Hahn Racecraft LSJ GT35R Turbo Project PICS RELEASED!
12-20-2007, 02:01 PM
#51
Senior Member
granted you can control spool with turbine housing size, blade clipping, attempts at a on-throttle anti-lag, ect but were forgetting the things that are needed to make a large turbo (well at least a large compressor wheel) work properly and efficiently....shaft speed, cover PR, ect....that tiny turbine housing will limit all of those because of the smaller flow you can squeeze thro it....it might spool alright (no chance in hell shes gonna make full boost in the 3s) but it'll also limit power.
the exhasut side controls this cars fate.
just an observation.
just a little?
i was almost at ROFL stage.
Last edited by 06black; 12-20-2007 at 02:01 PM. Reason: Automerged Doublepost
12-20-2007, 02:06 PM
#52
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The term 'tiny' is not entirely accurate...'properly matched to engine displacement' would be more effective. This is why turbocharger manufacturers provide a series of different turbine flows, to accomodate different engine sizes. As an illustration, when we use two GT35R's on an LS7 ZO6 Corvette, we will utilize a considerably larger turbine housing to match the units correctly to engine flow.
Last edited by Hahn RaceCraft; 12-20-2007 at 02:09 PM. Reason: Automerged Doublepost
12-20-2007, 02:16 PM
#53
Senior Member
so an IG turbo feeds both its exhasut and wastegate dump into the same exhasut pipe cross section.
and with that first 1-2ft of exhasut pipe being vary critical to its performance,we've often ran a larger dia pipe for that distance before dropping back down to what ever side the turbine outlet is and its proven to help spool times and boost response.
so now you've got a 3in turbine housing feeding a 3in exhasut pipe, and then the waste gate dump feeding into that same pipe but on the "back side" of the turbine wheel. that pressure from the gate dump builds onto the turbine wheel and introduces a pressure on it, thus effecting max power and it can, and has in the past effect spool times.
its been proven time and time again on the scoobie and dsm side of the world(so it applies here) that if you run the same turbo with a IG and then with an external gate we've always seen more power, and better midrange response (rite on the edge of the gate opening and closing)with the external gate because of that exhasut reason.
now from the pics, which are limited in there views, they lead me to believe that you had to make the manifold so small and tight that mounting an external gate was a "last resort" option if need be, so the IG 35R was perfect for your requirements.
12-20-2007, 02:17 PM
#54
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Great job Hahn on whats clearly going to be a beast of a set up. Who else here on the site has more Turbo experience than the guys at Hahn? I think that they have done there homework on this and will produce a streetable turbo setup that will appeal to alot of members!
Great work Guys! I look forward to seeing the finished product!
Great work Guys! I look forward to seeing the finished product!
12-20-2007, 02:19 PM
#55
Senior Member
Are you folks willing to elaborate on the 'oddness' you perceive? I'm not following so far...are you of the impression that an internal wastegate produces positive pressure on the outlet side of the turbine during spool-up?
The term 'tiny' is not entirely accurate...'properly matched to engine displacement' would be more effective. This is why turbocharger manufacturers provide a series of different turbine flows, to accomodate different engine sizes. As an illustration, when we use two GT35R's on an LS7 ZO6 Corvette, we will utilize a considerably larger turbine housing to match the units correctly to engine flow.
The term 'tiny' is not entirely accurate...'properly matched to engine displacement' would be more effective. This is why turbocharger manufacturers provide a series of different turbine flows, to accomodate different engine sizes. As an illustration, when we use two GT35R's on an LS7 ZO6 Corvette, we will utilize a considerably larger turbine housing to match the units correctly to engine flow.
i did the calculations and got my engine PR and CFM thus giving me the info i needed to pick my exhasut housing.....theres two that seem to fit the bill the best, I had picked the larger of the two so i would have room to grow as my project continues. with this guys suposed ported head, ect his VE and CFM rates would both be higher, so he would need a larger housing unless hes going to run this turbo past the surge line.
like i said, with just pictures its hard to tell....
EDIT-----
not meaning this to be an attack in any form....just a few educated questions and worries....its hard to tell whats exactly on the car with just pictures.
i have faith and trust in you guys (hann) but i just have to ask a few questions and make a few points before i just jump on board like every one else.
