89gta383

iTrader: (5)

While trying to diagnose my lean high rpm fueling issue, I stumbled upon some old forum data from the corvetteforum from users running the miniram and having issues with the way the fuel rails deliver fuel.

Hoping this info helps someone else in the future when trying to run forced induction and the miniram intake:

The fuel rails supplied by TPIS are supposed to support 500FWHP. The rail design supplied by TPIS has two transfer chambers. The fuel is fed through a -6AN line from the factory feed line at the L front of the engine. The gas is fed in through the back R fuel rail, then supplies the R bank injectors. The fuel then reverses through a seperate channel back to the rear of the R rail where it enters the transfer tube (look at the id of that 1/4" tube, also pull the -6AN adapter fitting and look inside the rails for the seperate channels, quite small). From the transfer tube it enters the L bank and feeds to the front of the L bank, then reverses to feed the injectors. After passing all injectors, the excess fuel exits the L rail at the AFPR (highly prone to diaphram failure). The AFPR then feeds through a -4AN line back down the R side of the engine to connect to the factory fuel return plumbing.

This design is hardly made to support 600+ WHP. When I was running the MRII on mine, I modded mine to feed both rails from the back and discharge both rails from the front with an external regulator. I have installed numerous MRs and have had probably the same number of supplied AFPRs fail.

I talked to TPIS on the phone yesterday, and they said the rails in stock form are good to 600fwhp.

They can mod the rails by drilling through each injector hole through the channel and said this mod will support 700fwhp.

I am sending my rails to them so they can add a -8an fitting at the back of each rail, weld up the crossover tube opening, bore out the center channel on each rail, and weld a -6an 90 degree fitting at the front of each rail to be used with an external fuel pressure regulator with 2 in ports and 1 port returning fuel to the tank. They estimated $125-$150 for this work.

zz17iroc

iTrader: (4)

If your going that far, just install that Pro-Ram single plane intake you have collecting dust and sell the Mini to offset the swap. I'm just saying.

89gta383

iTrader: (5)

Don't think I can.

I would need a throttle body $400 (used), a carb hat $150 and not even sure if it will fit under my stock hood. Right now I have about 2.5 to 2.75 inches of clearance at the throttle body to the hood.

Not sure if I could sell the miniram to offset that cost or not. Plus the miniram is ported, the single plane is not, that was $250 for the port work.

anesthes

iTrader: (12)

Did you do this?

I just re-installed my fuel rails with brand new Orings (shipped to me by TPIS) and the crossover still leaks on one side.. I'm getting pissed.

-- Joe

89gta383

iTrader: (5)

yes I did. I have some spare crossover tube O-rings if you want them, I don't have the crossover anymore.

Orr89RocZ

iTrader: (20)

150$ for that fuel rail mod is welll worth it.

Its a shame they got away with selling that intake and rails for 2 times what its worth imo. The design could have been alot better


Only other thing you could try is jack the fuel pressure up alot and try to compensate for the small port size in the rails. But most fuel pumps dont like to be run over 65 psi else flow falls off. May need a single 340-400 lph to compensate or better yet a bosch 044

anesthes

iTrader: (12)

Could you toss 'em in an envelope and send 'em my way?

This is driving me nuts. Not sure if TPIS gave me the wrong size or what. When I key on it sprays out the passenger side, but holds about 20 psi. Anything over and it sprays.

-- Joe

89gta383

iTrader: (5)

pic of modified rails

TTOP350

iTrader: (8)

I'm wanting to step up to the coil on plug/LS computer from those guys also.
What are the ups and downs you have encountered?

anesthes

iTrader: (12)

I ran CNP for about a week. I may switch back eventually, but the actual hurdle was finding a place to mount he coils. It was actually more of a mess than a dizzy.

I like having access to my valve covers for adjustments, but then when I put them all on the firewall it just looked horrible.

