Req. for comments & questions on my turbo upgrade plan

[RETed]

Originally Posted by Pete_89T2

Planned Upgrades to support the BNR Stage 1 turbo:
Fuel Injectors: Replace all four FIs with 720cc injectors. From what I’ve read so far, these would provide more than enough fuel capacity to support my goals, and putting them in all 4 holes provides the tuner a bit more wiggle room to optimize drivability around the primary/secondary transition point, and throughout the power curve. Questions: (1) Is this true, or for my modest goals would my money be better spent elsewhere by running my stock 550’s in the primaries and just upgrade the secondary’s to 720cc? (2) Where can I source a set of 720cc injectors that are drop in replacements (mechanically and electrically) to the stock 550cc high impedance FIs currently in there? I really don’t want to mess with the stock fuel rails; but can handle the electrical mods to change FI harness connectors if needed.

Because you're using the oval, high-impedence fuel injectors, there are not too many options in terms of "drop-in" upgrade replacements.
I've only seen "Japan" (I think it was SARD?) that offers a larger fuel injectors that uses that oval plug.
Else, if you're willing to splice in a Bosch-type (i.e. older, rectangular) plug, you open up a lot more options.
Impedence isn't a problem, as you can splice in resistors to compensate for the impedence change.
GReddy offers 720's that are drop in, but use the older, Bosch plugs.
There are other aftermarket offerings, but most of them are crap - that's a whole nother thread in itself.
Just stay away from Venom and Deatchworks...

If you do replace the primaries, you run into possible cold-start issues, unless your fuel control can effectively adjusting cranking fuel delivery.
(I dunno if the RTEK can do this?)

Playing with the Rotary Performance fuel injector calculator:
http://rx7.com/cgi-local/2ndgencalc.cgi

4 x 720's give you about 280 at the wheels.

Fuel Pump: Assuming that I verify I have good voltage at my rewired stock FP, will the stock FC pump be sufficient for my modest HP goals? If not, what replacement FP do you guys recommend and why?

The stock (FC turbo) fuel pump can barely handle the stock fuel injectors @ 4 x 550's.
It maybe maxes out at around 250hp at the wheels.
This is why an upgrade fuel pump is highly recommended.
Walbro's are the cheap standard, but be careful about fakes...
Look for the "255lph" Walbros.
(The stock FC turbo flows right around 180lph - 190lph.)
(Do a web search on keywords "walbro fuel pump fake", and you get a lot of hits.)
I like the stock JZA80 Supra TT fuel pump.
It has OEM quality and reliablity - made by NipponDenso.
It flows slightly more than the "255lph" Walbros.
It drops in.
It's priced slightly more than the Walbro at closer to $200, but I think it's worth it.

Fuel/spark control:

Can't comment on RTEK, as I'm a Haltech guy.


-Ted

[Pete_89T2]

Thanks for the input Ted.

WRT the fuel pumps, are you saying both the Walbro and Supra TT pumps will mechanically drop right into the FC tank and mount up without any fabrication work? I assume I'll need to splice in an electrical connector? From a reliability standpoint, I'm thinking the Toyota pump is the better of the two. Another dumb question - is JZA80 the P/N for the pump, or is that just Toyota lingo for a Supra TT (i.e., as FC3S is for us rotorheads)?

I ran into those Venom injectors while searching the net; "too good to be true" came to mind, given the cheapo prices. Thanks for the warning! Looks like the Greddy 720's with the Bosch pigtails will do the trick for me. Given what you said about potential cold start issues, I may have to reconsider putting 720's in the primaries, after I learn more about how the RTEK works.

WRT the RTEK, what I gather from their website is that for fuel correction, they give you a 14x18 (252 points) RPM vs. boost table to play with, where each cell is a correction factor the user can set, in a range of +/-37% of whatever the corresponding stock map values are. I'm not exactly sure of what quantity the +/-37% refers to -- is it injector duty cycle, AFRs, or something else? More questions for the RTEK guys!

[TitaniumTT]

Originally Posted by Pete_89T2

Hi guys, this is a follow up to my other post, reference:

http://www.rotarycarclub.com/rotary_...ad.php?t=13083

The skinny is if I decide to purchase a BNR stage 1 upgraded turbo (vs. the stock rebuild) as discussed in the ref. thread, I need to address fuel & fuel/spark management. After a little research here & elsewhere, I've drafted a plan that should support running the upgraded turbo safely and meet my goals. What I'm looking for is your critical review & comments to the plan - pros/cons, etc. I'll also pose a few associated questions along the way that I need answers to prior to executing this plan. This will be a lengthy post, but hopefully will generate information useful to anyone starting out on the FC mod/tuning adventure.

