rotaryhardcore

I'm trying to assemble as many tips and as much advice as I can on how to treat a daily-driven RX-7. So, if you've got some input it would really be appreciated.

-C

racer1

Drive it normal like any other car.

pianoprodigy

Don't get into boost until you're warmed up (I wait until at least 80C on my Microtech Dash Display)

Don't drive it hard with less than a quarter tank of gas (especially around corners)

technician

^^ exactly. I would only drive it hard after the gearbox and engine have completely warmed up. I think you could also prolong the life of the engine if you laid off the turbos unless you need them (she get's up to 60 just fine without the turbos!). After all, people are getting over 250K miles on the older generation's original motors...no reason why a 13B couldn't do the same.

dgeesaman

iTrader: (7)

For me, I go by my water temperature gauge - I wait until it's at 180F before allowing myself any boost. And if I need to boost a little, I try to keep it light and brief. I keep rpms under 3-4k.

If the first 5 min of your drive has any hills, or if you also drive in cooler weather, you need a boost gauge and/or water temp gauge to really know if you're boosting and how warm the engine is. Sometimes a feather's weight is all it takes to go from -5 in. Hg to 5 psi boost, and without watching a boost gauge you could be dumping a lot of heat into a cold engine and never know it.

Dave

95R2-89TII Ground Zero

go single turbo....that helps.

dgeesaman

iTrader: (7)

How does that help?

(Esp. considering single turbo owners always go higher HP, and higher HP will reduce engine life)

Snook

iTrader: (12)

remember its when people start to mod them they become unreliable. If your car is stock with the stock ecu youll be fine.

all the above is great info. water and boost gauge and always let it warm up and cool down before parking.

I would also not be going through all the gears at full throttle each time you drive it. Maybe once a week do that.


I daily drive my 7 it's my only car if I can do it you can...time for me to drive to the welder for my cutout hahaha

pianoprodigy

It seems to me (and considering I have a single turbo) that it is easier to control when you boost with a single turbo. I wouldn't consider my turbo to be horribly laggy, but it doesn't spool up under light throttle below 4k RPMs either.

When warming up, it is very easy for me to "stay out of boost" considering I have to make a conscious effort to apply generous throttle and therefore get boost. With a twins car, the spool comes much more easily and therefore would be much easier to boost when you don't want to.

Also, with regard to single turbo cars having higher HP:
Once again, I only make "high HP" when I want to. Although a twins car at around 15 psi could make the same power that I do at say 12 psi (my daily boost setting), the twins car would be much more likely to experience a greater load on the engine more often taking into account similar "conservative" driving styles simply because the twins will spool without much effort.

That's my reasoning anyways...I'm hardly an expert

pianoprodigy

Good point Surge. I used to occasionally run the car hard maybe up to 30 seconds before I park it and then let the turbo timer run for 2 minutes or so. Now, I try to actually drive with no boost for 2 minutes or so before I get to my destination so that air is actually flowing through the radiator and out the back of the car (through the trans tunnel area I'm told). When I used to park it and let it run for 2 minutes, temps would go up much more quickly because all the heat is being trapped under the hood with nowhere to go.

dgeesaman

iTrader: (7)

Sounds sensible. Thanks for the follow-up. But still, 15psi dumps a lot more heat into the engine than stock.

Marc01

You should remember as well, PSI is not a measure of what the turbo is putting out. A single turbo pushing 12psi may have much higher flow than the stock twins. Which means while your boost isn't high, you are still flowing a lot of hot air. I could be wrong though.

adam c

iTrader: (2)

Do the fan mod. I like to turn on the fans several minutes before I reach my destination. They reduce the coolant temps to 180, so the engine is as cool as it can get when I shut it down. This way, the engine doesn't "cook" itself and it sorrounding components after shutdown.

http://www.scuderiaciriani.com/rx7/fan_mod.html

Drive the car easy the last 2 minutes. Turn the car off when you reach your destination. Do not let it idle. That only creates more heat. Get a downpipe.

importrx7

That is very true, also your underhood the hood temps will drop a bit going single, and boost problems are a lot easier to address.

lopedl

iTrader: (1)

get a downpipe if you don't already have one, boost gauge, and temperature gauges are a must.

dgeesaman

iTrader: (7)

Right - I was referring to the higher heat output of the engine. Higher intake pressure equals higher intake temps, more oxygen available (and higher combustion rate) equals higher heat output. Plus the fact that most people running 15psi are running at higher flow rates.

All this is not just a reminder of the importance of a bigger intercooler, but how much heat is available to warp your block if you start cooking on a cold engine.

Dave

t-von

iTrader: (8)

Here's something....make sure you replace those fuel filters and spark plugs on a regular bases.

Bad plugs can lead to additional carbon build-up due to incomplete cumbustion of the air/fuel mixture. Carbon build-up is very bad for these engines especially if they sit up for very long periods of time. Personally with my last 2 Rx7's I've replaced them once a year or at 12k miles. Trush me all rotary engines like fresh spark plugs.

This may be overkill but, I usually replace my fuel filter at the same interval as my plugs. This will help prevent fuel starvation (bad for FI rotarys)because of clogging.

