Hey Guys. Posted in Dyno section but thought I would post here as well. I've just finished my Nitrous Motor build. The old motor only made 420 rwhp n/a on almost the identical set-up except the custom Nitrous CAM swap. Anything else that changed is highlighted with **NEW**. Old LS2 block refreshed in 2012 with cylinders honed to 4.06 and together with custom Diamond Nitrous Pistons held up for 250 runs at 250 shot. Total 500 passes on the block. On tear-down cylinders were ballooned and piston #8 was cracked and 3 others were rocking. Cracked piston sent back to Diamond for analysis and request for stronger piston that could compensate for the longer stroke. They re-designed the piston out of billet, moved the ring-lands down to allow more material up top and added vertical gas ports.

Off to CHAMPION MOTORS for a new tune for the mods on Thursday then I'm finally racing!

The motor is obviously built for nitrous and I plan on hitting it with 250-300 shot on regular basis through the N.O. Plate. Personal Best run on the old combo was 10.05 at 137 on a 250 shot and NANO (1.5 - 60ft) in Oct 2012. Average times on the 250 varied from 10.2-10.4. Appreciate any feedback on the build or if you think this will get me into the 9s?.

2001 Camaro Specs

ENGINE (new May 2015)
**NEW** LS2 Block stroked to 402 c.i.
Callie's Compstar forged crank
Compstar H-beam forged rods
**NEW**Diamond custom billet nitrous pistons with gas ports
**NEW**Morel 5206 tie-bar lifters
**NEW**Custom Tick Nitrous Cam
243/258 .624 and .595 113+3
(Old Cam 228/235 at .598 lift and 114 lsa)
AFR 225 Mongoose Heads
ARP Head Studs
2.080 intake and 1.60 exhaust
Flows 320 intake and 250 exhaust at .600 lift
New stainless valves in 2015
**NEW** BTR .660" lift dual valve spring kit and titanium retainers
**NEW**Trunion Upgrade
**NEW**Trend 7.45 X .105 - one piece push rods

INTAKE
FAST 102 mm Intake and Throttle Body
100mm MAF
104mm lid

TRANSMISSION (rebuilt May 2015)
- Performabuilt 4l60E - Level 3
- Smart Drum upgrade

STALL
- Pro Yank 3600 stall (refreshed 2014)

REAR-END (rebuilt in 2013)
- Moser: 3.73 gear
- 33 spline axles
- true-trac

EXHAUST
- 1 and 7/8 inch Headers - catless
- Stainless 2 and 1/2 duals to 3 inch merge and Borla cat-back
- **NEW**Stainless twin 3 inch electric cut-outs off headers

 

Lots going on in that motor! Let us know how you make out when Kevin's finished tuning it.....

 

Don't have graphs yet but made 476 rwhp unlocked and 505 rwhp on a DynoJet N/A locked with 28 degrees of timing and cut-outs open.

On nitrous....

On old motor with 25 degrees of timing I pulled 13 on a 250 shot. I had the tuner give me a separate tune with 22 degrees of timing to give me a big window for use with my timing device which can pull 15. I pulled enough timing to match total timing on old motor configuration as a place to start

Run#1 - 89 and 40 pulling 10 spun on the dyno - had to get out only showed 100 rwhp gain and 92 mph
Run#2 - (changed tire pressure from 24 to 18) 89 and 40 pulling 10 showed 646 rwhp. Pulled plugs #4 and #5 which showed fuel looked rich and no timing mark.
Run#3 - 89 and 42 pulling 9 showed 666 rwhp. Pulled fresh plugs in same cylinders and fuel looked rich and still no timing mark.

No time for more dyno pulls. Clearly I need to lean it out and put timing back in it and I'll figure that out at the track and pulling plugs. We had 8 fresh plugs for the 1st run but with the aborted run that tainted the plugs. I'll pull all 8 at the track to get a good base-line. I'll post plugs on the weekend from last run - would not mind some thoughts on a good starting point for my next runs - plugs should be hotter at the track than on the dyno.....

 

.089 and .042 pulling 9 from 22 for total timing of 13 degrees on 250 shot. Made 190 rwhp. To me the plugs are rich and there is no heat in the strap - still see the coating on the strap. Question: Since this is on a dyno and not a full 1/4 mile pass, where more heat would be created, what would a good starting point be on this jetting? I feel I could put 1 degree back in which could clean up the fuel and see where that takes me. We gained 20 rwhp adding back 1 degree of timing on this run. Alternatively, should I could clean up the fuel and then starting adding back timing?

PLUG#4


Plug#5

 

fuel looks very rich. you need to pull a degree or 2 of timing and clean up the fuel before you start putting timing back in.

 

Leave it where it is and get a good 330 hit in.

 

I wouldn't do anything until you get to the track.
See how it reacts there and adjust accordingly.
I also wouldn't be chasing the perfect looking plug, instead tune it for MPH.
You can make yourself crazy chasing a perfect looking plug.

 

Finally got to the track! N/A ran a 11.35 @119.68 mph. I started with a 68 and 28 jet (150 shot) with 22 degrees of timing. Ran a 10.77 @ 127.34. Plugs showed timing just on the tip and fuel looked good. Then ran a 78 and 36 jet (200 shot) on 20 degrees of timing. Plugs #4 and 5 below. Ran a 10.427 @ 131.56 mph. I thought the timing looked a little aggressive so I pulled one and ran a 10.49 at 129.7 so seemed to like timing where it was. Just taking my time working up to 300 shot. Any feedback on these plugs - NGKR5671A-11 plug on all runs....

