Hey y'all. Bought this car as a project. I know, I know, when you're buying someone else's project you're buying someone else's problems. Don't worry, this car is NOT my DD. I just wanted something to wrench on and have fun with. Anyway, I was hoping y'all could look over my mod list and dyno graph and tell me what you would change or upgrade first. I'm trying to shoot for a "safe" 400 whp.

Car is a 1990 CRX Si with a semi-built JDM B16A (SiR-I, converted to OBD1) with T3/T4 turbo.

What I've done since I got the car:

• Compression and leakdown test. 140 +/- 2 on all cylinders. Less than 10% leakage (appeared to be about 5% avg on all cylinders).
• New inlet piping
• New distributor
• New main relay
• New resister box
• New MAP sensor
• New TPS
• New coolant temp sensor
• New IAT sensor
• New valve cover gasket
• Adjusted valves
• New grommets
• New cam seals
• New tires and alignment
• All fluids flushed and replaced
• New optima redtop battery
• New timing and alternator belts
• Fixed pinhole leak in downpipe (welded)
• New wastegate dump pipe (WG was just facing the radiator before)
• New DP flange to match turbo

Now for the mods (only listing power/engine mods, won't bore you with the suspension and cosmetic stuff):

• SRP 81.5mm 9:1 Pistons
• Eagle H-Beam Rods
• ACL Bearings
• ARP Rod Bolts
• ARP Head Studs
• Polished Crank
• Mild ported and polished head
• GSR Cams
• DSM Blue Top 450cc Injectors
• XS Power T3/T4 Turbo (.84 AR exh. .50 AR compressor)
• Huge ebay FMIC (32x12x3)
• 2.5" downpipe to 3" exhaust w/ Megan muffler
• Two catch can setup (10am off valve cover to one, 2-10an off block to another)
• Greddy Type S BOV
• CC Fab Mini-Ram Manifold
• Knockoff 10 PSI Wastegate
• Short Throw Shifter
• YS1 Cable Trans (non LSD)
• ACT Xtreme 6 Puck Unsprung Clutch
• ACT Heavy Duty Pressure Plate
• Aluminum 12 lb Flywheel
• New radiator/slim fan
• Hasport Mounts
• Rywire Conversion Harness
• NGK One Step Colder Plugs
• Tuned on chrome for 93 octane and 10 PSI

Annnnnd here's the dyno graph from yesterday. 4th gear pull, I don't think he took it all the way up to 8k, but this is what I've got.



Sorry for the shitty pic. Next time I'm in the shop I'll just take a screenshot at the dyno comp. Seems to be leaning out after 6k. What do y'all think? I'm thinking either the tune wasn't done right, or something mechanical is preventing it from getting the fuel it needs. Injectors appear to be clean, but I haven't had them flow-tested.

Anyways, here's what I'm thinking. I think most of the pieces are in place for my goal, but I was thinking I should get:

- Bigger injectors. Would 1000cc's be overkill for my goals?
- Bigger fuel pump (was thinking Walbro 255lph)
- Hondata S300 or Neptune (and a GOOD tune on the dyno)
- Wideband A/F gauge that sends narrowband 02 to the ECU (car currently doesn't have an 02 sensor for some odd reason)
- Obviously a boost controller of some kind

Any other suggestions or better ideas? I'd like to not spend more than 2 grand, but I will if I have to. Any input would be greatly appreciated!

 

1000cc isn't a bad idea to use I'm running that. I would look into itr cams it's not needed to hit your goal, but the cams can help out more so than gsr. Your going to need that Wally fuel pump. As for the turbo itself, is that a knock off brand? Wastegate you want to use a name brand, dont want to run into other issues with the no name down the line. So the vehicle has no o2 sensor at all? Tuning software is up to your tuner

 

Oh yeah, XS Power is sort of a knock-off brand. Mani's are known to crack, but I've had no problems yet. I wouldn't mind changing turbo's. I was thinking something like a Precision SC61. Anyone have experience with that particular turbo? On the pricey side for sure, but it shouldn't put me too much over my budget. For wastegate, I would probably go with tial. I've had great experiences with their BOVs.

Will definitely look into ITR cams.

Yeah, NO O2 sensor. Ridiculous, I know. But I figured instead of buying a regular O2 sensor I might as well get a wideband gauge that sends narrowband A/F to the ECU as well. It'd be nice to see the A/F's in real time if I'm going to be pushing 400whp.

 

i have my stock o2 and my wideband separate. yeah i could wire in the wideband o2 to the ecu but i feel the narrowband is best left alone, its a matter of opinion. but you need some sort of o2 sensor for your ecu because i cant see how it can figure what the air to fuel mixture is

as for the turbo, you can search the feature for that

 

I don't want to sound rude, but why is the HP on your dyno so low? It seems like 10 PSI through (forgot your turbo) should put out more than that.

