Forced Performance Hta Turbos

[scotty nm35]

Forgive me but I may have missed it somewhere in the last 40 pages but how does the HTA3076r compare to the GTX3076r?

Realistically no-one could really tell you, as at that power level dyno results can be easily skewed, and everyone's setup is different. Believe me, if you run either turbo at high shaft speed, traction will be your biggest issue, not the brand on the compressor housing.

[Lithium]

Forgive me but I may have missed it somewhere in the last 40 pages but how does the HTA3076r compare to the GTX3076r?

I don't know of anyone who has done a back to back - it's not really the kind of change you'd expect to see someone go out of their way to make and no workshops have, or are likely to do a shoot out with them unfortunately. Trawling around the internet however, and talking to people who have driven both or even one and comparing results, and just looking at the specs on paper the evidence has been overwhelmingly in favour of the HTA in terms of overall performance.

The only potential performance advantage I know of the GTX3076R is that it has a 64lb/min rated wheel, however given it's commonly accepted that it's too much compressor for the turbine (especially on an engine which has a decent bit of flow itself) and is better suited to a GT35 that difference over the ~59lb/min of the HTA is probably negligable, or at least all but negligable in terms of real world advantage in this comparison. For what it's worth, so far the highest power figures I've seen for GT30 framed turbos so far have been HTA3076s - I'd not say for a moment that it's because the GTX can't match or outflow it.... but if anything, it's got to be an indicator that on the GT30 hotside the GTX isn't looking like it's holding anything tangible over it - and in a lot of circles (EVO and R35 GTR, who have used these turbos more than anyone else) it seems the overall opinion is the HTA actually is capable of at least as much power.

In terms of spool and response, the HTA3076 is well proven to be a very responsive beast - that is an area I am really confident that if someone did a back to back that they are two different beasts, all subjective info (talking to people who have driven them), dyno info, and again looking at the basic specs on paper it becomes pretty clear that the HTA is physically a substantially smaller compressor and it'd be hard to imagine the GTX being an equivalent in terms of response. For what it's worth the GTX3076R has about 6% larger compressor inducer diameter than the HTA3076, which is right in the middle territory of how much of a step up in inducer size you should expect to see when going up to "next size up" compressors when selecting for power versus response. The GTX3076R may as well be a larger turbo, but so far there are no results I have seen to indicate that the trade-offs you make going to one are justified.

Here's a thread from the GTR world with people from Subaru and Mitsi backgrounds who have had experience with all options weighing in on the same topic: http://www.gtrlife.com/forums/topic/79848-gtx3076-vs-hta3076both-has-63-ar/

And another GTR thread with a bit (for those who follow TX2K) a low key road car that showed up to TX2K14 and dealt to a lot of much more serious setups with a twin HTA3076 setup: http://www.gtrlife.com/forums/topic/97897-precision-51mm-vs-sir-usm-vs-boost-logic-hta3076/

No direct comparison (well, perhaps aside from trap speeds and side-by-side races ), but clearly the perception is like the HTA does the business

[RiseofBrutality]

Wow I didn't expect such an in depth response like that.

Response is probably the main thing I'm looking and I think you have covered that above.

Cheers Lithium

[scotty nm35]

For response you are better off comparing it to a GTX3071 though.

[Lithium]

Wow I didn't expect such an in depth response like that.

No worries, there are too many throw away comments on this kind of thing and instead of "nah, no difference" or "I reckon this is better" I figured it easier to just explain why you go for an HTA, though I'm sure most of that is covered in this thread already. Ask Mat, he picked my brain for weeks when he was pondering the decision. It's well known the GTX3076R is slightly laggier (or at BEST comparable) with a normal GT3076R for spool, and the HTA has clearly made his car a different beast in terms of spool or response - without even taking the solid hike in power he got out of it. When had asked me about it, he was looking to improve response and hoping it might possibly nudge 370kw - and if you think about it... managing the same power with substantially better response is an impressive feat, so picking up 30kw and doing arguably at least similar for spool than going to a GT3071R (if you compare GT3076R and GT3071R dyno plots, there isn't much in it) they really are bloody good.

For response you are better off comparing it to a GTX3071 though.

Agreed. GTX3071R is one of the best/most worth while of the GTX range - and I'd be really curious about how the GTX3071R and HTA3076 would compare in spool and response, it wouldn't surprise me if the GTX3071R had an edge (the same as it wouldn't surprise me if the GTX3076R made slightly more power) but at the end of the day that when the HTA3076 could conceiveably be compared with the GTX3071R for response, and with the GTX3076R for power.... to me it makes having to decide between any of those three turbos very easy

Also, I am sure FP would do a 3073 if you asked them to.

