Me and my dad were out last night and I noticed his exhaust was white. I didnt think anything of it till this morning and he saw it. Does anyone have any idea what your exhaust being white means?

Info, 94 FD running on 110 octane if that helps.

It has a racing beat exhasut sort of like this where the pipes are inside the two mufflers. the inside pipes are white

 

What does the exhaust smell like? White, sweet smelling exhaust is typical of burning coolant. I.E... bad water seal.

 

So if there was a bad water seal, the car would be loosing coolant? im about to go check the coolant

 

Is it smoking white or do you mean there is a white residue on the inside of the exhaust pipes?

 

Is the 110 leaded?

On subaru forums they seem to be asking about gas too.

 

Look at the picture I posted and you see how the inside pipes are like well normal color? those inside pipes are white on the fd.its like someone spray painted them white.(obviously not though)

Yes, its leaded.

 

Really lean would do that too, right? Maybe I'm losing it though...

 

well it could be.. but im not sure. i have yet to run it because im changing the spark plugs

 

When I've run leaded race gas in the past I had a whitish residue on my exhaust tip. Smells wonderful too

 

We just ran it on a back road and hit about 105 and it didnt blow up so i dont know. were gonna try and take it to a local rotary guy, JR. It sputters though or missfires, not the turbos the spark plugs, but the spark plugs are new.

yah the white stuff came back after i wiped it off. so it has to d wth the engine

 

all race fuel leaves that kind of residue. even when I ran 100 unleaded I had white exhaust tips. don't worry about it.

 

Whats done to the car to make you run 110??

 

Nothing major. basic bolt ons. 3" all the way exhaust, greddy intercooler, alot of greddy pipping. and 99' spec rx7 twin turbos. Its a really long story. He doesnt want to buy a boost gauge(mostly cause theres no money) and hes scared to run 93 with the boost hitting 15. Should he stop running race gas? if you cant tell me and my dad are new to rotarys. mostly me.

Btw, its the stock computer, and theres no main cat.

 

15psi of boost + stock ECU = BAD IDEA!!!! (is that even possible? fuel cut hits at 11-11.5psi depending on RPM iirc...)


How are you "saving money" by running 110 Octane versus buying a boost gauge? I should think you'd be able to purchase a good boost gauge with the extra money you are putting into that extra 17 octane..

Best insurance policy ever you can have for running high boost on standard fuel is an Auxillary Injection system. There is a sub-forum here dedicated to it. You should check it out. There are plenty of forum members who are safely running over 15psi on stock fuel by running AI, myself included (I run 17.5psi all day, every day on BNRs).


Read the forum and learn before you start modifying your car and upping the boost.

 

tell your pops to fork out the cash for a wide band and a boost gauge. think of it this way 200 bucks for the wide band, another 60 for a cheapo boost gauge Vs. $2500.00 rebuild. the choice is yours.

 

I would source a stock cat and a boost gauge ASAP before your next thread is "engine blown, what happened?"

Until you can get a PFC, i would stop driving the car, especially if you're hitting 15psi.

 

there are so many things wrong with what you're doing. i'm not trying to be a dick, but it sounds like you or the previous owner just slapped on a bunch of parts without researching at all.

how do you know it's hitting 15 psi without a boost gauge? have you hit fuel cut (the car would feel like it suddenly cut power off)?

don't drive the car any more until you figure out what your boost level is and get it under control.

You can get a good VDO boost guage for 30 bucks and you can make a pair of manual boost controllers for $25 in parts. You'll probably have to make restrictor plates for the exhaust system to increase resistance in order to get the boost back to normal since all that flow is probably enough to overwhelm the wastegate.

 

Ok dude step back for alittle bit.

1) How do you know you are boosting 15 psi without a boost gauge?
2) with all of those mods it is very likely that you have elevated boost levels and or spiking.
3) you need a boost gauge and a boost controller
4) Have your dad purchase a boost controller preferably the greedy profec B spec II. it has digital display that shows boost accuraely as well as controlling it. Note: If you get that you don't need a boost gauge.
5) When you get the boost controller keep the boost down to 10 psi and you will no longer have to worry about running high octane gas. But it must be 10 psi SOLID no spikes nor creep.
6) Spending money on race gas will be more expensive in the long run that just just doing it right now.
) if your pop is worried about spending $300 bucks on this car this is the wrong car for him.

