Engine Build Questions for 12v

murphy41

murphy41

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Jan 22, 2009
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What kind of pistons are you higher HP guys running? Whats your overall compression, ring end gap, piston to wall gap, etc... How much over all boost your running? I plan on running close to 18:1 compression for my single turbo application for my drag truck, but want some more opinions and input on other set-ups. Beings itll have extensive head work and only bout 50-55psi of boost I figured Id gain from running a higher compression. Whats your thoughts?? And ill maybe turn 5k at most, plan on running between 4-4500 rpm, so im not gonna need a big sloppy motor like most pulling trucks. Ill be mainly drag racing and pulling just for fun every once in awhile. Shooting for 850-900 at most on fuel, but will be spraying of course at the track to spool and what not.

Thanks,
Brandon
 
850-900 on fuel is a pretty stout motor, and trying to do that on street-able single is going to be even harder. You are almost looking into 13mm territory. You will have way more than 55psi of boost at 850hp with a 12v on fuel, even with head work and a cam. You will also be pretty hard pressed to be making 8-900hp on a single at 4500rpm... a single big enough to make that will need at least 5k.

How about lower fuel numbers, and spray to 850-900hp?
 
It wont be totally street driven, maybe 50miles to the track or dyno and thats it. I planned on a 13mm 850cc pump set at 650-700cc, I think Chris and I have decided on a 472 on my current 469 turbo just switch housing and wheel. I like the fact you pointed out my hp goal, I dont mind making 850 or so on spray but my 2wd is 680hp on fuel at 4500ft, so I figured with extensive head work,cam, and full build on the motor it'd make closer to 800 on fuel with the 72 and my 7x.015's at 3.2lpm? I figured with the 13mm pump, and everything else itd be way close to 800-850hp on fuel? Am i way off then? If so be straight up and tell me Im wrong. I am the one askin for the critisism. And this one will be 4wd, cage, suspension, etc. So it wont see much street time at all, this will be my toy and my 2wd back to pretty much stock/DD.
 
I daily drive my 469 form ED with the A/C on full blast at 4500ft elevation,with merely a haze all day long. Ive spent ALOT of time tuning though, but I know the jump to 13mm and a 72mm with be virtually impossible. Thats why I am building another truck to be strickly a toy. Thanks guys.
 
Why stop at a 472? I think the goal your looking for is going to be tough (fuel only) but im not going to say its not possible by any means. My truck doesnt like the dyno when I had the A5k and 093 lines. I read where Jim Fulmer says dynos dont like big lines to begin with. I still made 675hp 1191ft lb. With my race weight and quarter mile times the calc says its making between 748-751hp thats pretty close. I havent dynod yet with the S475 on. Id rather go fast then dyno high but thats just my 2. Just like guys would rather pull the sled farther then dyno high. If your looking to dragrace my question is how fast do you want to go?
 
Thats exactly what I was gonna say, Im not real set on a dyno number. But what I did was calculate the goal weight with me sitting in the truck, ET id like to run, over all gear ratio, rear end ratio, trap speed, RPM i want trap at etc... Ive spent countless hours calculating "approx" what HP its gonna take to hit my ET goal,, And thats a mid-low 10 sec pass. And the estimated HP was 850hp. At 4500ft here in Salt Lake City. Again that was estimated.

I think with the 472 will be a good overall turbo with the ETT wheel and .66 cover, with the extensive turbine work Chris did to the turbine on my 469 I have now , with a 50mm gate, and 72 wheel itd have the potential to hit 900+hp. spool better than the 475 and be more of a "gradual" power range than a hard hitting 475? But then here again that an assumption Ive never ran a 475, How does yours feel?
 
Feels like a silverbullet on roids the way it spools and as hard as it hits. No problem spooling it with a 1.0 theres a vid floating on here of my last run to show you how it spools.
 
Who built it? (turbo) What head work, cam, and turbine wheel?
 
How about your time slips. Best E.T so far, 60' times/, Trap speed, trap RPM etc. Just trying to do as much research as possible. Actually man, can you post up a run down of your set-up, including suspension mods if any?

