Single or Twin turbo? opinions from people with these please

Sonicblu0311

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man an 88 is huge on stock everything, i mean you have an auto but hows spool time? im pretty set on the Precision 7675 CEA especially since i can pick up a used one of LS1tech for $800-$1000 all day long, my friend just got a Comp billet 78/79 and it is rly nice but seems like its choking up on his engine (its a 6.2 LS) but i also think he should have an 88 on his since its an auto/6.2 car
 

w3bb3r04

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I have a 3v but I am running a single. It's at full 9 psi from 3000-3500 rpm depending on the gear. I'm running a 6765 cast wheel with an .81 AR from comp. Very satisfied with the turbo!
 

tt335ci03cobra

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That's good power for 9psi on a single 67 cast wheel, hell ya. Great spool too.
 

tt335ci03cobra

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Cool thing too about that 67/65 from comp is that its fully upgradable/ rebuildable if I recall correctly. I believe you can go as large as 7x/7x if its a t4 ct4 hotside (snail) with 4" outlet, 3" inlet. I could be wrong though depending on the model.
 
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RussZTT

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Twin 6262's here and wouldn't trade it for a single at anytime, and I have the Sully upper and lower. Car is very fun and fast. Numbers in the sig were with my 61's.

I drive it literally every single day to work.
 

tt335ci03cobra

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Russ am I right I guessing your 62/62's are comps? I'm on tapatalk so I dont know if more info shows up in your sig on the full svtperformance site. If you don't mind saying, which options did you spec up and what kind of power did you gain vs the 61's at xyz boost levels?

DD status ftw, who says big power can't last??
 

Sonicblu0311

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I was just looking into the cost of going twins and its a shame it seems to be a bit out of my price range for now since I can pick up a PT7675 for so cheap. I wish I could find a deal like my buddy got when going TT, he found twin precision 6262 CEA billet turbos for I think 1600 new for both. Its interesting to see everyone's setups. If people don't mind filling me in, what are peoples setups and how much power at what boost levels? And what are we looking at in terms of spool time? With my new setup and a PT7675 I'm hoping I can see full boost between 3500-4000 rpms and I plan to push as much boost as I can with 80# injectors and twin 255LPH pumps on a return system. It'd be nice to see between 700-800whp through a 6spd on pump but if I have to strap methanol injection on so be it.
 

tt335ci03cobra

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I think 660-750 is realistic on pump with alcohol or meth injection able to take ya close to or at 800 with a bit of boost. I don't know all of your supporting mods and am assuming stock longblock, if you have a worked block, higher cp, head work and or cams (any or all) then it'll make an extra 30-80whp give or take depending on combo etc IMHO assuming a healthy engine.

You don't need much timing with a turbo car from what I've seen but the alch or meth will just be a nice safety net IMHO. I'm prepping to go alch but still researching it.

Combo wise, we hit 885-920 on 20psi (5.5 though) (various minor changes) but had way too much back pressure using 57/48 t3's and 2.5" plumbing. New setup should easily make an additional 200whp at 24psi vs those numbers. T4 62/65's with 3-3.25" plumbing.

The 57/48's were great on low boost but after 12psi, they would get a little temperamental with back to back runs thru 4th gear.
 

RussZTT

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Russ am I right I guessing your 62/62's are comps? I'm on tapatalk so I dont know if more info shows up in your sig on the full svtperformance site. If you don't mind saying, which options did you spec up and what kind of power did you gain vs the 61's at xyz boost levels?

DD status ftw, who says big power can't last??
Thanks man. I was on my 61's with the 842rwhp and at 19psi, I haven't put it back on the dyno with the new Precision 62's. Currently I have a Teksid block, stock crank and rods with CP pistons with stock compression, stock heads and cams. I maxed out the injectors I have now so im waiting to get some new ones before I put it back on the dyno. I also want to try it with good gas too. :rockon:

I have had this turbo kit on my car for 4 years now. I installed it at 30K, now have 74K. Had to get one rebuilt, had to put new gaskets on the wastegates other than that, not a problem.
 

Sonicblu0311

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My engine is a 04 cobra block, 5.0L stroker, ported heads with oversized valves, stg 4 blower cams, and Sullivan upper/lower with accufab monoblade tb. I will have Sullivan rails, 80# injectors, twin 255LPH pumps in the return style hat and a static fuel pressure set at 50psi. I plan to set my wastegate spring to 14psi and run an eBoost2 and raise boost to 20-24psi if my fuel pumps and injectors will support that, and I may run methanol injection as well.
 

Sonicblu0311

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Just go on LS1tech, they only stay for sale for a day or 2 because its a great turbo for your a 346ci stock LS1 or even 6.0, and they get sold for bigger stuff. I have 3 friends locally that paid no more than 900 for their 7675s .... not exactly what I was looking for but its one of the first things in the search, each turbo is about 1000 a piece new, they were 1500 for both.... not too bad Precision 6765 Billet turbos - LS1TECH .... all day long is a phrase where I live and it basically is saying if I look at the classifieds often, they can be found, and ive seen LS1Tech usually is best deals
 

gt347mustang

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^ Oh, ok.

I took the phrase "all day long" as you could easily find them.

I'm in the market for a 7275 or 7675 and haven't see any in the f/s forums for under 1200 in the past few weeks. I guess I'll have to start looking on ls1tech now.
 

kweb288

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I got twin 255 pumps, stock long block with 01 intake, pt88 making 16.5#s of boost, on 93 octane, full boost by 3800 and made 627hp and 567trq through a 400 (would be different for u since its manual)
 

tt335ci03cobra

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RRcobra, with the long block you have, you should have no problem hitting 650-750whp IMHO. The high stage blower cams are probably too much for a turbo car but otherwise, your na motor is easily making 400hp at the crank so making 800hp (730whp) should be a cake walk with 15+psi. I've seen single 76 stock long block terminators hit 650-700 pretty easy so you should be solidly into the 700's easy IMHO
 

Sonicblu0311

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Yea I debating swapping out the cams but I dunno if I feel like doing that cuz then all the timing would have to be redone and custom "turbo" cams are pretty costly considering places like MMR won't share what the specs are, so its like why would I buy when I dunno what I'm getting. I thought of calling Crower or comp and having a set spec'd to my needs cuz I Rly don't wanna run a stock cam since I plan to eventually try and push 24+psi. I'd like to maximize power before boost to increase longevity.
 

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