H1C vs. HX-35 map

[sparks57]

You guys be nice to CB. He asks alot of questions that I enjoy hearing the answers to. I'm hoping some of you guys will come up with a good twins combo that would spool faster than what i have and give a real low egt at around 400 hp. Something like a 35-9 over an Hx-50 , 45psi with 1100 deg egt. Would be way usable and not over stressing everything. Small injectors, 20mpg 375 to 400 hp and no headgasket worries.

Ron

Ron:



A 35/9-hx50 setup would spool well, but the drive pressures would be insane. I'm sure you already know that high drive pressures cause high EGT's. Let's not forget that drive pressure, coupled with boost pressure, can create some pretty heavy lift on the head and call for extra large studs. I've also not heard much good about the hx-50.



I'm going for the 35/40-ht3b setup because of my auto, and my altitude. I have a strong suspision that I'll be using an external wastegate on the 35/40 to balance drive/boost pressure, and dump the excess drive pressure into the ht3b, thus giving me a more efficient setup and giving better overall boost and power handling. I don't think I would need the 40 on top anyways...



That, coupled with a cam, and a tight 89 or light 91 converter would give me great spoolup, a broad powerband, and respectable HP. (500-550?)

 

[RonA]

The combo would not work for big hp. But for a cool running 400 or so a smaller set up has to work. I have 1100 deg egt at 500 hp. So if a smaller setup would give 1100 deg egt at 400 hp and spool alot faster I think it would be interesting. The 50/55 hybrid with a housing around 18cm or so and a 35 with a 9 or 12 should work. I'd like to try a 12 for starters. A slightly smaller diameter hotpipe might help keep the velocity up for spooling the bottom turbo. Once again not expecting huge power. But if the truck built boost faster it would be easier to enjoy the power in day to day driving. You wouldn't have to go out on the interstate. Mine doesn't start getting the boost up untill 4th gear.

 

[Forrest Nearing]

Ron, I think you'd want to go large on the bottom turbo than an 18... maybe an H2E w/ a 23-27?



Forrest

 

[RonA]

I don't think the 27 would work. I put the 26 on my truck yesterday and It spools slower than the 23. I didn't like it. The H2 and the Hx50 are rated at about the came cfm. Which ever one has the lightest rotating assembly would be the one to try. I don't know how large an exhaust housing is available for the Hx50 and Hx55. So far I was told 18. Around 20 would be nicer. But porting the heck out of an 18 might be ok. I'm trying to keep in mind a slightly more modest VE fueling level for first gen use. Sorry for the hi-jack CB. I'll stop.

 

[JLEONARD]

Ron,

Just put all the turbo numbers/combos you guys talked about in a hat. The first one you pick goes on top. Second on the bottom. :-laf

Call it twin turbo lotto.

Jay

 

[RonA]

You're mocking me aren't you. Now my feelings are hurt. :{

 

[Greenleaf]

You's guys want the cutting edge of TECHNOLOGY???

HeHeHeHeHeHe



I'm getting a bit dizzy myself. Even with a single turbo you have more options than you care to know about.



We will never know what is "best" ... ... ... ... . As soon as you buy an outfit some wise-butt out there R&D's another combo and it's the BOMB untill someone else betters that guy. Then there is the fact we don't leave well enough alone and go add some mopow'r goodies and find that our current set-up no longer is viable #@$%!



I spoke with a Nationally known turbo shop who will be willing to set me up with a sweet HX35 , but admittingly said it will be outdated by the month of January



The technology applied to our trucks seem to resemble the 'puter industry. Wait untill tomarrow to get the latest technology, only realize you didn't wait long enough :{



Just pick somth'n you guys already :-laf



My humble . 02 worth



Greenleaf

 

[bgilbert]

Well Since you sold your edm's to NeedMorePower over on the DTR

Hey don't remind me, those should be in my truck, I had the cash, but waited a few hours too long... . I'll never forget ... .

 

[RonA]

HeHeHeHeHeHe



We will never know what is "best" ... ... ... ... . As soon as you buy an outfit some wise-butt out there R&D's another combo and it's the BOMB untill someone else betters that guy. Then there is the fact we don't leave well enough alone and go add some mopow'r goodies and find that our current set-up no longer is viable #@$%!



I spoke with a Nationally known turbo shop who will be willing to set me up with a sweet HX35 , but admittingly said it will be outdated by the month of January



The technology applied to our trucks seem to resemble the 'puter industry. Wait untill tomarrow to get the latest technology, only realize you didn't wait long enough :{



Just pick somth'n you guys already :-laf



My humble . 02 worth



Greenleaf

Exactly!!!!!

There isn't enough difference between most of this stuff to argue about.

It would cost a fortune and you'd go crazy trying to come up with the perfect setup. The number of combos that could work is mind blowing.