 

^^Ditto that.. $300 is a small price to pay. For anything with these cars really...

I am not sure what 110 is around where you are but here it is FAR more than premium and will easily be the price of a boost gauge.

As mentioned above 15psi on the stock ecu (even if that is possible, I don't know b/c I have never used the stock ecu) is one of the worst things you can do with this car EVEN running 110 fuel.

I run 15psi on my 500R single turbo (more air than 15psi on those lil twins) and run 91oct (highest available here) and have great compression at my last check. BUT I have appropriate suppourt to do that.

We are not trying to bash you or your dad, but just trying to help you guys save the motor. Either way there is money that needs to be spent on necessary tools preferably before you pop the motor. And if you loose that motor, you will STILL need those tools installed on the car.

 

Ok, wow so many repsonses from a miss-type. Yes, there is a boost gauge, I meant to say controller.
As far as the fuel cut off the people who he bought it from somehow bypassed it or just did away with it, im not sure either way because it wouldnt spike to 15lbs if there was a cutoff. Now when he shift normally or up to 6k it goes to 12lbs, which is good, but the other night he went to 7k and it spiked to 15lbs.

So until he gets a boost gauge hes just not going to drive it that hard. Yes, hes going to go back to 93 octane. As as mentioned before about the wideband, I have no clue what that is.. someone explain? We havent put the car to any computer or no kind of tuning has been done yet.

So were not sure if its the stock computer, were just going off what the previous owner told us. which wasnt alot, he pretty much screwed the car up. As far as the white residue on the exhaust we checked the coolant and it was fine. So for now were assuming its just because of the race gas. Thanks guys.

 

yup. race gas = white exhaust tip.

 

A wideband O2 sensor is a device used for monitoring the air to fuel ratio. This is one of the tools that tuners will use to adjust the amount of fuel being sprayed into the motor. I am not sure if it is possible to bypass the fuel cut. Although I am sure someone more knowledgeable on the stock ecu will chime in at some point. To help anymore we need to determine if it is boost spiking or creeping that you are dealing with. Based off of the exhaust you mentioned it is most definately boost creep, and that cannot be controlled properly with just a boost controller. You will need to port the wastegate, OR add some restriction back to the exhaust. Do a search on here in to learn more about boost creep. It has been discussed hundreds of times.

If your dad does not want to spend the cash on an electronic boost controller then he can purchase much cheaper manual controllers but they are more time consuming to set up. Although like I mentioned, if the boost is creeping either of these will not help much. If your dad is so unwilling to spend a measly $300, then like mentioned by another member, this is DEFINATELY not the car for you guys. Parts are expensive and mistakes concerning boost are VERY EXPENSIVE. The rotary motor does not tollerate detonation well...

 

that is a HUGE f'in mistype.

I doubt you have a stock ECU given that it should hit fuel cut. Who knows what you have in there.. pettit, PFS purple box (A.K.A the motor eater), ect, ect,? Note no piggie backs are safe at 15 psi. You need to take a look at your ECU to see if you can find any identifiable markings. Who knows you just may have a PFC without the controller...

oo7arkman is correct it sounds as you are experiencing boost creep. A boost controller controls elevated boost levels as well as boost spikes, it does not do anything for boost creep. Do a search and educate yourself on what it is, and how to stop it

Ok you are doing it again please get your terminology correct. Boost gauge MONITORS BOOST that's it. A BOOST CONTROLLER keeps you at a safe boost level for YOUR car so it does not blow up. Big DIFFERENCE.

Drive it that hard? He shouldn't even drive it hard at all!

A wideband is not the smartest thing to get right now. Purchase it when you have a stand alone and are actually tuning the car.

It's very important that you mod this car correctly. Try and cheap out and the FD will teach you otherwise an heartbeat.

Good luck.

 

Well its not that he doesn't wanna spend the money he just doesn't have it right now. as far as the boost creep were gonna get that worked out with jr but what a alternative buying a main cat?

 

Make an exhaust restriction plate. Basically a metal gasket for the dp -> midpipe connection which does not have a 3" opening. Make it with a 2.5" or 2.75" opening (whatever is enough to keep the boost under control).