Anyone running low boost
 

This may seem like a dumb question to you guys, buttt are turbos running stock wastegates supposed to boost to a certain point (from 3k to 4k for me) and then just stop accelerating? It feels as though when it reaches that point the car is being held back and accelerates less than a naturally aspirated miata would at 5k RPM. I do have a manual boost controller installed but turned down (I'm still trying to run through all my 87 octane and not trying to blow up my car 40 miles from home). I have only just installed my first turbo, so I don't quite know what a low psi turbo'ed car is supposed to feel like, but my friend's evo seems to accelerate all the way to redline. I know thats a big difference but thats how I assumed all turbos would feel.

Because there is a constant increased pressure when the turbo has reached its peak, there shouldn't be any decrease in acceleration, only a stop in increase in acceleration, right? The only way I'm thinking this is possible is if my fuel is maxed out, or if there is a leak in my intercooler piping that somehow gets worse at higher RPMs and fixes itself at low RPMs. I am still running stock injectors and fuel pump but stock wg psi. If thats just how turbos somehow work or if anyone has any ideas, please enlighten me. Thanks in advance. :)

Whatever you're doing just stop driving it until it's sorted out, shit is definitely not running right. Are you even running a wideband? What are you even boosting at? And drain that 87, shame on you.

your car is not running right.

You should have had 91 in the tank when you installed the turbo, tsk tsk.

Give us some more specifics, starting with what you consider to be "low" boost. FWIW, your friend's EVO runs at least 19 psi, so don't expect to get that same feeling on the stock injectors.

no wideband, no gauges yet. I got eager.:) why would this happen though? I won't be taking my car to a shop so I'm trying to diagnose it and figure out a way to fix it within the week.

uhh low boost as in whatever my T3 50 trim stock WG psi is. I believe it came from a 1970's volvo? I could give you specifics about the part number and such if necessary by tomorrow.

so it is running great except that at 5k rpm it feels like it just hits a wall?
A few questions:
1. What modifications have you made to your fuel system? From what it sounds like, you have not made any changes at all. That is no bueno.
2. What modifications have you made to your ignition system?

From what I can tell, if you have stock fuel system and no rising rate FPR installed, then you are running out of fuel up there and bogging from being too lean. Dangerous situation, motor could get fucked up doing that.

Jesus dude, most people are at least a little cautious about diving right in to the boost, not you apparently. No boost gauge, no wideband?

Part numbers won't help, no one can tell you what psi you're running based on that. Get some gauges so we at least have something to go on. In the meanwhile, get that crap gas out of the tank, check for exhaust leaks and boost leaks, and make sure your fluids are new and that your other maintenance (such as fuel filter) is up to date. I'm guessing (hoping) you've undone the timing bump in your sig?

Ok dude, you are on track to fucking up your car seriously with that sort of lax attitude toward the whole thing. Answer the questions i posted above please and we can go from there. Don't drive it in boost anymore until we figure it out.

i bet there is no fuel management :)

oh god here we go....if you dont have proper fuel/timing management and are running "whatever wastegate pressure is" on stock injectors with no knowledge of boost or afr's, give yourself a swift kick in the stomach. if you are you need to let us know exactly what you're running

so it is running great except that at 5k rpm it feels like it just hits a wall?
few questions:
1. What modifications have you made to your fuel system? From what it sounds like, you have not made any changes at all. That is no bueno.
2. What modifications have you made to your ignition system?

yes, that's the feeling exactly. Sorry, I have a 12:1 vortech FPR. I have NGK blue wires and iridiums.

I have, of course, retarded it to 8. If I've been 87 octane and not knocking with my timing for the past 45 miles, I should be getting away with it. The gauges are currently being shipped to my house. I have replaced all fluids and checked for leaks, 5k miles on the fuel filter. I was a ridiculous and outrageously reckless for having driven the car right when I got it running, but I'm sure you all know the feeling. I do however, know how to maintain my car correctly and have adequate skills and experience, despite my age. not trying to brag, just trying to provide a little more background information :)

Thanks to everyone for the warnings though

guys, could this be a need for an O2 clamp?

