JRSC->Greddy complete, the help solve the inevitable issues thread
bought a 91 with a standard no frills JRSC kit almost exactly one year ago. I took it down around May to finally install a used greddy turbo kit that I've had lying around for ages. Just finished a couple weeks ago. Changed a whole lot of other stuff too, which is why it took so long.
Here is what is installed:
JR AFPR carries over, with autometer fuel pressure gauge
Bipes carries over, settings were for 6psi non intercooled
Greddy manifold, must be later version, has relief cuts that are obviously factory
TD04H, no shaft play. Drains straight to oil pan. new hardware, nordlocks everywhere.
Turbo Tony 2.5" downpipe
CX racing ebay intercooler, the biggun, adapted down to 2" coldside to use some old stock begi pieces
Knockoff greddy-s BOV recirculating
New K&N filter
ACT XT PP and disk (was braineack owned, auto +10hp)
torsen from a 96
autometer EGT tapped into cylinder #4 runner of manifold
Oil temperature gauge
LC1 wideband feeding simulated narrowband to autometer A/F gauge
radiator barn all metal dual core raddy w/ 14psi cap
Begi basic coolant reroute
Begi 2.5" hiflo cat
magnaflow 2.25" catback
That's all that is really relevant to the turbo install, did a lot of other stuff too, suspension, brakes, engine/diff mounts etc but more on that later if anyone cares.
Here are the three MAJOR issues, broken up into three posts so that it doesn't suck so bad to read:
#1 - the tony DP leaks bad from inside the flex section. When I heard the leak I jacked up driver side of the car and if you put your hand over the flex section there is quite the breeze. now, I have a crappy harbor freight wire feed flux core mig - its my first welder, first welding. Used it to weld on a bung for the wideband, and to weld up a bracket for the IC. I could remove the downpipe and weld on a new flex section, which are $15 off ebay. But being just about done, and the DP being such a PITB to get off the turbo I decided to run it by Midas to see what they would charge to weld in a replacement flex or straight pipe. This being northern Va the guy immediately tried to bend me over with an estimate of $150 for the flex section (lol) and $178 for labor, guessing two hours to weld it up. Maybe if he took ten smoke breaks and a long crap. He refused to weld a straight pipe in its place, said something would crack. I really don't think so, other miata kits do not have flex sections. But whatever. I told him I could get the flex section and give it to him. He looked disappointed (no easy $150) but would do it, for the $178 labor. So, do I do that, or do I deal with taking it off and trying to weld it myself (assuming I could do that without farking it up). Or third option, I take off the pipe, sell it cheap to someone here who can weld it or have it welded, and use the cash to buy a Begi DP or a turbotony, if I can get a hold of him.
Issue #2 -
Blow off valve. It made a sound pretty much exactly like the prodrive P2 from this top gear video, 2:02 in
I can't even say with certainty if it is compressor surge or BOV flutter. It did that with the adjustment screw in the position as I received it, and it still does it when it is all the way loosened. I took it apart, and everything that should be there, looks to be there. there was only one large spring, not two - I've heard that there is a "mod" to the real type-s that involves removing one of two springs. It's possible that the one spring I have is just too stiff for low boost I guess. It also doesn't have the second, lower nipple like a real type-s, it has a little tiny hole there that does go all the way into the housing. People leave that nipple open on the real S so that shouldn't be a prob? Vac source is the unused nipple on the throttle body, no other devices on that line. Ideas? I could maybe try stretching the spring and cutting off part of it to weaken it. Or I could bite the bullet for a real $125+ used greddy s, or type-rs. I'd rather not use another BOV as it would mean redoing the IC pipes. One more thing, the BOV is mounted on the hot side of the IC pipes, routes back to the air intake pipe, post AFM, about 2.5 from the turbo inlet. I kind of had to put it there for packaging reasons. The begi coolant reroute didn't leave much room by the throttle body. I'm not noticing any terrible behavior associated with the sound...it sounds pretty sweet actually but if its surge or flutter then its not doing its job, and I am pretty sure the type S should just go pssshhhhh. Yeah, knockoffs suck, but i'd seen people run this one successfully. Oh well.
