First impressions after 370 cc injectors/JWT ECU...

[MarkEmark]

Well I FINALLY figured out why my alcohol injection system wasn't working so I was able to take the car out last night-it's the first time I took it out since changing the fuel injectors, ECU (JWT) and boost controller.

First impression-It felt a LOT laggier than my old set-up. I think I'm running quite rich-Would running rich make it feel laggier? I really need to go to a dyno and soon--I think I'm waiting till March 20 though when AceInHole set up a CT dyno meet in Bristol.

From around 3-4k rpm, the car felt VERY nice and responsive; however, ONCE again, I'm having serious boost drop-off problems. I'm getting so sick of not boosting the same psi throughout the rev-range. HOWEVER, I think this is due to my changing my "crappy" MBC to one designed for boost (Joe P MBC). Before changing my ECU/injectors/MBC, and after re-working my downpipe, the boost would go from 10 psi at around 3k rpm to 8 psi at 6k rpm--I can deal with that drop-off, although ideally it would be at 10 psi the ENTIRE rev-range.

When I took it out yesterday, it had as much boost dropoff as it did before I reworked the downpipe into a lot freer-flowing one--it stabbed to like 11 psi (in 2nd gear only) for a second; then was at 10 psi from about 3-4k rpm, then gradually waned to 6, yes 6 psi at 6k rpm. I'm pretty pissed as I've heard only good things about the JOE P MBC and I was hoping it'd at LEAST be as good as the standard needle-valve MBC that I was using before. However, I was wrong. When I have time I'm going to take it out with the old MBC installed and see what it does.

So the question is: Was it worth the $450 for the ECU and $100 for injectors and $128 for cleaning? It doesn't really feel like it...However, I'm being unfair as before I had 8 psi toward 6k rpm, now I have 6 psi toward redline, which is theoretically a ~20 whp loss up top, which will definitely make the car feel slower.

Next thing I'm doing to my car will probably be the JGS starion intercooler-I'm hoping that will give me some decent power as well. And I'm definitely going to invest in some good gauges--oil temperature, a/f, and maybe water temp. (I disconnected so many sensors when removing my fuel rail--one of them was the red connection with a clip toward where the inlet radiator hose connects to the engine--and my water temp doesn't work any more--which I hope is due to how I connected, or didn't connect, that red connection (even though it seems like it's pretty secure).

Now for some questions:

If I am indeed running quite a bit rich, which I won't know for sure for a while, what are some ways to lean the engine out? I don't want to go the S-AFC II route as it's very expensive ($300 at least), will be pretty complicated to install, and even harder to tune. I was reading Brian's posts on FA about upping the fuel pressure at idle to run a bit richer--what about LOWERING the fuel pressure at idle to make it run a bit leaner? Will aftermarket FPR's allow one to do that? This of course, would take some tinkering as I have no idea how low I'd want to take the pressure at idle. But if my injectors truly are 400 cc (which according to RC-Engineering they are--but this is by THEIR standards of flowing them @ 43 psi with a completely synthetic, non-gasoline solution), then I could be running quite a bit rich, and we all know lean is mean. Or, how about doing the reverse of the hacked MAF setup and making my MAF a bit SMALLER for the inner diameter?

Now onto the boost drop off:I was reading an old post in december asking for suggestions to remedy my boost drop off, and the general consensus is that my turbine a/r, .48, is not what's causing the drop-off as people have used it with very good results on high HP Ka's. Reading the post, people agreed that my compressor wheel was too small. Would increasing the actual compressor HOUSING to increase the A/R compressor help with flowing more pressurized air up top? Or would this merely veil the problem of my too small compressor wheel? (Not exactly sure what size it is; it's a T3 super 60 which is almost identical to a T3 60 trim). I really wish I had gone with a t3/t4 from the get-go.

About the T3/T4-the turbine will be exactly the same as a standard T3 internal wastegated turbo, correct? Meaning it'd have the same 5 bolt pattern on the back, with a 3-bolt pattern for the downpipe? I would only use this turbo if the turbine part bolts right up to my downpipe-I'm not going through the nightmare of refabbing that thing again. Would the turbine have the same physical dimensions as the one I'm using (I'm assuming you can get the T3/T4 with quite a different turbines; obviously I'd want to keep the T3 part of it the same as I have right now). I'm not worried about the compressor itself being larger as I'll be remaking all the pipes when I intercool it anyhow-and I can keep my CAI for the turbo and just change the connector where it goes to the turbo inlet if the T4's inlet is bigger (which I'm assuming it is-anyone know what's the OD on the inlet?) Anyone know of sites with the physical dimensions of various T3/T4's?EDIT--What about an upgrade kit so I can keep the turbine section? (http://cgi.ebay.com/ebaymotors...21900)

Otherwise, if the boost drop off is still being caused by the lack of a good boost controller, I'd rather sell my turbo (almost brand new) for $300 or so, pay another $200 for a T3/T4 than pay $200+ for a digital boost controller which I've heard can remedy pretty much all boost creep.