Most people on stock injectors retard to 6*, run whatever premium is in their area, and have a boost gauge at minimum so they at least know if they're on target or not. It seems like you need to learn to be more patient. No one mentioned anything about your age, but frankly I'm not shocked. Just calm down, keep out of boost for awhile, and no one's engine gets hurt.

thanksthanks. but does anyone have any ideas on the diagnosis?

You don't have so much as a boost gauge and you want us to diagnose why your car is falling flat on its face? You must be joking. Get a wideband and a boost gauge and spend some time reading the Useful Posts section here, and you'll learn enough to diagnose your own car.

Phone conversation:
"Doctor I have a terrible headache! What is wrong with me?"

"Are you running a fever? Did you hit your head? What's your blood pressure? Are you taking any medications? Do you have any other symptoms?"

"I can't tell you any of that, Doc, but you've got to help me."



No gauges, no answers, too many questions, no way to know.
Park it until you equip it with proper diagnostic tools. Wideband o2 sensor is a minimum requirement for a DIY.

And FYI - you typically won't hear knock with the top down.
It will already be too late when you figure out that you've had it.

Diagnose your car. Ditto to all the advise given. Nobody on this forum knows what's wrong. You need to get a wideband and boost gauge. Swap in a new set of plugs gapped at 0.020", new wires, and begin diagnosis. Also check fuel pressure.

You really should get some kind of engine management. You're being a little over confident in your skills and in the end it's going to trash your motor. Either your ballsy as fuck or just ignorant when it comes to this stuff. You really shouldn't have even installed the turbo until you've read all the essential information. Wait for your gauges before you mess with it anymore.

Fail Points:

1> Lack of gauges - you can't troubleshoot without useful information (boost/wideband)
2> 87 octane - You can't be serious.

Change these above mentioned points, and you'll get some useful posts.

change thread title to:

"Anyone running unknown boost?"

Dude, the 1st thing you need to do is park your car and hide the keys. Then go inside and read this until your blue. https://www.miataturbo.net/forum/t4288/
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thanks for the opinions and bits of advice. I do understand that I am driving an unfinished project. Wires and plugs are at 2k miles. I don't want everyone to misunderstand that I would just install my gauges never to look at them again. I was, in fact, planning to make further diagnosis based on the air/fuel readings, but in the meantime, I thought that I would try to figure out why this was happening conceptually in case I missed anything, being my first time turbo'ing, and that's why I thought I would dare to ask for help and advise here.
I have thought of a very probably theory, however. I think that not enough fuel is getting to the cylinders and either I installed my FPR wrong or it is faulty. I'm not sure of the number of incidents of broken FPRs out there, but I will do a test this weekend when I'm back at the shop. Thanks again guys.

Something just occurred to me, I hesitate to post it, lest you try it and blow up your engine if it solves the problem.

I had some plain-jane NGKs in my car, and my friend who's watching the car thought he'd help me by putting in some NGK platinums. Over 4-4.5k RPM, the thing would hit a wall and refuse to accelerate, coupled with the low-pitched sound of sputtering like the mixture wasn't getting lit. I got another set of NGK coppers and the car sang to redline, no hint of a miss. This was with the plugs at .040 (with COPs) but you might try .020 like Pat said.

I take no responsibility if you do this and blow your shit up.

So are you implying that, should anything go amiss when the OP puts your suggestion to the test that you will be held accountable for any repercussions be them good or bad? :dunno:




:D

Sometimes, it takes time to digest information, assimilate and understand it well. I suggest you re-read my advice, particularly the last sentence, before you comment.

:bowrofl:

reading up further on spark blowout, I am almost convinced that this is the cause of my issue. thanks to patsmx5 and kotomile for the knowledgeable suggestion. I plan to test this by lessening the gap by small increments until the problem is alleviated, therefore keeping as hot of a spark as possible. If it does not change by .020, I will try a different approach. I will update when I test this, as by the many search topics I dug through, this seems to be a common unsolved problem of many other first time turbo installers.

