Ice_Wolf

When I did the throttle body mod, it said to remove the secondary plates so I did. I'm not sure if the injectors are leaking exactly, because if they were, I have a feeling I wouldn't get as good of gas mileage as I am getting.

I did a compression test last October, and came up with like 98 PSI or so on both rotors. I have a N/A and it's only got 106k on it, so I'm pretty sure it's gonna have decent compression yet. I guess it wouldn't hurt to check it though.

I'm sure the injectors could use cleaning, but I don't have another car to drive right now to take them out. Is it possible to run fuel system cleaner through a rotary that's on pre-mix or is that going to cause problems? It's not that the fuel cutoff switch starts it, it's just that it starts easier with it it seems, but then again, I haven't got the chance to use it when it was -20 degrees, so I can't be for sure. If you're using a deep cycle battery, then why do you recommend using a starting battery?

Normal driving to me is daily driving, not exceeding 4k RPM's. I drive to get the best gas mileage that I can. Maybe I'll start doing 1/2 ounce per gallon then since I don't do much hard driving at all.

RotaMan99

I can't say for sure if it depends on how they are gumed up. Ex. can't completley shut or can't completley open. Maybe it does depend on this? Its always a good idea to get your injectors cleaned even if you don't have an issues. I say every 50,000 miles.

You have really good compression. Better then most. I would put my hand on the injectors possibly leaking.

same here. I noticed, if I only fill the tank to half, I get better MPG then if I haul the extra weight of the next 8 gallons. I get about 200-220 MPHT (miles per half tank) when filling to half a tank. Atleast I used to when most of my driving was highway. I now got a great job but im only on the highway for about 2 minutes, then im off the highway for about 35 minutes. Where it was the other way around before. So I have been getting 180-190 MPHT.

Ice_Wolf

Yea, I know the compression is pretty good, because the guy who had it before me compression tested at 79k and had like 106 PSI on each rotor face. I tested at like 96k and had like 98 PSI on each rotor face. If I get another car to drive, I'll send the injectors out to get cleaned.

I only use half a tank too. I can usually get 210 miles per half a tank without cruise control, so maybe if I get that hooked back up, I'll be able to get even better.

I'll make sure I switch to 1/2 ounce per gallon pre-mix to see if the car starts easier and get the injectors sent out to be cleaned ASAP. Also, I'll start looking around at starter AGM batteries and look at prices. Any other suggestions besides putting the cold start and BAC systems back in Aaron?

Aaron Cake

iTrader: (1)

I think that's half the problem with a lot of the writeups for this "mod". They don't properly explain what is being done, and why to do/not to do it. If the secondary throttle plates in the NA are working properly, they are open all the time when the engine is warm anyway. It's vacuum controlled.

If the injectors are dripping slightly, they are going to drip after the car has been shut off. The fuel collects at the bottom of the housing and then strips the oil film off the sealing surfaces next time the engine is cranked. Hence compression falls and the car is hard to start. The slight drip is not a problem when the car is running since the injectors are opening and closing rapidly anyway (and the fuel is being burned).

There's nothing you can do to clean the injectors while they are installed in the car. They need to be removed and cleaned professionally (using either ultrasonics or chemical cleaning processes).

I use a deep cycle battery because I have stupid habit of leaving my MP3 player turned on overnight. So I sometimes end up draining the battery.

Seriously, stop thinking about it and posting about it and just buy a battery. This thread is a week old. Not only has this all be covered before (did you search for "battery recommendations", "optima", "deka", "hawker odyssey", "deep cycle", etc. at all?) but your question has been answered several times in this thread. In the amount of time spent considering it you could have just bought a battery several times over...Time is money, how much did this thread cost you?

Ice_Wolf

Alright, that all makes sense to me Aaron and yes, I did do a search about it, but couldn't find exactly what I needed. I think I may go with a deep cycle battery too because sometimes I accidently leave my parking lights on, and I'm going to be building a stereo system for the car. I believe I've got all the answers I needed from this thread.

ericgrau

iTrader: (1)

NiCad batteries can't be used in a car. They are for power tools. They need a special charging circuit; your alternator won't do it. And anyway they're lousy. I'd say NiMH makes them obsolete in every way, including cost (again, NiMH needs a NiMH charger).

I'm still confused why anybody would care what kind of battery they use, besides weight and reliability.

This is just another daydreaming idea, but I was thinking of making a NiMH battery with built in charging circuit. It'd last virtually forever, be maintenance free and weigh 1/3 as much as a lead acid, but it'd cost 2-3 times as much as a lead acid battery (plus more on top of that for the built in charger). Anyway I believe it's quite feasible but I'm not gonna bother with it for a long time b/c I'm not interested enough in it for my own use. I'm just wondering if anyone else would be interested.

cluosborne

Don't forget that to ensure the longevity of a battery, when you store your car, you want to maintain the charge. For the record, I have an Optima Red Top--that I purchased in 2002 before the Johnson Controls acquisition--and use a Battery Tender during Winter storage and it has never failed. For my next battery, I'll probably follow Aaron's lead and get a Deka Intimidator (one is going to be in my brother's 300ZX eventually).

Never, ever, use a regular car charger on a battery to maintain a charge--it'll just ruin the battery. Regular car chargers are meant to charge a battery up quickly and keep charging it whether it's fully charged or not. A trickle charger brings a battery's charge back up to full and maintains it--which keeps it "fresh."

As for alternative battery technologies, I'm all for it. NiMH or Li-Ion or Li-Polymer are the most current--and more expensive than Lead Acid. NiMH, followed by Li-Ion are the most common (with Li-Ion being more expensive). Lithium Polymer is the most expensive of the three, but apparently (I don't know for sure) also has the most energy density.

There's a converted 4wd Subaru Legacy coupe that's all electric and setup as a race car with a top speed of 125MPH and a range of 100+ miles that uses Lithium Polymer cells. Watch out though, the battery pack alone costs them 20 thousand US.

ericgrau

iTrader: (1)

Looking at some batteries. It would be $300+ to make a NiMH pack with a 50Ah capacity (same as a lead acid battery). Probably another $50 to control the charging & discharging. Total weight would be about 15lbs. Weight of a typical battery is 36lbs., so you'd be saving 20 lbs. Compare that to spending $100 on an aluminum hood to save, what, 30-40lbs.?

Problem is I haven't found any large NiMH batteries at a good price. The above numbers come from AA's, which are the cheapest per Ah that I've found so far.

Hyper4mance2k

iTrader: (40)

I've gone through 4 optima yellow tops with in the past 6 years. I think they suck, but thank god my buddy works at the place I bought it ans I can keep warrenty exchanging the piece of *****. This is in multipule applications. new alts, grounds, pos and neg terminals, and these things last about 18 months tops...