Remember reading this:
From:
http://www.duramaxdiesels.com/forum/showthread.php?t=17335&highlight=14mm+studs
single vs twins please help im not trying to start a flame war
- Thread starter mplv
- Start date
Remember reading this:
From:
http://www.duramaxdiesels.com/forum/showthread.php?t=17335&highlight=14mm+studs
wouldnt the cheetah flow the same if not more than twins with a stock vvt
Are you talking Cheatah by itself or in a twin setup Larry ? In a twin setup a Cheatah is going to have a freeer flowing turbine side and comnpressor side so it should help a bit with drive pressure and be a bit more air . If your talking about the cheatah by itself outflowing the twins then no it wont , I dont know how the mapping changes with twinning but do know there is sustantialy more air with the size of the secoundary charger not to mention that the top turbo is still putting out/compressing air also so lbs per minute should be more and def more boost which in turn should make more power .
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the way I read it it sounded like the cheetah would not flow enough to be considered in a twin setup, hopefully someday someone with a cheetah will either prove or disprove this theory. Has anybody tried a twin setup with a cheeetah yet, if so were the results posted
, hopefully someday someone with a cheetah will either prove or disprove this theory. Has anybody tried a twin setup with a cheeetah yet, if so were the results posted
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the way I read it it sounded like the cheetah would not flow enough to be considered in a twin setup
Zach Kit seems to be working pretty good with his danville 2 and a S480 but his danville wouldnt ever flow on the exhaust what a HTT would . How much better than a stock VVT twinned truck with the same bottom charger ? who knows unless you literally tested it both ways same day, i dont think you will ever know . The only comlaint i have ever made against it was that it was alot of extra money to spend for not much gain unless the charger or twin kit was designed around it, point would be adding it to a GT 42 style kit the added turbine flow might not even help depending on if the gt42 could expell the extra gasses ?
I do know know what ever i did to improve turbine flow on my top charger it had little to no gain overall because my S480 would not flow anymore so the drive pressure loss was very minimal after a certain point . Now if you already have a cheteah It is a different matter
IMOP the bigger kits that use the T6 S4 series turbos it would be a decent upgrade but the smaller older style gt42 type kits i personally wouldnt do it . I wish some one would do some testing on it though to say for sure !
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I am working on this for Zach and myself. We actually installed the MPI kit on our shop LLY with a S480 over my 2.6 Stg2 charger. It is sweet how it all works together and the power delivery is amazing. Made a road trip to VA in it and the EGT's never went over 900 degrees pulling the hills. The small tune is 575rwhp and makes 40-50psi total boost. The plan is to make a stg3 charger just for the twins setup and it will be a gated housing. Got to get all these pulling trucks out of the shop and on the track so I can get back to this project. Will keep you posted but so far so good!
I can comment on a few different configs that have been on my truck.
I started off the new motor with the new Garrett AVT 3794 (same exhaust housing as the stock LLY charger i believe) or whatever it was a year and a half ago... and the MPI twin kit, which was a modified 42 series based charger T4.
Drive pressure as soon as i had the motor broke in and started turning the fuel up would peg my 100 PSI guage above about 2600 RPM. no bueno.
Then i started researching more.... and liked what i learned about both Cheetah and Danville. Lots of phone time and time spent reading about the chargers wherever i could to replace the Garrett i had just put on there as we had determined that it was part of the problem.
I chose the Danville stage 2 because from what i learned about the differences and similarities between it and the Cheetah, the Danville charger started as a stock LLY charger which, if i remember correctly, had a bigger exhaust side than the stock LBZ charger, which i believe (again, if memory serves) is what the Cheetah starts it life as.
Because of the modifications and wheels i was able to learn about going into the Danville i picked it. I drove my truck to Gillett for the turbo swap when the new Danville got there, and immediately with same tuning and everything else, saw a 20+ psi drop in drive pressure - down to the high 70s and into the 80s above 3200 RPM.
Some more tuning and i was able to get it to peak about 85 PSI total at 3600 RPM. Still too high for my blood, but definite improvement.
Then i put on RDL up pipes. Helped with EGTs for sure, and saw maybe a 3-4 PSI total drop in drive pressure with them. Still not enough for me....
Then the larger turbo took a dump and got pulled off and replaced with a 'standard' 4202 i believe it was (borrowed from SubMan!! thanks again!)
Drive pressure dropped about 10 PSI - even though was still same GT 42 based and T4 flange. so now low to upper 70's by 3600 RPM. still good improvement and improved EGTs!
Then I got the original turbo back, and boom - back to 80 PSI drive pressure. This time the turbo lasted about a week of daily driving and one night at the track. Was pretty well screwed at that point.