12-20-2007, 02:38 PM
#56
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yea, I'll try to get my point across....sometimes a keybord kida makes it hard.
so an IG turbo feeds both its exhasut and wastegate dump into the same exhasut pipe cross section.
and with that first 1-2ft of exhasut pipe being vary critical to its performance(we've often ran a larger dia pipe for that distance before dropping back down to what ever side the turbine outlet is and its proven to help spool times and boost response.
so now you've got a 3in turbine housing feeding a 3in exhasut pipe, and then the waste gate dump feeding into that same pipe but on the "back side" of the turbine wheel. that pressure from the gate dump builds onto the turbine wheel and introduces a pressure on it, thus effecting max power and it can effect spool times.
its been proven time and time again on the scoobie and dsm side of the world(so it applies here) that if you run the same turbo with a IG and then with an external gate we've always seen more top end power, and better midrange response (rite on the edge of the gate opening and closing)with the external gate.
now from the pics, which are limited in there views, they lead me to believe that you had to make the manifold so small and tight that mounting an external gate was a "last resort" option if need be, so the IG 35R was perfect for your requirements.
so an IG turbo feeds both its exhasut and wastegate dump into the same exhasut pipe cross section.
and with that first 1-2ft of exhasut pipe being vary critical to its performance(we've often ran a larger dia pipe for that distance before dropping back down to what ever side the turbine outlet is and its proven to help spool times and boost response.
so now you've got a 3in turbine housing feeding a 3in exhasut pipe, and then the waste gate dump feeding into that same pipe but on the "back side" of the turbine wheel. that pressure from the gate dump builds onto the turbine wheel and introduces a pressure on it, thus effecting max power and it can effect spool times.
its been proven time and time again on the scoobie and dsm side of the world(so it applies here) that if you run the same turbo with a IG and then with an external gate we've always seen more top end power, and better midrange response (rite on the edge of the gate opening and closing)with the external gate.
now from the pics, which are limited in there views, they lead me to believe that you had to make the manifold so small and tight that mounting an external gate was a "last resort" option if need be, so the IG 35R was perfect for your requirements.
In this instance, the internally wastegated turbo serves a number of excellent purposes without significant derisive effect, certainly nothing approaching the 'odd' or 'ROFL' stage.
As we build street-intended systems, we just don't ever do open wastegate dumps. Sure, you've seen others do it, and other companies sell it...I just won't. Its a philosophy I've gained in over three decades of turbosystem experience. I don't care for the noise, I don't like the concept of safety issues regardng a 1600-degree, 20-PSI blowtorch at WOT (seen more fires from this than you can imagine!), and it's also an emissions no-no.
As for your theory regarding spool-up, well...you are entitled to it, but I don't agree. During spool-up, the wastegate won't even begin to crack open until we see significant boost pressure, and at that point, we are still nowhere near maximizing the flow of the 3" downpipe, so adding the bypassed gases emitted by the wastegate into that 3" downpipe offers inconsequential flow impediment. If there's any impediment at all, it comes nowhere near adding 'positive pressure' to the turbine outlet side during spool; remember, there's atmospheric pressure at the other end of that exhaust system, so the ability to create positive back pressure with wastegate flow (a small percentage of overall engine flow) just isn't there. Further, the gas flow escaping from the turbine wheel creates a scavenging effect on the wastegate's outlet port, further enhancing flow.
In summary, sure...at 600 HP, we could probably gain more power with an external wastegate dump. Would this gain justify the additional cost and complexity, and numerous shortcomings I am uncomfortable with? Would the additional power even matter? Not in this market...with all due respect, it's hard enough to get Cobalt folks to buy complete turbosystems, and everything we can do to make the turbosystems simpler and more affordable is a real move towards actual product viability.
Last edited by Hahn RaceCraft; 12-20-2007 at 02:55 PM. Reason: grammar snafu
12-20-2007, 02:42 PM
#57
Senior Member
While id never argue that in unlimited applications, an open external wastegate dump can can produce more power, it's all very relative. The applications you cite are considerably more advanced than what we are doing here, what with many more enthusiasts pursuing the ultimate results in much more expensive vehicles. However, that argument can be applied to just about anything, that 100% optimization is always achievable if we just change this or that or put more money into a given area. In my part of the business, we strive to design and offer turbosystems that take all of these factors into account, and determine the best course of action based upon meeting objectives of affordability and streetability, constraints that individual enthusiasts are not limited by in their custom builds.
In this instance, the internally wastegated turbo serves a number of excellent purposes without significant derisive effect, certainly nothing approaching the 'odd' or 'ROFL' stage.
