Ok, I was researching turbos and started with the Garrett Powermax, Stage 1, 2 and 3. I found their compressor maps, which include a comparison to the HX35 stock turbo. You can see a big difference. But then I found a Hybrid HX35/40 compressor map, converted the units, and plotted it on the Garrett map. The result was interesting. The right side of the curve compared very closely to the Stage 2 curve, but topped out at a pressure ratio of 4 compared to about 4.2 for the Stage 2. Doesn't this mean that the Garrett Stage 2 and the HX35/40 should be capable of supporting the same HP levels? Garrett says that the Stage 2 is good for 450 HP. Shouldn't the HX35/40 also be in that range? For the price, I think I might go with the hybrid conversion unless someone can tell me why I shouldn't.

 

Where did you find a map for a 35/40 hybrid? I'd be very suspicious of its validity, as Holset never made a 35/40..

It's tough to beat the 35/40 for the price..

But it's definitely not the same as the pricey Garrett turbos.... The Garretts are much better overall because they are DESIGNED for this exact application.

The 35/40 clearly is NOT.

jh

 

CityDiesel.net has the Dodgezilla compressor map on their sight.

The Garrett turbo looks to be very refined, but if the performance is similar why spend the money?

 

Many run the hybrid happily at 400 hp. The 450 hp should be workable for short spurts...racing etc.

To me, max HP for a turbo is at 1500* for no more than 5-7 sec. max in a qtr mile pass!
For some, the max hp of a turbo is how much HP will sustain no more than 1200* EGT for long stretches of hwy!
We all (including Garrett) need to better define our terms. JMO

RJ

 

Good point. I am seeing 1400F after running thur the gears at 95 mph. So if that is the case maybe I don't need a better turbo.? But with my fueling, maybe I could see a bit more HP with some extra air....

 

I'm pretty sure you're overfuelled with mach 4's, smarty, and a stock turbo. You should pick up some ponies by swapping turbos.

 

Yup! My expirience is...if your still getting smoke, or even dark haze, at 20-25 psi boost, there is HP to be picked up with bigger turbo.
My first turbo over stock added 30 HP to a 330 hp truck (EZ and DD3 injectors)!

RJ

 

I just need to do a little more research, $1400+ is alot of money to spend when there are so many options. I don't think the companies are advertising very well, they need to post data so we can make an educated desision.

 

I agree. What a turbo can support is totally up to the user. IMO, if you are past 1450-1500* at the 1/4 mile, then its too hot(need a bigger turbo), but that is just me. I am planning to go with 191 Delivery Valves in a couple months, so I may check into making my turbo a hybrid. What is a safe estimate of the WOT temperature decrease you will see with a hybrid turbo? Does it raise, or lower boost(or the same)? How much more Laggy will it be? Right now my temps are a solid 1250* or so at the end of the 1/4 which is plenty fine for me. I dont ever look at the pyro unless I am pulling a load, and hit a hill working it hard. I just want to keep it as cool/driveable as possbile without loosing much spoolup, and not spending a lot of $.

Eric

 

I just noticed your location. You can get some fine turbos locally from II. I'm curious how the BB turbos are going to perform, but the Phatshafts from II are top notch.

http://www.industrialinjection.com/

 

Yep, I visited both HTT and II.

HTT completely discounted comparing turbos with compressor maps, they rely on real world results. That works great for them comparing their turbos on there trucks, but doesn't help me compare there stuff to the competition.

II was very nice, I was escorted into the back workshop and all the innerworkings of their turbos was explained and shown to me. Based on workmenship, II gets and A+. But I still left without a good understanding of the data that supports the claims that "our turbo XXXXX will out perform anyone in the market". Show me the data! Not a sales pitch based on "my buddies truck".

I am not bashing either company, I am just interested in getting all the right information before making a purchase that empties my wallet. Maybe I am asking too much...

 

I don't think you'll find the info you seak. Not sure why but MAPs seem to be proprietary.
What your looking for is out there...but needs to be interpolated from many threads where EGT's are reported.

Really all you can do is read up...and guesstimate what's best for you. You can live with what you have...and not play too hard; you can get a Hybrid and play hard for short bursts, or you can go with II PS62 and play all you want...and never worry about the egt gauge!

No wrong choices, IMO

 

I suppose you are right. If I get the II PS62, then I will be obligated to get a TST box too, hehehehehe.

 

Now that is clear headed, engineer type, thinking!
But if you do the TST box...go for the PS 64... and do keep 1/2 an eye on the Pyro. I have to with mine (also a 64mm Compressor bore) .

RJ

 

I hit 1250 once with that turbo- but only once. Easy to get to 900 but hard to get over 1100 with my current fuel. Once I get that dern tst working it might be another story