Engine/Transmission (1998.5 - 2002) turbo

[mrineer]

I've got to get my stock HX35W rebuilt (bearing seal leak). I'm undecided on upgrading to a 40 wheel, I don't want to decrease the spool time or increase EGT's. I'm confused by reading all the posts on changing to a larger wheel may actually increase my temps? Can any one give me the straight scoop on if a 40 wheel will help me to lower EGT's.











99,4wd,5sp,drw,service truck 1200lbs GVW, 4" exhaust, FASS, walker airsep, fuel;pyro;boost;guages,

 

[PC12Driver]

It's a trade off. Bigger wheels typically take from the bottom end and add to the top. You'll get a bit of lag on the bottom, thus higher temps before the turbo lights off. Once the rpms/fueling is there to light off the turbo, then there is enough energy to drive the compressor to make useful boost and cool the egts.



Bigger/more aggressive wheels are capable of moving a larger quantity of air, but that larger/more aggressive wheel takes more energy to turn. Extra fueling will provide more energy, but that only happens at full throttle. If you're "daily driving" you aren't using that extra fueling, so you will have more lag than the smaller turbo.



Long story short: yes, it will lower your egts in the higher rpm band, but bottom end egts will suffer. How much of a trade off you experience depends on how much more aggressive of a wheel you're planning to use.

 

[16919]

According to your sig you really dont have any power mods... so yu need to think about the future use of what you want to do to your truck before you buy a turbo. If you leave it how it is I would say get a re-worked 35 (pdr hx35) they change a few things here and there on it and it is supposed to cool a little better and spool just as good. A hybrid turbo might be good for you also (35/40 hybrid) such as a dodgzilla. If you plan on more mods and fuel then you have opened up a whole new box on possible turbos.