Nitrous limit ??

so what are the limiting factors on how much nos you can put to a motor ?? is it cubic inches ? cam? intake volume of heads ?? can anyone elaborate on this one

I do not think there is a set limit, I think each motor is different and based on all the factors you mentioned. i have seen as much as 400 plus on a 306 sbf 40 nos pill fogger, the guy kept spraying until it finally give up, there is a guy that runs a BBC in the Rengade class at Piedmont NC he sprays a 36 jet in both foggers. as long as it runs faster you keep spraying and keep tunning just hope you have money for parts.

I have heard the limit explained like this:

One size smaller jet than the one that just caused your junk to grenade.....

Greg_P wrote:I have heard the limit explained like this:

One size smaller jet than the one that just caused your junk to grenade.....

Yup and how ever much you as the driver can handle

My uncle is has a 500 shot, and is putting 2 more 300 on it, but it is a 636 Profiller motor

To me the limit is somewhat decided by the engines components... Block, crank, rod, pistons and so on.... The nitrous system being properly set up and tuned has a lot to do with the final output as well as the reliability as well.. Thanks, Steve

I have a 532 built to take all i can throw at it. How much nitrous can i spray before it stops making power? What determins the limit?
Thanks in advance for any input!

JoeH_88 wrote:I have a 532 built to take all i can throw at it. How much nitrous can i spray before it stops making power? What determins the limit?
Thanks in advance for any input!

Assuming the tune is correct, you don't break any parts, and have enough spark to get things lit, the exhaust flow will be the limiting factor as to when it will stop making additional power when more nitrous and fuel is added.

Exhaust flow in this case is more than just cylinder head flow numbers, it includes cam timing, header size, etc.

How much nitrous have you guys put through a 532?

JoeH_88 wrote:How much nitrous have you guys put through a 532?

what heads/cam/etc......... need more details

Most of the time its not what the motor will take but what you can get to the ground. We run a 28/24 jets at 6 1/4 fuel pressure and pull 6 out of the motor. we are able to get it all to the ground. Last weekend we had some 1.05 60' times. Its all in the tune up

bruno wrote:so what are the limiting factors on how much nos you can put to a motor ?? is it cubic inches ? cam? intake volume of heads ?? can anyone elaborate on this one

In one word....budget

Fuel and the mechanical limits of the components.

resurrect this topic please....

Given that there are a large number of variables that play a part in the "how much" question, I would like anyone that has had experience to let me know what they have found with amount of nitrous vs durability.
Do you see any obvious durability challenges in my combo that would restrict more nitrous?
How big can I go without an obvious challenge?

Current combo - 36 jet (about 350 shot)
Dove-A block - filled and 4-bolted w/ CAT splayed caps (stock bolts, studs where the windage tray is)
Lunati forged crank (4.5")
Scat H-beams w/ ARP 2000 bolts
Diamond pistons w/ H13 tool steel wrist pins (.185)
P51 heads w ARP studs (.088 quench - 11.55-1)
Innovative West balancer
2" primaries to 3" full exhaust (I know this is a restriction, but don't know how much) Personal best - 5.40@129.9 w/ 1.26 60' - 3400lbs

Buddy Thomas wrote: Last weekend we had some 1.05 60' times.

That's getting it!! that would make an awesome mud truck engine where we only run 100-150 feet. What's the whole combo consist of?

460Dave wrote:resurrect this topic please....

Given that there are a large number of variables that play a part in the "how much" question, I would like anyone that has had experience to let me know what they have found with amount of nitrous vs durability.  
Do you see any obvious durability challenges in my combo that would restrict more nitrous?
How big can I go without an obvious challenge?

Current combo - 36 jet (about 350 shot)
Dove-A block - filled and 4-bolted w/ CAT splayed caps (stock bolts, studs where the windage tray is)
Lunati forged crank (4.5")
Scat H-beams w/ ARP 2000 bolts
Diamond pistons w/ H13 tool steel wrist pins (.185)
P51 heads w ARP studs (.088 quench - 11.55-1)
Innovative West balancer
2" primaries to 3" full exhaust (I know this is a restriction, but don't know how much)  Personal best - 5.40@129.9 w/ 1.26 60' - 3400lbs

The only thing I see as of restrictions is the 2000 rod bolts (I would replace with new if they have a good amount of pass on them) and 2" primary headers with full exhaust.... IMO the 2" primaries are good to about 500 then they slowly start to be restrictions.

Also the thickness of the piston top also has alot of play in more nitrous ( first ring land to top of piston)

As stated above: header size, camshaft, quench distance, ring placement, and over all parts quality.

Camshaft is a huge deal. We have some guys spraying huge amounts on large cubic inch motors and its hard to even grasp some of the numbers we put in a cam. Not even comparable to small motors (under 588).

You will get to a point that adding more nitrous will not net you anything. Crazy as it sounds.

their is a formula that the nos gurus use I don't know what it is but I have an idea.cubic in X jet size or jet size verses cubic in not sure.

With big shots....pulling enough timing is the biggest deal.

Sho nuff .... ^^^^