Don't worry I won't be holding anyone accountable for my own risks and mistakes :)

How many people run into spark blowout at low boost though?

May I suggest getting a fuel pressure gauge.
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:bowrofl::bowrofl:


How many people run into spark blowout at unknown boost?


How many people have read the sticky about o2 clamps?


We may never know the answers to these questions.:bang:

You don't have spark blowout. Your issue is fuel related, but until you get a boost gauge and a wideband you're just pissing in the wind.

holy shit dude, can you just stop for a minute and READ THE FUCKING POSTS????????????/

DONT drive the car running unsafely and in god knows what condition.
DONT try to fix shit before actually DIAGNOSING it. for DIAGNOSING you need the proper equipment, the two gauges being the very least of the required stuff.
seriously, people are trying to help you here, and if you just keep doing random shit to a car you dont know what boost/afr's its running, it will break. then no one will care to help you because you went ahead and fucked it up despite all the warnings.

touche.

"They knew the risks, I say let'em crash!" -Counterpoint

The stock computer starts actually adding a little fuel after 5K, so you may just be getting too rich, which would be ironic.

But you really need to start from square one and get your setup in order. The miata is durable and a turbo miata is about the best modified car out there, but you won't regret putting a little study and thought into it to first. If you don't, there are lots of things you will definitely regret.

Read the sticky, start a list of tasks, and then put them in order. We will then be happy to help, many of us did the FMU thing for a bit and have experience.

Good god...

1.) you should NEVER have let yourself even turn the ignition key to on with the turbo installed without AT LEAST 91 octane in the tank. If the day came to do the install and you had half a tank of 87 you should have driven in circles till it was gone and then filled up the the proper octane fuel BEFORE installing the turbo.

2.) "I got impatient" is probably one of the #1 causes of people blowing up a motor, be it getting impatient and boosting before the tune is dialed in properly, before you have the necessary gauges, before the setup is right, etc... gauges are not something to get after you install the turbo. You should buy and install the gauges BEFORE you install the turbo and verify that they are working properly so that when the turbo goes in, you know you can trust their readings.

3.) ANY DIY TURBO SETUP REQUIRES INTIMATE KNOWLEDGE OF ALL OF THE COMPONENTS USED. Someone who goes out and buys a kit can trust that the company that designed the kit knew what they were doing and does not need to know the exact details of each little part even though I personally still would not recommend taking such a minimal interest in things. You do not have such a kit. You cannot afford such a lackadaisical attitude. You should know EXACTLY what psi the wastegate on the turbo you are using should be boosting to. Not an approximation, not an "I can find out tomorrow" - you should know down to the tenth of a psi what it is designed for.

PARK the car, have someone with a brain TAKE AWAY the keys from you until you DRAIN the gas, fill it with proper fuel that won't blow up the motor, and INSTALL at the BARE MINIMUM a Wideband Air/Fuel ratio gauge and a boost gauge. Then the next time you drive it, CAREFULLY edge your way into boost and keep your eyes glued to the gauges. Do not just impale the throttle with your teenage foot, you need to make sure that you are maintaining a safe air/fuel ratio throughout the rpm range during boost, so accellerate up to 4k and back off. If the ratio looked good, do it again up to 5k, if it was still good again up to 6k and so on.

THEN if you are getting good air/fuel ratios all the way through the rpm range and the car is still falling on its face at 5k, come back to use with some proper info and we can work with you to determine probable causes.

Oh, and you should be at no more than 6* of timing if you have no form of timing control. NOT 8.

-Ryan

My wife filled up my car with 87 and I promptly drained the tank, a day before a track weekend, what a pain in the ass. I just ran the fuel line into a gas can, not super safe, but less messy than pulling the plug.

I was under the impression that O2 clamps were only for when the signal is in closed loop (under 4k RPM), correct me if I'm wrong? No problems there, its only after 4k or so.

It may as well be a fuel problem, thanks for the suggestion.

I want to reinstate that I wasn't planning to touch the car until this weekend when it is back at the shop.

