New Turbo, supporting mods?

[Dan_Gyoba]

Okay, got a new (used) turbo. Very happy with the deal, but I want to ensure that I'm not going to do anything bad bolting it on.

It's a Turbonetics bolt-on, internal wastegate, should bolt up to the manifold (with a spacer) and LIPP elbow.

Supporting mods (Either installed, or will be) as follows:

• LIPP Elbow, RT downpipe, and Tanabe exhaust. (installed)
• Lexus AFM, PTE 550cc injectors (installed)
• MBC (Will be installed when turbo goes on.) 12-14 PSI manifold pressure is the target.
• Spearco replica IC. (Will be installed ASAP.)
• 2.5" IC piping (to be installed with IC)
• HKS SSQV w/ recirc fitting (ditto)
• Walbro 255lph fuel pump (To be installed ASAP.)
• 12V mod + upgrade to 14AWG wire to handle Walbro fuel pump demands.
• AFPR? (Don't have yet. Recommendations?)

Anything that I'm missing in that list? A MAF-T pro is on the list of things that I'd like to upgrade to eventualy, but I'll stick with the Lexus AFM for the time being. I believe that this should be adequate to my needs for the stated goal of 12-14 psi manifold pressure.

I get some conflicting data on the AFPR, some say "absolutely a must" but I've also heard that just removing the restriction in the "J" tube should be adequate with the stock FPD. Solid reasons why an FPR is a must appreciated, thanks. Not just "the stock system can't keep up with the flow" -- after all, it's the stock system that's carrying the flow from the FP to the fuel rail, so it should certainly be able to handle returning it to the tank, provided that there aren't other restrictions in the line not there to create fuel pressure.

Of course adjustability in fuel pressure gives me some gross A/F tuning capability, which I don't otherwise have. Anyway, I'd like hard data on why this would be needed (or not) as opposed to a "nice to have". It'll go in eventually for sure, but whether that's before or after the turbo upgrade is the debate.

I like to understand mods before I do them, so that I am aware of the consequences, and the other implications of doing them.

Thanks!

 

[GrimJack]

Gee, that setup looks AWFULLY familiar. Except I'm running the BIC DDP. Same turbo, same IC pipe size, same BOV, same IC (well, close enough, I have the original Spearco)... I run the RC 550cc injectors instead of PTE. I'm running a wideband and the MAFT Pro. I have the Walbro pump, but I haven't installed it yet - haven't run out of fuel pushing ~12psi, either.

I couldn't get mine to pass smog tests at idle out here without messing with the FPR - I have the aeromotive unit. It was still running fine, just not clean enough for the exhaust sniffer.

You'll likely get 12-14 psi even if you don't hook up the MBC. I did!

PS: At 12-14 psi on that setup, you better have DAMN fine tires for second gear - first gear is just going to be a writeoff. R-compound rubber might hold second if the road isn't cold. Anything less will spin third gear when boost hits. How's your clutch?

 

[Dan_Gyoba]

Right. I have an eBay special 6 puck clutch. Apparently though it turns out that the clutch I have is a stock disc with the ACT pressure plate. I think I'll test both pressure plates when I put that clutch disc in and use whichever one shows more clamp force.

So even the fuel pump upgrade I should be able to get away with not installing first?

Now, that being said, once I do install the Walbro on 12V full-time, would the AFPR become something necessary at that point, or would simply removing the J tube restriction be enough? I'm not concerned with smog testing, since we don't have that here in Alberta.

Thanks for the information, given that your setus is similar, your experince is invaluable to me.

 

[jdub]

Dan - As you surmised, an AFPR allows for a "global setting" to adjust AFR. It's not required, but if you have an over rich condition at boost, it will be the only way to help solve it. I had this exact thing happen to me with a Lex/550/Walbro set-up with a SP-61 turbo at 18 psi... had to drop fuel pressure to 27 psi (w/ vac line connected) to get it to stop. The Walbro flows quite a bit more fuel than the stock pump...to control it, an AFPR comes in very handy. When you get a MAFT Pro, you can further refine AFR to get the performance you want.

I also have the Aeromotive AFPR. You will need to eliminate the J-tube or drill it out to stop the orifice in it from increasing pressure from the Walbro.

 

[sneakypete]

Dan - As you surmised, an AFPR allows for a "global setting" to adjust AFR. It's not required, but if you have an over rich condition at boost, it will be the only way to help solve it. I had this exact thing happen to me with a Lex/550/Walbro set-up with a SP-61 turbo at 18 psi... had to drop fuel pressure to 27 psi (w/ vac line connected) to get it to stop. The Walbro flows quite a bit more fuel than the stock pump...to control it, an AFPR comes in very handy. When you get a MAFT Pro, you can further refine AFR to get the performance you want.