[discopotato03]

Interesting reads at GTR Life though the suggested Garrett tech time line was wrong . HKS was marketing GT BB Garrett cartridge turbos a bit before 2000 and they go back to the early 90s , a spin off from Garrett's competition BB turbos .

Again interesting but shooting with a modern 3.8L V6 is a bit different to a 2.5-3L RB 6 , I know R35s are heavier but the capacity to weight ratio is better than 89-01 era GTRs .

I noticed that they are using 0.63 AR housings and comparing the GTX76 to the HTA76 and not surprisingly the HTA spins up earlier . The HTA wheel is slightly smaller and is very likely lighter so inertia has to play its part . Back in the day HKS used to sell twin GT3037 kits for earlier GTRs and they specified 52 trim GT compressors as well . You'd think having slightly less compressor capacity in a TT app would pay off spool wise and if you get a wide enough power range starting early enough it can be better than outright top end .

My gut feeling is that the HTA76 is a better match for the GT30 turbine than the GTX76 , both seem to need higher boost levels to make strong numbers but I think the HTA makes more efficient use of its turbine power/exhaust flow . It's probably closer to a "TR3076R" than the GTX76 is just without exotic turbines and housing materials .

I also think marketing and hype is something Garrett went looking for with the GTX3076R . I guess they can boast that it makes virtually GT3582R power in the same sized package as a GT3076R though the only difference externally is the compressor housing . I think they were aiming to downsize the GTX turbos in comparison to the GT versions for same or better capacity . It's hard to argue that a smaller lighter billet comp unit is a bad thing .

Obviously FP has chosen to develop wheels that squeeze the most out of GT30 turbines which were high speed units to start with . Getting the balance of high speed performance with good spool would take time but I think they nailed it here with that turbine . We know they can or did do 71 and 73mm versions but not much info seems to be available on how they compare to their own 76mm version let alone the GT/GTX ones .

Lastly price and availability is an issue because FP is on the other side of the world where Garrett is off the shelf here . In a perfect world FP would sell compressor and housing kits to a few trusted turbo mobs here so you could have local support and fast repairs etc .

A .

[Lithium]

Again interesting but shooting with a modern 3.8L V6 is a bit different to a 2.5-3L RB 6 , I know R35s are heavier but the capacity to weight ratio is better than 89-01 era GTRs .

I noticed that they are using 0.63 AR housings and comparing the GTX76 to the HTA76 and not surprisingly the HTA spins up earlier . The HTA wheel is slightly smaller and is very likely lighter so inertia has to play its part .

Agreed with much of what you say - including here really, though comparing turbo to turbo regardless of the platform will paint a bit of a picture of an equivalent HTA and GTX - just the final numbers are obviously going to be a bit different depending on a few things. That thread had Subaru, Mitsubishi and GTR people weighing in - Audi, BMW etc people have also tried some of these combinations and the conclusion is pretty consistent. Again, we have our own 34GeeTeeTee who has laid down numbers beyond what GT and GTX3076s have managed on the same dyno with the same engine - let alone with the power delivery

[scotty nm35]

Yes, the GTX76 is a larger compressor and as such needs the larger rear to shine. As no-one is willing to try that in most cases, or worse strangles it with a .63, we are not going to see any decent results any time soon, no matter the dyno. It surpasses the capabilities of a GT35 in most cases from my experience.

Seeing my old GTX76 made 380kw on an auto 34 on a stock manifold with a cheap Kando housing, I am very confident there is at least 450+wkw in it, on Chequered's dyno at least, assuming more appropriate supporting mods are added and it was a manual car. That is why I suggested comparing to a GTX3071, as it is much closer to matching the spool and power output of the HTA76, at least in externally gated form on e85. Just my opinion, any of them will fry tyres nicely though.

Hopefully someone does an unbiased bolt on comparison one day, on an unrestricted setup, but I can only guesstimate the HTA will make somewhere in between the Garrett offerings.

[Dajae]

Love how in one of those gtrlife threads, the comment was made, "1000whp is like the old 500hp" ... They love their R35s over there, that's for sure. Some of those results are just spectacular. Love it.

[Lithium]

Seeing my old GTX76 made 380kw on an auto 34 on a stock manifold with a cheap Kando housing, I am very confident there is at least 450+wkw in it, on Chequered's dyno at least, assuming more appropriate supporting mods are added and it was a manual car. That is why I suggested comparing to a GTX3071, as it is much closer to matching the spool and power output of the HTA76, at least in externally gated form on e85. Just my opinion, any of them will fry tyres nicely though.

Hopefully someone does an unbiased bolt on comparison one day, on an unrestricted setup, but I can only guesstimate the HTA will make somewhere in between the Garrett offerings.