 

How big of as shot were you running at the track?

 

78 n2o and 36 fuel jets would be a 200 rwhp set-up.

 

Moving on up! 250 shot plugs. After pulling all the plugs for a couple of runs #5 continues to be my hot cylinder so I'm tuning off that. First time on the 250 set-up on a .089 N2O and .040 fuel pulling 11 from 28 for total timing of 17 degrees. Picture at top below. I thought the timing looked too aggressive but the fuel looked good. Next run I used a .089 and .040 pulling 12 for total timing of 16. Picture at bottom below. I thought this plug looked better on the timing - mark just on the tip and fuel looked good. We were running at an Old School Drag Event at an old Airport which is still used so has no prep and grass growing though the pavement. With such limited traction I was using a 1 second ramp starting at 30% and still could not hook up. Ran a best of 10.70. I can't believe this new motor with the Nitrous Cam that Martin spec'd for me. Every set-up so far is 3/10 faster than previous and I'm just using N.O. revised charting and plugs are really close every time. The Cam should really shine on the bigger shots. On the old set-up I was always chasing the tune and it seemed to change every time out! I'll get back out to the track next week and the 300 jets are going in for sure. Goal is 9s!

Anyone want to comment on the plugs. I think the set-up with 16 degrees looks pretty good (maybe a little lean?) but interested in others thoughts for sure....

 

That damn porcelain looks clean boss!!! I would like to think you need some full runs beam to beam without the traction issues to get a little better read on the plug but if you pull a degree out and the mph falls way off, sneak it back in and continue tuning.

The plug is only one tool as mentioned before. The mph and the vacuum(if you have a data logger) are the biggest two along with the plugs.

 

It looks like youre making really good progress.

 

Anymore updates?

 

Finally - tonight into the 9s on a 250 shot (.089 and .040 on 15 degrees of timing). Small ramp on the progressive at .2 starting at 65%. 1.48 - 60 ft, 1/8 mph 6.37 and 109.79 and 1/4 mph 136.72 and 9.95!

I have to thank Martin for this Nitrous Cam! It's night and day from the old cam. I just put in the (revised) suggested N.O. jetting and plugs are near perfect every time. The hot plug #5 showed a little too much heat so I would run 14 degrees of timing next time out. Pic of #NGKR5671A-11 plug below with 110 in the dedicated and a healthy dose of 110 in the Main Tank mixed with 94 octane.....

Martin - that optimized Nitrous Cam is an animal both N/A and on the juice. It's like a whole new experience with the jetting producing predictable and repeatable results every time! I feel I can now get this beast into the mid-9s on a 300-325 jet no problem on a 3850 llb car.

 

Congrats on the 9's! Its awesome to see the progress you are making.

What is the compression ratio of your motor? NORMALLY an 11 heat range plug would be too cold for a 250. It looks right on yours but I'm wondering if its not because of how lean it is. It might just be the camera angle that's making it hard to see the fuel ring. Try putting a little bit of fuel to it and see if it doesn't pick up? It might take some heat out of the plug. If you can't see any heat on it after putting some fuel to it, then we need to look at the plug heat range. Feel free to give me a call!

 

Compression is around 11:1. Interesting on the heat range of the plugs. I was recommended the 11s when I was saying I was running 300-350 shot. As it turns out, as per Martin, my cam was not able to injest that amount of nitrous so those big shots likely capped out at 175-200. That also explains why I was also chasing the tune as I would add more fuel for the bigger shot but the nitrous side would cap out and the overall tune would go rich. I'll definately try adding some fuel next time out and see how it impacts the plugs. On a side-note, on the old set-up on a 150 shot I ran a best of 11.1 at 124. Same shot last night on the new cam ran a 10.38 at 131! Then ran the 9.95 on the 250 shot. I'm just using your revised jetting charts which is getting me close but I also run NANO which may explain the need for more fuel. I keep posting because when I started out I would loved to have something to help me understand the tuning aspect - many people helped me out on this forum over the years! Thanks for the input....

 

I agree with Brandon. On a 250 shot with 11:1 compression, I'd most likely have a 9 heat range plug in it.

That will show more heat on your current tune, but as Brandon said putting a little fuel to it will remove some heat from the plug. You might try going to a -9 heat range plug, pulling a degree or degree and a half of timing to start with and giving it a half pound of fuel or go up a jet size to .042. You can always put that degree or degree and a half back in it, and/or remove the added fuel if it doesn't like it. Learn your engine and what it wants, and it will reward you, trust me!

Remember, nitrous is the medium in which we use to burn more fuel and fuel is what makes the power. Anytime you can burn more fuel and keep the tune-up "clean" you should always make more power and go faster.

 

Thanks Martin....that makes perfect sense. I'll try that next time out!

 

Congrats and welcome to single digits! I've read your posts w/your struggles over the yrs and glad to see you got it together.

However, I would think your mph would be a tad higher, even at your race weight. Looking at your mods, I saw that you had a 2 1/2" duals. That's a restriction for your setup as well, especially on the bottle. I see you edited your mod list and have 3" cutouts off of the headers now. Was those installed AFTER your pass?

By looking at the plugs, I would keep the #11 plugs in there, especially if you plan on upping the shot.