fp hta68 update

[yan tang]

dyno'd the hta68 today on my 9:01 motor with comp 101100 cams, stock intake, and meth injection.  made 390hp and 340tq.  pulls like a mofo and spools like a 16g.  will see what she can do at mission next week.

[Lowell Foo]

Actually with the 4" intake it made 394whp and 350tq.

[Ivan Skare]

That's impressive.

I bet it's a blast to drive.

[yan tang]

Yeah it's super fun to drive. With the 9:01 motor it feels like driving a stock turbo car when off boost but gets up and goes when you put your foot in it. Besides some surging at low rpm from a third gear roll on, I'd say this is the ultimate turbo for a daily driver.

[John Hartman]

tres cool. 394/350 is plenty for me.  Hell, 350/350 is plenty for me on the RG dyno.  I like spoolup and throttle response.

Look for a for sale soon I think on a big bb turbo.

Thanks Yan

[Zach Holt]

Nice!

[KevinBuckham]

Fantastic!  Glad you got on the dyno.

What is the boost threshold?  If I don't like the FP3052 I might downgrade to the HTA68.

[Lowell Foo]

If you don't like the 3052, upgrade it to a billet wheel

[John Hartman]

whats not to like about the 3052?

[yan tang]

Fantastic!  Glad you got on the dyno.

What is the boost threshold?  If I don't like the FP3052 I might downgrade to the HTA68.

i'm not sure what rpm i see boost at.  all i know is, when i put my foot in it, it goes.  maybe lowell can post a graph.  i'm kinda interested in seeing a comparison of my new setup vs my evoIII 16g as well just to see where the gains and losses are

[yan tang]

whats not to like about the 3052?

i have no complaints about the 3052 at all.  it's an awesome turbo.  now that people are starting to show interest in this turbo, i'm starting to think twice about getting rid of it.  every time i go into the garage, i see it sitting there on my tool box just staring at me begging to be put back in.  i sure miss the semi truck like turbo sounds....sigh. 

[KevinBuckham]

If you don't like the 3052, upgrade it to a billet wheel

Yeah, that's the plan, but I've never found a back to back comparison that shows any better initial spool than a 3076R / 3052.  It definitely has better flow potential, but a ball bearing 50trim seems to out-spool it, but obviously with less ultimate overall efficiency.   I almost picked up an used 76HTA, and the guy was trapping close to 136MPH on a full weight car with it.  (And shattering transmissions regularly from the torque.)

whats not to like about the 3052?

Lag, I'm expecting about 3400 (+/- 200) RPM to see 20PSI, but more importantly I care about how long (in time) it takes to get to set boost say from a 2nd or 3rd gear part throttle roll-on at 4000 RPM.  Many turbos that have similar spool (RPM for particular boost), have very different times to the same boost.  (One is probably dictated by turbine and compressor wheel design, the other probably by total wheel inertia.)

I'm really curious to see the outcome If Yan does overlay an EVO16G vs. his HTA68 plot.  Obviously the initial compressor designs are quite different, but if it does equal or out spool an EVO16G it might convince me to get this one upgraded.

[John Hartman]

the 3052 has very good transitions and low lag for a larger turbo.  Its what sets it apart.

[Kristopher Rozon]

If you are comparing the time it takes a turbo to spool without equalizing the pressures and flows on the exhaust side you are missing the point.

You should only be concerned with how the power curve looks based on what you're trying to achieve. Drag cars don't need a massively torquey engine and doing so would just break parts. That's not the same as saying you want a late spooling turbo either.

Spool = boost pressure/time = inefficiency of your engine to ingest the air.

[Chad Giffen]

Spool = boost pressure/time = inefficiency of your engine to ingest the air.

not quite. Volumetric efficiencies of engines are around 98%. That is the measure of the engines ability to ingest air. Not spool.


Spool strictly has to with how long it takes for the exhaust gases to accelerate the cartridge assembly (turbine and compressor). Considering the density of air is rather small, even a few grams of rotating weight from a bigger compressor wheel will make a huge difference. Thats ALL it is.

Volumetric flow rate * density = mass flow rate

mass flow rate accelerates the cartridge. (momentum)

Grams of weight are HUGE. Not to mention the added weight of the compressor is at the out most diameter making the moment of inertia bigger.

Moment of inertia = resistance to accelerate.

But once that bigger compressor wheel starts flowing....    watch out!


Sometimes I love taking Mechanical Engineering