Is there any feedback from those with modified fuel systems? I would appreciate an update and what tweaks have been made if any. How are the TTM injectors working out? Fuel rail with crossover? Does an upgraded fuel pump need to be installed as well? What does a fuel setup like set one back?

My zt-2 came in and I need to get the exhaust bung welded up. Can anyone recommend types of places where they have had this done?

 

Meineke? Any exhaust shop can easily put in a bung.

 

Maybe, but most of them will use MiG with a carbon steel wire, not a good thing. I found a specialist tuning shop, (it was actually a GM LSXshop ), and they TiG'd it. Be sure to ask what they are using, as our exhaust is SS
I used the Needswings/Waldig upgrade, using the Zt2 to control fuel pressure. I probably could have got away with the upgraded pump, and adjustable regulator, as currently my system does not need to supply any additional pressure via boost. Total cost was about $1200

 

There are two fuel related links in my signature that you might find interesting. The SL55 solved my lean issue with the 181pulley, adding 5 MPH to my trap speed.

Once I went stacked, it started running lean again. That was solved with TTM injectors and looped rail.

 

Great feedback guys, thanks. I am only starting out with a 62mm SC pulley with DCAI. Magredvet, did you have a lean issue with the 181? If I plan on going stacked one day would it hurt to invest in the TTM setup or will this run too rich?

 

Without the upgraded fuel system, I was going dreadfully lean above 5000 rpm, at one point it even threw a lean misfire code..............that's why I decided to go the whole hog, and fit the Zt2, so I could monitor the AFR all the time.
OT ...........where in South Texas are you located ?

 

I recommend you keep it as simple as possible. If you run lean, get the SL55 pump. If that alone doesn't cure it, you need to decide which of the two proven paths to take (or go your own route) TTM or NW.

I like Rob and have a car full of his stuff. However, in this one instance I not a fan. I don't like the complexity of the system. To me, running a solenoid, AF trigger, adjustable fuel pressure regulator, etc is way too invasive and complex of a fix. IMHO there are too many things that can go wrong.

With the TTM setup, I installed the injectors, modified fuel rail (with front crossover), and got a retune. That's all it took and I'm seeing a pretty flat fuel curve across the board even when I hit 22.7 PSI.

I really don't know what the TTM setup costs (as I got it at a discount for being a guinea pig) but I suspect the price is comparable between the two.

 

I'd be interested to know the answer to the second part of the question - "is the SL55/TTM/looped system good for low rpms as well as high".
In my business we call this "turndown" - the system might be good for your 550-600cc/inj/min WOT needs but what about your 'round town 130 needs at idle - is it rich or show poor fuel consumption (...as if that matters when you're in this zone)?

My calcs suggest you need 576 at 6000rpmm, 100% duty, 21psi boost but at only12AFR - something larger may be "safer" and more future proof....but by all reports Steve and Grip Grip's outcomes with the pump/injectors/rail were bang on with their stacked 22psi setups and Steve logs the crap out of every detail.

I've read there are Bosch 750's out there which could possibly put you in a sweeter duty spot (target 80%) and allow your tuner to hit 10AFR's (690cc - if he needs to) - but again - I'm not aware of the turn down capabilities and needless to say - Steve know's his $hit and would have explored all options...

Not to mention, the gamut of cooling issues you run into over 20psi....

PS - I got a quote from TTM in Sept at $420+post
https://www.crossfireforum.org/forum/crossfire-srt6/53768-stacked-pulleys-23-psi-no-codes-3.html#post645398

 

Here you go. This is stacked (22+ PSI) with the TTM setup and SL55 pump:

 

as a staged approach - would going the TTM's as a direct replacement for the stock - without doing anything else have any adverse effects?
Would you need to set them up with pulse/tune etc or a simply 2hour slip out stock and slip in TTM?

 

I've heard second-hand from a user on here that the car runs fine in closed loop without a tune. Obviously the ST's are are going to be fairly high right out of the gate, but maybe if you drive long enough for the LT's to set, the open loop AF might look pretty good.

The only adverse effects I would watch out for is washing out the rings. Give the car enough time to adjust and set the LT's before going open loop and you might be fine. If it's still pig rich in open loop, get a tune. Other than that, I don't see an issue.

 

My album shows the exhaust work I did, unbolted it and did it on the floor, you can go to a shop and save some money doing a walk in. Woody

CrossfireForum.org - waldig's Album: Exhaust bolts and hardware - Picture

PLEASE do not click on the left right arrow. Click on the works :Exhaust bolts and hardware

 

You may not be running lean. I am running a 185mm pulley and with the EC tune when I logged I was not running lean.

 

I can't wait to learn all the data logging crap...lol..... we've started tearing into to things... Tearing doesn't sound very professional does it...routing wires, and figuring out where I want the dashdaq, and plumbing in the meth tank and pump...still up in the air as to whether to hook it up now or data log, then hook it up and data log some more which probably makes more sense. Anthony, sound like you gained a lot with that little tweak....

