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Uhh, Allen Partin is made over 700 on a stock bottom L83 with a blower for a long *** time. Then went turbo and made nearly 850.
If someones breaking L83 rods at 650 its because their fuel system sucks or their tuner sucks.
I would like to what fuel system he has. I know there are options on fuel. Like LT4 and the high performance setup ($6000). Also cam and fuel lobe increase.
I made over 620rwhp but broke some parts. Blew out the exhaust flex joint. That is why I increased the turbo size.
I would like to what fuel system he has. I know there are options on fuel. Like LT4 and the high performance setup ($6000). Also cam and fuel lobe increase.
I made over 620rwhp but broke some parts. Blew out the exhaust flex joint. That is why I increased the turbo size.
Pretty sure he's got it all. DI fueling is expensive no doubt. He's allenp on here if you wanna pick his brain. 550whp range is about all the farther you wanna go on the stock system otherwise you end up breaking things.
I have wheels and tires now but it was 100% stock on the dyno. 265/65r18's. Stock suspension.
They're claiming 500-550 but even their test truck with a 76mm is only making 494.
The lt1 injectors flow 30% more fuel than stock but even the high side pump was running dry at anything over 527. It made more power but was getting sketchy on the fuel side. I think you will have plenty of air with your turbo. But their claim for 550 is a stretch. I was expecting to see over 550 with my injectors, boy was I wrong.
I haven't had it on another dyno to compare but mustang dynos are usually heart breakers. Mine might make 550 on a dynojet or one of the ones you see at car shows.
If I could do it all again I would leave the stock fuel system and just put a CAM in. There are trucks making 680 with a +32 fuel lobe on the CAM and stock fueling. I don't trust myself to do the work. CAM is only 900 but labor is crazy expensive.
Thanks for the addl info. I have LT4 pump(high side and in-tank[not sure this is even doable but I bought it on a whim long ago]), injectors sitting in boxes waiting. I figured rather than doing cam, I would install the 6.2 with cam already in it. Of course then the subject of a light build on the 6.2 came up. Because...stupid.
Honestly, until I get a couple of my other projects back running(so they could take some driving duty), I am probably happy with 475-500RWHP. With the heavy tires I am running, that's probably about On3's stated "limit." My priority has changed a little in the direction of getting this truck back on the road semi-permanently so I can stop tearing up the V every day.
Never use a flexjoint like this pre-turbo
If you have to use one, use a bellow like this style. They may still crack but they won't put metal into a turbo and potentially thru its oil return and into your pan.
I have the ON3 kit on my 2016 sierra denali. I now have the 76/75 BMF Gen2. I know a few things about these. I will say
Best not to wrap the manifold. there have been issues, not needed and waste. I have a egt just before the t4 flange max I see is 1200 on highway.
Best wires are the simple acdelco performance set Super cheap and then the titanium boots with the metal rings pull them on and zip tie the top. Never a issue for me.
Stock fuel is good over 550rwhp Few truck I know of are at that. I'm at 12psi now, stock WG spring is only 6psi so I was seeing spikes over 12psi. Have new spring as I have run 14 also. And BOV has yellow spring, was to stop the surge noise but just made it louder, may up the spring again.
I have a backup engine but think the stock block may hold for a little bit. I will add intake, tb, injectors and HPFP, oh and E85 just cause that is cheap PNP upgrade.
There is a l83 out there with 624rwhp and 620-650 is about where the rods break. Lt1 engines are better but even the lt4 fuel is limiting depending on goals and fuel type.
What stall do you have and what tuning software? No break out? Slip percents? Did you change the TCS?
I definitely liked the Taylor Firepower angle-boot wires better but have had terrible issues with the conductors pulling out of the wires; starting with those. Same with the ceramics. I may revert back to those and the boots if/when I have it all off another time in the future. Are you able to install/remove the plug wires with manifold in place without issue? I've done my best to respect the angle of the plug and still manage to lose at least two conductors each time.