I know you guys are religious about using 91 octane with 6 degrees, but I did manage to drive 45 miles on the stuff and am only planning to use up the 87 for another 40 miles at the same speeds and in the same cautiousness. I did plan, then, to flush and replace with 91. I don't want to be mistaken for rude and want to mention that I do, however, take into consideration and appreciate your guys' concerns for the safety of my car.

I fabricated half my setup, installed all of it, and tune it myself, and I wouldn't back my car out of the fucking garage on 87 octane. Take that as you will.

detonation the 87 octane is destroying ur motor way to go now u get to see DIY engine rebuild in progress. A high octane fuel is essential to your turbo car staying alive, and boost guage etc even temporary and taped to your windsheild hood etc will help tremendous.

Once u remedy the fuel i would do a compresion check and then. Come back to us with ur numbers and the folowing list
Fuel management system specs= IE injectors, fpr vodoo etc
Timming control= bipes, timing retarded manualy
this will help us help u

This has got to be a joke.

Dude, O2 clamp is for going into boost. if you get past 4000 rpms you don't need it.

Basically you are probably running lean, NEED 93 OCTANE! Make sure your lines are on correctly. If they are backwards it will act like this.
I would first guess too lean for your boost.

Swap your fpr with a buddys that works right. It sounds like your fuel pressure may not be rising, or your boost is to high for the injectors and pressure you are running.
For 5psi do not do 6*

But you need at least a boost gauge to see what boost you are hitting..........

And afr would be great too... once you can aford it.

AND GAP your plugs .28.

It really sounds like you are running lean. Boost is probably too high.

Once you figure out how much boost you have. We will then talk about timming. Timming could be doing it as well. BUT PROBABLY THE LEAN FUEL AND 87 OCTANE.

I still can't get over the fact he's got no gauges and trying to boost on 87 octane and wonders why his car is messed up. Good luck though.

Knock Knock
Who's there?
Detonation.
Detonation who?
*bang-clunk-paw*
Fuck


OP needs to listen and take advice. Just because it's ran 40 miles like that doesn't mean it's ok, nor does it mean it's safe to continue. Detonation will break your shit and you'll never know it happened till it's too late.

In retrospect, I've surprised myself that I even spent the time to write a detailed response to such an absurd thread.

NO shit?

Of course you don't have enough fuel... that's why it feels like you're hitting a wall around 4k rpm. Your T3 comes up on boost and immediately runs out of fuel. Which kills your power, skyrockets your EGT's, and starts melting your pistons... I guarantee this is happening. With the stock fuel pump blue-tops, even with a 12:1 disc, I bet you're out of fuel before 5psi, especially considering this next paragraph...

The stock fuel pump on it's best day ever gives 80psi... but yours is 19yrs old... guess how much it probably gives. I'd say you'd be lucky to see 60psi... but you need a fuel pressure gauge to see that. What it means is that you're OUT OF FUCKING FUEL!

The turbo you have is probably a TBO363, the standard turbo Volvo has used in just about every car in the 80's and 90's... but I don't think Volvo was turbo'ing in the 70's. In any case, it's a good bet the thing is over 20yrs old. If so, the wastegate is probably shot. If it came from the factory with a 7psi spring (as it probably did), then age and several thousand heat cycles means there's not telling what it's going to give you. As wastegates get older, I've seen them get both weaker and stiffer. You might be getting 10psi+ from that thing.

Unfortunately, there's nothing you can do about this except get another wastegate. If anything, I'd remove whatever piece of shit manual boost controller you've got installed (no matter how "low" you've set it) so you know for sure exactly what the wastegate actuator is doing.

Another hint. The fact that you've repeated several times, and seem to be lending some heavy weight to your plug-wires and iridiums, means you've bought into some hype about how significant they are. NGK BKR7E or Autolite 3922 and Magnecore wires (NGK wires are fine, but they don't necessarily do anything). The plugs are like $2 each and the wires can be had at any of the standard autoparts stores. DON'T CHANGE THE GAP, USE THEM EXACTLY AS THEY COME OUT OF THE BOX. You're not running near enough boost to have spark blowout, you're just not running enough fuel.

