My first post and build thus far

[rjyentsch21]

First let me say that although this is my first post, I have been surfing and reading

through nico for about a year now as I find a topic of need, and this is one of the most helpful and congenial forums I have ever seen. Thank you to all who have made this great community which I am now proud to be apart of.

I bought my 91 hatchback about last fall rather unexpectedly, and began my first turbo build over the winter and finished it this summer. From the beginning this was destined to be a college kid's budget build, and it shows in a few places...but I'll deal with that later. I don't plan to go for over 5-7 pounds of boost max at this point, but I'll continue to evaluate this as I get more comfortable with forced induction.

I'm leaving the suspension upgrades (coilovers, sway bars, strut tower bracers), the body work (repair some minor damage, paint, and a lip spoiler), and the interior work (fiberglass trunk woofers, rest of the sound system, leather "racing" seats, shifter, steering wheel, etc.) until I've gotten her running reliably. By the way, does anybody have any thoughts on coilover setups they like? I'm looking for something camber adjustable, damping adjustable, not rediculously firm, but still sport minded. Oh...and I'm cheap.

First, what I have done:tubular manfold, ebay .50 AR T3/T04E? turbo (yes, I know that I am stupid for that), intercooler and piping, hand bent hard oil lines, external wastegate, manual boost controller, atmosperic blow off valve (which will be recirculating soon as I get the adaptor to replace the horn), locally bent downpipe, 255lph fuel pump, top feed fuel rail and 50lb high Z injectors from AMS, fuel pressure regulator, battery relocated to trunk, narrowband Air/Fuel gauge and boost/vacuum gauge, oil pressure gauge, egr, pair valve, and all the rest of the emissions removed...I think that is it so far.

Second, the area's where I still have some work to do: 1.) Never buy an e-bay manifold; the manifold itself was actually well made in the sense of excellent welds, polish, porting, and fit to the flat surfaces, however, it placed the turbo so far back that the downpipe would have been touching the brake lines; this simply wouldn't do, so the only solution I could find was to remove the brake booster to allow the master cylinder to come back about four inches. This solved my clearance issues, but left much to be desired in the stopping area. Right now I'm working on finding a master cylinder with a smaller piston diameter that will still fit well (pressure = force / area, so lower area increases pressure is my thoughts) and changing the lever ratio on the brake pedal itself. If anybody has had experience with this, comments would be appreciated.

2.) Tuning in general; I've gotten her to idle fairly well, and she run great when I have my foot in it, but I'm having trouble with keeping it running when I take my foot off the pedal. First, when going from the crossover point of vacuum to boost, the car acts like its going to die for a second and then just keeps on roaring through during acceleration, but when decelerating she makes a horrible racket (which I can't really describe very well because I still have an open downpipe and can't differentiate the noises) and tried pretty hard to die. If I rev it at an idle she'll rev up very smoothly, but coming back down there is a lot of poping and racket, and she dips pretty low (~400 rpm) before catching and coming back up. I still have the stock ecu so I imagine it is still a little out of whack with what's going on, so I'm going to have that taken care of in the next couple of weeks (I'm thinking enthalpy or JWT since I don't feel ready to do my own yet, any comments?). I'm also running about the stock fuel pressure (~40 psi), should I move that up or down? Lastly, I can't build boost while when I'm not under load, id est, while in neutral...is this normal? When driving, I can start to build boost at about 3,500 rpm (about, since it is hard to watch the road, tack, and boost gauge).

3.) I'm trying to decide on what kind of muffler will give me the best sound and performance, without being too loud all the time. I really like my music, and would like to be able to hear it. At the same time, I know that I will occasionally want to hear the engine and nothing else. I don't want a coffee can muffler, so does anybody have any experience with anything else? I'm running 2.5 exhaust.

If anybody has any thoughts for me, I'm more than happy to hear them. This is my first turbo build, and I'm doing everything by myself, so I'm a little out of my comfort zone for sure. Fortunately, this car isn't my daily, so downtime is no problem.

