Hi speeders,

I'm really thinking about bolting a set of TIAL AlphaHTA3076 instead my upgraded VTGs (rated 66mm) but I'm a bit lost between wHp and crankHp powers:
My car is dynoed 670hp on a Superflow and 680 on a Dynojet, crankHp.
Achieving 60-130 in high 6' and 100-300 in 21'.

Will the step with HTA3076 with Pumpgas really huge?
How much power could I achieve? (I mean crankHP to compare with my actual numbers)
I will run pumpgas the most of the time so I don't care with racegas results, in that case, are this turbos a good or inutile mod?

Thxs,

P.

 

very intresting...i am in the same position..i am thinking to exchange my bigger VTG with something different(bolt on)...but why 3076 and not 3071?i think 3071 will be better in low rpm..lets see what sponsor tuner will say for that...

 

I thought about 3071s first but I'm now afraid the top end gain won't be enough for the buck.
I did many investigations with the "research" button on the forum (and 996TT's) and I noticed guys who run A3076 and achieve 850 to 1050 hp (GTOvan, Megio for example) run 1.75 to 2Bar boost and race gas; so I guess with pumpgas boost (about 1.4 maxi?) the power won't be up to 750 crank Hp, which is not much more than our actual position, so let's forget the 3071...
It is my today position, I'm open to change my mind with speeders experiences...
in one word I'm looking for a reliable very fast pumpgas 997.1TT!

 

yes..but if you stick with 1,4 bar you will no need 3076...for 3076 probably you need around 1.7-1.8bar to see good gain...with 3071 and 1,5/6bar will be at 800bhp....with good low and top end results...IMO...dont know for sure lets see some other experieces as you said..

 

Right, but I don't how much boost pumpgas can support with 3071s or 76s, 1.4bar must be different than with vtgs because of the larger flow and air volume compressed.
My goals are reliable 750hp/950Nm on pumpgas.
Perhap's alphas are only interesting if you run racegas, I hope not or we are sticked at little 700 crank hp...

 

Little 700 crank hp?? lol im still working on 600 crank hp....

 

P, I think Todd had told me previously that you could get around 700 wheel hp with a3076 on low boost with pump gas. It would be interesting to see what kind of 60-130 you can get with that setup. I think you should just go ahead and do it so we can compare your results, lol. Don't forget about all the other things you'd need like fenderwell intake, ebc, lines etc... That's why I'm still looking at Champion 68s.

 

K24F....if you're using a 66mm VTG you definitely have a lot more room for more power. I would see if your tuner can offer some input before you abandon the VTG's altogether.

To give you an idea....our 65mm VTG's produce 600 WHP on pump gas, which would conservatively equal about 750 BHP at the engine. Without knowing too much about exactly what VTG's you're using, I still think you have some room for improvement with your current setup. You might just need a few little mods and a new tune to get you where you want to be.

 

Hi Tom,..600whp is veryyyyy good gain for a car VTG..are you using anothers camshafts also?..what dyno are you using?any chart?

 

No camshafts...completely stock engine. Here's a dyno chart. This was a 997TT tiptronic car with our 65mm billet VTG's, even using stock headers. We've gone a lot higher with out larger 68mm VTG's...as high as 840 WHP on a couple cars.

 

P--Talk to TK. He's got all the dynos with different boosts. I personally wouldn't go over 650-700 whp on pump gas. You would get to that power level with lower boost on alphas than vtgs. Much safer in my opinion. The 3071s would probably be best if you're always going to run pump gas. Boost would hit probably 300 rpms earlier than 3076. Alternatively, install meth kit/3076 and take full advantage of the turbo. Good luck and have fun.

 

Here's some compressor wheel flows:

65HTA - 43 lb/min
68HTA - 47 lb/min

Multiply those with 9.5 and then again with 2 and you'll know how much VTG turbos can produce in correct housings and tuning. Max crank hp in optimal conditions.

 

Tom, it is possible my setup could be improved, Todd told me he will send me an improved tune soon.
But I guess it won't be enough, I'm really "addict" of power since I was a kid...

I don't really understand the different power measures, how much my car would show on your dyno? It shows 670hp on a Superflow and 680 on a Dynojet?

Anyway, I begin to believe the bottleneck is my pumpgas now, no racegas easily available here, and no one able to bolt seriously an Aquamist.


Thxs Dave for input, confirms pumpgas is my "brake"...
and Pete, but I must admit I don't understand nothing with that theory...

 

Just sayin' that 43 lb/min equals about 815 crankhp and 47 lb/min about 890 crankhp. Max available wheelhp is about 20% less...if planets are aligned and all parts and tuning optimized. Everything above that is done with dyno settings...

You asked about your different dyno numbers from different dynos. Some 10 hp is about 1.5% which can be explained with different outside air pressure or temperature or even your tyre pressure.

How does your current dynoed hp correlate with 100-200 km/h (100-300 km/h) acceleration times. Available hp can be calculated from longitudinal G's if you have a datalog.

 

Last "goodie" for my Vtgs received last night, logging and vboxing soon...