Ron

 

[Forrest Nearing]

I don't think the 27 would work. I put the 26 on my truck yesterday and It spools slower than the 23. I didn't like it. The H2 and the Hx50 are rated at about the came cfm. Which ever one has the lightest rotating assembly would be the one to try. I don't know how large an exhaust housing is available for the Hx50 and Hx55. So far I was told 18. Around 20 would be nicer. But porting the heck out of an 18 might be ok. I'm trying to keep in mind a slightly more modest VE fueling level for first gen use. Sorry for the hi-jack CB. I'll stop.

an H2E turbine wheel is a good deal smaller than an HT3B turbine wheel... that will make it spool much quicker... you're already going to be spooling very quick w/ the small top turbo. I would just hate for you to run into an engine choking overboost situation.



Forrest

 

[sparks57]

Staying on the "cutting edge" is not for the majority of us. I like to get my truck where it needs to be, and tune from there. If you were to change things around every time something new came around, you'd never have a good setup because you'd never have the time to perfect it!

 

[JLEONARD]

You're mocking me aren't you. Now my feelings are hurt.

:-laf :-laf

You catch on quicker than your twins can spool!!!!

No not really mocking... . just poking fun at the thread not you particularly... .

Trying to lighten things up a bit.

I think it's funny... . one more page to this thread and we'll be talking tripletts :--)

Anybody ever consider a pair of H1Cs or HX35s in parallel?

Never mind... . I think I just violated GL's cardinale rule!! (not Claudia)

BOMB on. I'll be happy to stay at 250 hp... .

OK... did ya hear the one about.....

Jay

 

[sparks57]

I have heard of people trying parallel's (including one grumpy old man on this forum) but I've never heard of anyone succeeding.

 

[Forrest Nearing]

parallels would be good on an engine twice the size... we don't need increased CFM at low boost, we need increased BOOST at low CFM!!



Forrest

 

[JLEONARD]

we don't need increased CFM at low boost, we need increased BOOST at low CFM

OK. Makes sense put that way.

In other words with twins you are boosting your boost.

 

[Greenleaf]

Thanks Forrest for making this clear as mud.



Over on the free forum, KTA stated just the exact opposite. No joke, he did! ... ..... and I agree with him. It's not how much air pressure we can pack into the intake system (boost) it is flow that we want (CFM)... ... ... no?



Unless I am reading something different than what is written?



Someone can claim high boost #'s, however it means little if you do not have flow. 45# boost sounds great, but what is the drive pressures/EGT?





Some food for thought. Chew on that.



I'm getting a headach



GL

 

[Forrest Nearing]

GL,



engine CFM is dictated by displacement, cylinder head flow, camshaft profile, etc.



and yes, a ported head and bigger cam, ported exhaust manifold, etc. will help to increase engine CFM, but it certainly won't double it.



now... the only other way to get oxygen into the engine when you've maxed out the air FLOW is to increase the air MASS... mass... density... BOOST



you can't magicly flow more CFM through a given passage, that's all there is to it.



now, you can play with compressor efficiency so that you're moving more oxygen molecules at a given boost level (cooler boost), but that's only going to account for 10-30hp on your average single setup.



where we get our power is by compounding the turbos so that both of them are operating in the center island of their efficiency map (cooler boost) and working together to pressurize... to make compact... to make DENSE... all that oxygen so that we can cram it into our itty bitty engines.



the big turbos we use on the bottom of our compounds are designed to feed engines that are more than twice the size of our engines... so where they'll support 500-700+hp at 30-50psi on a 14+ liter engine, they would be in constant surge on our little 5. 9 liter engines because our engines can't FLOW the CFM those big engines can...



so we have to take that 500-700+ hp worth of compressed air and blow it through another smaller turbo that FURTHUR compresses it into a itty bitty package that our engines can actually accept.



if you take a pair of HX35's, they'll support 600-800hp... but they're going to do it at a low boost level... 20-30psi... that's where they're EFFICIENT... our engines won't make that kind of power at that kind of boost... I don't care if god himself ported your head and you're turning 5000rpm, it ain't gonna happen.



we don't need more CFM at a given boost level (general statement about our engines... more CFM is good obviously, but you're only going to go so far)



we need more boost at a given CFM



Forrest

 

[TKingsbury]

Staying on the "cutting edge" is not for the majority of us. I like to get my truck where it needs to be, and tune from there. If you were to change things around every time something new came around, you'd never have a good setup because you'd never have the time to perfect it!

Boy, you hit the nail on the head there. I know a guy who had a mid 12sec Dart, by the time he stopped throwing parts at it, it would barely get into the 13s . Every time he put something on and it slowed down he wouldn't try to tune it or figure it out, he'd just buy something else. It was comical to watch.

Travis. .

 

[Greenleaf]

Thanks Forrest for taking time to write that. I'll bet that clears up things for a majority of us. Good stuff to remember. Thanks again





Scott

 

[sparks57]

Yep, it's very simple. It all comes down to looking at the differences between NA and turbo'd engines.



A 350 chevy can only make so much power because it can only suck so much air/fuel mixture. The reason we can make so much power compaired to them (even though we don't have much more displacement) is the fact that we make our engines seem bigger by compressing the air. More compression to the intake air=magically more displacement... more displacement=more power.



Just another way to look at it.