 

thanks everyone for all the info, lots of good stuff here. I can't wait to figure out datalogging after doing some reading and logging of my own.

Billy you said the TTM route was $420 + shipping? Did you happen to get a price for fuel rail with crossover loop (that's even if it comes from them or is it a DIY)?

Sounds like the AFR could go either way and that is why it is important to datalog...




I am just north of San Antonio

 

Remember that the boost is reducing the pressure differential across the pintal limiting your fuel available. I have run a car without a fuel pump, at idle when the manifold vacuum actually sucked the fuel from the injector. Open the throttle and it dies though.

If you have a rail pressure of 60 and a boost of 20, you only have a 40 psig differential to fuel the engine. I did testing and posting showing how raising the rail pressure solved it all.

I used the boost to feed back into the regulator fitting and at high boost got 80 psig on the rail and consistant 9:1 F/A ratio. Way too much, on my car I only needed to boost the rail pressure a few pounds to keep in the proper range. This is why I did not choose to try changing the injectors.

Enjoy, Woody

 

running a looped rail shows true fuel pressure. in oem form i was logging 59 psi. looped it and dropped to 55 psi at idle wot dropped to 52 psi. 7 psi lower than it read in oem form at wot. remember the rail builds pressure from the front back towards the firewall so the 2 back cylinders are running leaner than the others. adding the sl55 pump raised me bak up to 60psi at wot and the car idled like a bone stock car. scaling the injectors is the key to a smooth idle and fast throttle response.
420$ plus shipping would be for the injectors and harnesses from ttm. figure another 300 or so for the modified rail and fittings and hose. thats not a stated cost just my knowledge as to what you could be spending for a complete setup from ttm. not cheap but simple safe and proven.
if anybody wants any of the ttm parts let me know with contact info and ill pass it along to bruce
btw on my final tune i was running 12.2 at wot and ran 11.8 at the 1/4 mile in 80* heat. tuning is the key to all these mods be it stacked, s/c pulley , crank, rails etc etc. find a proper tuner and the parts all fall together. get a canned tune add these parts and you will chase your tail forever.

 

I was surprised to learn this. On the turbo cars I've had experience with the OEM fuel pressure regulator is referenced to the manifold pressure/vacuum. Thus the fuel pressure across the injectors is constant, the spray pattern consistent, etc.

As long as the pump is up to the task (i.e. Walbro, SL55, etc), I would think the stock injectors could provide all the fuel you'd need with an adjustable boost/vacuum referenced fuel pressure regulator. Sounds like your results Woody already proved it.

All things considered, a fuel pump and regulator upgrade is pretty cheap and easy. And maybe throw in a looped fuel rail to assure even distribution. You would need to get a TUNE specifically for the variable fuel pressure though.

 

I actually used a fuel pressure regulator to build an analog pressure controller, that was controllable.

The initial setting was variable and provided the following pressure signal out to " boost compensate the rail pressure" I did not want to connect the boost to the regulator because if the idle pressure was say 60 psig, at 5 psi boost Id get 65, and at 10 pounds of boost Id get 70 psi. This will simply drown the engine in fuel.

The regulator was cross coupled to provide the following output response, and Iam kinda proud as I have never seen a regulator setup like this before. I have over a dozen patents and if there was an use, this could be good for another - simply dont see a need what with digital contols.

Rail pressure // Boost PSIG // regulator output // Rail pressure modified

60 / 0 / 0 / 60
60 / 2 / 0 / 60
60 / 4 / 0 / 60
....../...
ditto
60 / 14 / 0 / 60
60 / 15 / 1 / 61
60 / 16 / 2 / 62
60 / 18 / 3 / 63
60 / 19 / 4 / 64

and on and on and on. NOTE THE NUMBERS DONT LINE UP DUE TO THE WORD PROCESSOR, YOU HAVE TO READ THE TOP LINE AND SEE THE COLUMN OF NUMBERS THAT MATCH UP TO IT. TABS DONT WORK HERE, grrrreeeee

As you can see the cut in prevents and output signal till some adjustable set point - the example above the cut in was set for 14 psig of boost. Above this setting I modify the rail pressure to elevate the pressure 1 psig per psig of boost ABOVE the set point ( here 14 psig as an example ). Kinda need to allow the open loop of the car to keep the lean effect at bay, and since the cut in is adjustable you make it what you want , even the STOCK fuel regulator under the passenger seat has a pressure fitting to allow this to work. Currently the stock fuel regulator is connected to a vent pipe for atmospheric pressure.

Enjoy the weekend, best wishes to the Jersey and New york area people. Woody

 

Since I am an amateur at this, I'd like to know where to purchase the modified rail and injector setup. What is TTM anyway? I've seen this mentioned several times but am not familiar.