I have a hx35, and it takes forever to spool like. 4200 before I feel power. Can I change the powerband so it comes on earlier around 2000-2500 somehow?

** Some gear feels like 4700 before the power kicks in **

Get a smaller turbo. Like a 16g if you want that.

Drop some viagra pills in the intake next time you go for a rip, that'll do 'er good I bet!

Jokes aside, there's a lot of very technical factors which affect spool up. To tell you how you can improve it (to a fairly lesser degree in reality), you first need to understand some of the basics which affect spool up. Things like compression ratio, head/manifold flow, valve size, valve lift, valve duration, exhaust manifold shape, type, whether it's twin scroll or standard. Whether it's got a cat or not, diameter of downpipe/exhaust. There's many, many other things, I could go on for awhile.

That said, I'm personally not familiar with the Holset turbos or the HX35 in particular. I believe it is twin-scroll? If so, twin-scroll should always be a quicker spooling setup than standard. After a quick search I saw that in general, this turbo tends to spool up at about 3500 RPM, but again it could be affected by lots of factors. IF you have a huge boost leak (or exhaust leak), it would definitely impact spool up and boost amount.

Hopefully some other users who are running an HX35 can chime in and share when theirs spool up and what sort of supporting mods they're running.

But yeah the hx35 is a decent size turbo its not going to spool up quick. A 16g you can make good power and have a quick spool.

Naazzz, NOS.

@Jeff D Desantis : For anyone to be able to provide any useful advice, you may want to update your build profile. Provide as many details as you can about your particular setup.

Are you trying to find the right combination of components for a quick spooling HX35, or are you trying to see what you can do without changing parts?

There are both 7 and 8 blade versions of the HX35, not to mention other options.

What turbine housing are you using? This will greatly affect spool characteristics.

Have you tried basic diagnosing for this issue such as an exhaust inspection, BLT, etc.?

Do you happen to have a log of what you are noticing? With upgrades using a Holset turbo, you should be able to have a way to capture a data log.

I think there is some sort of exhaust/boost leak. I'm ok with it building turbo around 3500 but its around 4500-4800 right now which is a whole world of difference it feels like. Any easy way to test for boost/exhaust leaks? I just have a gut feeling after driving the car that it does feel like theres a leak in the flow.

Do a boost leak test, that thing should light before 4500. As stated, post up a log if possible and fill out or update your car profile so we can see what you are working with.

I'm not knocking the car, it's really fun and quick when the turbo kicks in but I had a truck blow me away at a red light and I cant have that happen again. I wasent really trying to race him anyways but still. The car gets a lot of attention and I don't want it to be one of those fast looking slow cars

do a boost leak test,sounds like a leak to me! should be coming on sooner then that

Gives no real information and no mention of what turbine housing he's running, but expect us to give him an an answer.

That spool up sounds about right/maybe a bit slower for a stock turbine housing with open t3. Aside from thst, you need to BLT.

Not sure what stock housing we have here is a good question, most of the HX35 housings I have seen that are stock are twin scroll. It may be in a BEP housing that is DSM flanged. Jeff, do you know what housing that 35 is in?

I will take some pictures, and hopefully that will help. I'll upload them here within a day or 2. see what we have.