K-Tune

iTrader: (26)

T04B H trim compressor wheel in a .60 trim cover. I'm referring to the gap between where the compressor fins curve to the exducer and the compressor cover. The clearance is around 1-2mm. Is this acceptable?

bobybeach

Ive heard figures greater than .5m will lose noticeable efficiency? and noticed more on diesel engine apparently?

Theres great efficiency gains to be made apparently with tighter tolerances between wheel and cover. so generally tighter bearing tolerances are needed to reduce that gap.

At the end even with that gap it will probably blow enough air to make boost and decent power. give it a whirl

gxl90rx7

iTrader: (1)

ive never tried using teh wrong wheel in a bigger comp cover, but im sure flow will hurt. why not just find the cover or wheel that fits?

bobybeach

I don’t think thats what he’s done.

.6a/r cover is to4b cover. So is H trim wheel.. It looks like its just been badly profiled...

Unless he means he’s replaced the super trim T04B 60-1 wheel with an H trim????? that would be a no no for sure....

seandizzie

iTrader: (1)

The 60 trim cover is a 2.950 major/ exd. I think you have an H wheel thats 2.75 major/exd. Thats why the exducer is so loose, pretty big gap there. From the photos and the info thats what I come up with... I wouldn't think it would work well.

pic below is of a proper h trim

See your in NWFL. Do you ever make it to Fort Walton Beach??

RotaryRocket88

iTrader: (7)

We machined the compressor cover on my hybrid to have 0.5mm clearance between inducer and housing. This mirrored the clearance it had with the original smaller wheel (U-trim) before machining & with what I was able to find through searching around. Supposedly 0.5-0.6mm clearance is the norm.

Knockers

If you look at the pics there is alot more than .5mm of clearence as you move from the inducer to exducer

rxspeed7

iTrader: (5)

Why not stop all the guessing and just pull the cover off and measure the actual clearence? Can't believe that wasn't the first suggestion.

RotaryRocket88

iTrader: (7)

Yes, in addition to having what looks like too much inducer/housing gap, the housing does not follow the contours as the wheel transitions from inducer to exducer. You can't just mix and match housings; they're machined specifically for ONE compressor wheel.

0.6 is not a trim. That's the A/R of the compressor, which is unrelated to wheel size. My guess would be that's a 60-1 housing, which would explain why that T04b H-trim wheel has such large gaps.

409826-0015, 70x58.40 mm, 70 trim, H trim

Turbonetics 60-1, 76.2x59.0 mm

https://www.rx7club.com/2nd-generati.../#post10674115

A 60-1 compressor wheel has a slightly wider inducer (0.6mm) and the exducer is a lot wider (6mm), which would require a wider opening to follow the curve.

K-Tune

iTrader: (26)

When I ordered the comp cover I simply asked for a T04B cover suitable for an H-Trim wheel. I sent it back and will hopefully get the right cover this week.