Lengthy? I'd use long, detailed, and thought out... someone's doing thier homework

Originally Posted by Pete_89T2

My goals: I'll be more than satisfied if my car even comes close to producing the 300~320 rwhp BNR claims their stage 1 turbo upgrade is capable of. My philosophy is in line with "resto-mod" thinking. Meaning when replacing worn out parts, if you can improve upon stock performance & reliability without compromising the car’s original looks, its character or baseline reliability, then go for it! Reliability is orders of magnitude more important to me than the end HP #'s I achieve. Also, since I’m too lazy to be swapping out emissions components every time the state of MD orders me off to the sniff tester, I will retain the factory emissions components needed to pass the sniff test. Regarding schedule, I MUST have this done and fully tuned before I hit the road for DGRR-11 (28 Apr 11). My gut tells me finding a competent tuner to optimize my tune on a dyno within that short schedule is going to be my greatest obstacle!

Call/e-mail Dave @ KDR now Speed1, he ususally books a few weeks out, but around that time it might get a little more difficult as EVERYONE want's thier car done around that time. So I would finalize your plan, set a generous timeframe, then get in touch with Dave and setup a playdate. I don't know if he's used the RTeks... I'd imagine he has, but I would double check

Originally Posted by Pete_89T2

Baseline car & current mod list: Car as it sits is a nearly 100% stock ’89 turbo, faithfully restored to “like new” condition. For those of you who attended DGRR ’10, it’s the black-on-black T2 that took home 1st place in show for 2nd gens. Engine was rebuilt about 50K miles & 12 years ago, all stock internals, no porting was done to it. ECU is stock N370, with no mods, but I did install a new Mazda engine wiring harness back in 2008. Currently the stock 550cc injectors are in all 4 holes, which are periodically sent out for refurb & flow testing once every other year. Fuel pump is stock, but I did the FP rewire job some 10 years ago to ensure the FP gets the voltage & current it needs. I’ll need to check my handy work to verify if it's still up to snuff. Exhaust system is a Bonez DP out the turbo (2.5" diameter pipe), going into the stock mid-pipe & main cat, then into a Borla dual cat-back exhaust. Intake is all stock, other than a K&N panel filter installed in the stock box. Other than removal of the pre-cat, all emissions equipment is installed, works and is functional; car easily passes MD sniff test. Other mods relevant to this discussion include a Koyo radiator upgrade which will soon go in (part ordered), and WRT lubrication, I did the e-shaft thermo pellet mod.

The first thing I would do is a real comp test and inspect the engine as much as possible. Are you still running the stock OMP? I would be concerned with carbon buildup and some possible sticking seals. After all, 50k on a turbo engine is practically unheard of

Originally Posted by Pete_89T2

Reiterating from the referenced post, the BNR Stage 1 turbo upgrade I’m considering is basically a rebuild of all my stock S5 turbo wear parts, to include balancing. BNR replaces the stock compressor wheel with a T04b V-trim wheel, running inside the stock compressor housing which is machined to fit the new wheel. The waste gate is ported, and the turbine wheel gets some clipping to reduce back pressure. The waste gate is preset to open at 7~8 lbs. They claim this turbo is good for 300~320 rwhp with the right setup.

"the right setup" I would imagine is close to a full open exhaust, non-stock airbox, and some playing around on the dyno. So I wouldn't be surprised if you're setup produced a little less HP than that, but if that's not an issue as it doesn't seem to be, than I think this would be a good choice. While it's an upgrade, the only way to put less stress on the engine at about the same power outputs would be a totally custom exhaust mani and turbo. EMAP has a HUGE role in power output and stress on the engine. So IMHO, if you do upgrade, the BNR is definately the easiest, but not the most effecient or effective, but it's also the cheapest.

Originally Posted by Pete_89T2

Planned Upgrades to support the BNR Stage 1 turbo:
Fuel Injectors: Replace all four FIs with 720cc injectors. From what I’ve read so far, these would provide more than enough fuel capacity to support my goals, and putting them in all 4 holes provides the tuner a bit more wiggle room to optimize drivability around the primary/secondary transition point, and throughout the power curve. Questions: (1) Is this true, or for my modest goals would my money be better spent elsewhere by running my stock 550’s in the primaries and just upgrade the secondary’s to 720cc? (2) Where can I source a set of 720cc injectors that are drop in replacements (mechanically and electrically) to the stock 550cc high impedance FIs currently in there? I really don’t want to mess with the stock fuel rails; but can handle the electrical mods to change FI harness connectors if needed.

