Nitrous, who runs it?

[Dolomite_supafly]

I am building an engine that I would like to spray. Never ran nitrous before. I know I need forged pistons but I was told I needed custom "nitrous" pistons with the rings farther down.

Just curious if that was needed or if standard forged pistons will work?

Only shooting 100 hp shot if that matters.

[E4 No More]

I'd wager that MikeW would be the person to ask. He was heavily involved in the SVTOA website. I've known people that run 75 shot in hypertechtic piston engines. Personally, I'd do forged pistons and rods.

[Dolomite_supafly]

I am going to run custom, lightweight forged rods and forged pistons.

Was told I needed to move the rings farther down the piston to protect them. Still trying to figure out how it will burn up a set of rings without burning up the aluminum piston.

[E4 No More]

12 minutes ago, Dolomite_supafly said:

I am going to run custom, lightweight forged rods and forged pistons.

Was told I needed to move the rings farther down the piston to protect them. Still trying to figure out how it will burn up a set of rings without burning up the aluminum piston.

I'm not an engineer and only had supercharged GT500, but what I've read about the thermodynamics of the engine, (several years ago), is that the greatest heat from combustion is at the top of the chamber coming from the area where the spark originates - which makes sense to me because of advanced timing. I don't see how it would be possible to burn the rings. Have you thought of contacting the manufacturer of the pistons of choice? I'd think they'd know more about it than the average gear-head.

[No_0ne]

37 minutes ago, SWJewellTN said:

I'm not an engineer and only had supercharged GT500, but what I've read about the thermodynamics of the engine, (several years ago), is that the greatest heat from combustion is at the top of the chamber coming from the area where the spark originates - which makes sense to me because of advanced timing. I don't see how it would be possible to burn the rings. Have you thought of contacting the manufacturer of the pistons of choice? I'd think they'd know more about it than the average gear-head.

This.  The piston manufacturer can give you far better recommendations based on your particular setup than most anyone else ...

[No_0ne]

BTW, the primary reason for moving the top ring down in the bore is to increase the "top" land thickness, which is an area that is prone to failure under high cylinder pressures.  The prevention of "burning" rings is of little consequence, power adders drastically increase pressures in the combustion chambers, the ring lands are some of the thinnest areas near the top of the piston and are most likely to fail.  Pistons made for blowers, turbos, and nitrous injected engines are also normally beefed up around the bin boss areas for the same reason.  The use of forged pistons is generally considered a necessity in these applications.

Edited February 1, 2018 by No_0ne

[Dolomite_supafly]

Got it. BTW, this is on a 2.3 Ford four cylinder. Hoping to get to 200 hp with 100 shot for when I will be going in a straight line which will not be very often. Matter of fact I am not 100% positive I will be running nitrous but it is a lot easier to build it for it now than to rebuild it later.

 

[Sidecarist]

I think I remember you mentioning that you're building a Caterham Lotus 7. 200hp and that will be lively to say the least especially if it is getting the sudden hit from nitrous. Sounds fun!

[Fourtyfive]

My dentist....

[Alleycat72]

100 hp isn't much on a v8. Most stock engines will handle that. Ring gap for NOS is something you should look at.

 

[Murgatroy]

I ran a 250 plate on a small block Chevy back in the day. The entire rotating assembly was forged and it cost me a lot of money. While it might be true for folks running 500+ shots to have custom pistons for that purpose, I don't think it is required. I haven't heard of moving the rings down (there is a lot I don't know) but I have heard of using dished pistons to decrease C/R. Just like any form of forced induction, too high of a C/R can lead to detonation and your shiny inside bits escaping the engine in a very nasty manner. N2O is forced induction.

 

I don't think that 100 shot of the giggle gas will be enough to explode a built 2.3L Lima. I don't recall if you said you were going turbo with it or not. IMO properly sizing a turbo would be better than spraying it, however, a proper sized turbo with spray will mitigate lag.

[Dolomite_supafly]

8 hours ago, alleycat72 said:

100 hp isn't much on a v8. Most stock engines will handle that. Ring gap for NOS is something you should look at.

 

It is a 2.3 Ford four cylinder, not a V8.

[Dolomite_supafly]

 

11 hours ago, Sidecarist said:

I think I remember you mentioning that you're building a Caterham Lotus 7. 200hp and that will be lively to say the least especially if it is getting the sudden hit from nitrous. Sounds fun!

Should be fun, without nitrous it will be a little over 200 HP in a car that should weigh 1,100 pounds. I might even be able to get that weight with me in it. The frame weighs only 120 pounds, I can straddle the transmission tunnel and pick it up by myself. Engine and trans should tip the scales at ~600 pounds with an iron head. Then there is the 7 gallon tank, battery and seats. The ONLY things going in the car are what is required to run and to be safe.

Going to run lightweight, forged H beam 5.7" rods instead of the factory 5.2" rods. Pistons will be lightweight nitrous pistons. Factory crank. Everything should be able to handle 400 hp easily so there is room to grow. Going to get it sorted out before adding nitrous but plan on running nitrous, maybe a few stages.