I semi agree with this too - I'm going to be cautious on calling what I think both will do, but one thing we clearly agree on is that the GTX3076 (and I believe the HTA3076) will go comfortably into the 400kw range on Chequered's dyno with good setups on E85, and yeah - the GTX (and also the HTA) need more than the .63 housings to shine. In my opinion the best of the flow potential of the GTX3076R compressor actually needs the GT35 turbine, I'm not sure it's flow potential is going to show itself much or at all will a GT30 so without proof that it will - it's all academic, one way or another.

As I mentioned above, HTAs have so far made no less on equivalent setups (ie, same housings and engine setups) than GTX3076R - power wise a HTA3076 is definitely much more comparable to a GTX3076R than a GTX3071R, if it doesn't match it. The fact that the HTA3076 provides is something which will make power more or less comparable to the GTX3076R with response more or less comparable to a GTX3071R I think is pretty cool.

[34GeeTeeTee]

Left foot braking

Or No2

Yeah i gotta try get on the throttle earlier... First time really having a go on the track with sticky tyres so a lot of learning and improvement to be had!

What do the HTA35's sound like, do any HTA's sound like a GT3076 or a HKS T51? Looks like the cost of a GT3076 has come up closer to a HTA now or maybe im looking in the wrong places.

Mine went from super whistle with the GT3037 to super silence with the HTA3076 Until it cracks gate then all hell breaks loose

What's stopping you exactly? Traction or what?

Just getting down off boost due to low road speed!

[Tonba]

^ 100% think your right there lith. The 76mm wheel on both those turbos (GTX76 and HTA76) will not make any more power, 100% due to the turbine. The turbine is simply too small.

For this reason, I think the HTA76 is a better combo. The smaller inducer, encourages fast turbo response, while playing to the GT30 turbine wheel strengths. The GTX76 flows more air, but as stated before, it means nothing as the GT30 turbine cant flow as much air.

the GTX76 is much more suited to the GT35 turbine configuration. (to make use of the extra airflow!)

[Tonba]

Yeah i gotta try get on the throttle earlier... First time really having a go on the track with sticky tyres so a lot of learning and improvement to be had!

Just getting down off boost due to low road speed!

Deffo gotta try to pick-up the throttle earlier.

If that isn't possible due to car reaction to earlier throttle (oversteer or understeer), might be time to start thinking about a little bit of aero to keep corner speeds up a little more... a few more kph might make the difference!

[34GeeTeeTee]

I semi agree with this too - I'm going to be cautious on calling what I think both will do, but one thing we clearly agree on is that the GTX3076 (and I believe the HTA3076) will go comfortably into the 400kw range on Chequered's dyno with good setups on E85, and yeah - the GTX (and also the HTA) need more than the .63 housings to shine. In my opinion the best of the flow potential of the GTX3076R compressor actually needs the GT35 turbine, I'm not sure it's flow potential is going to show itself much or at all will a GT30 so without proof that it will - it's all academic, one way or another.

As I mentioned above, HTAs have so far made no less on equivalent setups (ie, same housings and engine setups) than GTX3076R - power wise a HTA3076 is definitely much more comparable to a GTX3076R than a GTX3071R, if it doesn't match it. The fact that the HTA3076 provides is something which will make power more or less comparable to the GTX3076R with response more or less comparable to a GTX3071R I think is pretty cool.

Lol i miss this thread

And the HTA is still the best thing i have done to the car to date! It changed everything

[Tonba]

What? I thought Anti-Lag would be a good idea!

[34GeeTeeTee]

Deffo gotta try to pick-up the throttle earlier.

If that isn't possible due to car reaction to earlier throttle (oversteer or understeer), might be time to start thinking about a little bit of aero to keep corner speeds up a little more... a few more kph might make the difference!

Yeah well like i said, first time out was a lot of learning and a shitload of fun! Pretty happy with the result apart from the broken gearbox lol

Will try throttle earlier next week and see if i can get it sorted, if not.....MODS!!!!!!!!!!!!

What? I thought Anti-Lag would be a good idea!

You are a bad idea

[Tonba]

Yeah well like i said, first time out was a lot of learning and a shitload of fun! Pretty happy with the result apart from the broken gearbox lol

Will try throttle earlier next week and see if i can get it sorted, if not.....MODS!!!!!!!!!!!!

Dude, you did f**king awesome. Honestly. 1.07's is damn quick mate! You will be deep into the 1.06's in no time at all!

You are a bad idea

I know you love it.....

[34GeeTeeTee]

Dude, you did f**king awesome. Honestly. 1.07's is damn quick mate! You will be deep into the 1.06's in no time at all!

I know you love it.....

Ill give it a crack Might use some brake pads that work this time!!

Haha

[r32-25t]

They just slow you down, you're trying to go faster remember : p

[Tonba]

Ill give it a crack Might use some brake pads that work this time!!

Haha

Brakes....???

Less brakes, more boost!