Nathan had been working on the new s480 T6 setup for the LLY. I think i got the first one of the LLY kit. Put that on, and poof - drive pressure down into the 60s and will hit about 74 ish at 3600 RPM, but total boost went up 12 PSI, EGTs went down 200+ degrees at WOT on big tune... sits around 1500-1600* by end of track now, instead of 1800* plus. Power is better. Everything is better.
However, now i'm back to the Danville stage 2 turbo. Everything i've tried to get drive pressure below the 65 - mid 70s mark is failing, and i believe it's simply because i've reached the limit on what the exhuast side on the smaller charger can flow. I still love the charger - from the whistle to the ease of spooling it up... but to safely move into some big fuel and dual fuelers (which of course will REALLY start stressing the exhaust flow) - i need to be able to vent more exhaust to the big charger. I don't believe i am able to drive the s480 to full potential.
Marks new stage 3 he's tinkering with i think will be the ticket.... gated VVT - so best of both worlds on that charger.
I may find that after dual fuelers are added, that i'll be needing to also gate the big charger - but at this point - i think it'll be just fine from what i know of it's performance for other people when it's spun to full potential (Trent being the one i've eye-witnessed)....
Anyways - there is my experience and the best comparison i have for anyone that might care.
I started off the new motor with the new Garrett AVT 3794 (same exhaust housing as the stock LLY charger i believe) or whatever it was a year and a half ago... and the MPI twin kit, which was a modified 42 series based charger T4.
Drive pressure as soon as i had the motor broke in and started turning the fuel up would peg my 100 PSI guage above about 2600 RPM. no bueno.
Then i started researching more.... and liked what i learned about both Cheetah and Danville. Lots of phone time and time spent reading about the chargers wherever i could to replace the Garrett i had just put on there as we had determined that it was part of the problem.
I chose the Danville stage 2 because from what i learned about the differences and similarities between it and the Cheetah, the Danville charger started as a stock LLY charger which, if i remember correctly, had a bigger exhaust side than the stock LBZ charger, which i believe (again, if memory serves) is what the Cheetah starts it life as.
Because of the modifications and wheels i was able to learn about going into the Danville i picked it. I drove my truck to Gillett for the turbo swap when the new Danville got there, and immediately with same tuning and everything else, saw a 20+ psi drop in drive pressure - down to the high 70s and into the 80s above 3200 RPM.
Some more tuning and i was able to get it to peak about 85 PSI total at 3600 RPM. Still too high for my blood, but definite improvement.
Then i put on RDL up pipes. Helped with EGTs for sure, and saw maybe a 3-4 PSI total drop in drive pressure with them. Still not enough for me....
Then the larger turbo took a dump and got pulled off and replaced with a 'standard' 4202 i believe it was (borrowed from SubMan!! thanks again!)
Drive pressure dropped about 10 PSI - even though was still same GT 42 based and T4 flange. so now low to upper 70's by 3600 RPM. still good improvement and improved EGTs!
Then I got the original turbo back, and boom - back to 80 PSI drive pressure. This time the turbo lasted about a week of daily driving and one night at the track. Was pretty well screwed at that point.
Nathan had been working on the new s480 T6 setup for the LLY. I think i got the first one of the LLY kit. Put that on, and poof - drive pressure down into the 60s and will hit about 74 ish at 3600 RPM, but total boost went up 12 PSI, EGTs went down 200+ degrees at WOT on big tune... sits around 1500-1600* by end of track now, instead of 1800* plus. Power is better. Everything is better.
However, now i'm back to the Danville stage 2 turbo. Everything i've tried to get drive pressure below the 65 - mid 70s mark is failing, and i believe it's simply because i've reached the limit on what the exhuast side on the smaller charger can flow. I still love the charger - from the whistle to the ease of spooling it up... but to safely move into some big fuel and dual fuelers (which of course will REALLY start stressing the exhaust flow) - i need to be able to vent more exhaust to the big charger. I don't believe i am able to drive the s480 to full potential.
Marks new stage 3 he's tinkering with i think will be the ticket.... gated VVT - so best of both worlds on that charger.
I may find that after dual fuelers are added, that i'll be needing to also gate the big charger - but at this point - i think it'll be just fine from what i know of it's performance for other people when it's spun to full potential (Trent being the one i've eye-witnessed)....
Anyways - there is my experience and the best comparison i have for anyone that might care.
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:thumb:Nice write up Zach and I can't wait to get the Stg3 out to you to see what it does for you. Should definitely help you out.
x2 Lots of good technical info. I'm very interested to see your results with the stage 3.