And this ISN'T a drag car. It is a corner carver that will spend a lot of time on the Dragon. Adjustable coil overs at all 4 corners. 4 link rear. Manual rack but I might add a Saturn electronic power steering unit. I have a controller that lets me dial the assist. Wilwood dual master cylinders.

With nitrous it will have 300+ hp and should go low 9's @ ~140, if I can get it to hook. It will run a C4 with a 2.79 8.8" rear.

[peejman]

If it's gonna be a go-kart auto-x car, I'd be more inclined to turbo it rather than NO2. The turbo will be much more controllable from a throttle response perspective, particularly when you're talking 50% power boost.  Slow is smooth and smooth is fast. NO2 isn't smooth. 

I don't think the electric steering unit would be worth the weight and loss of feel. They're heavy and it'll likely feel like the column is made of plastic.  

[Dolomite_supafly]

I probably didn't word it right. The nitrous will only be used on a drag strip, not going around corners on a race course. If I want to take it to the drag strip I will throw the bottle in the car and go but most of the time it will not run nitrous.

You can actually get a controller to dial in the NO2 and how it comes on. It can be set it so it takes seconds for it to go from 0% to 100% of the shot. I know you can do the same with an electronic boost controller but I plan on running without a power adder most of the time. Only time it will get hit is in a straight line at the drag strip.

Talked to a lot of guys racing these kind of cars and if there is one thing they ALL said was do not add a turbo. The ass end is so light they said it would only lead to a car that is uncontrollable when the power comes on coming out of a corner. My original plans was for a ~300 hp turbo engine but they all said it was a really bad idea. I even have all the parts to build a turbo engine for it, which are now for sale. Another thing I am not to fond of is the complexity of a turbo engine as well as tuning it. It will also add cost because it will require a custom ECU to be able to tune. I want reliability, even at the cost of horsepower, and a turbo definitely adds complexity to the mix. I spent six months prepping and making parts to install a turbo engine but decided to listen to the guys who race these cars and go NA.

[MikeW]

   1100lbs will be fun! Using the 2.3 will at least help with traction. A V8 upfront would make the ass end crazy and a heavy nose in the corners. So your wondering if your ring gap needs to be set lower (wider) for a 100 shot?  As someone else said, your piston (ring) manufacturer will be the best source. I have heard people that run nitrous say that they run a wider gap, but too much of a gap may cause a blowby or other seal issues. If it were me (not the sharpest tool in the shed) I'd run a nitrous tune on my regular setup and spray it as is (wet kit)  . Especially if you're only going to do it on a drag strip, if ever. Heck Ive seen 100 shots on factory, untuned, cast piston cars/trucks that survive for a "good while".  BUT I've never seen it done on a 2.3. All of the 2.3L's that I've seen were SVO Mustangs (turbo).
What will your compression be? What tuning software? Suspension coilovers?

Do you have build thread on a site somewhere... I'd like to watch the progress.

[2.ooohhh]

I've run it on several builds I've worked on. The hardest thing with some forged pistons I've used with big nitrous setups is allowing for the thermal expansion. This can make them loud(loose) at startup, and require a lengthy warm up before driving. Not terrible for a track ride, but quite annoying if wanting to drive it daily. Tuning for a turbo or nitrous shot on track is far more than just the motor, many cars I've set up needed pretty extensive overhauls of spring rates and damping in the suspension to better handle the sudden weight transfer. As for control, I've worked with the max xtreme controllers from some guys in the UK that were pretty nice if they fit in your budget.

Wizards of NOS Controllers 

Here are a few fun shots of the builds my buds at FMU have done on a few BMWs(one dry, one wet)

[Sam1]

On 2/1/2018 at 3:19 PM, Dolomite_supafly said:

I am building an engine that I would like to spray. Never ran nitrous before. I know I need forged pistons but I was told I needed custom "nitrous" pistons with the rings farther down.

Just curious if that was needed or if standard forged pistons will work?

Only shooting 100 hp shot if that matters.

you're fine with any forged pistons.  If you get up to putting 40% of motor hp (and up)of nitrous through it, then you may want to consider going with the nitrous pistons for the differences in ring design.  Som epeople say 40%, some people say 50%, everyone has their backyard mechanic number.  I think it has more to do with the piston design itself and not necessarily a power level that should be the determining factor.  the thicker the skirts and ringlands are, the better.

Edited February 5, 2018 by Sam1

[Sam1]

On 2/1/2018 at 4:54 PM, No_0ne said:

BTW, the primary reason for moving the top ring down in the bore is to increase the "top" land thickness, which is an area that is prone to failure under high cylinder pressures.  The prevention of "burning" rings is of little consequence, power adders drastically increase pressures in the combustion chambers, the ring lands are some of the thinnest areas near the top of the piston and are most likely to fail.  Pistons made for blowers, turbos, and nitrous injected engines are also normally beefed up around the bin boss areas for the same reason.  The use of forged pistons is generally considered a necessity in these applications.

disregard my post, looks like no_0ne covered it