Most of you haven't heard much from me in the past few months because I've been tied up with work and school. The TT Trans AM is doing well and I have done several mods to it this summer. One of which is a true 3" dual side exit exhaust...I'll have to get some pics up soon.

Ok, here's the situation: The car is currently running 16psi on 93oct and is making 750rwph & 750rwtq. All this with basically a forged truck motor (6.0L iron block, eagle rods, arp L19, arp head bolts, MLS, stock truck heads/gold springs, ls1 intake, ls1 TB, Z06 cam). I am about to purchase a BIG custom ground turbo cam and a coolingmist progressive and programmable meth inj system. My goal after the install and a proff. dyno tune is 900rwhp. Is this realistic? I am hoping to hit 20-22psi on pump with the meth in full blast. Is the ls1 intake sufficient for this setup? Will it cause a major lean issue with #7? I have a innovative lc1/xd16 wideband hooked to the drivers side DP to keep an eye on it. I know a single plane intake is ideal and I will do it later but just don't have the $$ right now. Also, is it absolutely necessary to go to bigger injectors? ...since the meth is 118octane?

I know the ideal situation would be to save up and buy all the parts, install them, then get a tune but I'm in a sticky situation. I currently have access to a shop where I can do the cam swap w/my buddy who has done it before. After spring I will be moving and won't be able to do it so I have to do the cam install now. I don't want to be driving around with an untuned cammed turbo car and not be able to go into boost for the next few months so I want to get it tuned right away.

So here's the current plan: Install new turbo cam+meth system then get a proffessional dyno tune. In the future replace intake w/single plane but keep same tune. And the goal is to hit 900rwhp/tq with everything else being the same.

Your educated and experienced thoughts please....

 

It depends on how much meth you are going to be spraying. For 900rwhp, the 65lbs you have in your sig probaly wont be enough. What do you have for a fuel system? Is there still a pump in the bucket that you are drawing through with the two walbros?

 

I have the tron65lbs injectors and a sumped steel tank with twin external walbros. Also big ss lines going to speed inc billet rails & boost referenced fpr. I was thinking of bumping the fuel pressure from 60 to 70psi to give a little more flow... Since the meth/water will be adding octane as well as a big drop in AIT temps I'm thinking it might be possible....?

Also, the meth system I'll be using will be a made to order kit to fit my power goals, it will be a twin nozzle setup and the controller has 10 different spray curves so it shouldn't be hard to dial in. If that doesn't work then you can make a map and load it on to the controller for an exact fit. I'll be spraying as much as possible....

 

Nice numbers, how high do you plan to spin the engine?

 

If your FPR is boost referenced as you say....then at 70psi base fuel pressure, and 20psi boost, you are aksing those little Walbros to generate 90psi.

If you look at most flow data, they are really starting to struggle beyond 75psi, as flow ability does drop off.

Buy a decent pump ( s ) that can maintain flow at such pressures, and that should make a big difference. A pair of Bosch 044 pumps would do well. They pretty much maintain a steady flow rate up to around 110psi.
Dont know what the injectors will do if you tried say 80+psi static though.

Here's another question though. Why not just wind the boost up to 25psi NOW along with the methanol, and leave the cam as is ?

 

All I know is Im runnign rc 75#ers and at 933 rwhp im at 89% duty cycle.

I wouldnt take that chance with your 65's if I were you...

 

i wouldnt chance twin pumps let alone the injectors..... with that much fuel pressure....with twin pumps you arent even getting 1.5 times the flow of a single pump..... 3 pumps inline isnt even double the flow...... Go with one single big pump..... my reasoning for that is..... if one goes out you would never know until its to late and your already in boost.....by then its to late... see what i mean......
The fuel system is something you never want to do small... over kill there is better....

Kyle

 

Thanks for the replies so far.

PSJ: Plan on revving a max of 7K but will set limiter where power peaks.

stevieturbo: I'm tired of the car being so quiet, I want the big cammed car sound comming from the duals.

2000TranzAM: If you did 933 on 101oct then your fuel system was flowing 100% of the fuel and that would not be the case with me because the meth will cool the charge and add 118oct at the same time-on top of the fuel system.

Nasty: Before I did the build I researched the big hp single pumps but none of them are designed to be run 8hrs at a time as I sometimes do. Whereas the walbros were designed to run cool and quiet all day. Also as mentioned I have a wideband hooked up so I can monitor AFR conditions.

The fuel system was modled after MightyMouses so I feel confident it can handle that power. My second pump is currenty activated via hobbs but I don't feel good about it so I'm thinking about running to a toggle on the steer wheel so I can engage/disengage whenever I like and know it's working. Something you guys seem to be missing is that my fuel system doesn't have to be able to flow 900rwhp worth of fuel since the meth system is in essence a standalone separate fuel system.

 

My 2nd Bosch 420L comes on at a certain TPS value.

