Gt30r v t618z
 

How much more air does the GT30r flow, compared to a t618z?

i know MM sells a Modified gt30r, but i am looking at other options that i can replace the T61 with. also that will fit the Header area, and wont bring in more heat.

T61 Chart:
Attachment 248850

there is some great info here, i just want to know if anyone is running anything bigger with the greddy set-up.
https://www.rx8club.com/series-i-major-horsepower-upgrades-93/adapting-gt30r-gt35r-greddy-flanges-105690/#post1665616

There aren't many options, its either the MM( not sure if he is even still offering it), or the BNR to4E upgrade. Nothing else will really fit...

dam.. well if i follow Rotory gods advice in the link, i can use the greddy manifold and extend it for more room. then maybe i could use a bigger turbo

Out of curiosity... what are your goals? How big of a turbo are you talking?

I believe that MM now uses the GTX3076 which from what I can gather is all the turbo you would ever want on a renesis .

You can build a new low mount manifold and motor mount then you can fit a bigger turbo down there, but its a real pain. I tried to come up with a nice design for an entire day. Decided it wasn't worth it in the end...

Still not enough turbine wheel...

eh.. possibly no bigger than the gt30r. the reason why i ask is because i have heard that the Airflow in the gt305r is better in airflow that the t61, it seems like it would be a better upgrade; but i want to gather more info first.

I'm interested in low-mid power gains and as fast spool. at a good psi Range, i have read that the greddy kit struggles past 7psi.

The stock greddy can make 10psi to about 5500 - 6000 rpm if set up right . Upgrade the compressor a nothch and push that to 6500 and you have a very fast spooling turbo that will make in excess of 300whp (this is my setup) .
For most people this is all you would wish for .

i love! your top mount set-up, honestly i think doing a top mount would better suffice my needs, my only concern is the tuning. i will only upgrade the t61, if i know i can tune it with the A.P; read too many threads were people get screwed on tuning. honestly i think MM is the only tuner i would trust with a tune.

i was also looking into this, increasing the compressor wheel, also i was thinking of porting the waste gate to help with "boost Creep". i can modify the T61, but if the cost of modifying the t61 is greater; i would just rather buy a "Better" turbo.

Boost creep does not happen unless you restrict the WG opening so don't know where you got the idea this was a problem .
In fact I induce boost creep on purpose on my turbo much to the horror of all and sundry on here.



I agree
When MM offered his 3071 upgrade it was about $2000 (all up including mods) and upgrading the wheel via BNR is $1000ish .

ah! that's good to know, i read from an old post that some guy was getting crazy boost spikes with the greddy kit. i will most definitely also look into upgrading the t61

could have been due to bad setup (poor BOV /boostcontrol setup etc) or a stuck wastegate , It certainly does not do that when it is functioning as it should .

You still have the issue of the greddy manifold cracking, we've seen two crack in the past month here..

/\ True dat .

They all seem to do it . Once welded up properly they seem to last a while ....

has yours cracked? since you are running a stronger turbo, i assume the extra heat puts more stress on the mani?