2ft long flame. is this normal? thanks a lot guys.

-Phil

 

doubt you have useful power that high...well...u got that mivec...7300rpm is plenty...no point shifting so high if u aint got ponies up there...

 

As long as you are not knocking up that high in the rpm (knocking due to a/f or timing) you should probably be ok. I definitely wouldn't rev to 8000 with no fuel pump but you east coast bastards have 93 octane so you're probably cool. You should get headstuds because you are running 23 psi and are only a few psi away from needing them. I would get them just to be safe. The real question is if you trust your tuner and if YOU yourself know that there is 0 knock in the top end.

 

Curious as to how you know what preset boost level the oem head studs are good for

 

8k is fine on stock cams, or low lift cams.
If your car is slow then u dont need to worry. If its fast and traps 115+ then youll see what i mean about not worrying about 8k+

 

Did you get the mail in or email tune or a custom tune out of curiousity? Also, you only need head studs when your running high boost. In addition, like everyone else said you don't need to rev that high as you'll probably be losing power due to your sotck turbo being insufficient in those high rpms and your current mods. You probably shot out a flame because you bounce your rev limiter which is normal if you do that.

 

i am curious about that too.
i think he dont need headstuds. if he install cams then he can put the arp headstuds.

 

awww only a 2ft flame? It's purposely a bit rich up top for safety, so when you bang the rev limiter it'll do that sometimes. Hopefully you didn't scare any children

I have the rev limit set to 8k on my own car with HKS 280's but that doesn't mean I take it there every chance I get. I use it sparingly and as needed, not daily driving. It's especially nice on the Autox because it saves me from losing time with shifts and nosing over when you bang the rev limiter accidentally.

 

for IXs at what rpm do i start to lose power? where should i shift at? i was told that VIIIs usually stop making power at 7300 but IXs make more a little more power up top due to mivec.

 

Hey Mellon, the tune is amazing. thank you for your help with the whole process. I want to get dyno'd so bad. any ideas to how much whp i'm putting down?

 

get with me tonight and we'll run one of your logs through DLL to see where power falls off and roughly what kind of whp you're putting down. We'll need a log of a 3rd gear pull on very flat ground if possible.

 

Ok here we go dude! The limiting factor on reving a car is valvetrain and or the botom end...

The Evolutions valvetrain especially on stock cams wich I assume you have since you didnt mention aftermarket ones is fine at 8k. Would I spend all my time up there? NO. Is there any power up there on the stock turbo? NO the turbo is simply out of breath up there... The only reason reving to that point on the stock turbo is if you are drag racing it helps you cross in 4th gear instead of shifting into 5th and hurting your Et's and your trap speed...

Now the stock botom end is another story. The 4g63 while very capable and strong internaly for making power in stock form , really doesnt enjoy super high rpm like that.... The rods are the limiting factor there , 4g63's have chop stick rods and shouldnt be reved to that point. Will the motor rev? Yes it will. Will it brake the first few times you reve that high? No... But the piston speed and stress will eventually take its toll.

As for the head studs... They have nothing to do with how high you can or cant rev. The purpose of the head studs is to hold the head down to the block and keep it from lifting and blowing out your head gasket...

Do you need them at this point with your mods? No you dont. But they are cheap insurance and piece of mind , and they deff. wont hurt anything if you put them in correctly. I would throw them in whenever you do cams Once you start running race gas and very high boost you wil deff. want to get a set though. I ran 32plbs of boost tapering down to and holding 26 psi on the stock turbo for a very long time with stock head studs with no ill effect. And before anyone gets theyre panties all in a bunch and says that the stock turbo doesnt do anything at that high of a boost level... My car ran a 7.24 at Irwindale in 90+ summer heat last july... On pump gas and only 21 psi the car ran 7.8x's in the same day.. So I think it deff. did something Anyways I have since gone to a big turbo and have put in a set of ARP's.

Anyways I hope this helped you out a little bit. Cause when I was new to this car in Feb. 06 and I asked questions everyone just flamed me and told me to search or give me answer like they knew what they were talking about... Giving answers you arent 100% sure on or never had personal experiance with is bad... You can make someone hurt theyre car or make someone waste money on something they dont need

 

Sorry I double posted by accident somehow...

 

Its fine....Just cuz you can rev it that high dosent mean you have to...Like he said if you trap higher than 115 you GOING to want it. Mines set at 8030, I almost felt like a honda.

 

I'm interested in that 2 ft flame part.