Here's what you need to do... in this order.

#1: Pull the wastegate actuator arm off the wastegate.
#2: Drive to Autozone gently and buy a couple small bottles of OCTANE BOOSTER (enough small bottles to make a gallon).
#3: Drive to gas station, pour in bottles, fill up with 91.
#4: Drive home, park car.

#5: When boost gauge arrives, install and go for a drive (WITH WASTEGATE ARM STILL DISCONNECTED). See how much boost you get doing 4th gear pulls... should still make 1-2psi. See how car feels. If OK, connect arm... make some very gentle pulls in 2nd/3rd. If you go over about 6psi, LIFT THROTTLE. Don't boost over 5-6psi, you certainly don't have the fuel for it... probably not even for that.
#6: Come back here and report your findings... until then, there is no more help to be given.

PS: Unless you have a fuel pressure gauge or wideband, even if we manage to get you a wastegate actuator that will only make 5psi at WOT in 4th, you're still gonna want a reliable source of used motors.

update:
Got the boost and A/F gauges installed. It seems as if I had forgotten to turn the MBC all the way down and was boosting ~8 psi. I was experiencing fuel cutout via maxed out fuel pump. I turned the MBC back down to stock wastegate which was ~5psi. The fuel system did much better handling this, but barely to 5 psi. I may be seeing a 190 HP Walbro pump in the near future. Another thing that worried me was that when I pulled out the plugs, and they were black with a white tip. I did expect rich conditions due to the Vortech ,but did mot expect that the indiums may be running too hot. I have changed the plugs back to plain ones and we will see how that works out.

You were in no way running rich, you were in fact running extremely lean. Reading the plugs is useless unless you shut the engine off during a 2nd-4th gear pull above 5k (where your problem is.) DO NOT run above 4.5-5psi with your stock injectors and fuel pump. Make sure your AFR are no where near stoich, and borrow/buy a fuel pressure gauge to verify your pump is working correctly.

And why the fuck do you care so god damn much about these shitty iridiums?

fuck iridiums

I had one experience with them in the Miata. I always ran NGKs, and car ran great. Some guy at ORrly recommended them to me, and said I'd love them.

Me and the car both hated them. Folks underestimate just how great regular, cheap, easy to read NGKs are.

Better to put in new $2 plugs every six months than $8 plugs once every two years IMO.

Have you thought about larger injectors?

typically, which maxes out first, original fuel pump or stock injectors? I will most likely do both at the same time, but just out of curiosity.

Injectors.

Your still pushing the same pressure through them. One set of injectors let more gas through.

Like my car with MS, I have a stock fuel pump. But I am running RC440cc injectors. And I can get too much gas at 13psi.

I am just beginning to max my stock fuel pump at 16psi with 460cc injectors.

With proper engine management I am doing 7 psi with stock 1.6 injectors and stock fuel pump alongside the greddy's vortech fpr. Aside from the fuel map looking goofy (numbers get smaller the more boost pressure is seen rather than larger), it is running like a champ at 12.2:1.. nevermind the 105% theoretical duty cycle ;) In fact I could do richer if I wanted.

+1 on going with NGK's. But NOT THE STOCK ONES. With a turbo you MUST get the NGK-BKR7E plugs (stock is BKR6E).
-Ryan

Great, I was trying to not give him any ideas that its possible, way to go

The ring lands.

lean is mean.

I'm not sure how old this kid is but I just wanted to state (in defense of my age, 17), we're not all this dumb. Been on the forum for about a month with a low number of posts due to my eagerness to learn. Not due to an eagerness to be a pain in the ass or to blow up my engine.

LOL, good job newb, I know you're trying to say you're not dumb, but go and look at the date of the post above yours.

lol, dumbass.



I'm not sure how old this post is, even though there is a date on it, haha!

Perhaps a teeny bit more reading and a teeny bit less posting would keep you from coming across so... seven-teeny.