MPI Twins questions

That big of a difference between the guages seems fishy, I guess I'm set up different, but with the zz intake I don't see 50 degrees difference on the data logger between front and back.
 
Anthony mine runs 200 degrees differrence between the front to back. One reading off of the TST and the other on the guage. When I took the A5000 off and put back on the stock manifold and HTT they started reading pretty close to the same. The only thing I did differrent was I didn't use anti-sieze the last time. Don't know
 
MPI Twins

lcaad1249 said:
Right now I'm only running the Smarty TNT Revo and EZ on the lowest setting. TST hasn't been turned on. I seem to have good rail pressure although I can say I can't watch too much while the big turbo hits. WOW!! I can't run at WOT yet but I haven't seen over 1300 but thats also mainly cruising. We'll be installing head studs, injectors, valve springs, and dual CP3's later this week.

One other wierd thing I noticed was that I installed 2 EGT probes, one for the TST and one for my SPA gauge. The SPA is in the front half of the manifold and the TST is in the back. Seem pretty close temps at idle but cruising can be about 200 degrees warmer in the front half.
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EGTs were Never an issue. Something is NOT adjusted right or like Nathan said for possible problems. I had a 64/71/13ss not a 66/71/13ss unless you had it modded or something.
 
Boost

lcaad1249 said:
I mean it cooled down the front three 400 degrees. Like instead of the back three being at 1000 and the front being at 1200 the front three are now at 800. It's kind of hard to pay attention to everything but that was probably around 50 pounds of boost. It will hit 70 easily.
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I was running those at 52lbs of boost and that was the max. Dave at HTT and Nathan both said that was A-ok. Something really changed to get those at 70psi boost.
 
Joesixpack said:
That big of a difference between the guages seems fishy, I guess I'm set up different, but with the zz intake I don't see 50 degrees difference on the data logger between front and back.
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I was suprised at the difference too but under no load conditions both gauges read the same usually within one degree. Maybe at higher temps the error could be greater. Only reason I posted this new info was to show the difference I noticed with the Bladerunner.

OT-OF-Here said:
EGTs were Never an issue. Something is NOT adjusted right or like Nathan said for possible problems. I had a 64/71/13ss not a 66/71/13ss unless you had it modded or something.
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I've done a lot more tweaking since the original post. I never had it modded but as someone else replied to me the bore is different at the wheel than further forward on the turbo. I'm still waiting on switching around a CP3 before adding my dual CP3 kit and doing some real tweaking. Figured I'd do it only once.

OT-OF-Here said:
I was running those at 52lbs of boost and that was the max. Dave at HTT and Nathan both said that was A-ok. Something really changed to get those at 70psi boost.
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Currently it can hit 70 pounds quickly but the highest my gauge has read is 72. Nathan told me that this setup is efficient to around 80-85 so I haven't changed anything.
 
Something I thought of since my previous post

lcaad1249 said:
I was suprised at the difference too but under no load conditions both gauges read the same usually within one degree. Maybe at higher temps the error could be greater. Only reason I posted this new info was to show the difference I noticed with the Bladerunner.



I've done a lot more tweaking since the original post. I never had it modded but as someone else replied to me the bore is different at the wheel than further forward on the turbo. I'm still waiting on switching around a CP3 before adding my dual CP3 kit and doing some real tweaking. Figured I'd do it only once.



Currently it can hit 70 pounds quickly but the highest my gauge has read is 72. Nathan told me that this setup is efficient to around 80-85 so I haven't changed anything.
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My head and the exhaust manifold I provided with the twins to you had been Extrude Honed. They are slick as s.....t! I was told that will provide less resistance to flow than stock and that would account for a lower boost in MY setup using the same twins. Now if that accounts for almost 20psi difference I can't say but perhaps some others could comment on that.

I can tell you I never saw more than 1250egt at wot on the drag strip. Pulling or around town egts weren't ever an issue and it was really nice not having to watch the egt gauge no mater what I was doing with the truck.

From other posts on this thread and things you've said then another major difference in our two setups is I ran the Mitusa Gusher pump. I don't recall what you are running but the principle of the Gusher vs pretty much anything else is lower pressure with MORE volume. This is why I was really HIGH on the Gusher. No matter what condition or load you had on the truck my fuel pressure never varied even 1 psi. Mark Chappel was VERY impressed with it when I dynoed at his shop and he had his rail pressure setup hooked up on my truck at the time. At first he didn't think much of it as he said it is always easier to push fuel than pull it but after two days of seeing the Gusher do it's thing I believe he was more impressed with it than any of my other mods at the time.

