Going to add 150 shot of Nitrous

[bcredliner]

I have been reading posts for several years about power adders. I had already gone to everything Dinan except the supercharger. I just couldn't justify the gain vrs. cost especially from 0-60. I considered a turbo and costed that out. Would cost less than supercharger, get about the same hp and torque benefits for about 3 grand less. Almost did that but problem was how long my 4.6 would be in the shop as it is entirely a custom install. Decided to add 150 shot of nitrous. This weekend will begin install with a Snow Performance M/W injection system. My favorite shop will then add a Nitrous express dry kit. The install will be such that I can use the M/W injection by itself but I can't use the Nitrous without the M/L injection. I have a dyno run as is. When we are done we will do new run as is and at the same time do a run with just M/W adder and then a run will all the adders. If there is enough interest I will post the results. I would love to hear your comments even if they are negative, and, if you would like me to post the results.

[Roadkill]

how many miles are on the car? have you done a compression test yet? sounds interesting.

[bcredliner]

Have just over 100,000 miles. No, no compression check. We are not concerned as oil has been changed every 5000 miles and engine is great design and just getting 'broke-in'. I bought it new.

[SlickGT1]

Damn post progress and results. I am curious.

[PropellerHead]

I think you're starting out aggressively on a 150 shot. Whatever you do, you need a progressive controller and a staged shot. Search for "JimLev Nitrous" for the right- and safe- gradual approach to get this done.

Now, your 4.6 with the 10.5 compression ratio- higher than JimLev's 4.4 at 10.0- is also ripe to grenade (run lean) if you do not find a way to deliver a LOT more fuel and a LOT more fire. Hopefully this injection system is up to the task. At 150, my prediction based on experience with E39 friends (similar M62 motor, nearly identical intake mani) is that you will disintegrate the plastic back end of your intake- the PCV. That is exactly what happened to a buddy of mine with a 100HP shot. The increased air had nowhere to go and this caused it to seek the path of least resistance- right out the PCV.

I don't know enough about the drive train to understand if it will take the power you want to add. I will only suggest that when BMW wanted to hop up a v12 X5 for demo/press purposes, it did so without the AWD running gear. If you don't grenade your motor, your transfer case may be the victim.

Nitrous CAN be done. It MUST be done safely, and after a TON of well mapped, gradual planning. It has a bad reputation because people want $8000 worth of performance for under $5000 and on the quick. They end up turning a few screws and blowing things up. No one here wants to see a nice X5 with an even nicer Alpina M62B46 motor blown to smithereens.

If the only difference between a nitrous install and the Dinan SC route is $3000, for a special car like the 4.6is that you have had since new, I would have absolutely ZERO question for my own choice:

I would go for the infinitely more tested and probably more reliable SC kit- Dinan or not. When you add all the $ spent on maintaining that car for the past 9 years, the initial cost to purchase it when new, a $3000 delta makes absolutely ZERO sense. I would spend the money so I could continue to enjoy my ride as I had since new.

[bcredliner]

Not starting with 150, will have 150 capability. Will start with 50 and work up.

Not going staged, will be on WOT. My sense is simplicity will be easier to control and keep constant and in the long run be safer.

Will not be a lean concern with Methanol/water injection coming in to support the Nitrous add. Will boost the octane, cool the charge and prevent lean condition. Will have to be careful about not getting too rich as more problems more problems come from rich condition.

Drive train handle SC and should not be a problem. Likely reason BMW didn't use AWD is the increase in the loss of hp and torque to drive all 4 wheels rather than concern for transfer case.

I didn't go into all the details we will be installing to make it a safe system--safe as nitrous system go.

Difference between this nitrous system and Dinan SC is about $8,000 installed.

If I was concerned with Delta I would have left it stock. I was looking at an X5m or getting more out of what I have. I am going to go this route first--just for grins and wows. Going for more performance never makes sense to me, I don't want it to make sense. I just want to do it because it can be done.

[PropellerHead]

Originally Posted by bcredliner

Not starting with 150,

Not going staged,

Will not be a lean concern

Drive train handle SC and should not be a problem.

I didn't go into all the details

Difference between this nitrous system and Dinan SC is about $8,000 installed.

I just want to do it because it can be done.

Looks like you have all the answers you require. Have fun.

[bcredliner]

Don't have all the answers, appreciate your input and will dial it in. Am concerned with running lean, that is reason for M/L. Will do the search and Please continue to test my assumptions, at this point that is all they are. I don't want to make an a-- out of myself and have to post that I blew the engine apart.

[JCL]

Originally Posted by bcredliner

Drive train handle SC and should not be a problem. Likely reason BMW didn't use AWD is the increase in the loss of hp and torque to drive all 4 wheels rather than concern for transfer case.

Reason BMW didn't use AWD on the Lemans V12 X5 is likely that the oilpan and the front differential occupied the same space. They never talked about it being rwd, in fact they seemed to want to pretend that it was still awd. I think that if there was any way that they could have kept it awd they would have done so.

[bcredliner]

entire cost of Snow performance system and Nitrous should total out at $3,000, which makes it about $8,000 less than the Dinan SC---$3000 less is an error in original post.