Sorry for the long post--Ideas, input, suggestions?

Marc

[huguetpj]

Or, how about doing the reverse of the hacked MAF setup and making my MAF a bit SMALLER for the inner diameter?

To run leaner you would need to go bigger on the MAF, more air going through without being measured.

Quote » Anyone know of sites with the physical dimensions of various T3/T4's?

[/quote]

Don't know if this is standard or not, but...

Compressors:http://64.225.76.178/main.htm

Turbines:Shoot the site doesn't list turbine sizes, but it does say:Quote »NOTE: All TURBONETICS Performance T3 Series turbine housing of the same trim are physically interchangeable. (Identical pattern to late Ford 2.3L Garrett). [/quote]

Maybe that can help.

Quote » pay another $200 for a T3/T4 than pay $200+ for a digital boost controller which I've heard can remedy pretty much all boost creep.[/quote]

Just as long as your turbine and compressor can handle the boost you want the boost controller to reach. Also, this will help if you can use the auto function of the boost controller. If you have to use the manual setting (as I have to) then it does nothing for boost drop-off.

[MarkEmark]

To run leaner you would need to go bigger on the MAF, more air going through without being measured.



Don't know if this is standard or not, but...

Compressors:http://64.225.76.178/main.htm

Turbines:Shoot the site doesn't list turbine sizes, but it does say:

Maybe that can help.



Just as long as your turbine and compressor can handle the boost you want the boost controller to reach. Also, this will help if you can use the auto function of the boost controller. If you have to use the manual setting (as I have to) then it does nothing for boost drop-off.

I realized that I'd need to make the MAF bigger right after I posted, and I tried editing it; guess it didn't go through.

I'm going to try and hook up the old mbc and see what she does.

[WDRacing]

TurboXS makes a great manual BC. I used the dual stg for 4 years at boost up to 28 psi. It was like a rock the whole time.

Running pig rich on boost will kill alot of those ponies you have on tap bro. Keep it under 12.5 for safety, but try to stay in the 12's if possible. High 11's at most. You should grab a wide band since they are fairly affordable now. It beats having to pay 50 here and 50 there for dyno time.

WD

[MarkEmark]

I'm not gonna go down the route of another MBC-i have a feeling it's just a band-aid for a gaping wound.

plus, this JOE P MBC has been lauded as one of the best MBC's money can buy--and it is a LOT more inconsistent than my home-depot MBC.

If I buy the $150 turbo XS MBC, i'm sure it'll be just as bad as the Joe P one that I have--plus, for $200 I can get a digital one. But there's no reason that a good MBC (Like the Joe P) shouldn't be allowing rock-solid 10 psi boost--the problem is with my turbo, me thinks, specifically the low cfm compressor wheel.

Does anyone suggest upgrading the compressor to a T4 and leaving the T3, doing this by myself? I have some experience disassembling/reassembling a turbo, but that was only to swap turbine housings--would this be easy/straight forward enough to do myself? My dad's also rebuilt a couple of turbo's in his day, and he could help me if he's around.

I don't think I'm running "pig rich," just a little bit rich. It shouldn't be running any richer than any other KA-T with a JWT ECU and sr 370cc injectors (since I determined mine are essentially 370's, even though they flow 400 with a synthetic substitute for gasoline).

However, I'm thinking that a larger compressor, which will obviously flow more air, will help lean out the a/f ratio--right? It makes perfect sense, because if I'm flowing 10 psi at 6k rpm, or even 8 psi, which I'd be happy with, the a/f would be a lot leaner than running only 6 psi at 6k rpm, when the engine's really seeing a lot of fuel.

I can't run a solid amount of boost on the setup I have right now because of some limiting factor--part of it's the MBC I'm using, part of it's the compressor's size, I think. I wanted to run 10 psi all day up and down the RPM range, but that doesnt happen--it's only at 10 psi for about 1000 rpm.

I also do not want to up the boost past 10 psi, even though the fuel system can handle it, because my engine has 95 k miles on it, and I feel 11 or 12 psi is just a bit too much--and if I DID want to run 11 or 12 psi, I'd have to set the boost controller so that it first hit like 14 psi, then decreased to 12, then 10--and I am definitely not running 14 psi on stock internals.

I always hear about wide-band, but I'm completely ignorant as to what this entails....

Marc

[MarkEmark]

Not that any of you care (wow, only 2 responses! ), but after switching to my old crappy needle valve boost controller, it loses less boost up top--with that Joe P one, it was dropping as low as 5 psi by 6k rpm--that is HORRIBLE.

At least with this one it doesnt drop past 7 psi--but still, WHY WHY WHY is it losing 3 psi up top?!? I feel so cheated--I wanted 10 psi all around.

