Tommy42088

So I've got a 2000 silverado 5.3, gen 3 block, gen 4 pistons and rods, 243 heads, port, polished and milled, btr stage 3 cams, 4l65 tranny, 3800 stall, 410 gears with Minny spells, on e85 with aeromotive pump and truck on giving me 14s, am I missing something? I feel like with everything on the truck I should easily be 13s, so I hooked up a nitrous outlet 150 shot and when I spray the truck just spits and sputters. Truck has a solid tune so I don't understand what's the issue

Tommy42088

Any help on this??

Kawboom

Is it a dry or port fogger wet kit? Are you engaging the nitrous at the right RPM, with timing retard in your ECU?

Tommy42088

Wet, it's a nitrous outlet plate kit. Rpm and tps activated by nitrous outlet windows switch and timing is being pulled by lnc2000. Everything is activating, the truck just spits and sputters when it engages

Nitro Dave's Nitrous Outlet

iTrader: (25)

Good morning,


What spark plugs are you running? What gap do you have them at? That is where I would start. NGK BR7EF is a good plug for your setup, gapped at .032 to start with.

Tommy42088

Your the 2nd person to tell me that, i actually just ordered those plugs and received then yesterday. I have ngk plugs in the truck already but I didn't change the gap. Someone else told me Gap to 25 and you say 32, how is it determined what gap to set? I'll do the 32, I just want to understand why I'm doing it

Nitro Dave's Nitrous Outlet

iTrader: (25)

There are a lot of factors involved in choosing plug gap (ignition type/strength, head design, fuel type, cylinder pressure, etc.). If your gap is too small, you could be giving up efficiency, and if it is too large, you may have spark blowout or misfires. We have found that most LS based engines mild to moderately modded with 150 shot run well on .032 gap.

Tommy42088

Oh ok I see, it's a 5.3 gen 3 block with gen 4 pistons, 243 heads, port, polished and milled. Btr stage 3 cams with dual springs n trunion upgrade on e85, fast 102 intake

Tommy42088

My tuner is telling me my intake is to much for my cam as well, because I have the 102 mm intake and throttle body and the cam I have is a truck cam that's good to about 6200. He telling me I need a cam that can push higher rpm and possible down size my intake

Forcefed86

iTrader: (4)

Missing a lot of info here, hard to pinpoint something.

N20 is super simple. If the car runs well without it, and falls on its face when activated... the N20 is likely not flowing. You need to test and verify it is. If N20 and Fuel are spraying… then what ever you are using to retard timing is wired incorrectly or not setup right. Disconnect the fuel and N20 and test the kit’s timing retard device on its own in that case.

Lastly, your intake may be less than ideal, but has nothing to do with the nitrous not working well. A btr stg 3 will pull WELL past 6200 on a 5.3. What are the cam card specs? You should rev that combo out to 7000++ IMO. In general, the higher you rev it and the longer you wait to spray the better.

Sounds like you may need another tuner... Also if you "Test" the N20 with the engine not running be sure not to try and fire the engine with the manifold full of nitrous. Give it time to disperse.

Tommy42088

218/224 .553/.553 110+0, is the cam specs, and it's actually 2 separate issues. The motor isn't performing as I expected on motor and my tuner told me the 102m intake was basically a bad combo with the cam. I dropped it back off to the tuner, he's putting it back on the dyno and suggested I need a different cam that revs higher and then with the nitrous. I tested the solenoids to make sure they are engaging, I even disconnected them and sprayed the nitrous into the sky. And I'm using a lnc2000 for timing and it's very simple to wire up. My nitrous outlet windows switch is what supplies the power for timing to it and I can tell it's pulling because when I disconnected the solenoids and Rev the truck up like that it runs like the timing is retarded. I have it at 6 degrees because it's on a 150 shot

Tommy42088

My Rev limiter was set at 6200 with the tune so that's why I mention 6200

Forcefed86

iTrader: (4)

Want to say I’m not here to argue, just want to see your setup run well. And what your tuner is telling you sounds suspect. Or at least how the information is conveyed doesn’t make sense.

