Late build thread. 94 rcsb street/strip

[jasonc]

Originally Posted by 850cummin

I definitely want to do both of what you mentioned. Would like to get some decent tires on it. And I would like to play with the traction bars/tire pressures to see what I can make happen with a 60 foot! Do y’all think i should run the boost just as high as I can launching it or find the best consistent pressure/rpm and stick with that? Like I said it was the first trip to test and tune and hopefully I’ll have some more data to play with this weekend if I can make the track again down here.

Leave at a steady consistant boost.
I'd shoot for 20psi on street tires and that big single charger.

[jasonc]

Ever thought about putting together as set of compounds? Makes things so much easier on a 12v.

[850cummin]

November 7, 2019 - YouTube Try that maybe that worked

[850cummin]

Originally Posted by jasonc

Ever thought about putting together as set of compounds? Makes things so much easier on a 12v.

Once I get real serious I thought about putting a 84 or 88 under the 72. But for now I am gonna have fun with it. It is my belief that I can get it down to 7.20s with some suspension tweaking, tire change, and bumping the timing to say 25 degrees. We will see here shortly. Honestly it isn’t really a pain in the ass to drive on the road. Sure you have to whip the rom up there before you lock the converter but I also love the simplicity of a single charger. Nitrous is a option for sure.

[850cummin]

In cab. 7.57 pass - YouTube
Here is a little in cab shot with no od shift. Ran 7.57 hauling a buddy with me. Tried to leave at 25 psi, btw it cut the same 60 foot as the 7.44 pass

[zachu812]

Originally Posted by 850cummin

Once I get real serious I thought about putting a 84 or 88 under the 72. But for now I am gonna have fun with it. It is my belief that I can get it down to 7.20s with some suspension tweaking, tire change, and bumping the timing to say 25 degrees. We will see here shortly. Honestly it isn’t really a pain in the ass to drive on the road. Sure you have to whip the rom up there before you lock the converter but I also love the simplicity of a single charger. Nitrous is a option for sure.

You should be able to get 7.20s no problem, I've got a cast wheel 72/83/1.0 that's been 7.0 at 6500lbs, little different setup but still. There's an 88 feeding it now, real fun setup.

Looks like the leave is pretty aggressive, I'd try what Jason said and leave at 20psi. See how it responds and adjust from there. On a similar wheel and tire I run 30psi front and 20psi rear, works well for me.

[Vincejax]

Originally Posted by 850cummin

In cab. 7.57 pass - YouTube
Here is a little in cab shot with no od shift. Ran 7.57 hauling a buddy with me. Tried to leave at 25 psi, btw it cut the same 60 foot as the 7.44 pass

Maybe try shifting sooner, sounds like its really falling off above 3600rpm or so. Stages fast!

[850cummin]

Originally Posted by zachu812

You should be able to get 7.20s no problem, I've got a cast wheel 72/83/1.0 that's been 7.0 at 6500lbs, little different setup but still. There's an 88 feeding it now, real fun setup.

Looks like the leave is pretty aggressive, I'd try what Jason said and leave at 20psi. See how it responds and adjust from there. On a similar wheel and tire I run 30psi front and 20psi rear, works well for me.

I’m definitely airing down next trip out. I bet your **** is a riot with a 88 under it . I believe I am dropping fuel pressure so I have to look into that. With me in it I’m 58-5900 depending how much fuel is in it so I know it’s fairly light. Next trip out we may have some better times, hopefully bumping the timing to 25 and fuel pressure issues have us held back. O and traction issues

[850cummin]

Originally Posted by Vincejax

Maybe try shifting sooner, sounds like its really falling off above 3600rpm or so. Stages fast!