Im gonna be sending the block off in the next couple of weeks if not within the month and want to keep researchin and hearing what other guys are having/not having sucess with. I think Ive found the pistons Im gonna run. Thier a non-intercooled Mahle with the bowls tightened up, and valve reliefs cut. With the head and block both decked at .010 each, itll put me at 17.5:1 compression which will also help with our high elevation. Considering the NADM event this weekend had an altitude denisty of 8500ft all weekend. Which is quite often. Lets hear if anyone has opinion on running a higher or almost stock compression??
 
murphy41 said:
It wont be totally street driven, maybe 50miles to the track or dyno and thats it. I planned on a 13mm 850cc pump set at 650-700cc, I think Chris and I have decided on a 472 on my current 469 turbo just switch housing and wheel. I like the fact you pointed out my hp goal, I dont mind making 850 or so on spray but my 2wd is 680hp on fuel at 4500ft, so I figured with extensive head work,cam, and full build on the motor it'd make closer to 800 on fuel with the 72 and my 7x.015's at 3.2lpm? I figured with the 13mm pump, and everything else itd be way close to 800-850hp on fuel? Am i way off then? If so be straight up and tell me Im wrong. I am the one askin for the critisism. And this one will be 4wd, cage, suspension, etc. So it wont see much street time at all, this will be my toy and my 2wd back to pretty much stock/DD.
Click to expand...

Ok, I was looking at it more like you were just wanting XXXhp. What you want is deffinatly possible. If your planning on going with a 13mm anyway, you are a big step ahead. As far as using a 472 I would think you would need something bigger, but if the guys from ED say itll be good, I would trust them. Personally I would spray it on the track either way, because for me NX is more tunable. It looks like you have a pretty good parts list so far, what are you looking for as a race weight?
 
I got my turbo from borg warner curtesy of the snedge man, sorry for the mix up I get all these mixed up lol. My set up is simple. Dddp comps, S475 1.0, kmp head o ringed with studs etc, hamilton cam hamilton push rods, cummins block stiffner in there, 12mm pump, Goerend trans built buy us, balanced rotating assembly, mahle marine pistons, water/meth, full interior except for the rear seat, only suspension mods are Rancho 9000's and the rear springs are clamped in the front, 35 in at's.
My last run was with a full tank of fuel like a knuckle head. With a quarter tank and me in it truck weighs 6900lbs so on this run it was a pinch over 7000lbs

60 ft was a 1.71 best I have to date is a 1.669
1/8 et 7.35
1.8 mph 95.22
1/4 et 11.535
14/ mph 116.58

The way it sits in the driveway it should go a 11.4x with the 60 being off a shade. That was the first time out with the S475 I was leaving around 20lbs where I usually try to leave around 24lbs.
 
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650-700cc's is too much, 7x0.015" are not enough, 75mm would be a better choice.
 
SPEEDSHIFT said:
Ok, I was looking at it more like you were just wanting XXXhp. What you want is deffinatly possible. If your planning on going with a 13mm anyway, you are a big step ahead. As far as using a 472 I would think you would need something bigger, but if the guys from ED say itll be good, I would trust them. Personally I would spray it on the track either way, because for me NX is more tunable. It looks like you have a pretty good parts list so far, what are you looking for as a race weight?
Click to expand...

Im hoping for 5000lbs with me sitting in it, and half a tank of fuel. Thats my "goal" though
 
Btp 2332 said:
I got my turbo from borg warner curtesy of the snedge man, sorry for the mix up I get all these mixed up lol. My set up is simple. Dddp comps, S475 1.0, kmp head o ringed with studs etc, hamilton cam hamilton push rods, cummins block stiffner in there, 12mm pump, Goerend trans built buy us, balanced rotating assembly, mahle marine pistons, water/meth, full interior except for the rear seat, only suspension mods are Rancho 9000's and the rear springs are clamped in the front, 35 in at's.
My last run was with a full tank of fuel like a knuckle head. With a quarter tank and me in it truck weighs 6900lbs so on this run it was a pinch over 7000lbs

60 ft was a 1.71 best I have to date is a 1.669
1/8 et 7.35
1.8 mph 95.22
1/4 et 11.535
14/ mph 116.58

The way it sits in the driveway it should go a 11.4x with the 60 being off a shade. That was the first time out with the S475 I was leaving around 20lbs where I usually try to leave around 24lbs.
Click to expand...

Thanks for all the information, will give me some more ideas as well. Thanks man, also what is your elevation by chance?
 
Smokem said:
650-700cc's is too much, 7x0.015" are not enough, 75mm would be a better choice.
Click to expand...

Ya the 7x.015s were built for my current set-up. They will be changed of course for the 13mm pump. And Ill ask Chris about the 75mm seens how Ill benifit from the air at my elevation. Thanks for the input too
 
Actually Smokem, did you mean 650-700cc is too much period,.. or for that injector?
 
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