I'd upgrade to a $300 greddy profec b boost controller but I'm afraid it will do the exact same thing as the Joe P one which has been praised as the best MBC out there--Would upgrading my compressor to a T4 ensure a hard 10 psi of boost all the way up top?

[andrave]

if you are getting that wild fluctuating boost with the boost controller, don't abandon any hardware, just take a look at your vaccuum routing and your MBC's... try and borrow an electronic one. Better yet, tell a shop you want one but you only want it if it solves your problems... if it doesn't take it back. actually ebc's hold their value enough you wouldn't lose money if you resell it.

[Nathan]

I sincerely doubt it's the boost controller. I know people running 15-20psi rock steady on Joe P MBC's, and it sticks right where they set it, no matter what.

[MarkEmark]

I know, I'm confused as to what the hell is causing this--I've checked all my vacuum lines/couplers, etc, there's no leak anywhere.

It may not be my MBC, but my old MBC works quite a bit better than the Joe P MBC---

I'm going to play around with a variety of setups probably tomorrow with the MBC--maybe even use two in conjunction with eachother, and possibly use no boost controller at all and see what the turbo does, maybe disconnect part of the exhaust again (even though a new exhaust is a non-issue as it'd be too expensive--not to mention, I thought 2.5" mandrel bent all the way back with no cat would be plenty high-flow for 10 psi).

I dono, I'm getting kinda frustrated playing around with the boost controller and trying to get a consistent reading...

But again--especially if people think my MBC is not causing this, would a T4 compressor be more likely to keep high boost up top? I'm thinking about keeping the T3 turbine and upgrading to a T4 compressor; they sell upgrade kits for ~$200 (cheaper than an ebc).

[Nathan]

If you wanted to upgrade your turbo, you could keep the same exhaust housing but upgrade to a T4 compressor and the appropriate chra. Other than it being your turbo, I'm really at a loss as to what it is. Whats the internal wastegate of the turbo "set" to? If it's high enough, you could see if it was still falling off just running a direct vacuum signal straight to the wastegate.

[AceInhole]

going to a new compressor may be a bit extreme. i'm running a T25 and I've got no problems keeping it at 8psi. with a T3 he should def. be able to stay at 10.

If you want you can try my MBC on your car real quick to see if that might help. That would require you driving your car over here though :p

[MarkEmark]

If you wanted to upgrade your turbo, you could keep the same exhaust housing but upgrade to a T4 compressor and the appropriate chra. Other than it being your turbo, I'm really at a loss as to what it is. Whats the internal wastegate of the turbo "set" to? If it's high enough, you could see if it was still falling off just running a direct vacuum signal straight to the wastegate.

Yes, I think I'll try it without any boost controller, as the wastegate is set to the max as far as turning up the boost. However, if it is dropping off so substantially, wouldn't it be more likely to drop off with higher boosts (10 psi to 6 psi) than with lower boosts (if it's at 6 psi max, it may stay there and not drop, not due to the absence of a boost controller but due to the fact that the turbo can handle 6 psi anywhere...)

Here's a pic of the existing setup:

http://www.eniety.com/pichost/pic/129-2902_IMG.JPG

It's hard to see, but after the needle valve, there is a vacuum tee that bleeds air back into the intake. Why bleed air back into the intake? I've found boost is most consistent that way, and higher too.

Here's a pic of the old setup, which worked better than the one shown above:

http://24.59.109.135/pichost/pic//116-1668_IMG.JPG

In this setup, the tee that bleeds air back into the intake is BEFORE the needle valve.

I've tried running the Joe P MBC in the same setup as the ones shown above and it hasn't worked out well; i've also tried running it directly in-line with no air being routed back into the intake--it ran the worst like that.

I'm going to go back to the "old" setup, see how that works--if it still works crappily, then I think I'm going to keep everything the way it is in the "old" setup, and install the Joe P MBC in-line to where I have the vacuum tee bleeding air into the intake-that way I think I'll be able to control everything better. It may sound superfluous, but if it works, I'll be happy. If none of the aforementioned does work, I'm going to kill myself. Well, maybe not kill myself, but I may be drastic enough to change to a T4 compressor--BTW, how hard would it be to convert to a T4 compressor? Is it as easy as tearing down the turbo and just removing some bolts? Or does it need to be done professionally with specialized tools?

PJ--I thought you just had a simple needle-valve as well for your MBC. Do you have it set-up like the ones shown in the picture?!?

[TrunkMonkey]

MarkEmark, you're running non-intercooled?

-demetrius

[MarkEmark]

MarkEmark, you're running non-intercooled?

-demetrius

Only for another few weeks or so; I have the intercooler sitting on my desk. Of course, I'd never dream of running 10 psi in the summer non-intercooled (although it's been alcohol injected since day one), but in this cold weather, my intake temps never get past like 70 degrees anyhow-and that's after a hard run.

I wish I had more time to screw around with the MBC's before I leave for Fort Lauderdale, (I'm on feb break), but I'll gladly take the nice weather