What intake is on the car? 102mm is the TB diameter. Once its open, its open. The less restriction there the better. A 102mm TB isn’t going to cause issues with WOT performance… or your power adder. Only drivability… esp if it’s a cheap/poorly made TB. If you have a short runner cheapy intake, this will cause the performance below 5500-6000 to drop well below what a factory intake manifold would be, BUT it will still make great power once you smack it with 150 shot. It WILL NOT cause it to “spit and sputter”.

Poor NA performance can be due to several things… converter slip, vehicle weight, poor 60’ and 330’ times etc… What it your 60’ time? What does it weigh? What is the trap speed?

IMO, your limiter is set WAY too low for any factory small bore LS. Bump the limiter to 7500. Try shifting at 6800, 7000, 7300. And see if it picks up a ton. You need to remember there is likely a "soft limiter" generally set about 200 lower than the hard limit. I've seen 500 rpm soft limiters... So if your set at 6200 for the hard limit... it may start the soft limit as low as 5700. Also when it "spits and sputters" what is the RPM doing? Could it be blowing through the converter and hitting the limiter? What does the converter stall to? brand and specs etc?

I'd get it ironed out NA first. Then address the N20 issue.

Tommy42088

I'm definitely not arguing either, if it came off that way then that definitely wasn't the intention. The intake and throttle body are both 102 mm and drivable is good. It runs and drives great. I just feel like with the amount of work I've put into everything that it should be performing much better then it is. I'm not exactly sure on the weight, it's a single cab 2000 silverado. The converter doesn't slip, it's a 3800 stall. My 60 foot was around 2.2, and as far as the nitrous goes, like it completely stalled and stuttered when it engaged. Someone told me it was my spark plug gap but my tuner is telling me that wouldn't cause that. Maybe something just shorted out I'm assuming but I was thinking of switching the cam and I'll definitely raise the rpm. My tuner is suggested I put a stock ls intake on the truck. He done good work for me so far and been very helpful but I just wanted a second opinion because I see guys with similar setups that perform much better then mine.

Forcefed86

iTrader: (4)

Not at all, I just didn’t want to come off as a forum commando telling you what to do in a rude way.

What brand/model is the intake manifold? Are you saying it’s an LSX FAST 102MM intake? If so, there is zero reason to change that. And if the tuner is telling that or the cam will cause spitting/sputtering with nitrous activation.. Don’t use that “tuner”. The FAST 102 works almost as well a factory down low and makes decent gains up top.

Plug gap can certainly be an issue. That’s quick and easy to trouble shoot. Gap them at .015 and try it. If that solves your issue, bump them up .005 at a time until spark starts to blow out again. I generally gap small and don’t worry about the few HP lost in doing so.

I understand the converter may be advertised at 3800. But if you stab the throttle from a stop does it actually stall to 3800? If so that should work well. But I doubt it does.

A 2.2 60’ is pretty bad. Do you run a drag radial tire? If not I’d start there. Leaving a half second or more on the table with a 2.2 60’. For every tenth you knock off the 60’, you gain 2 tenths in the ¼ ET.

Post your slip. Really MPH and weight will tell you power, not ET. Try to weigh the truck with you in it and a full tank sometime. At the track, truck station, dump etc… What is it trapping? Trucks are VERY heavy. 2000 single cab is listed at 3900-4400lb curb weight. Then add the driver weight. That’s a TON of weight to move. I also wonder about the gear choice. With such a low limiter are you able to finish the ¼ in 3rd without going into overdrive?

That cam will pull to 7k with good springs and a 150 shot no problem. It may not peak power wise over 6500, but it will carry the power fine. I’d stay away from the tuner for now. Try the plug gap, and work with what you have instead of throwing expensive parts/labor at It right away.

