33 replies to this topic

[evo-gsr]

Bottleneck city.

[razza]

Personally I think, and others have already said it, is that you have unfortunately gone too extreme on cam spec. These big cams push the powerband way up high in the revs. I found the below mentioned on google about the cams you are using:

 

"These 284/280 cams have an aggressive lift and duration, designed to shift the powerband to the right...increasing high-rpm efficiency for large turbochargers that can use the higher rpm to really make power. Requires engine management and upgraded valve springs and retainers."

 

 I know the cams I am using, Kelford 272's, did the same to my car. Possibly I should of used the 264's. 

[BMGTZ]

post a pic of the O2 housing.....I remember a car that had an ebay stainless housing doing something similar to this as the first bend was very tight. went better with an e3 housing

[Bobbit]

Sorry for the really late reply been quite busy lately, anyways here's a picture of what the previous owner put on the car..

 

And here's the o2 housing i had to modify and then flatten because the flange was warped..

And here's some of the downpipe i threw together.. i really should've taken my time lining things up better because i had to cut into it to make it line up correctly with the rest of the system when bolted to the o2 housing.

Then to top off the dodgy ness of it, i ran out of Argon and had to finish it up with the damn gasless mig..

 

It looks allot nicer when it was cleaned up but it was late and i had pretty much given up on pictures and caring.

 

It fixed the stutter though a majority of the rev range but it was still there in the really low rpms, so obviously something was wrong still.
Two weeks later i ended up putting the 20psi actuator on it for the sake of seeing if it'd help with why it was running out of puff at higher rpms but that didn't help, then i floored it in 1st gear coming out of a carpark and either the shaft bent or i sucked in a rock and it caused the compressor wheel to undo it's nut (or it was like that for a while who knows).
Drive on it for 10+ minutes before i decided to pull over and see if i could fix it.. as soon as i touched the nut it fell off, so i guess i lucked out on that.. kinda did the nut up as much as i could (shaft had worked its way out and the wheel was seized tight against it) and drove home on that.

TL;DR Stupidity happened and i ruined my new 18g wheel (Use red instead of blue loctite).

 

So now i am deciding on a new turbo seeing as the replacement/upgrade to a 20G wheel still wont be able to move enough air volume to feed my hungry cams..

Anyone have an opinion on the HX35W?
Or any other turbo options that could be had cheap?

I already have all the parts here to make a new manifold so the only thing now is turbo and flange choice, i'd prefer internal wastegates due to the hassle of piping in an external, although i can go either.

 

Also if you want to look at the album there's 2-3 extra pictures on there of what i did
http://imgur.com/a/8uhRl

Edited by Bobbit, 06 February 2016 - 09:53 AM.

[evo-gsr]

I have a Holset HX35W on my Evo...I love it.
Best turbo I have ever had.

[Bobbit]

I have a Holset HX35W on my Evo...I love it.
Best turbo I have ever had.

 

Do you get any boost creep or anything like that?

Is it the twin scroll/divided T3?
What rpm does it usually spool up for you?

[evo-gsr]

No creep...but I have external gate.
Not twin scroll...but I have the BEP rear housing.
Full boost by 3800 on eflex.

[Bobbit]

Managed to snag a second hand GT3582R with "small play in bearing" so we'll see what that means when it rocks up, i'll most likely pull it apart and inspect the internals.
Only downside is the A/R is 1.07 but it may work with the cams i'm using so i won't really know if its a bad or good thing until it's on.

[Benzo4gT]

1.07 rear? Whoa! Now you can start a new thread titled "Installed new cams and turbo now the car takes 45+ seconds to spool up"  

[evo-gsr]

Ha ha ha ha ha ^

[Bobbit]

Well the choices i can think of are an internal wastegate with a .84 A/R from what i can tell is the best to go for (Well at least with the externally wastegated housings) only looking at the internal wastegate if i can because it'll be cheaper than an external and with the psi im going to run the surge (if any) shouldn't be a problem at all.
Or
A Twin scroll 1.04 A/R housing which spools about the same/faster (From what one guy was running on his evo) although its the FP HTA version of it so.. i assume billet wheel and anti surge housing.

Either way the soonest spool time i'm looking at is 4.5K RPM mark at the soonest and i should be able to bring the motor out to 9K RPM if i need to.

[BYBY5L]

What valve springs are ya running?

[EV0300]

You can use a smaller turbo and have the tuner adjust timing so it pulls further 8n the rev range you dont need a massive turbo for that

[Bobbit]

What valve springs are ya running?

 

Just some BC springs with Ti retainers so it should be fine, if i had the cash i'd pickup some kiggly behive springs but that's not gonna happen in a long time.

 

You can use a smaller turbo and have the tuner adjust timing so it pulls further 8n the rev range you dont need a massive turbo for that

 

Either the current turbo couldn't supply enough flow for the size of the cams within their operating range or the exhaust housing was too small causing a restriction at higher rpms.. either way the "new" turbo is on its way and the current one goes into hiding until i decide on what to do with it (maybe 20g it and turbo the 4G54 in my old Pajero? who knows).