I'm guessing by now you know you set the 40mm wastegate on that setup with that pitcock looking thing on that smaller pipe off of the big turbo. I'm guessing that thing is closed tight for you to see 70+ psi. If memory serves I ran it 1/4 to 1/2 turn open. I set mine while simultaneously watching the gauges that were hooked up to monitor drive pressures. That was the setting that provided optimum drive pressure on my truck which is why I wanted the external 40mm waste gate to begin with in my setup as that is the only way to tune your drive pressure and boost. I may be all wet here and certainly someone will take a swipe at me if I am, but my reasoning was to 1st achieve maximum drive pressure ratio's and then see what boost that left you with,.... and from what I learned while having that setup, which I thought was the mack daddy for all around doing everything you can think of with your truck, was that anything over 50psi is plenty good enough for boost. These guys running 80psi to 100psi are doing basically one thing with their truck.
 
OT-OF-Here said:
My head and the exhaust manifold I provided with the twins to you had been Extrude Honed. They are slick as s.....t! I was told that will provide less resistance to flow than stock and that would account for a lower boost in MY setup using the same twins. Now if that accounts for almost 20psi difference I can't say but perhaps some others could comment on that.

I can tell you I never saw more than 1250egt at wot on the drag strip. Pulling or around town egts weren't ever an issue and it was really nice not having to watch the egt gauge no mater what I was doing with the truck.

From other posts on this thread and things you've said then another major difference in our two setups is I ran the Mitusa Gusher pump. I don't recall what you are running but the principle of the Gusher vs pretty much anything else is lower pressure with MORE volume. This is why I was really HIGH on the Gusher. No matter what condition or load you had on the truck my fuel pressure never varied even 1 psi. Mark Chappel was VERY impressed with it when I dynoed at his shop and he had his rail pressure setup hooked up on my truck at the time. At first he didn't think much of it as he said it is always easier to push fuel than pull it but after two days of seeing the Gusher do it's thing I believe he was more impressed with it than any of my other mods at the time.

I'm guessing by now you know you set the 40mm wastegate on that setup with that pitcock looking thing on that smaller pipe off of the big turbo. I'm guessing that thing is closed tight for you to see 70+ psi. If memory serves I ran it 1/4 to 1/2 turn open. I set mine while simultaneously watching the gauges that were hooked up to monitor drive pressures. That was the setting that provided optimum drive pressure on my truck which is why I wanted the external 40mm waste gate to begin with in my setup as that is the only way to tune your drive pressure and boost. I may be all wet here and certainly someone will take a swipe at me if I am, but my reasoning was to 1st achieve maximum drive pressure ratio's and then see what boost that left you with,.... and from what I learned while having that setup, which I thought was the mack daddy for all around doing everything you can think of with your truck, was that anything over 50psi is plenty good enough for boost. These guys running 80psi to 100psi are doing basically one thing with their truck.
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I'd thought about your head being tweaked on but like you said didn't know how much of a difference it would make and easing the boost restriction.

Was that 1250 with your Flux 4.x or the 2.x or the EH tips? I ended up running Flux 3.4's. I know I currently haven't been over 1400 in the front 3 cylinders (checking recall). Back I would assume would be close.

I'm running an Airdog 150 currently and can pull it down some before having the dual CP3's installed.

When I talked to Nathan about my setup and getting a drive pressure gauge to monitor things he told me that drive pressures shouldn't be a problem till around 90# boost.
 
Response

lcaad1249 said:
I'd thought about your head being tweaked on but like you said didn't know how much of a difference it would make and easing the boost restriction.

Was that 1250 with your Flux 4.x or the 2.x or the EH tips? I ended up running Flux 3.4's. I know I currently haven't been over 1400 in the front 3 cylinders (checking recall). Back I would assume would be close.

I'm running an Airdog 150 currently and can pull it down some before having the dual CP3's installed.

When I talked to Nathan about my setup and getting a drive pressure gauge to monitor things he told me that drive pressures shouldn't be a problem till around 90# boost.
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It was with my Flux 2.5s that I dynoed at TST.

I'm sure the 150 AD is not enough. I never sold my S06 & TST and just those two alone with stock cp3 and stock injectors I can pull my 150AD down to 3 psi. That can't be enough for your truck iMO.
 
OT-OF-Here said:
It was with my Flux 2.5s that I dynoed at TST.

I'm sure the 150 AD is not enough. I never sold my S06 & TST and just those two alone with stock cp3 and stock injectors I can pull my 150AD down to 3 psi. That can't be enough for your truck iMO.
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Sounds more like a bad Airdog, IMO.
 
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