Tommy42088

it will stall till about 2600, and he's telling me the cam and intake together isn't working well together, not that it's the sputter problem but that's its the reason that I'm losing low end power, and I have Mickey Thompson et streets on the truck, honestly on the street it spins pretty bad but on the track it hooks fairly decent, my reaction time was like .4. I left the slips in the truck but on motor it went like 14.4 at around 90 mph, im out of town so there not readily available but its Very disappointing and as far as gears it's a 4l65e tranny with 410 gears with Minnie spool, and it doesn't see 4 gear on the track, and I have dual springs and trunion upgrade as well, and the heads are port polished and milled. I will weight it whenever I get to a scale. Also the truck is on e85. Idk if that makes a difference in my gap or not.

Forcefed86

iTrader: (4)

I’d have to argue you don’t want to focus on low end power if you are drag racing. You want the focus on power above the torque curve and get the car into that zone as quickly as possible. That said I’d guess you’re down about 100hp from where you should be.

2800rpm isn’t enough to launch “hard”. Luckily you have 150 shot to offset that down the road once everything is ironed out. The intake and cam will easily get you into the 13s with a good tire and more power off the line.

The Fast 102 and TBSS or prior truck intake manifolds all performed very similar up to 6k. The Fast makes a decent amount more above. No reason to change that IMO. Down the road I’d want a larger cam and looser converter. But I’d get it working correctly first with that you have. I’m sure it has quite a bit more in it “as is”. Throwing parts at is when its not running right isn’t going to change much. The combo you have will run much better, something is “off”.

90mph @ 4500lbs puts you at 253 HP. That’s about 100hp off where you should be I’d guess. You may be heavier than that, but it still seems down on power.

What ECU is in the car? Id go back the basics. Do a compression test. Get a timing light and make sure the timing is sync’d properly to the ECU. I just built a car that was WAY down on power. Come to find the timing was off 12* between actual timing and what the ECU displayed. If your tuner doesn’t have a dyno, might look for one that does. Much easier to see what’s going on.

2.2 60’ is bad for a drag radial. For reference my 275 street tires would routinely pull 1.9 60’s in a 3500lb gbody. That alone would get you into the 13s. You should be closer to the 1.6 range with a good set of drag radials and decent suspension.

E85 will be slightly harder to light off, but shouldn’t be a major issue. Again, just gap plugs at .015 to eliminate the possibility of blowing the spark out. You can always add gap back once the combo is ironed out.

Once you figure out the missing power issue NA. You shouldn’t have to pull timing with a 150 shot on E85. Most don’t. I’d try a 50 shot and eliminate the “timing retard” device. See if your Sputter goes away. Work your way up to 150 watching the plugs.

Tommy42088

see that's what I was thinking with the rpm thing as well, 6200 seemed awful low. He does have a dyno. Also its a factory ecu, its tuned through hp tuners. I'm wanting to get the truck to some point in low 11s, even if I have to change some things around or whatever it takes. Buying the parts isn't an issue but buying stuff with no results is definitely a different story. But I'll definitely check all those things and when I get it sorted of ill repost an update.

Forcefed86

iTrader: (4)

Another thing to check is if the cam was degree’d correctly when installed or just thrown in “Dot to Dot” and not checked. Had a cam that was 8* retarded when installed dot to dot. Simply degreeing the cam to the card net me 12 MPH Increase at the same boost.

What kind of power did it make on his dyno? What kind of timing? Even if that setup isn’t “perfect”. It *should* make every bit of 400crank HP NA. If it doesn’t, its not the parts IMO.

Tommy42088

turned out to be the knock sensors and a vacuum leak at the map sensor. The truck normally pulls 32 degrees timing on e85 and it was only pulling 12 degrees. Charts were scattered all over the place from the knock sensors. This is what my tuner explained to me. So he's fixing that and re tuning it. Power was only at 283 so you were pretty spot on with your guess.