I have a Cobb Accesport, a Kline exhaust (from Sam),... ByDesign intercoolers (from Sam),... ID1000 injectors,.. DO88 turbo inlet tubes, and my stock turbos were converted by Blouch to 63.5 VTG's, and my car makes 625 hp / 630 torque at the wheels on 93 octane pump gas on a Dynojet dyno. ( Roughly 720 crank ? )

I also have an Aquamist HSF-3 meth system spraying 75% meth out of two 1.0 mm nozzles, and with that activated and the meth tune installed, it makes about 715 wheel hp. (835 crank ?? )

Tuned by Sam of course.

What I found is that with the meth system on and the 1.0mm jets,.. it would stumble momentarily when I rolled into the throttle until it was fully warmed up. (Until the oil temp was past the first line at 8 o'clock. 175 F ?) The bummer of that was,.. I often will take the car up to the store,.. and I can't accel hard until I'm almost home.


SO,.. I dropped the jets down from the two 1.0mm to some 0.4mm ones,... so I'm spraying like 19% as much meth, and put the 93 oct pump-gas tune back in it. Still,.. this is enough to drop intake temps 20 + degrees, and keep there from ever being any knock (You see,.. even on a great tune, there is sometimes a couple degrees pulled momentarily in a couple cylinders). So now I do a 3rd gear pull on a hot day, and the intake temps drop 10 degrees F during the pull instead of climbing 10. So it pulls really hard, EVERY time.

Still,.. that amount of charge cooling along with the extra octane is enough to add probably 30 wheel on the pump-gas tune when it's hot out,.. and not much when it's cold.. (655 wheel in total?).

The car runes like a raped ape,.. drives like factory,.. and I only have to put a few gallons of water/meth mix in a year.

My advice ? Ask Sam.

Deciding on parts? Ask Sam.

Need a tune? Ask Sam.

 

I ask Sam a lot of things and he always has an answer - fast! That's strange that you had a stumble with 1mm jets. I used the Aquamist instructions to calculate my jet size and went with a pair of 1.2 mm jets. Before Sam tuned for the meth it was still doing a great job of keeping the IATs down but never made the car stumble or feel any faster - just consistent. After some logs to Sam and a new map the meth is noticeable especially at the high RPM range. I'm on stock injectors so using IDC to control the amount of meth (stock setup on HFS3) works great.
Next think I'm considering is a pair of his 65mm billet VTG's. For now I'm extremely pleased at what he was able to accomplish with stock turbos but I know I'm pushing their limits.

 

The stumble is likely how the Aquamist is tuned.

I was running the gain in neutral, with the thresh set to come on at about 10 psi.

I suspect that I could run a lower injector multiplier, and turn the gain up,,... then it wouldn't be spraying so much when it begins to spray, but would still be spraying the same at full boogie.

I could also turn the thresh up a tad. Then just data-log a few pulls to see if I went too far.

How do you have yours set?


I would mess with it more,.. but it's a rocket either way. Most of the gains to be had lie with the driver at this point

 

Mine is set to spray based on IDC data from the ECU using the default values from Aquamist. I have the IDC and MAP data tapped from the ECU to the Aquamist controller but the injector duty cycle is what is controlling the Meth flow. Page 20 on the instructions explain how to solder the board on the controller to use a mix of IDC and MAP data or just to rely on MAP data. I didn't want to solder the board and because of the flexibility of the controller you are exactly right, it is possible to change the multiplier used to control the spray volume. The default setting is fine for stock injectors but for larger injectors they suggest increasing the spray multiplier adjustment since the IDC is typically lower (unless running an ethanol tune).
I ran the same sized jets on my 996T but I remember adjusting the spray because my injectors were about 30% larger than stock.

 

I am using IDC also. It is currently set so that it comes on around 10 psi,.. but it is not using MAP to do that.

I was wondering about what boost pressure yours comes on at ?

I have my injector scaler set to 1.50 I think,... as my injector never get past 58% or so, and I want a long pulse width on the meth. Gives me a duty cycle of 87% ish on the meth.

So you have gain set to neutral?

 

Yes I've got my controller set to neutral (default). It sounds like you've got your setup just right based on your IDC. Mine isn't tied to manifold pressure either but it also starts flowing at 10-12psi. It is a really great system that benefits performance and makes these little stock turbos perform at the maximum potential. On my logs I see that they are delivering 22.5psi and timing is consistent even after many consecutive full throttle applications to redline regardless of outside temp. I am considering Sam's billet 65mm VTGs since I know I'm pushing the stock turbos beyond their efficiency range. I already have all the supporting mods in place so it's a relatively small investment.
Did you remove and replace your stock VTG's with the Blouch upgrades yourself? If so was it a simple swap?

 

I did mine myself. About an 8 hour job.

(Pull rear wheels, rear fender liners, rear bumper cover, remove inter-coolers / mounts, un-do the inlet and outlets from the turbos (two of which are exhaust of course),. then remove the 5 stainless hard-lines with O-rings. (2 coolant, 3 oil).

And reverse.

You'll want to have 3-4 new exhaust studs on hand, and perhaps a couple of the exhaust nuts. It's unlikely that you'll get them all off without breaking one or two (3 per side from header, and 4 per side to exhaust, So there's 14 in total). And you'll want a few of the o-rings for the coolant / oil. They can certainly be re-used,.. but once in a while they press back in odd,.. and you're not confident in them. So it's good to have a few spares.