Also, if anybody else has a turbo 240 in the Cookeville, TN or Manchester, TN areas, let me know. Thanks for looking.

RY

Hm...I was going to insert some pictures, but I can see that it isn't going to be as simple as just attatching them...I'll put them up sometime soon...they aren't much to see anyways...



Modified by rjyentsch21 at 8:08 PM 5/24/2007
Modified by rjyentsch21 at 8:11 PM 5/24/2007

[Carl H]

remove the hose going from the valve cover into the intake track asap, you are pressurizing the crank case under boost, this is a bad thing.

[rjyentsch21]

Thank you. Should I run this from between the filter and the turbo, or will it run fine on its own small filter?

[mrzabala]

I highly recommend heat shielding your brake master cylinder and your p/s reservoir as theres a chance of fire and you dont want your fluids to be at a high temperature (wear and tear).

[480sx]

I had one of those manifolds and sold it before i put it on my car. Your right the sections on the runners where they tigged it up look great, but the collector is done really poorly and theres a lot of spots that could have used alot more atention. Theres a guy on here who ran it and had the wastegate flange actually blow off under boost, twice, with two different manifolds. Also have heard of people running the manifolds with no problems, but good luck with yours.

Coilovers are stiff no mater what type you buy. Megan racing has come out with some really nice ones but they are stiff as heck iv been told(they are made in the same factory as teins) They are reasonably priced as well. I have heard that Tein Flex's(expensive.. as all teins are) are really nice on the street but again, all coil overs are stiff.

You dont see much boost in neutral, just how it is. On my SR i can see maybe 1-3 psi if im lucky.

Most of your problems will go away when you take your vac line off your crank breather.... I would imagine that your boost response is going to go wayyy up after you do that. Also recirculating your BOV will stop most of your stalling problems, and your car wanting to die at idle.

Just run a small filter for your breather.

[VeloceDrift]

looks great to me.. i just finished my KA T with a top mount turbo.. lets just say that you were much more successful then me. i have had so many clearance problems with mine and am soon to just buy new manifold and piping to put it on the bottom. i like it though and think its sick looking. love what you did with the brake boost:) my last 240sx had a bad booster anyway and after awhile you dont even notice it.

[rjyentsch21]

So...let me make update:

I removed the line from the cold pressure lines to the valve cover; Now the valve cover vents through its own filter I rigged up from stuff I had lying around. Question though: according to the factory service manual, the valve cover port is the intake, which then enters into the manifold. By venting the valve cover to atmosphere, won't I throw off the MAF readings by introducing unmetered air into the system?

She runs better now for shure, although I am still having issues with it trying to die when I let off the gas, and very rough running when cruising at constant spead near the switch point from vacuum to boost. One curious thing I did note is this: I expected that some of the problem was due to the atmospheric dump of my BOV, which caused there too be less air than expected for the amount of fuel, which would cause me to run rich for a second. However, my A/F gauge shows me running lean after I let off the gas during the period of rough running. I am confused.

The braking situation was made a little better by removing the brake pedal (a pain in the *** in and of itself) and changing the length of the lever arm to give me more mechanical advantage. This has given me (guestimated) 25% increase in braking ability. I haven't yet looked for a master brake cylinder with a smaller diameter, so if anybody else knows of a good candidate please let me know and save me the trouble?

No progress yet made on the heat shield; I tried to make something myself out of some very thin aluminum sheet I had lying around, but the geometry is too complex for my extremely limited fabrication ability. Anybody have any advice on fabrics that reflect heat (kinda like header wrap, but in reverse)?. For that matter, What is the general opinion on using header wrap on the downpipe?

Thanks for all of your help so far. I will continue to update as it happens.

[480sx]

No.. The air in your crank case is typically pulled out by the vacuum of your engine. It has nothing to do with your MAF reading, that measures the amount of air thats pulled into the combustion chamber.