I also have the Aeromotive AFPR. You will need to eliminate the J-tube or drill it out to stop the orifice in it from increasing pressure from the Walbro.

had the exact setup and problem when i had the lex afm. was resolved when i went maftpro. maftpro made it a lot easier to fine tune compared to the afpr alone.
my vote is that a afpr is a must when doing fuel mods. and at least get a wideband and/or maftpro with wideback tracking.
-pete

 

[Dan_Gyoba]

Okay, here's another question:

The wastegate actuator that's on this thing is a dual-port. I gather that the diaphram is between the 2 ports.

So, this means that the diaphram should open on a pressure differential between the 2 ports, but which parts of the intake system should be represented here?

The one side is obvious, and will represent the intake track, pre-TB. This is the same then as a single port actutor.

The other side though...

One posibility (And the way it was connected before) is to leave it open to atmosphere. This then makes the pressure differntial the difference between atmospheric and IC pipe, which we know works, but then what advantage to the dual port? Maybe to filter the air?

No. Somewhere else in the intake then.

The only place that I can see this then working is if it's in the intake, before the turbo, so someone set me straight if this is wrong.

This would then have moderate vacuum applied while you're boosting, which would open the BOV a bit sooner and easier when you hit max boost/flow, which in itself doesn't make much difference over just a weaker spring in a single port. So I started thinking about other situations.

How about when you snap the throttle shut, say in preparation for a shift. Suddenly there's not so much vacuum there, and if you've got a recirculated BOV, then there might even be a slight positive pressure (Though unlikely) for a but. That's going to close the wastegate a bit faster. Doing so (I surmise) could help with re-spool times.

This is the scenario that makes sense to me, but I could be way off in where the second port goes, and what it's purpose is.

Another possibility would be for boost control. Supply boost to both ports, and the wastegate doesn't open. When the desired boost pressure is reached, allow the front port to vent pressure, which opens the wastegate.

These are very different scenarios, pretty much mutually exclusive, and possibly both incorrect. I'd like to know if there are any advantages that this wastegate actuator gives me, after all I hate wasting equipment that can do better.

 

[IJ.]

Dan: 5psi spring in the gate supply 5 psi to the 2nd port through a boost controller = 10 psi.

Doing it this way means you can run a nice light spring and the exhaust pressure won't blow the valve off the seat.

 

[ForcedTorque]

First, if those PTE's are from ebay, it would be a great idea to take them out and have them flowed before you up the boost. Mine are ebay PTE's, and I was somewhat (?) lucky in that they are all matching. But, they came back as flowing 615 rather than 550. Cleaninjectors.com will flow (only) them for $25.

And, if that 6-puck clutch is also the XTD off of ebay, it would likely be a good clutch for you now, but not quite enough once you complete your mods. It has a bad reputation around here, but I loved mine when I didn't have much power.

When you go to install your Walbro, I used Shaeff's write up to post a thread with many photos along the way in the tech section for those who don't know what to expect in there. It's really not a bad job at all.

 

[Dan_Gyoba]

Okay, so I was coming at it backwards, but that's basically the second scenario then. Boost goes to both ports, but instead of venting the second port, you just put a limit on pressure to it.

Hmmm... The MBC that I have won't do it, since it's designed to be off until a desired pressure is reached.

So this would be more like a pressure regulator then, free flowing until the shut off point is reached. More complex mechanically, but I do see the value in it.

Edit: The PTEs I got second hand from someone who's moving on, and they've been taken care of. Yeah, they're a bit more than 550, but I don't have a longer screw for the Lexus AFM either, so...

The clutch is the eBay "F1" clutch, which I decided that I'd take a chance on since it's 1/3 the cost of an ACT. I figure that it'll either last okay, or it won't. At this stage of the game, I can't send it back, so I might as well install it. It doesn't look like poor build quality, and at worst, it's a stock PP and a 6 puck clutch. Nothing wrong with the (oem) pilot and throwout bearings, though.

 

[Dan_Gyoba]

Well, 2 years later, and let's see what I've done...

I never did install the eBay F1 clutch. Just bought an Action Stage 3 from Aaron, which I will be installing ASAP, because the clutch I had (as expected) is done. The setup I had was never too hard on the tires, since the clutch was a weaker point. (It wasn't EASY on the tires, either, but it wasn't as hard as it would have been.)

I bought and installed the Aeromotive AFPR. (Also from Driftmotion.)

I also haven't yet installed the Walbro, since dropping the tank is a pain, and so far, I haven't had fueling issues at the boost levels that I'm running. Still, since the car is out of commission 'til I get the clutch in, I'll probably try that this week. Going to be a pain running the wire, though.

 

[GrimJack]

More like three years.

Running the wire for the pump isn't that bad... getting the tank out is a PITA, though.

 

[Another MkIII]

I personally found the tank to be fairly easy to remove. Having said that, I had an empty tank, no rust at all, and a motorcycle jack to make it go very smoothly. Still, if you have access to a motorcycle jack, it is probably the best tool for raising and lowering the tank unless you are using a lift and a trans jack.
-AM3