Thinking of ditching the twins and going KY turbo kit???
11-05-2011, 11:21 PM
#45
I don't think he took offense. I think that he was referring to me not wanting to argue with others in his thread.... At least I hope thats what he meant 
I have noticed that in the last 6 months I have been getting more and more questions about back pressure. It seems as if its the latest thing that my customers are afraid of when picking a turbo. I am sure that it is due to forum talk as it can influence people greatly. I would like to point out that back pressure isn't the "nail in the coffin" that it is made out to be.
Remember this, a turbo operates off of back pressure. Any turbo setup that spools up fast has a decent amount of back pressure. Back pressure = turbine wheel acceleration. Its the point that when the turbine stops requiring acceleration (read "desired boost level") that it can become a "CHOKE POINT" and I use these words loosely because you all have labeled them that way.
The following video is a SBC 406 with NO INTERCOOLER that is running an 87mm ind X 80mm exd turbine wheel S480 that flows almost exactly the same as my XT80. The only difference between the two performance wise would be the spool up. My turbo would spool up slightly faster since the wheel is 2.5mm smaller and power would be very slightly less for the same reason.
Also, I would like to point out that my inducer is 1mm larger which most likely fairly compensates for the very slightly smaller exducer size.
http://www.youtube.com/watch?feature...&v=5XcLfWh4uHo
http://www.youtube.com/watch?feature...&v=A4wXJQfKYxw
When I said crazy heads I was referring to heads that were VERY EXTREME. Your trick flows will not have issues with this size turbo whether its an ST80, XT80, S480, etc etc etc.
The only way you are going to hit 2:1 back pressure vs boost without extreme measures being applied is if its one of the following; marine application, super light weight rail car, or on the DYNO. Notice that all three examples are low load situations.
I would also like to point out that "desired max engine rpm" comes into play more than the heads being used. What rpm does the OP intend to turn the motor?
thanks for reading,
Rob @ modular
I have noticed that in the last 6 months I have been getting more and more questions about back pressure. It seems as if its the latest thing that my customers are afraid of when picking a turbo. I am sure that it is due to forum talk as it can influence people greatly. I would like to point out that back pressure isn't the "nail in the coffin" that it is made out to be.
Remember this, a turbo operates off of back pressure. Any turbo setup that spools up fast has a decent amount of back pressure. Back pressure = turbine wheel acceleration. Its the point that when the turbine stops requiring acceleration (read "desired boost level") that it can become a "CHOKE POINT" and I use these words loosely because you all have labeled them that way.
The following video is a SBC 406 with NO INTERCOOLER that is running an 87mm ind X 80mm exd turbine wheel S480 that flows almost exactly the same as my XT80. The only difference between the two performance wise would be the spool up. My turbo would spool up slightly faster since the wheel is 2.5mm smaller and power would be very slightly less for the same reason.
Also, I would like to point out that my inducer is 1mm larger which most likely fairly compensates for the very slightly smaller exducer size.
http://www.youtube.com/watch?feature...&v=5XcLfWh4uHo
http://www.youtube.com/watch?feature...&v=A4wXJQfKYxw
When I said crazy heads I was referring to heads that were VERY EXTREME. Your trick flows will not have issues with this size turbo whether its an ST80, XT80, S480, etc etc etc.
The only way you are going to hit 2:1 back pressure vs boost without extreme measures being applied is if its one of the following; marine application, super light weight rail car, or on the DYNO. Notice that all three examples are low load situations.
I would also like to point out that "desired max engine rpm" comes into play more than the heads being used. What rpm does the OP intend to turn the motor?
thanks for reading,
Rob @ modular
Last edited by ModularTurbo; 11-05-2011 at 11:31 PM.
11-05-2011, 11:56 PM
#46
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im with this guy about working with these kits lol, Im building offaxis's car and were convinced that whoever designed this kit was smoking some serious **** lol, although it is honestly the most complete and stealthy kit out there.....makes me love my truck manifold pt88 kit, sometimes the more simple design is the best
11-06-2011, 08:36 AM
#47
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thanks Rob. i was just looking for info as always. i dont see me turning more than 6800rpm. my cam is not that big
APS is not a bad setup at all its just i like too keep things simple. just like camaro383 stated
i have a buddy that has a old OFI hot side with a T6 flange. i might look into building some thing off that
anyone play with a OFI set up?