If you recirculate your BOV you will be fine.

[rjyentsch21]

Update: BOV recirculation adaptor ordered and should be on its way...tuesday...darn these holidays.

In reference to my concerns over venting the valve cover to the atmosphere is the below picture pulled from a dealer service manual describing the PCV system. It shows pulling air in from the plastic intake setup which had been metered by the MAF, and then dumping it into the intake manifold where it rejoines the previously metered air and enters the combusion chamber. Id est, that air which enters the top of the valve cover does eventually find its way to the combustion chamber and was metered air when the vehicle was stock. Is this just such a small amount of air that I don't need to worry about it? I have noticed many pictures of setups venting it to atmosphere through a filter, seemingly with no ill effects.

[img] http://viewmorepics.myspace.co...52967 [/img]

[180sx]

GO any sports store buy urself 5 hockey pucks.5$ take 3 tape it, drill a hole in the center. take remaining 2 tape em drill em as well.

Now take out ur driver side engine mount, go homehardware and buy a 2 bolts some washers and nuts. 1 bolt should long enough to go through 3 hockey pucks and enough lenth past pucks , just like on oem engine mount. 2nd bolt should be shorter than 1st by a hockey puck but long enough to go through remaining 2 pucks and again have enough thread , just like OEM engine mount.

Now use ur hockey puck mounts as replacements, run 3 puck on driver side , 2 puck on passenger. It will shift ur engine enough to clear damn xs power manifold and allow you to retain oem brake booster. You will need a copper shield or turbo blanket to prevent exesive heat to ur master. Clerance is like 10mm but its a cheap easy solution. I just went through the same on my buddies det over the weekend. Pricks at ssac show you picture of sr20 manifold and turbo mounted in s13 bay if you look closely , thats why it fits.

[Tulsa_S-13]

Maybe I missed it, but what tuner are you using? S-AFC? FMU?

[rjyentsch21]

Thank you to 180sx for the hockey puck suggestion. I haven't looked at it yet, but that is just the kind of cheap-*** solution I love!

As for the electronics...not much. I'm still using the stock ECU, which yes: I realize that is probably causing a whole heck of a lot of my problems. I'm hesitant to invest in a new one yet as I'm still not sure of the final details of what I'm doing (id est, will this be my final turbo, what pressure do I intend to run, what camshafts will I be using, etc). Since my A/F seems to be staying right where it needs to be, except during those times which I hope to remedy with the BOV recirculation, I'm going to try to milk it for all it is worth.

ECU modification/replacement/programming is an area where I am still totally lost, and I would love the community's input on it.

First, what I have:1.) access to a laptop computer to do programming in car if need be2.) a decent familiarity with the principles of computers and the internal combustion engine3.) The patientce to sit down and read an instructions manual, and the education to do more or less any calculation that I need to (Mechanical Engineering junior at TTU, 4.0, deans list, salutitorian of high school, all that crap that doesn't seem to be helping me much with this project )4.) the rest of the summer before I would like to have the car on the road permanently

Second, what I don't have:1.) any sort of familiarity with mixing an internal combustion engine and a computer2.) any local shop that knows what to do, or that I trust to do it3.) any local place to tune on a dino4.) I would prefer not to have to get a wideband O2 sensor, since I don't really see much value to it after initial tuning (I already have a narrowband O2 sensor gauge); this is merely a symptom of my omnipresent cheapness

So if anybody has a recommendation based on that, I'm all ears.

[rjyentsch21]

So ignore the last half of my last post. While browsing through I found more or less just the kind of thread on choosing ECU's that I have been looking for (dang...I suck with the search function).

Based on what I've read, I am heavily leaning toward an Enthalpy tune. This brings me to a few questions:

1.) Has anybody heard of the guy on e-bay selling ECU's under the name of "enthalpy"? Is he legit? I didn't see any mention of it on the enthalpy site...

