I own a 2004 evo viii rs. It came with the 9.8 hotside turbo. My car is in the bodyshop right now due to an accident and i noticed that the wastegate "flapper" is broken. I found a 10.5 hotside turbo with the wastegate at a great price and purchased it.

I know once you change anything... It is recommended that you re-tune the car. Is it really necessary that i re-tune the car if i go with this turbo?

Any help is appreciated!

***EDIT*** MY CAR IS NOT BONE STOCK. THE TURBO IS STOCK.. BUT THE CAR MADE 380WHP.

 

I have the same car. I changed over to the 10.5 and really didn't feel a thing. You won't need a retune just for that.
If it makes you feel better, you get more from a catback and you can just reset the ecu and be just fine.

 

im about to do the same and also heard there is no need to get tuned

 

on 25psi.. my car made 380whp. so i guess i should be fine!

 

Should be fine. I wouldn't retune less your air/fuels are dramatically different

 

Thanks for the info!

 

A tune may be needed. AFR's will change. It'll look to lean out on the topend when going to the larger housing. So. it'll probably want more fuel. So, to squeeze all the potential out of the swap you'll probably want a retune.

 

Maybe a dumb question, but: Is the turbo you are considering an VIII turbo with the 10.5 housing? If so, then the only difference between your present turbo and the new turbo is the turbine housing(10.5 vs. 9.8). Every other part between the two turbos is the same.

So, it would be a lot easier to remove just the 9.8 housing from your turbo that is already on your car and just swap on the new 10.5 housing. What are you going to R&R the two turbos for? It is a lot more work and hassle than a simple housing swap,

 

Just curious kind of related question, what about if you were to go from a cammed stock turbo tune at 25psi and replace it out with an fp black? Obviously you would benefit a lot more with a tune, but in the meantime would it be alright to drive the fp black untuned at 25psi?

 

I wouldn't trust the VIII turbo tune at 25# with a swapped on Black. Turn the boost down to 17# and drive the car very gently on over to your tuner and Get a Tune!

 

Sparky is right.

 

This could lead to all sorts of possible nightmare scenarios. Is evocivicmarc88 still on the stock injectors even? The stock injectors would probably go static at 25# on the Black. Wouldn't they?

 

Just swapping the turbine housing, you will be fine. I did this for a kid when I was doing his timing belt and anti-freeze change, so removing the rad was no biggie. I logged afterward and nothing changed. One run would have a slightly higher load, next would be slightly lower. NB02 V didn't warrant any changes and no knock was present. To my knowledge the car still runs fine.

 

I have the pte1200cc injectors tuned. But if its not recommended I wont do it. Just wanted to see if I could kill a little bit more out of my stock clutch before replacing it and getting a tune.