I know how it sounds but damn it feels like it’s still pulling 3rd hard when your in it. I’ll try shifting earlier and see if I can get the speed up. Makes me wonder if at 3500-4K I’m dropping fuel pressure. I’m gonna sling a gauge on it and have someone monitor it on a wide open pull

[850cummin]

So after a month of chasing a issue we finally found the culprit . It spit the intake plenum gasket out under the stock fuel filter. Decided it was time to redo some ****. We were running a raptor 100 for fuel(I know not enough). So when I decided to add the raptor 150 dual feeding the pump, we also decide to move battery to bed! We mounted dual pumps with their own line/filter off the fuel cell. Each has its own line and filter Both are on a toggle in the cab. We moved battery to bed and put a battery switch/relay board under the bed in the back for the pumps and transmission fan. Sent a 2/o forward to starter and jumped from there to the fuse box. Now we get all this done and make a street hit. Charger is making 60 lbs, fuel pressure holds at 32 WOT. All is good. Well today we took it to the track(alabama) and made some hits. Out the gate it runs a 7.67 staging at 20 pounds it hops and acts stupid out of the hole. So we go to tire pressure. Next hit it does 7.69 with a 1.75 60’. Took some videos and turns out our front was lifting hard off the line. So we played with traction bars and bam leaving at 20, on 20 degrees of timing she ran a 7.41 at 94 mph. New truck record!!!! Then we get informed we’re leaking. Crap. We put it on the trailer and bring it home(suspected cam plug leak). Got her on the rack and yanked the trans out and it was definitely the cam plug. So we pulled the front clip and got the cam out and I’ll be dammed if it hadn’t walked 5/16 of a inch backwards. So now we’re on our way to a bolt in cam retainer and gonna get it ready for Milikens event March 13/ 14

[850cummin]

February 15, 2020 - YouTube

The link to a slow mo of the 7.41 pass. What y’all think? This was leaking on 20 lbs

[850cummin]

Leaving^^^^**** we got one hit in with the tires on 22.5 psi, timing 20, fuel 400cc, dual fed holding at 32 psi wot making 58-60 psi. She went 1.70 60 foot and ran 7.41. I believe there is still some to be desired with this setup without nitrous just by tuning the suspension. Stay tuned, hopefully she gets a coat of paint soon and a new truck record soon!

[850cummin]

Went back to the track this weekend with the timing on 26 and Cam issue fixed. Ran a 7.27 at 95.90 mph with a 1.64 60’. She still choking up at 4K rpm plus. So today we swapped the 1.0 housing on it and ditched the .90. Hoping to throw a little more fuel at it with the timing bumped to 26 and the bigger 1.0 housing on it. We will see it how she does shortly

[850cummin]

Well we tuned it down to 20 degrees of timing and moved fuel plate back to approx 240 ccs of fuel and dialed her in to run 7.70. Headed down to emerald coast for the spring shakedown. Ran it I. 4 different classes(Friday 8.0 index and heads up n/t) got put on the trailer Friday. Saturday we bumped tuning to above numbers and went number 1 qualifier with a 7.701. Cut good lights all night and made the finals. Was a damn good race but couldn’t make the cut. All said and done the truck had zero issues other than slipping the timing Friday. Met and hung out with some good folks

[zachu812]

Man you really had the truck dialed in for 7.70, sounds like a good weekend of racing.

[SPEEDSHIFT]

Originally Posted by 850cummin

Well we tuned it down to 20 degrees of timing and moved fuel plate back to approx 240 ccs of fuel and dialed her in to run 7.70. Headed down to emerald coast for the spring shakedown. Ran it I. 4 different classes(Friday 8.0 index and heads up n/t) got put on the trailer Friday. Saturday we bumped tuning to above numbers and went number 1 qualifier with a 7.701. Cut good lights all night and made the finals. Was a damn good race but couldn’t make the cut. All said and done the truck had zero issues other than slipping the timing Friday. Met and hung out with some good folks

It was good talking to you man, you were kicking ass for sure.

[850cummin]

Originally Posted by zachu812

Man you really had the truck dialed in for 7.70, sounds like a good weekend of racing.

We did. We knew about what it would run on 2 notches of fuel and afc full forward on 20 degrees. So we set it and made a hit went 7.55 running as hard as it would out the back door. Pulled in the pits between qualifying rounds and moved fuel plate a smidge and hit it right on the head! Ran 7.70s all night in 7.70 index and e.t

[850cummin]

Originally Posted by SPEEDSHIFT

It was good talking to you man, you were kicking ass for sure.

Thanks man. We ended up in the money. I should’ve split with the guy I raced but that’s inexperience for ya. I just didn’t think about it. Was a hell of a race for the finals. .038 margin of victory was anyone’s race