2.) If I don't intend to do any internal rebuilding of the engine and keep power to a reasonable level based thereapon (about 300-350 at the crank), is it worth upgrading to a z32 MAF?

[Tulsa_S-13]

If you're not running any fuel management you shouldn't be driving the car. That's a good way to blow ringlands and everything else.

[spooled240]

I have the same mani, turbo and wg. so I also have the same problem with my master cyl. I was going to ceramic coat my downpipe, then maybe hit up jegs for some heat wrap and heat deflector material and heat wrap the hell out of it, brake lines and downpipe. Brake fluid is somewhat heat resistant on its own so I think this should work fine. I'll keep you posted on how it works.[IMG][/IMG]

If you're not running any fuel management you shouldn't be driving the car. That's a good way to blow ringlands and everything else.

[rjyentsch21]

Dare I say, spooled240, that you bought even so the exact same "kit" off of e-bay that I did, then. Did you get the intercooler pipes and silicon couplers that came with the kit to work? I eventually had to cut some of the pipes and buy two new couplers to get mine to work. I would be most interested to see any pictures of your setup that you have.

As for running without any aftermarket FMU, if I stay within a relatively stoiciametric range according to the O2 sensor readings, is there any danger? Of course if I run lean hell follows swiftly, but as long as I don't do that, and don't experience ping, am I really in any danger? I'm not going to be any drag races anytime soon,

[spooled240]

Mine came with only the turbo, wg and manifold. But you look like you got your ic piping to work with some modifications.the exhaust manifold, turbo i think is the same tho which is why the master cyl is an issue

As for running without any aftermarket FMU, if I stay within a relatively stoiciametric range according to the O2 sensor readings, is there any danger? Of course if I run lean hell follows swiftly, but as long as I don't do that, and don't experience ping, am I really in any danger? I'm not going to be any drag races anytime soon,

if it doesn't ping then you're good but that would be hella scary

[S13FX]

Wait how do you even get the car to idle with 50lb injectors on a stock ecu?

[rjyentsch21]

Wait how do you even get the car to idle with 50lb injectors on a stock ecu?

That actually surprised me too. Sure enough, though, it works. I know that the ECU takes readings from the O2 sensor to adjust the pulse width, so I suppose that it simply adjusted the injector width narrow enough to remain in the stoiciometric (sp?) range.

I also have an adjustable Fuel Pressure Regulator, but I have it set nearly to stock (~40 psi). I found that I could adjust it down to 30 and up to about 60 and the O2 sensor readings would remain normal, at least at idle.

For more information, I have a 255 lph Walbro fuel pump from ebay, and 50# Precision Injected brand fuel injectors and a top feed fuel rail both from AMS motorsports, and a no name adjustable fuel pressure regulator also from ebay.

[rjyentsch21]

So...I have made progress!

So to all those who might be wondering out there...a Greddy RS recirculation adaptor does not work with a type RS knock-off...

And along those same lines I now have a 32mm Greddy type RS recirculaiton adaptor for sale for $25 including shipping.

So once I realized that my purchased solution was SOL I got off my lazy *** and fabricated an adaptor composed of some thin walled tube from an old tent frame or something and some rubber hose. Turns out what I had was just the right size that I could unscrew my horn and screw the tube with the hoze around it into my BOV. Then I just ran a rubber hose from there to another piece of the same tube welded onto my pre-turbo, post MAF intake pipe. It's not the best long term solution, but its in there pretty darn tight and should work until I get around to making something better (already got a quality idea for that, but I can't weld aluminum...)

That has solved all of my rough running/wanting to die on me problems.

Now I have a qustion about adjusting the soft/hard screw on my BOV...and I suppose I should search the forums before I actually ask it shouldn't I? Dang it, but dial up makes everything a chore!

Working on a solution to my braking problems. I could probably get by with my brakes as they are now, but coming from a riced out Toyota Paseo which stops pretty dang well, I just don't want to. Right now I'm in the process of acquiring a set of Q45 front calipers and rotors. I'll update when I get those, I suppose.

