thats what i said. more useable power = more area under the curve.

 

I would say the HTA is spooling 150 later as well. At 5000 rpm the blue line is 30hp up on the red. It takes 150rpm for the red to catch up to that same level.

 

Interesting.

 

Well all we can do now is just wait to see what martins car shows us what happens with those two setups

 

What doesn't make sense?? How can you say that? Who else has tested an AMS 37R vs a FP HTA 37R and came up with different results for you to base this statement on?

You can't assume that just because something has "HTA" in the name that two completely different producs being compared to two other completely different producs are going to have the same results. THAT doesn't make sense

 

Its interesting that you coined this phrase.

I have some points to interject upon my limited experience with these turbos.

David Buschur has seen some great success on the with some of the HTA turbos on his car and others like the Bad Bish which were cars that MAX out the potential of a GT35 turbo. Certainly the BAD BISH's car that we just bought makes more power than any Gt35 I have seen - 747 whp. It seems likely that the HTA wheel is helping that car - just a guess.

I am not so sure how the gains Mr. Buschur observed on his car translate into set ups that do not approach the limits of a Gt35 normal wheel.

In other words - what gains can be realized on a car making say 500 dyno jet whp with a GT35 at a moderate boost level.

Before I make an opinion one way or the other I need more seat time with these turbos.

I WILL say that I tested a GT35 turbo set up on a fully built 2.3 L car recently where ALL we changed on the set up was to send the wheel out to FP to get the HTA upgrade and I did not see any gains worth spending $450 on. In fact it was hard to see any gains at all, other than a tiny bump in the midrange of about 8 - 10 whp.

What that means in the big picture is unclear to me.

Certainly the results shown in the dyno sheet posted by the OP do not really impress me with a $450 turbo wheel.

Also we recently did a GT37HTA on a DSM style back housing like what the FP30 series of turbos uses - a cast FP turbine housing. That turbo was a huge disappointment with that back housing - i would not recomend that set up to anyone.

Personally, I would prefer to get a regular Gt35 or if that is not enough just go to a T67 P trim (aka GT37 dual ball bearing) unit. if you are seeking the last whp possible and need the last drop by all means go for the HTA wheels as they certainlly don't loose power anywhere. My issue is how much power you can pick up vs. the cost and also having to wait for 2 -3 weeks to have your turbo serviced.

I hear that other turbo shops may have other modified wheel projects in the works so hopefully the demand will fuel more and more innovation in this area of the sport compact scene.

I will interject more thoughts after I have a chance to test these turbos more.

Al

 

well in theory you would expect it to act the same on a 35r as on a 37r...

 

Off if FP's site

"Our version ditches the "t67" compressor wheel. That wheel was a 63 trim wheel that really left LOTS on the table when it came to high boost performance, giving only a max PR of 3.4:1 even at it's highest speed line of 120krpm. The HTA easily sustains PR in excess of 4.5:1 making 45psi or more boost pressures possible, consistent and dependable. "

Maybe because of the increase in reliable PR and wheel speed another advantage of the HTA is reliability? Also, if the regular 37R is only efficient to 42psi and the HTA is efficient to far past 45psi then maybe comparing these two turbos could because of their characteristics never be an apple to apple comparison? We all know that comparing two turbos at different boost levels is not a very scientific tests...... We also know that you cannot determine how reliable a turbo is by a single dyno pull....

/end thought

 

There's actually nothing unique about the polished/ridge. It's because the wheel is cut from billet on a 5-axis machine. When you're doing low production volume, it's cheaper to get them cut on a 5-axis than do all the tooling to cast wheels.

I'm actually not sure that the power gaines are from the wheels, but I'm guessing from the compressor housing inlet design; i.e. better flow into the wheel at high flow rates.

 

Good post Al, I think my second post in this thread covers my opinions regarding these turbos. Also one thing to note that is (If I understand correctly) that an HTA treatment is not equal between all compressor wheels. I think that the HTA treatment is different for every wheel and will effect every wheel differently. If you look at the specs on the 3076HTA you'll notice that the inducer and exducer measurements are different and actually smaller. Somehow they rate the turbo at 5lbs more of air which is remarkable. This must be because of the increase in reliable PR, which in lamens terms means more boost.

::biggie's mom's voice:: "Misses Wallace wants to know just hoowww the HTA wheels allow for an increase in PR while maintaining the reliability" (No one will probably get this joke, but I seriously want to know why.

 

This is a good thought, but I didn't know that the HTA treatment included a new compressor cover? I thought it was just a new billet compressor wheel??

 

EDIT: Nevermind

 

This is very interesting. Not really what i expected to be honest but we will have to wait for more testing to take place before judging. Different exhaust housings, boost levels ect..

THANKS AMS FOR TAKING THE TIME TO DO THE TESTING!

Chris

 

I thought It would of done alot better

 

Excellent test, AMS! I wish all testing was done as objectively as yours!!

Have you guys done a HTA35R test like this?