As we build street-intended systems, we just don't ever do open wastegate dumps. Sure, you've seen others do it, and other companies sell it...I just won't. Its a philosophy I've gained in over three decades of turbosystem experience. I don't care for the noise, I don't like the concept of safety issues regardng a 1600-degree, 20-PSI blowtorch at WOT (seen more fires from this than you can imagine!), and it's also an emissions no-no.
As for your theory regarding spool-up, well...you are entitled to it, but I don't agree. During spool-up, the wastegate won't even begin to crack open until we see significant boost pressure, and at that point, we are still nowhere near maximizing the flow of the 3" downpipe, so adding the bypassed gases emitted by the wastegate into the main pipe offers inconsequential flow impediment. If there's any impediment at all, it comes nowhere near adding 'positive pressure' to the turbine outlet side during spool; remember, there's atmospheric pressure at the other end of that exhaust system, so the ability to create positive back pressure with wastegate flow (a small percentage of overall engine flow) just isn't there. Further, the gas flow escaping from the turbine wheel creates a scavenging effect on the wastegate's outlet port, further enhancing flow.
In summary, sure...at 600 HP, we could probably gain more power with an external wastegate dump. Would this gain justify the additional cost and complexity, and numerous shortcomings I am uncomfortable with? Would the additional power even matter? Not in this market...with all due respect, it's hard enough to get Cobalt folks to buy complete turbosystems, and everything we can do to make the turbosystems simpler and more affordable is a real move towards actual product viability.
In this instance, the internally wastegated turbo serves a number of excellent purposes without significant derisive effect, certainly nothing approaching the 'odd' or 'ROFL' stage.
As we build street-intended systems, we just don't ever do open wastegate dumps. Sure, you've seen others do it, and other companies sell it...I just won't. Its a philosophy I've gained in over three decades of turbosystem experience. I don't care for the noise, I don't like the concept of safety issues regardng a 1600-degree, 20-PSI blowtorch at WOT (seen more fires from this than you can imagine!), and it's also an emissions no-no.
As for your theory regarding spool-up, well...you are entitled to it, but I don't agree. During spool-up, the wastegate won't even begin to crack open until we see significant boost pressure, and at that point, we are still nowhere near maximizing the flow of the 3" downpipe, so adding the bypassed gases emitted by the wastegate into the main pipe offers inconsequential flow impediment. If there's any impediment at all, it comes nowhere near adding 'positive pressure' to the turbine outlet side during spool; remember, there's atmospheric pressure at the other end of that exhaust system, so the ability to create positive back pressure with wastegate flow (a small percentage of overall engine flow) just isn't there. Further, the gas flow escaping from the turbine wheel creates a scavenging effect on the wastegate's outlet port, further enhancing flow.
In summary, sure...at 600 HP, we could probably gain more power with an external wastegate dump. Would this gain justify the additional cost and complexity, and numerous shortcomings I am uncomfortable with? Would the additional power even matter? Not in this market...with all due respect, it's hard enough to get Cobalt folks to buy complete turbosystems, and everything we can do to make the turbosystems simpler and more affordable is a real move towards actual product viability.
with this projects approach not being my cup of tea persay i still must say this.....the main reason i respect you and your company is because i truly do see and agree with this point of yours....
good luck none the less.
with all due respect, it's hard enough to get Cobalt folks to buy complete turbosystems, and everything we can do to make the turbosystems simpler and more affordable is a real move towards actual product viability.
most things on here make me giggle, due to the lack of research in general....so its easy to jump from gigle to rofl stage
12-20-2007, 03:39 PM
#58
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"sir, it's mega maid. she's gone from suck to ROFL"
HA, i has jokes
bryan, yes yes i know, i just bring up little points to see if someone outside of the braintrust will pick up on them. now a/r selection enters a weird world in street cars. a .63 a/r would be more suitable than a .82 would be. for the simple fact it wouldn't fall on it's face so damn bad between gears. {this is what a friend did to his TT mark7 lincoln} not enough rpm could also result in this. odd as it may seem. exhaust a/r is a tricky creature to get right on a street car. drag car, with a two step wouldn't be that bad. it's just commonly known that a larger a/r housing will produce a higher hp number in the end, but also increase lag, but you already know this, so id have a better bet of pissing into a light socket and writing a how to about it.
i hated my IG turbo i had for the simple the boost was never consistant in the damn car.