APS is not a bad setup at all its just i like too keep things simple. just like camaro383 stated
i have a buddy that has a old OFI hot side with a T6 flange. i might look into building some thing off that
anyone play with a OFI set up?
11-06-2011, 12:21 PM
#50
I thought the guy was asking for advice. You gave yours and I gave mine. Not sure how that muddles anything up. The turbo that you are recommending is better suited for a 370ci or smaller LSx motor in my opinion. I'm talking about an optimized combo here based on my real world experience assuming that the turbo has not yet been purchased.
11-06-2011, 01:24 PM
#51
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I thought the guy was asking for advice. You gave yours and I gave mine. Not sure how that muddles anything up. The turbo that you are recommending is better suited for a 370ci or smaller LSx motor in my opinion. I'm talking about an optimized combo here based on my real world experience assuming that the turbo has not yet been purchased.
your WG is pretty low.
11-07-2011, 02:37 AM
#52
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U want the most simple and effective way, jus get a couple truck manifold weld some vbands to themweld merge pipes and then just route the dp out through the passenger side so u wont need a turbo kmember unless ur running ac then u need to work with some different parts etc..and instead of using an intercooler just spray it lol ( and they call me the problem solver)... The only way u can have a kit that suits all ur needs is by making it urself or paying someone for your custom built kit the way u want it
11-07-2011, 06:07 AM
#53
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U want the most simple and effective way, jus get a couple truck manifold weld some vbands to themweld merge pipes and then just route the dp out through the passenger side so u wont need a turbo kmember unless ur running ac then u need to work with some different parts etc..and instead of using an intercooler just spray it lol ( and they call me the problem solver)... The only way u can have a kit that suits all ur needs is by making it urself or paying someone for your custom built kit the way u want it
11-07-2011, 05:42 PM
#54
Hey Tom, is just saw this thread. Im kinda confused why you think this kit is so hard to work on? I definitely don't have a lift in my garage, and I don't think mine is too hard to work on. I will be running (1) 50mm BOV off the charge pipe in front of the TB, so that eliminates the twin BOV's. My starter drops in and out in roughly 5 mins. I took out my complete pass. side turbo setup and back in a day when I had an oil issue. And I did not touch my K-member, and I did it on jackstands.
I will be doing a build thread on mine in roughly 2 weeks, so I will show everything. But I do get ya on the power part. I will tell you exactly how I feel about the ApS kit...
"I will run the APS kit till the turbos max, then I'm going to a PT88 frontmount."
Good luck man, let me know what you're decision is.
I will be doing a build thread on mine in roughly 2 weeks, so I will show everything. But I do get ya on the power part. I will tell you exactly how I feel about the ApS kit...
"I will run the APS kit till the turbos max, then I'm going to a PT88 frontmount."
Good luck man, let me know what you're decision is.
11-07-2011, 09:02 PM
#58
There are some tricks to get a big single to spool also, that is at the track not on the street although some of them can be applied there too. I'm also at the point where I'm looking to take a big turn in direction for my car. Not to interested in driving it on the street and streetablility is a relative term anyways that only applies to the individual. I could live with a PG if it had 3.08's and 28's. I could also live with a T6 turbo and the lag on the limited street driving it would see if it'd get me what I wanted at the track.
At least do what every american does, be greedy and when in doubt, get the bigger one
At least do what every american does, be greedy and when in doubt, get the bigger one
11-07-2011, 09:14 PM
#59
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i think the 402 will spool it ok. hell ls1curt only has a 383ci and things are working great for him. beside alittle lag at this power level might help it hook up lol
11-08-2011, 05:58 AM
#60
How fast do you want to go? It seems the aps kit has potential and you even have the better LG turbo's. AGFormula02 has ran 8.57 with his aps kit, a big single will spool slower and any way you look at it a turbo car is a pain in the ***.
https://ls1tech.com/forums/forced-in...-154-47-a.html
https://ls1tech.com/forums/forced-in...-154-47-a.html