To Much TQ?

[MGSTANG]

My car A/F wise is safe with a 150 shot. Problem is, I have 452 TQ w/ it. It's only that high when it first sprays. Then drops a little, can a stock engine support it? I was using a 125 shot w/ no problem. So, can the 25 extra TQ really hurt anything? I haven't used it since the dyno, kinda scared

 

[mrvax]

Why not play it safe? Do you have money for a rebuild right now? What would you do if a rod came loose next week? I'd go w/ a 75 shot & a nice tune. PLUS, less refills.

 

[MGSTANG]

I've been using a 100 and a 125. A 75 shot is like nothing really

 

[hotmustang331]

Nothing? Its like the power betwen a 6 and a GT. Dang. lol How much RWHP? According to Tim 420RWHP is the limit he will tune a car to, doesnt mention torque.

 

[MGSTANG]

I had my v6 on a 100 shot and that held up just fine. I only have 344 on the 150 shot on a dynojet. With an SCT Tune. So, the TQ is all I have. I have 245 NA.

 

[MGSTANG]

Now that is with a safe A/F. 11.5-12.00 on the juice and 12.5-13.00 NA

 

[YtnGT]

I have played with 150 shot jets...
No damage yet...

I have only used about 40lbs with 150 jets. The other 120+ lbs were at 100 shot.

Just remember your rods are really storng with compressive loading but weak with pulling forces (rpms). So keep your rpms down to 5500rpms and don't spray to early. I usually set my WS at 3500-5800 with 150 jets. Oh yea be sure to use 2 step cooler copper plugs at .035" gap.

I would go ahead and invest in a wideband O2 meter for 100 shot plus.

 

[stangman]

My car A/F wise is safe with a 150 shot. Problem is, I have 452 TQ w/ it. It's only that high when it first sprays. Then drops a little, can a stock engine support it? I was using a 125 shot w/ no problem. So, can the 25 extra TQ really hurt anything? I haven't used it since the dyno, kinda scared

that's normal for nitrous to hit hard like that then drop off. you're fine as long as the tune is there for it. i've seen people running with 500+rwtq (with a good tune of course) & they are doing fine. the rwtq isn't what you need to worry about, it's the HP, so you're aight

 

[RedBullitt]

hehe i dont like the stock internals. just save up and forge that beast. then spray it like crazy. what about your rear and axles etc, how are they doing?

 

[SilverGTV8]

Auto or stick? you could be seeing convertor flash.

 

[96WhiteNight]

I have played with 150 shot jets...
No damage yet...

I have only used about 40lbs with 150 jets. The other 120+ lbs were at 100 shot.

Just remember your rods are really storng with compressive loading but weak with pulling forces (rpms). So keep your rpms down to 5500rpms and don't spray to early. I usually set my WS at 3500-5800 with 150 jets. Oh yea be sure to use 2 step cooler copper plugs at .035" gap.

I would go ahead and invest in a wideband O2 meter for 100 shot plus.

good advice

Do you have an upgraded fuel pump?

 

[mity2]

man u guys got nuts. 150shots? u'll blow weld on your intake....

 

[Justin03GT]

you only made 452tq with a 150? a buddy of mine put down 414hp/589tq on his 150 shot, ran a total of 50 bottles through the car, 30 bottles of 125 and another 20 bottles of 150...no issues what so ever.

here is his dyno sheet

 

[96WhiteNight]

Was this on a cobra?? Cause my buddy has a 97 GT with the PI's cams all the bolt ons with 3.73's and a 125 shot and is making 381 at the wheels around 415 i think tq

 

[MGSTANG]

Mine is an 04 GT 5 speed. It is with a safe tune, I've had it dyno tuned w/ X-cal 2. My A/F was fine on the dyno. I am very dissapointed with my #'s, kinda wierd an NX 150 shot only gave me 100 HP. But oh well. I am using Awsf 22c Motorcraft plugs. These #'s are from a dynojet. I only have 345 on the 150 shot.

 

[YtnGT]

good advice

Do you have an upgraded fuel pump?

I have the stock fuel pump.

On the 100 and 150 shot my wideband would indicate that a lean spike (sometimes a lean hump) would occur right after N2O activation. The spike or hump would rarely stay over 14.7 for more than .2 sec. Then it would go to say 13.5 a/f then 13.0, 12.5, 12.0 a/f. After a second or two you would be down into the 11 a/f range and sometimes (based off of bottle pressure) would drop to 10 or below.

Look at the graph posted by Justin03GT. You can see the hump in the HP curve (lower curve). That hump is usually caused by slightly lean a/f ratio. The oscillations after activation is the liquid N2O starting to convert to gas in the line, this will stop as soon as the line cools down (cooling happens quickly).

After doing a lot of research and talking to several nitrous "experts", I have come to the conclusion that the slightly lean (14.5-13 a/f) occurance at the beginning of activation and a little bit after is not an issue. The only reason you run rich with a power adder is to keep the combustion chamber cool. The excess fuel past stoichometric (14.7) is used to remove heat from the chamber. Nitrous definatly raises the combustion chamber temp and as long as a rich air fuel ratio occurs within 1-3 seconds after engagement the combustion chamber does not overheat.

What do you think

 

[MGSTANG]

I have the same thing on my dyno tuned 150 shot. I'm just worried that a 150 shot is to much hurt on the engine at that initial burst