I've never used meth, but it seems like using meth + 93 works like running 104 or 110 gas. Not 116-118 octane. I plan to get a meth kit from Julio or Snow and mess around with it. But you could maybe do 900rwhp on 93 + meth with an M6, but I would not get greedy with timing and I would cap the max IAT's at like 125F to be safe, and see happens. I hear that 150F Iat's can get problematic.

 

2 pumps mounted in parallel, will flow plenty.

Mounting them in-line...would be pointless, as you would still be limited by the most capable pump ( + a little extra perhaps )

I assumed from what he said, he was using in-line pumps, but mounted in parallel, as opposed to in-tank pumps ???

The Bosch pumps I am using will maintain their flow ability to 8 bar, as stated by Bosch.
I run them in parallel, all the time. So far I'd have almost 4000 miles on this setup, with no problems.

I'm running RC Eng 73lb's, at 4.25bar base pressure, and seeing as high as about 1.4 bar boost, which is about 83psi total fuel pressure.

My fuel pressure is rock solid.

I wouldnt be that impressed with the RC injectors compared to the 60lb Siemens I was using previously at 4.5 bar base. TBH Inj pulse widths arent that much different to maintain similar AFR's. I had to use a lot more pressure with the 73's than I had wanted to, or indeed ever expected to.
But as my ecu cannot drive low Z injectors...I had little choice, as I didnt want to fart about with resistors or convertors. If I have to do that, I'll buy a better ecu.

Havent actually checked IDC's, but recorded pulse widths are in and around 19ms at the higher rpm's so they are prob over 90% IDC

 

The walbros are externals mounted parallel each with it's own feed from the tank then into an aeroM Y block then up to the rails. I understand that I wouldn't have 118oct but instead a mixture of 93 and 118 probably netting 105-110oct average. IATs should not be a problem as the meth/water will cool the intake charge down to 60-80degrees from what I've read on here. I'm pretty dead set on doing this and unless I get a tuner on here that convinces me otherwise I'm going to do it. I don't think running 2 pumps all the time is efficient so I'm still leaning towards the toggle on the wheel...

 

I dont think its the amount of octane that dictates flow in your injectors, I have a feeling certain horsepower will rely on certain fuel levels, being it maxing out in hp, not octane level.

 

The way I understand it is that the meth/water system will be adding "fuel" to the mix hence the injectors don't have to work near as hard as if they were supporting all the power without meth/water.

 

from what ive heard ive been told many many times that Meth is not a replacement for a fuel system, add a BAP to ur 2 walbros if u need fuel, but i say go carb style intake and cam with no meth, the carb style intak alone should bring u up 50RWHP+ at the same boost

but my main question is can u please explain to me y u need more then 725RWHP? id love to hear that answer, what are u pissed u cant spin 5th gear??

 

BAP will defo help the fuel pressure situation....I still say get better pumps that can handle the pressure.

Running them both all the time may be "less efficient" as you say. But its easy.

As for the carb intake.....Im still not convinced. When I swapped over from the LS6/Stock TB to the Victor jnr/85mm TB...
I dont have access to a dyno,, but I'm really not convinced it has a huge amount more power. Fuelling requirements to maintain similar AFR's has changed very little To me that indicates power hasnt changed.
Mid range, say 3-5000rpm it does feel a lot better and I did need to add a reasonable bit of fuel there.

But 5000rpm upwards....very little changed.

Perhaps I need a bigger cam or something to make the most out of it. Either way it doesnt bother me much, as I did it more for visual appeal. If it performed better, it was a bonus.
But I'm still not convinced of the merits of big cams on forced induction motors.
I kept most aspects of mine mild...smallish heads, mildish cam....and its working well for me.

 

93Form, I'm saying that 93 + meth is probably equivalent to running 104-110, and not 116-118. Yes folks have made like 800-850rwhp with 93 + meth.

Having the 2nd fuel pump triggered with TPS for example means that if you say get to 50% TPS (gas pedal is half pressed), the fuel pump comes on. Having it a be a switch sounds problematic and when guys I know have stuff like that they usually forget it and leave it on or forget to turn it on and run lean.

And I'd research the idea of having the timing get reduced if the IAT's go above a certain value, like have the timing cut back like 6 degrees if the IAT's go over 130F. That would be a good way to avoid damage.

 

PSJ, What are you using to trigger the second pump based on %TPS?
Micro-switch on throttle, or aftermarket ecu? Or??
I thought about it, but never licked the throttle microswitches Ive seen for nitrous apps...

 

It was a Hobbs switch, but maybe Intmd8 has mine triggered via the BS3 now.

 

Ahh, Ive been keeping my eye out for one of those TPS WOT switches from NX. If I find one cheap, it will replace my hobbs switch.

 

Once you're at a certain power lever for awhile you just get used to it and it's less and less impressive. Also I have a record to uphold. I haven't been beat as of yet. The record is: R1, 06 gsxr750, 05 porsche 911TT, & 94 RX7 TT. It's just a power goal I had since I decided to do FI on the car. So far, nobody has convinced me that it won't hit 900 or thereabouts.