Lastly don't use tap water in your cooling system. You would be surprised how much longer your radiator and hoses will last. The minerals present in tap water IMHO are more corrosive than distilled/filtered water. With my two 1st gens, those engines were mainly filled with tap water and they had a ton crap inside them when they were flushed. With my 91 vert and my Fd I have always used filtered water. Whenever I flush the system in these two vehicles, the coolant comes out very clear and not cloudy. It's so clear that the old mixture looks re-useable. Stock Fd's are prone to coolant seals failers. With over 84k original miles, I have no leaks(who knows, it may just be the water I'm using).

Oh yea, don't baby the car too much. Let that engine rev in all it's glory.

REFLUX

I notice you have an FD as your avatar but I'll put in my 2 cents anyways (TII owner):

-do the regular maintenance regularly (regular being regular ROTARY maintenance)
-let it warm up before you bag it, if you drive it soon after starting it, keep the rpms low...~3000rpm & down
-once warm, redline once a day
-once you get close to your destination, take it easy & use the last few miles as a cool down. You can then idle it for a minute or so for extra protection

Mark'sMazda

psi=psi, it doesn't matter what turbo you have, the boost guage measures the presure in the intake manifold. What happends is a larger turbo heats the air less, since colder=denser, you have more air molicules your motor is taking in at the same amount of boost, w/a smaller turbo. Also, a stock turbo usually has 2-3x the amount of boost, as back presure in the exhust manifold. Larger turbo's will let the presure, and heat out far eiser than a small one. so, yes a larger turbo at low boost levels would/could make the motor last longer, while making more power. I think we are saing the same thing..i just wanted to make it clear

I agree w/what everyone posted, but would add a *good* set of guages, boost, water temp, and if you can afford it a wideband would be nice. and a silicon vacume line job, by now the car's vacume lines have been cooked, and are starting to get brittle. This won't have a huge effect the way the car runs and drives normally as it does have an air flow meter, but it will most likely give you boost problems.

also i have a theory on cracked/leaky vacume lines making the turbo's over spin to hold the desired amount of boost, killing the turbo way before it's time...the owners wouldn't notice, since the car is making the right amount of boost if it's not a huge leak. Also, this would cause the turbo to be way out of it's effiency range..over heating the air..hot air=bad

dgeesaman

iTrader: (7)

I can't say I agree with all of your theories, sorry. But the middle paragraph is quality.

Dave

Mark'sMazda

thank you for respecting my differnt view. seriously, there is way too much flamming and **** on this forum, and respectly disagreing just doesn't seem to happen online.

however my description on why a bigger turbo makes power vs. a smaller one is correct. I have a couple books, in addition to online research on turbos/turbo systems to back me up. The idea that a bigger turbo flows more, at the same amount of boost, thus makes more power is a myth.

driving a car with a missing vacume cap or two *will* cause the turbo to over spin, and will wear it out prematurely. That is a proven fact.

My theory however isn't a fact, but seems to hold air. With the old brittle vacume lines, if you have enough pin holes/cracks, they will add up to one big hole...

dgeesaman

iTrader: (7)

I do want to think this through.

The vacuum lines control the wastegate, precontrol, and other valves. Lacking vacuum (or reduced vacuum), they will all tend to underboost or fail in the 'off' position. If there is a scenario where the turbos get overdriven because of a leak in the control system, it's rare. The only things I can think of is a CRV sticking partially open, which would cause the secondary to run all the way to runaway speed as it dumps air through the airbox. A partially sticking CCV would allow the primary to run to runaway speed as it dumps pressurized air back through the secondary intake path. In either case, the charge air wouldn't get to the engine any hotter than normal, only at a drastically lower pressure.

Leaks in the charged air path could have the effect you're talking about - if you're pumping say, 10cfs (just a number) at 10psi, and you develop a leak losing 2cfs, then the turbos may be allowed to generate 12cfs at 10psi to supply both exit paths. I imagine this isn't too common, since most boost leaks quickly expand to vent all of the pressure. But that's not the vacuum lines you were referring to.

Dave

dgeesaman

iTrader: (7)

I'm still not sure what this means. You're assuming the larger turbo will produce the same cfm/psi as a smaller turbo, but requiring less pressure drop from the exhaust flow. Or do you mean that on the intake side, a larger turbo will create 10psi of colder air, which is better than 10psi of warmer air a smaller turbo would generate? Since this is a closed-loop system, it's very hard to make clear conclusions without experimental experience (or heavy duty theory). I guess I need to read some on turbocharger design to really get this. This seems to be a very complicated topic.

Dave

Mark'sMazda

I was wrong.

This is the idea i was refering to. I don't own an FD, thus ignorant to it's twin turbo's vacume system. I do not know what lines receive boost, which ones are check vavled, and what each line does.

I didn't mean to say the turbos will heat the engine bay, they will heat the intake air, too much in attempt to produce the same amount at the same cfm.

I apoligize for my poor wording, but you have the genral idea of why a larger turbo makes more power. I don't have the brain power to paraphraise an entire book's worth of knowledge into a couple posts.

http://www.amazon.com/exec/obidos/AS...958580-0734562

http://www.amazon.com/exec/obidos/tg...glance&s=books

most of what is in these books seemed to be common since after reading it. however, reading these sure made a turbo project sound fun.

dgeesaman

iTrader: (7)

Thanks for the links. People have been asking me for christmas gift ideas

Dave