I'm thinking on pulling the trigger on the new Garrett GTW3884 6262 with the T4 .70 A/R housing (good price on ball bearing Garrett) to replace the Precision 5858 T4 .58 A/R v band outlet turbo that is dead rebuilt it but the wheels hit the housing so it needs to be replaced, but it is not clear to me if it is a direct fit or if I will have to modify my down pipe and recirculated dump pipe? or will my precision turbine housing bolt up and have it machined to the bigger wheel? if not I might just go with the new Precision 6062 gen2 ball bearing turbo and try precision one last time, QUESTION do you think it will be to laggy for my k24Z3 8.5-1 compression street driven car the 5858 running at 18 LBS starts spooling up by 2700 RPM but seems to be choking out at higher RPM's my budget is $1500 any advise on choosing a new turbo would be appreciated

 

GTW T4 v-band sizing is different than the one used by Precision. You have to see if the weld flange that you're using (as well as the T-bolt clamp) has enough give to clamp down on the new system. So, it will depend more upon the weld flange you're using than anything else.

As for the power level and boost threshold and whether or not it will be the same, the answer is a resounding NO. By how much the threshold changes really depends upon whether or not your in the efficient boost pressure range of the GTW3688R, which is using a MUCH larger exhaust wheel (V-band only uses the larger exhaust wheel, and not the same size as the 6262.. Its more like a 6265 if you want to compare with Precision numbers.)

Just because you're switching over to a ball-bearing CHRA with much larger wheels, does not mean its going to be have similar to what you already have. There's nothing similar to the two turbochargers in any way, shape or form.

 

Ooooohhhh so confused Just don't know what to get the next size smaller GTW does not have a T4 flange would my precision housing bolt up to it ? GTW the turbine inducer is the same size as my 5858, I really wan't a garrett

 

None of the GTW nor the other 458 series CHRAs (the ones I use included) from Garrett will come with a T4 flange. That's only for those that use the larger exhaust wheel similar to the 65 inducer, like the one I just described.

the GTW3884R that you're describing the inducer size is similar to the exducer size of your 5858. Completely different exhaust wheels being used in your example here, with different profiles.

So, the question is, which is more important to you? being T4? or being the correct turbine wheel?

There are a LOT of other Garrett-Hybrids that have the flexibility of the GTW, without being a GTW.

2 Questions.

1) Are you trying to get the same size and characteristics of your Precision 5858 in a T4 exhaust housing that's a v-band? If that's the case, then you must go to the GT-R, GTX styled turbine wheels and turbochargers. that means ball-bearing only using the 740902-14 or -15 T4 Exhaust v-band for the N32 60mm turbine wheel used in the GT30R family, which is the closest thing to the 5858 w/ similar boost threshold.

2) Are you trying to stay ball-bearing CHRA or journal bearing CHRA??

 

1) Are you trying to get the same size and characteristics of your Precision 5858 in a T4 exhaust housing that's a v-band? If that's the case, then you must go to the GT-R, GTX styled turbine wheels and turbochargers. that means ball-bearing only using the 740902-14 or -15 T4 Exhaust v-band for the N32 60mm turbine wheel used in the GT30R family, which is the closest thing to the 5858 w/ similar boost threshold.

Yes I would like to get close to the same characteristics a little more lag would be ok but not to much, with less back pressure if possible, I must use an open t4 or build a new manifold and the T4 allows a much smoother transition to my single port head

2) Are you trying to stay ball-bearing CHRA or journal bearing CHRA??

Ball bearing for durability and water cooled would be nice



Ball bearing for durability and water cooled would be nice


I don't want to build another manifold looks easy but it was a pain

 

Then your only option is using the GTX- GTR series GT30R or GT35R turbocharger family that use the T4 740902-14 (for .82A/R) or 740902-15 as a choice of T4 turbine housing for the N32 60mm turbine wheel family (GT30)...
or the 740902-17 (.82A/R) or 740902-18 (.63A/R) for the N111 68mm turbine wheel (in the GT35R family) that will give a bit more top end.

Cliffs:

GT30 "family" 60mm turbine wheel diameter
T4 740902-14 (for .82A/R) or 740902-15

This includes, GT3071R -22, GTX3071R, GT3076R, GTX3076R, TR3030R, GT3082R,GTX3067R for the GT30R family,


GT35R "family" 68mm turbine wheel diameter
740902-17 (.82A/R) or 740902-18 (.63A/R)
GTX3576R (Best choice), GT3582R, GT3584R Reaper, or GTX3582R in the GT35R family.

You cannot use GTW turbine housing options on GTX or GT-R turbos and vice-versa, because they use completely different CHRA part numbers and widths, in addition to the fact that the turbine wheel profiles between GTW and GTX are completely different and incompatible.

My honest opinion is to use the GTX3576R in a smaller T4 .63A/R volute with the larger exhaust turbine wheel. You're thinking more lag with better backpressure is the answer. Not the case for what you're trying to do here. Look more towards using a slightly larger exhaust wheel in a smaller exhaust housing volute.