I would look at the tune for reasons of your car being lean. 200 HP isn't even near the edge of DSM 450cc injetors. 400 whp shouldn't need 1000cc injectors either, but you can get them. Pretty sure 750cc injectors would more than cover your goal.

You will need a better fuel pump. That could be why you are running into lean issues.

Crome is really good. You can upgrade if you want, but if you are getting it tuned somewhere just let them use crome pro. Most of the tuners I know have a license and tune with it.

A wideband is a definite yes. I wouldn't run without one, just in case of failures. I bought an AEM UEGO with the bosch sensor for relatively cheap ($160), brand new too. PM me if you want a link.

And for a boost controller, if you plan on getting it tuned and running on that, get a manual controller to save money. The good ones, non knock-off brands, run about $75. Worth it though, since you don't want it to fail and give your motor twice the boost it is tuned for.

 

I may have the terms backwards, but I think open loop is when the ECU uses the O2 sensor. And that is only under cruising conditions and idle. It strives to hit 14.7 AFR. At least stock. On the other hand, closed loop, it pulls directly from the fuel table on the ECU. It uses the MAP sensor and the RPM to decide on the fuel and ignition timing. I believe some people tune and leave their cars in closed loop. I Know for a fact that you tune in closed loop, mostly.

But I do agree with giving the ECU it's own stock signal and then using your wideband separately. That is what I am doing too.

Can someone correct me if I'm wrong. I think that is how it goes, but if I am wrong I will delete this post. I don't want to spread wrongful information.

 

I think you've got it backwards, but you're on the right track. When running in closed loop (idling, normal driving conditions, etc.) the ECU looks to the O2 sensor and decides how much fuel to add/subtract to the A/F mixture depending on what the O2 is telling it.

When running in open loop (during WOT, for instance) the ECU just shoots for whatever the fuel map has told it to go for.

But, aside from the terms being switched, you're spot on. Tuning is usually done in open loop, otherwise the ECU will alter the mixture while idling/in between dyno runs.

Basically not having an O2 sucks, because while driving normally the ECU is not going to be getting any A/F info and it's not going to know what to do and run like ****.

 

Just curious, is there actually any verifiable evidence that running a stock O2 sensor is better than running a wideband sensor that sends a narrowband signal to the ECU at the same time? I've already got a bung in my downpipe for an o2 sensor, I'd rather not have to bother with making another one somewhere else just to have two sensors.

Also, I have used the search function, and the SC61 looks good. What's the harm in asking if anyone has had experience with it?

 

How are you doing your compression test? 140 is not a healthy motor, you must not be doing it correctly. open loop is when the ecu does NOT see o2 voltage. You have all that good stuff on your car and a pos ebay turbo shame shame. They work but dont last and they wont put out the power a real turbo will. also if its a 50a/r compressor its probably a super small wheel dont expect to much out of it.

 

all of this is exactly what I was going to post as well, with the addition of saying:
make sure you get the walbro 255HP, notice the "HP" part, its a different pump than the normal 255; it flows higher volumes at higher pressures than the normal 255, which is definitely what you want for a boosted application.

I'm not too familiar with gsr cams in a b16 SiR-I, but 140psi comp test does sound about right to me for a 9:1 piston setup if the primary lobes have decent duration, especially if you have adj cam gears and have dialed out any amount of valve overlap. it also depends on ring end gaps. larger gaps will lower comp test numbers.

I also didn't see anything about aftermarket valve springs. you should strongly consider getting some stiffer springs.

From here on out, I would start by double checking your valve lash adjustment, and setting it to the looser end of stock spec, just not anything beyond stock spec.
then upgrade your fuel pump to the walbro 255HP. then get a re-tune still keeping the boost and everything else exactly where you have it right now. the lash adj and pump will have a decent effect on your tune, and will give you a much better idea for a baseline on where you're starting from and what you might want to do to improve from there.

also, ditch that unsprung clutch disc. unsprung discs are ONLY for high profile wrinklewall drag slicks. running an unsprung disc on street tires will rock and rattle the engine and tranny like all holy hell because there is absolutely nothing to absorb impacts and vibrations through the entire drivetrain. sprung discs are specifically sprung to absorb vibrations and impacts to prevent damage to vital engine and drivetrain components. get the same disc you have now, but the sprung version.

 

leakdown is very high... and the compression numbers sound all wrong

how did you do the test? the motor has to be hot, unplug the injectors, pull all 4 spark plugs, hold the throttle wide open and crank....


and your dyno graph shows nothing.... nothing to indicate the car is boosted. most healthy NA motors with bolt ons make that kind of power

so either you have a massive boost leak, **** tune, or more likely your knock off chinese turbo is fucked, and the poor health of your motor is making it even worse

 

and the ecu needs to be seeing the 0-5v output from your wideband as it's primary o2 signal.... you cannot datalog accurately and tune the car properly without having the wideband lambda values in a table... the stock narrowband is useless to tune with

 

you should be making way more on 10psi with that turbo re do your compression test make sure the tb is at full throttle and engine warm