issue #3 - overboost
Greddy is meant to be 5.5psi stock....HA. I got on it hard today and I hit 8psi on my mechanical gauge before I panicked and jumped off it - who knows, I might have hit more had I not. I noticed that the wg arm was all the way tight, I mean all the way, so I loosened it until it sat even with the wastegate lever prong, then reattached. I have not driven it since. I know tightening the arm can give you another psi or so, but I was shocked to see 8psi, especially with a big IC and less than ideal IC piping. I guess the only fix for this is an EBC so some sort, since you can't MBC your way DOWN in boost pressure. That leads me to the wrap up post, where I am going with this build
My goals here are a daily driver that is quick, fun, and hyper reliable. I've got a pristine 94 RX7 that is the garage queen and money syphon, and a 99 miata that I'd like to store at my parents retirement place for a later project, and to kind of take a break from after four years ownership.
I don't have huge power goals for this car - was shooting for 10psi and ~200 at the wheels eventually. The idea was to get it running and all the little annoyances worked out at 6psi with the current timing/fueling, and then install the emanage blue and autotune, along with cleaned supra 305cc green tops, and a pierburg inline pump. I do have all that stuff. The idea there being that with Bruce's autotune, once it was set up there would be minimal fussing with the car, even between seasons, and I could devote more time to the RX7, a refresh of my wifes WRX, home improvements, etc. Of course now I am contemplating a megasquirt...I can solder wicked good and that might be a fun winter project. It's only $300 for all the goodies if bought unassembled. So there it is.
I've been a member of this site for a couple years now, been through about a half dozen miatas, and had several boosted cars, but this is my first turbo miata, so I guess I finally have a legit reason to be here. Having been here two years, I know what is coming next....flame on. Oh, and pics or GTFO. I'll try and grab some now for the inevitable.
If I were you I would cut off the old flex pipe and weld a new one on. The reason why they put those on cars is so when the exhaust moves it has a pivoting point and with out that pivoting point it puts a lot of stress on your manifold and down pipe. When your exhaust moves around its like a big breaker bar.
yeah I meant band clamping on a new flex section, the type with long nonflex endpieces like this
figuring the worst that can happen is that I am out $25 for the band clamps, but still have the new flex that I or midas can then weld in.
I would totally agree with you, apart from this is washington DC and there are no places that aren't trying to bleed you dry. It's one of the main reasons why I started working on cars actually. I called two other places (muffler shops) prior to midas, they both acted like it was a waste of their time. the midas in question was suggested by a friend who had an o2 bung welded on his viper by them for $20. But the pipe was off the car...
I'm going to give the band clamps and new flex section a try, if that doesn't work I'm going to take the DP off the car and weld it myself. I don't like taking my cars to any shop for any reason, apart from inspections and alignments - and even then I am picky about where the car goes, and demand to be standing there while all work is performed.
What's lamest about this all is that the DP was sold to me by a forum member here. I gotta think he knew.
Sorry about the comment. It wasn't that bad. I guess I was just tired. LOL
#1. There are alot of small towns in VA. You may have to drive 1/2hr or a 1hr. If you can weld good, I would do it myself. Or you can pay somone $25 to 30 to do it for you. Never go to midas or a name brand shop. Find a radom Bubba's used tire and muffler. LOL Or somewhere you know they probably need cash, and make sure you have cash. LOL
#2. You should be fine. I wouldn't worry about it. That $40,000 car made that noise. Both of my cars make the same noise. My cousins honda makes the same flutter type noise. And the Grand Nationals at the drag strip did too. I'm not going to buy something else for my cars. I think your setup is good.
#3. Your doing right by losening the arm. That will fix it.
It sounds like your done.
If you have other driver cars. I think I would go ahead and throw in the 330's, and try to run 10psi or +. Most guys say it burns gas with the 330's and fmu though.
But it will RUN.
it's either the wastegate or it's the Bov - I took it apart and cut off part of the spring, no real change except it got a little quieter. Looking at the boost gauge as I let off throttle at 6psi, it comes down in a linear manner, so I don't think it is flutter.
I got the exhaust leak fixed. Unbolted the DP at the cat flange, and then cut the downpipe with a sawzall ahead of hte leaking flex section. Then I mig welded the orignal DP flange to a new flex section (getting better at welding). Since I didn't unbolt the DP at the turbo flange, I couldn't weld the other end, so I used a butt clamp. Worked fine. no more leak.
Now I only have to move the begi coolant bypass tee from the upper to the lower raddy hose. Thanks all.