HA, i has jokes
bryan, yes yes i know, i just bring up little points to see if someone outside of the braintrust will pick up on them. now a/r selection enters a weird world in street cars. a .63 a/r would be more suitable than a .82 would be. for the simple fact it wouldn't fall on it's face so damn bad between gears. {this is what a friend did to his TT mark7 lincoln} not enough rpm could also result in this. odd as it may seem. exhaust a/r is a tricky creature to get right on a street car. drag car, with a two step wouldn't be that bad. it's just commonly known that a larger a/r housing will produce a higher hp number in the end, but also increase lag, but you already know this, so id have a better bet of pissing into a light socket and writing a how to about it.
i hated my IG turbo i had for the simple the boost was never consistant in the damn car.
12-20-2007, 03:58 PM
#59
Senior Member
"sir, it's mega maid. she's gone from suck to ROFL"
HA, i has jokes
bryan, yes yes i know, i just bring up little points to see if someone outside of the braintrust will pick up on them. now a/r selection enters a weird world in street cars. a .63 a/r would be more suitable than a .82 would be. for the simple fact it wouldn't fall on it's face so damn bad between gears. {this is what a friend did to his TT mark7 lincoln} not enough rpm could also result in this. odd as it may seem. exhaust a/r is a tricky creature to get right on a street car. drag car, with a two step wouldn't be that bad. it's just commonly known that a larger a/r housing will produce a higher hp number in the end, but also increase lag, but you already know this, so id have a better bet of pissing into a light socket and writing a how to about it.
i hated my IG turbo i had for the simple the boost was never consistant in the damn car.
HA, i has jokes
bryan, yes yes i know, i just bring up little points to see if someone outside of the braintrust will pick up on them. now a/r selection enters a weird world in street cars. a .63 a/r would be more suitable than a .82 would be. for the simple fact it wouldn't fall on it's face so damn bad between gears. {this is what a friend did to his TT mark7 lincoln} not enough rpm could also result in this. odd as it may seem. exhaust a/r is a tricky creature to get right on a street car. drag car, with a two step wouldn't be that bad. it's just commonly known that a larger a/r housing will produce a higher hp number in the end, but also increase lag, but you already know this, so id have a better bet of pissing into a light socket and writing a how to about it.
i hated my IG turbo i had for the simple the boost was never consistant in the damn car.
and yes my friend, AR is a tricky bitch but i happen to think i got it nailed down on my car.
only lag between the 1-2 shift, she hits the boost rite away on and the 2-3/3-4/4-5shifts. and theres no sighn of boost drop off at the top of the gears as well
if you do in fact **** into that light socket, please make sure to fallow up with that "how to"
12-20-2007, 04:05 PM
#60
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AHAHHA, dude i'm watching spaceballs rite now!!!!
and yes my friend, AR is a tricky bitch but i happen to think i got it nailed down on my car.
only lag between the 1-2 shift, she hits the boost rite away on and the 2-3/3-4/4-5shifts. and theres no sighn of boost drop off at the top of the gears as well
if you do in fact **** into that light socket, please make sure to fallow up with that "how to"
and yes my friend, AR is a tricky bitch but i happen to think i got it nailed down on my car.
only lag between the 1-2 shift, she hits the boost rite away on and the 2-3/3-4/4-5shifts. and theres no sighn of boost drop off at the top of the gears as well
if you do in fact **** into that light socket, please make sure to fallow up with that "how to"
i see!
the problem we were having with the TT mark 7 was the a/r housing. when he built the car, he didn't think about the consequences of a large a/r housing. now we i tried to tune this land yacht. i tried everything i knew on how to get it to spool faster. nope. it either killed it up top, or dumped at the bottom. so i just made it happy. he then proceeded to turn the boost up to 14 psi on a stock 302 and blew it apart.
round 2!
dropped the a/r down, retuned it. got the car dial in effin great on 12 psi. went from trapping 107 mph {and getting walked by my car} to 112 mph. driving the car now is an absolute riot. one of the funnest cars i have ever driven. the previous a/r was a .83. now it's a .62 i believe. makes a world of difference. it also outruns the stock cam by about 500 rpms. hehehhe. i giggled like a little girl when i first drove it.
the moral of this cute little story? turbo choice is a very tough choice, and you often get it wrong the first time.
12-20-2007, 04:08 PM
#61
Senior Member
ohhh god, a boosted 302.....YUCK
never a fan of that motor.....
none the less a turbo land yacht is always a fun time!!
I'm running a larger AR then your friend is, but i only have one!
gonna send you a pm in a sec.
never a fan of that motor.....
none the less a turbo land yacht is always a fun time!!