I've foregone e85 for now as that in theory should lower the headroom of the fuel system(more volume required for same power output). Definitely going to look into it after I decide what to do with the fuel system long-term.
Stall and trans is stock. Geoff @ EPS did my tuning with EFI Live though I do personally have HP Tuners. We were going to run it a while and then get into trans tuning.
I do have a build 6L80 and a Yank SS2800 on the shelf waiting if/when needed.
Never use a flexjoint like this pre-turbo
If you have to use one, use a bellow like this style. They may still crack but they won't put metal into a turbo and potentially thru its oil return and into your pan.
The latter is the style on the crossover in the On3 system. The former is what I used in the section between downpipe and muffler. Both seem to be holding but again, I haven't gotten that deep into miles before blowing gaskets.
With 4 new gaskets sitting on the bench, I decided to just give in and try RTV only. It's basically against my religion if I had one, but the "right" way hasn't worked right? Both head and manifold surfaces seem to be perfectly straight and flat.
I used Ultra Copper as it advertises +50 deg compared to red RTV but also it's orange and just cooler-looking(and brand new tube in my toolbox already). Smeared on a relatively thin layer with my finger(two sheets of paper perhaps?), let it sit for a minute or two, then tapped it lightly with my finger over the whole surface to raise "hair" out of it and give it some depth. Gave it about 10 minutes to tack up a bit further while I hit the head lightly with a stiff and straight sanding block and then some acetone. (Did same on manifold before RTV.) Torqued it down while installing plug wires, and walked away. For once I am actually going to give the RTV the recommended amount of time before "returning to service."
I feel like I got a good seal this time; everywhere I had issues before there is zero gap and it looks like 99.9% of RTV pushed out and that is the result I was hoping for.
With 4 new gaskets sitting on the bench, I decided to just give in and try RTV only. It's basically against my religion if I had one, but the "right" way hasn't worked right? Both head and manifold surfaces seem to be perfectly straight and flat.
Did you have a machine shop deck those flanges? I would have recommended doing that before putting them on. Any warpage is always a bitch to deal with.
The latter is the style on the crossover in the On3 system. The former is what I used in the section between downpipe and muffler. Both seem to be holding but again, I haven't gotten that deep into miles before blowing gaskets.
I respectfully disagree well at least on the on3 part. the metal is thin so it will flex but they mount in right off the first elbow so it sees all the pressure. also if your back pressure is too high as mine was exhaust gas goes right into that gap you can see inside the pipe. The first one is a vibrant part and what I have now the metal is thinker and it is folded over it's self in a z pattern then the braided part never sees the inside. I have seen these pre turbo all the time at high end fab shops on 1700hp cars. They work great. I had a free flex sent to me by on3 and compared them before going with the vibrate. Oh and the vibrate keeps a larger inside diameter. Just my 2 cents.
Oh and what torque you putting on those head bolts? I read the factory specs and was like hell no. Made some calls and you wouldn't believe the amount I'm at.
Last edited by 2FAST4U; 12-03-2018 at 03:39 PM.
Reason: add
I respectfully disagree well at least on the on3 part. the metal is thin so it will flex but they mount in right off the first elbow so it sees all the pressure. also if your back pressure is too high as mine was exhaust gas goes right into that gap you can see inside the pipe. The first one is a vibrant part and what I have now the metal is thinker and it is folded over it's self in a z pattern then the braided part never sees the inside. I have seen these pre turbo all the time at high end fab shops on 1700hp cars. They work great. I had a free flex sent to me by on3 and compared them before going with the vibrate. Oh and the vibrate keeps a larger inside diameter. Just my 2 cents.
I think the use of cheap flex joints plays a big part in it, but I've seen multiple posts about people showing where a braided flex joint blew apart inside and took out a turbo. Enough that I wouldn't use one.
12-02-2018, 02:47 PM
