t25 upgrade to t28
 

So i picked up one of the garret hybrid turbos the T28 (T25 with a t3 compressor and turbine) seems the wheel is about .5" bigger i was just wondering what kind of AFR change you think i will see.. I am running at about 10.8 -10.9 at full boost right now do u think i will run to lean with this turbo. I am scheduled for a retune on the 17th but wanna know if i should risk a ripper with the new turbo. Ill post some pics tommorow if i can find the data cable for my phone.

Re: t25 upgrade to t28
 

Don't risk it. It's only a couple days man. :P

Re: t25 upgrade to t28
 

you can rip it you didnt ge a bigger exhaust turbine did you nor did you raise your boost what fore retune :8

Re: t25 upgrade to t28 WTF???
 

So here is a nother big bag of fukin fail... The Garrett big T28 is a T3 compressor and turbine camparable to the GT28 minus the BB and should be around a 62 trim according to Gpop shop. So if you guys remember i made 176hp with the little T25 at 9psi so i figured i only want another 20 ponies and something like the t28 is bigger so should work and would bolt right up which means i can swap my turbo b4 work. So i install the turbo and first notice im not spooling while ----- footing anymore so there was definatly lag now so i figure i am gonna make a decent amount more power... Got down to Evan's shop get her on the dyno and what do i see full boost at 4800 instead of 3800 and a max power at 9.5psi is ..... 180hp WTF is that ----. I mean it holds power till 7k now but still damn near no power increase doesnt make sence. Jeff didnt see anything wrong with the set up, and Gpop shop said it doesnt make much sence as we all know a 60 trim t3 will usually get these Dseries above 200hp at 10psi and this turbo should have pretty much similar flow characteristics as its a t3 60trim wheel in there. I dont know where to look im just not the happiest guy right now.

Cliffs: bigger turbo, no power gain?

Re: t25 upgrade to t28
 

cuase that turbo is barely any bigger. sounds to me like you should be happy, you gained 5 horse and pulls till redline at the same piddly dick boost level. at 180 horse your probly starting to outflow that t25 hotside. if you wanted 20 horse and it was already on the dyno why didnt you just up the boost a few psi?

you could maybe make 200 hp at 10psi with a straight t3 turbo (bigger than yours) ....you made 180 at 9 psi with a smaller turbo... what doesnt make sense here?

20 hp difference with less boost and a smaller turbo.

Re: t25 upgrade to t28
 

and what motor is this on becuase that spool does seem very late for being a t28, its later than my 57 trim 60/63

Re: t25 upgrade to t28
 

its the Garrett big T28 T3 60 trim wheel it seems alot bigger than the small T25 both compressor and turbine wheel just from looking seems to be close to an inch bigger. It is on the D15b .... i was told the trim size is about 62. i dont know why but it doesnt seem like Evans wants to go above 10lbs even when i suggested getting a bigger map sensor he seems reluctant for some reason.

Re: t25 upgrade to t28
 

then its probly just your hot side holding you back. idk what that turbos from but its not much bigger. and evans probly didnt want your d15b blow up as its already making 180 hp

Re: t25 upgrade to t28
 

http://www.gpopshop.com/mitsdsmturbos.html its not a stock turbo its made by garrett as a high performance turbo... but yeah thats possible but he has done stock block Dseries motors with more power i donno but it still seems like it should have made more power thanx for the reply tho.

Re: t25 upgrade to t28
 

run more boost :6 :y