I'm running a larger AR then your friend is, but i only have one!
gonna send you a pm in a sec.
12-20-2007, 04:25 PM
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arrrr, mateys...methinks the Good Ship Hahn can let ye threadpirates off at the next PM port! Avast, blasphemers, bringing Fords onto the ship! I'll keelhaul the lot of ye! 
All kidding aside, let's get back to the topic. Anyone else have any questions, observations, or adulations they wish to add?
All kidding aside, let's get back to the topic. Anyone else have any questions, observations, or adulations they wish to add?
12-20-2007, 04:35 PM
#63
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arrrr, mateys...methinks the Good Ship Hahn can let ye threadpirates off at the next PM port! Avast, blasphemers, bringing Fords onto the ship! I'll keelhaul the lot of ye!
All kidding aside, let's get back to the topic. Anyone else have any questions, observations, or adulations they wish to add?
All kidding aside, let's get back to the topic. Anyone else have any questions, observations, or adulations they wish to add?
would it be possible to see inside the manifold? to me, on the outside it looks like a fat chick in spandex flows better. thats just my lil observation.
12-20-2007, 04:42 PM
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12-20-2007, 04:51 PM
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yepo!
in my mind, im picturing something a lot different then just a big open chamber.
im picturing some oval shaped velocity stacks. maybe half an inch tall, with a 1/4 inch rounded edge per runner.
dunno. i could be way off, this is just what im picturing
in my mind, im picturing something a lot different then just a big open chamber.
im picturing some oval shaped velocity stacks. maybe half an inch tall, with a 1/4 inch rounded edge per runner.
dunno. i could be way off, this is just what im picturing
12-20-2007, 05:04 PM
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It features CNC-machined plenum plates that have radiused port entries machined for the oval runners. The additional four PortFueler injectors reside on these oval port runners.
The manifold is a key component of our apporach with this car, as we've found the stock intake manifold on LSJ to be an airflow nightmare. We refused to allow our turbosystem to be hobbled by its shortcomings. For its intended purpose, the stock LSJ intake manifold is adequate, and as an engineering achievement, they did a fine job of fitting so many components into such a tight area. Unfortunately, the twists and turns neccessitated by such a crowded installation have led to some serious issues with airflow distribution across the four cylinders with the stock intake, and it is our belief that this mis-management of airflow is the leading cause behind #4 cylinder failures on hot supercharged LSJ's. Our manifold is intended to correct this problem while also adding a free-flowing, direct runner design to enhance power. It has the additional benefits of weight savings and significantly improved accessibility to underhood components, a feature made even better by the elimination of the stock intercooler coolant pump and related hoses and hardware.
12-20-2007, 05:43 PM
#70
me need your intake manifold. I woul just like to see what the difference in power woud be. i'm sill running the stocker til Someone comes out with one for now.
btw I love my open dump... nothing like undercar fireballs at 7000rpm WOT shifts
btw I love my open dump... nothing like undercar fireballs at 7000rpm WOT shifts
Last edited by 06blackg85ss; 12-20-2007 at 05:43 PM. Reason: Automerged Doublepost
12-20-2007, 05:55 PM
#71
Senior Member
arrrr, mateys...methinks the Good Ship Hahn can let ye threadpirates off at the next PM port! Avast, blasphemers, bringing Fords onto the ship! I'll keelhaul the lot of ye!
All kidding aside, let's get back to the topic. Anyone else have any questions, observations, or adulations they wish to add?
All kidding aside, let's get back to the topic. Anyone else have any questions, observations, or adulations they wish to add?
I'd also like to see it Bill, thats the 3rd next part on my list.
also, if you dont mind i'd like to ask another question.
can you tell me what the AR and hosueing specs are for the turbine?
also, why a 35R and not something else like the ever used gt28r or in my case a gt30r?
just a few questions.
thanks,
i love open dump!
Last edited by 06black; 12-20-2007 at 05:55 PM. Reason: Automerged Doublepost
12-20-2007, 06:01 PM
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I'd like to emphasize that Joe's car (as shown here) is but one iteration of the system, and that we'll also be doing a Super 20G equipped version that would be more comparable to the flow range you mention with GT28 and GT30. This Super 20G turbosystem will be aimed at those looking to make in the 300-500 HP range.
12-20-2007, 06:01 PM
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good times.
guess i need to make a trip to chicago and do some pokin around