-- Joe

anesthes

iTrader: (12)

Hrmm.. If I cant solve this leak I wonder if threading and plugging the crossover, and running it in the front would make more sense. A couple of 90 degree -6 and just run steel line under the intake. I've got an AN flaring tool and a box of tube nuts/sleeves.

-- Joe

89gta383

iTrader: (5)

My only issue with the efi connection 24x system was the timing cover/crank sensor. My block has been align bored cause I have billet splayed caps. This caused an issue with the 'gap' of the reluctor wheel to the crank sensor since the crank centerline moved slightly higher in the block.

I had the old style plastic flimsy vortec timing cover, and it would leak and flex. The new efi connection cover is much more robust and stable. I have to keep a spare crank sensor in the car though in case I have popping and sputtering issues. The bad crank sensor doesn't always give a code and only shows issues when the car has been run for 15-20 minutes. Other than that, the software is expensive but is light years ahead of the 165/730 stuff.

anesthes

iTrader: (12)

I have a bolt on 36-1 trigger wheel and pickup. The 24x stuff is cool but changing timing covers and having to also run a trigger at the distributor gets old. The Ford sensors are pretty reliable.

-- Joe

Orr89RocZ

iTrader: (20)

Lol you dislike most everything....



I ran the plastic vortec cover just fine, once i made sure all areas had adequate rtv seal in addition to the covers built in bead. I did have one sensor randomly die on me. Ever since then it was fine but it did seem to always have starting issues. Eventually found my ring had opened up on the crank key, my guess balancer walked forward some. Caused the ring to move i guess and made starting a boar

Other than that it was a decent system. Mounted coils on fuel rails with custom brackets. Looked decent and was functional

Doing it over again i would have went holley or ms3 pro. Spend a bit more for more capability

TTOP350

iTrader: (8)

That is something I'm worried about, I have a stroked and poked 400 that has splayed caps as well.
A friend just has the cover on his car and it leaks pretty good.

anesthes

iTrader: (12)

I get disgruntled with things easily, I admit. But I like to adjust my valves running, which is impossible when stuff is bolted to the covers.

And I didn't like the way it looked bolted to the firewall.

Then, lastly, because I was using an EDIS controller I had no RPM limit function. So I discarded it for now.

Maaaaybe in the future I might go back with LS2 coils. (they have built in dwell drivers).

-- Joe

anesthes

iTrader: (12)

Get a bolt on crank trigger and an MS. MS can run almost every ignition there is, and you can adapt any aftermarket trigger to an SBC.

-- Joe

92RSZ

iTrader: (6)

I modified the tpis rails myself with -6 fittings in the front of the rails and still using the rear crossover tube with orings I found at harbor freight. I'm sure in modified form they'll supply 700 horsepower easily. When my injectors were too small and goin static (60lbs that I believe I sold to you joe) my wideband was reading 10.2 at 6500+ rpm. No dyno numbers but trap speeds were in the low 130s at 3650 race weight. That was at 43lbs pressure and 1:1 regulator

anesthes

iTrader: (12)

I think I got it to stop leaking last night.

I let the pump run for 5 minutes and it held 45 psi with no signs of leakage.

-- Joe

anesthes

iTrader: (12)

That a naturally aspirated motor or blown?

Yeah I have the 60's right now. I had to get some TPI retainer clips to keep them from leaking though with the miniram, apparently they are a little short.

-- Joe

IROCZ1989

iTrader: (1)

Joe if this means anything to you. I modified a set of miniram rails years back. Basically gun drilled both rails out to rid the divider. And to solve the crosover I had 1/2 inch aluminum fuel line lying around. Open up crossover holes and leave a small ridge where line can but up against and weld it. No more leaks. 1/2 crossover. When you take the rails off they come off in on piece. Left the fpr where it was and welded and 1/2 npt to one rail opposite of regulator. These rails to me look way to small for much performance stuff. Its been a few years Ill try to find the pics.

92RSZ

iTrader: (6)

It's blown. D1sc at 10psi.