Thank you everyone for the help you have been.

[spooled240]

yeah, dial up is a biotch the greddy bov has a threaded screw on top. To tighten it, you loosen the nut at the base of this threaded screw then turn the threaded screw clockwise with an allen wrench.

[rjyentsch21]

Sigh...Ok...I'm not that out of it, I know how to tighten and loosen the spring.

What I don't know is how tight it should be to vent when it needs to and to not vent when it doesn't need to. Id est, what signs should I look for as I try to dial in its adjustment?

Other news, I'm in a bidding war on e-bay for a set of q45 calipers and rotors...so if anybody knows who is bidding against me, snip his computer cable for about the next four days...

Hey, spooled, how is that heat wrap around the master cylinder working for you?

[spooled240]

For the bov, the greddy instructions say to tighten the bov if you encounter any idling issues. As for myself I tightened it pretty good and works fine. No idling issues and opens when it needs to.

I just did all my heat wrap and stuff last weekend! I don't have a picture yet but I ceramic coated my downpipe ($185), bought about 15ft of fiberglass heatwrap ($20), fabbed up some aluminum heat shielding then slipped a heat-reflecting sleeve over my brake line. so far so good, nothing seems weird and my brakes work fine even after driving it for 20min in socal heat i'll get you a pic soon

[spooled240]

here they are:[IMG][/IMG]

[IMG][/IMG]

[IMG][/IMG]the heat shielding contours the turbo a bit and does not touch anything which is good later down the road I wanna get a carbon hood with air extractors to cool it down even more...

[rjyentsch21]

Alrighty...It's all gone to hell...

I went by and registered and insured the car after work today, then came home and took it for a relaxed 20 min drive to see how she is doing. I have a problem:

I can't get the car to run under boost. Anything below 0 psig she runs about like stock, but as soon as I cross over to boost she...stutters?...I don't really know the term for it. She will not acceleration, sounds like she is alternating between acceleration and deceleration of the motor at about 10 Hz, but after I let off the gas she settles back into normal in vaccum.

Also, I thought I had solved the problem of it dying after letting of the gas, but no such luck. I've recirculated my BOV to post MAF, pre turbo which I thought would fix it. A note of clarification, if I stay in gear she will run just fine when I let off the gas, but if I push in the clutch after letting off the gas she wants to die. I can sometimes salvage it by giving her some throttle until she stabalizes, but not always.

I am running just a little rich (by turning up the fuel pressure), but shouldn't be near enough to be causing these sorts of problems.

Hey spooled, the fiberglass wrap you are using: is that just normal header wrap or are you using something different?

Ammendum: I just went out and pulled the spark plugs to make sure that my A/F gauge isn't lying to me. They all looked normal (neither white nor overly blackened or sooty) and uniform. I have a stock ignition with one stage colder plugs gapped to .035;

I also didn't mention that my timing is set to 16 degrees BTC, and that during all of the trouble that I mentioned above my A/F's stayed stoiciometric, or maybe a little on the rich side. They bounced a bit during the stuttering but didn't go crazy by any means.

Fuel: I am running mid grade with one bottle of octane boost added about a third of a tank, so I don't think that is the problem.

As for my BOV, I had it fairly, but not rediculously, tight. My wastegate I haven't done much of anything with.

The pictures I have above are also incorrect (I don't know if everyone reads) in that I no longer have a line from the post IC line to the valve cover, but I have it on its own small filter. The line from the post IC is still hooked to the other two lines that used to run off the stock filtered air duct.
Modified by rjyentsch21 at 5:56 PM 6/5/2007

[spooled240]

it's fiberglass header wrap and was about 20-25 buckssounds like your fuel is cutting out in the boost range. What kind of fuel management are you running? Be careful w/ pinging and detonation, you engine will go straight to hell.