Don't worry so much about the transition. Anyone who knows what they're doing can make that little hiccup dissappear. I'm running 725/2000 and under any conditions, I can't feel any hiccups. Personally, I would sport for the ID1000'sx4. They're hi-imp injectors so they should work with the Rtek, there's a bunch of different configurations for length and width, so they can fit, the only issue is you'll need to crimp on the new connectors. You don't need to worry about idle quality either. The quality, linearity, and fine atomization of these injectors is unsurpassed. However, if you don't want to spend the money, than I would keep the stock 550's and get something along the lines of 1000-1300cc's

Originally Posted by Pete_89T2

Fuel Pump: Assuming that I verify I have good voltage at my rewired stock FP, will the stock FC pump be sufficient for my modest HP goals? If not, what replacement FP do you guys recommend and why?

Nope, get a new one. Walbro's are an option, but I hate them. Bosch's are another option, not a huge fan. Liek Ted said above, Denso pumps are the way to go. The Cosmo pump is a great drop in replacement. No fabrication required at all, RotorSports sells a kit or you can get the "One Time Fit Kits" that NipponDenso offeres. I saved the box from by Supra TT pump if you want the actual factory part number. The one that most resellers grind off the top so the secrets cant get out.... Well I know most secrets

Originally Posted by Pete_89T2

Fuel/spark control: I’m thinking the most expedient and cost effective path for me is to send my stock N370 ECU out to DTI for the RTEK 2.x upgrade. Details of what the RTEK can do may be found here:

http://www.pocketlogger.com/index.ph...age=2&ecu=S5T2

From what I’ve read, it appears the RTEK can provide enough tuning flexibility to support my modest HP targets, and it seems to mesh well with my resto-mod philosophy (i.e., no major hacking/wiring harness work, low risk to stock functionality and drivability). But I’m not 100% convinced yet – answers to the following questions might get me there: (1) Have any of you successfully used an RTEK to wring about 300 HP out of your turbo setups? If so, please share the particulars. (2) I have zero experience tuning ECUs, so out of the box, how easy or hard will it be for me to tune my RTEK modified ECU for the first time at least well enough for me to safely drive the car to a reputable tuner for optimizing on a dyno? This drive is likely to be a 3+ hour road trip, one way, assuming I can get Dave at KD Rotary to do this for me. (3) If Dave can’t do it for me, can anyone recommend a reputable tuner with RTEK & rotary experience within a reasonable drive from the northeast corner of MD?

Thanks!
Pete

This is really a conversation to have with Dave if he is the one that you want to tune your car. And I won't rec anyone else.

Originally Posted by Pete_89T2

Thanks Vex - from what I read, the Rtek v2 for S4/S5 T2's has a setting that disables stock fuel fuel cut, so if I understand them correctly, it should support up to 1 bar (14.7 lbs) boost. This is due to the measurement limit of the stock boost sensor. Supposedly once stock fuel cut is switched off, the Rtek massaged stock ECU can manage up to the 1 bar boost limit, since the AFM is its primary sensor. Anyone with more knowledge than I please chime in on this. At any rate, I don't see myself running boost beyond what the BNR stage 1 turbo has its waste gate set to at 7~8 lbs boost. Too bad your for sale Rtek is an NA - would have helped to keep me on schedule!

How does the Rtek calc load? I was under the impression that it was EITHER MAP or MAF, not both as I;m getting the impression.

Originally Posted by RETed

The stock (FC turbo) fuel pump can barely handle the stock fuel injectors @ 4 x 550's.
It maybe maxes out at around 250hp at the wheels.
This is why an upgrade fuel pump is highly recommended.
Walbro's are the cheap standard, but be careful about fakes...
Look for the "255lph" Walbros.
(The stock FC turbo flows right around 180lph - 190lph.)
(Do a web search on keywords "walbro fuel pump fake", and you get a lot of hits.)
I like the stock JZA80 Supra TT fuel pump.
It has OEM quality and reliablity - made by NipponDenso.
It flows slightly more than the "255lph" Walbros.
It drops in.
It's priced slightly more than the Walbro at closer to $200, but I think it's worth it.



Can't comment on RTEK, as I'm a Haltech guy.


-Ted

I tested the Supra TT pump and it put out something close to 300lph @ 43.5psi and a FULL 14.4 volts. The Walbro can't match that, they whine like a little bitch, and there's a reason they're not offered in any OEM apps that I know of, so I'm assuming there's some merit to the rumors that they randomly fail.

[Pete_89T2]

Originally Posted by TitaniumTT

Lengthy? I'd use long, detailed, and thought out... someone's doing thier homework

Thanks - I just hate having to deal with do-overs due to poor planning

Originally Posted by TitaniumTT

Call/e-mail Dave @ KDR now Speed1, he ususally books a few weeks out, but around that time it might get a little more difficult as EVERYONE want's thier car done around that time. So I would finalize your plan, set a generous timeframe, then get in touch with Dave and setup a playdate. I don't know if he's used the RTeks... I'd imagine he has, but I would double check

I know Dave is a busy guy, and getting on his calendar is key to me making my DGRR 11 target date. I've got everything apart now, my turbo is ready to ship out to BNR, so I intend to have my plan finalized & ready to execute in the next few days. Speaking to Dave will be part of that process.

Originally Posted by TitaniumTT

The first thing I would do is a real comp test and inspect the engine as much as possible. Are you still running the stock OMP? I would be concerned with carbon buildup and some possible sticking seals. After all, 50k on a turbo engine is practically unheard of

I’m still running the OMP, but I do add a supplemental amount of premix to the fuel whenever I expect to run the car especially hard. I’ve been toying with the idea of using the rotary aviation OMP adapter so I can run premix via the stock OMP injectors, but I’m not there yet – I need to figure out a where to mount a big enough premix tank that meets the gravity feed requirements of the RA OMP adapter and still fits in what little space is available. Periodically I do the old "suck some H2O thru a vacuum hose" trick to steam clean the internals about once a year, and I make sure my car sees redline often. Hopefully all of this will keep the carbon from mucking up the seals. I haven't done a "proper" Mazda comp test in many years, but last summer when I checked using the modified regular comp gauge method, I get 3 even bounces of ~125 psi on both rotors so compression is probably Ok. Never had issues with starting hot/cold, at idle or making power.

Originally Posted by TitaniumTT

"the right setup" I would imagine is close to a full open exhaust, non-stock airbox, and some playing around on the dyno. So I wouldn't be surprised if you're setup produced a little less HP than that, but if that's not an issue as it doesn't seem to be, than I think this would be a good choice. While it's an upgrade, the only way to put less stress on the engine at about the same power outputs would be a totally custom exhaust mani and turbo. EMAP has a HUGE role in power output and stress on the engine. So IMHO, if you do upgrade, the BNR is definately the easiest, but not the most effecient or effective, but it's also the cheapest.

My setup will be nowhere close to BNR’s “right setup” – I’m staying emissions compliant, so the main cat will stay, and that will ultimately limit the HP my car can produce.

Originally Posted by TitaniumTT

Don't worry so much about the transition. Anyone who knows what they're doing can make that little hiccup dissappear. I'm running 725/2000 and under any conditions, I can't feel any hiccups. Personally, I would sport for the ID1000'sx4. They're hi-imp injectors so they should work with the Rtek, there's a bunch of different configurations for length and width, so they can fit, the only issue is you'll need to crimp on the new connectors. You don't need to worry about idle quality either. The quality, linearity, and fine atomization of these injectors is unsurpassed. However, if you don't want to spend the money, than I would keep the stock 550's and get something along the lines of 1000-1300cc's

I think my FI selection is going to be driven by parts availability and/or budget. I did a few “what if” runs on that handy FI calculator Ted linked, and it looks like 720’s in all 4 holes will be plenty to meet my modest goals, or I can do as you suggest and stick 1000~1300’s in the secondary’s, and keep my 550 primaries. Tuning wise, the Rtek gives you pre-sets for running all 720s, all 550s or a 550/720 P/S split, meaning it will run the stock map, corrected for the additional flow of 720's, if selected. This makes my initial tune easy so I can get my car to Dave's without blowing it up. I'm not 100% sure, but I think 1000cc FI's may be getting close to the upper limit Rtek can manage - they say they can support injectors >720, but they don't provide any hard numbers. Need to talk with them to find out more.

Originally Posted by TitaniumTT

Nope, get a new one. Walbro's are an option, but I hate them. Bosch's are another option, not a huge fan. Liek Ted said above, Denso pumps are the way to go. The Cosmo pump is a great drop in replacement. No fabrication required at all, RotorSports sells a kit or you can get the "One Time Fit Kits" that NipponDenso offeres. I saved the box from by Supra TT pump if you want the actual factory part number. The one that most resellers grind off the top so the secrets cant get out.... Well I know most secrets

Shoot me that Toyota part # if it’s handy – I know a guy who works for Toyota, maybe he can hook me up cheap.

Originally Posted by TitaniumTT

How does the Rtek calc load? I was under the impression that it was EITHER MAP or MAF, not both as I;m getting the impression.

Best I can gather so far, Rtek simply allows you to tweak the input parameters that drive the stock ECU fuel/spark control algorithms - it doesn't do anything to change the algorithms themselves. It also allows some additional user control over certain stock ECU functions/behaviors under certian conditions (e.g., turn off overboost fuel cut, turn off AWS).