The Alchemist

iTrader: (19)

So I put a new Mcleod single disc in, organic/ceramic mix, with a new 2900# pressure plate and it's working beautifully.

Picked up a holley throttle body as the Bluemaxx POS I had was sticking so bad at 3-5% throttle.

Getting my tune nailed down still, but it's extremely safe, in the high 10s:1 afr, but that's the good news / bad news.
Now good news/bad news. I did a highway blast in third gear rolling into the throttle at 3500 rpm. Good news is I'm safe fueling and timing wise. AFR is high 10s, low 11s, timing is only at 13-14 degrees, but I'm making a little more boost than I had guessed, and subsequently, I've run out of injector. I saw 200.2kpa @ 6800 rpm (that's around 14.5psi), but also 115% duty cycle, which is very unsafe, I know, so I don't need lectures. I thought my 60's would be plenty, and might be as I need to do some diagnostic troubleshooting first.

I want to lean it out a hair to 11.4-11.5:1 afr and that should help, but I also need to put a fuel pressure sender on it and make sure I'm not losing fuel pressure in the higher rpms. I need to drop my shiftlight down to 6000 rpm to be safe for now.

For now, the car is an absolute blast to drive. I rarely go above 50% throttle, and usually shift at 4000-4500 rpm which is quite fun.

I will say this, my car finally feels fast. That third gear romp scared me a little. The car went 70-110 in roughly 2.5 seconds and forget about seeing the shiftlight.



So either:
1. I'm making a lot more horespower than I thought, and the 60's really aren't enough.
2. I'm dropping fuel pressure at the rail from running stock lines from the tank, but won't know till I get a fuel pressure sending unit. That might cure the fueling issue, but will mean running new fuel line.

Either scenario still doesn't account for the fact that I'm seeing around 14psi on a stock shortblock, which is a recipe for disaster, no matter how safe the tune is.

I don't race the car, so honestly, I'll solve the fueling issue by either adding methanol injection or possible an adjustible fuel pressure sending unit that I can up the pressure as the boost rises. I rarely see boost in more than one gear, so I'm hoping that will help with engine longevity.

All in all, the car is fun as hell and I'm glad I went this route.

Cam72aro

iTrader: (28)

What pumps are you running and what does the rest of the system look like? The injectors could be maxing out like that because the rest of the fuel system can't supply them. I don't know what power level you are making, but would assume mid 600's. Is the blow off valve still quiet with the filter on it?

Fbodyjunkie06

iTrader: (10)

I have 60's, a 255 in tank, a 255 inline about 8" from the tank, a brfpr, stock feed, stock rails and I can go anywhere from low to mid 12's to mid to high 9's just by adding or taking away methanol from the combustion chamber.

I'd look into the fuel pressure at the rail and/or adding meth injection. I'd add meth injection anyways just to be safe.

TracyRR

iTrader: (8)

I smell another upgrade!!! Hang a fuel pressure gauge and temp tape it to your windshield as stated and get some larger injectors.... sounds like good new/good news! It is making power. Good luck man

Nitroused383

iTrader: (10)

I wouldn't call 14 degrees of timing safe on pump gas and your compression. Especially with that much boost lol. I would say something is up but if you're not leaning out on the top end I don't think your injectors are actually maxed out.

The Alchemist

iTrader: (19)

I'm definitely going to look further into what exactly is going on. I fully intend to put a meth/water kit on the car as well, which will help with fueling. I have twin walbro 255s in the tank from Lonnies, which according to Lonnie should support 700hp on stock fuel lines, and 1000hp with an upgraded fuel line and adjustable fuel pressure regulator.

As for the safe timing, I thought 13-14 degrees was safe, should I back it down even more?

02LS1ram

iTrader: (17)

IMO I would re pulley the car maybe down to 9-10lbs. This way it will still be fun and safe, while still be making good power. At 14lbs your ringlands arnt going last too long

35thsscamaro02

What size blower pulley are you running?

The Alchemist

iTrader: (19)

I hear you, but part of why I went this route was because I wanted more midrange power. So I'll keep the rpms low, especially in the higher gears, and add a meth kit to keep it safe.

4.00". It was one of those things that I kindof guessed at when I put this setup together. I wasn't sure how my heads/cam combo was going to react to boost, so I didn't want to buy a pulley that resulted in 4-5psi of boost, but I also didn't want to build too much boost either.

I've talked to multiple people who say that anything lower than ~12.0:1 afr doesn't add any safety to detonation or heat. I thought 13-14 degrees was safe, and I'm at 10.5:1 compression ratio, which isn't ideal, but it's not 11.0 either. How much timing and what afr are you running as well as how much boost are you seeing?

Fbodyjunkie06

iTrader: (10)

IIRC he runs 7-8psi and is at 11:1 cr. I've heard him say and see some of his logs at mid 11's afr.

383camaroz28

iTrader: (22)

I had a 4.25 pully an peaked 12psi

02LS1ram

iTrader: (17)

Yea if u keep out of the pedal the motor will stay together for awhile. Look on the brite side at least you made the power you were looking for and have a really fun street car!

The Alchemist

iTrader: (19)

So I'm trying to figure out the easiest way to monitor and log fuel pressure.

My fuel setup is twin pumps in the tank, with one on a hobbs switch, which is the Lonnie's twin pump setup. It's then stock going into the engine bay, with Nasty fuel rails. I come off the factory quick connect, go into the rear of the driver's side rail, cross over the front by the throttle body, then into the passenger rail. I'm figuring the easiest thing would be to put a fuel pressure monitor into the back of the passenger side rail, then send the signal into the car and log that data with HPtuners.

Has anyone done this and can help out with some part numbers?

Thanks.

Nitroused383

iTrader: (10)

My buddies GTO that was a stock bottom end LS1 with trex cam (242-248 110lsa) with a d1sc ran around 9-10lbs of boost with pump gas + straight methanol injection. I usually run 11.3-11.8 afr average through out the gears. I want to say the timing was around 16-17 degrees and this was enough power to put a 4000 lb 6 speed car into the 10s (10.7) @ 2300' elevation. It seemed to be fairly safe at the stock compression ratio with the straight meth. He beat the crap out of it on the street and at the track. I run less timing on my car since it has more compression and a turbo. Turbo's can be at max boost as low as 2500 rpm so you make a ton of cylinder pressure which can destroy stuff in a hurry.

How much boost is it making at 4000-5000 rpm? 14-15 degrees of timing is probably ok on 7-8lbs of boost and pump gas. You can barely get much over 12 degrees of timing on a stock LS2 with a turbo setup before it knocks on pump gas (6-7lbs). Your intercooler seems to work 10000x better than the stock GTO procharger. My buddies IAT's were around 160-180 degrees before he had methanol.

98Camarod

iTrader: (43)

100* iat with no meth in the summer is a good thing

As mentioned, log the fuel pressure and see where that's taking you

The Alchemist

iTrader: (19)

At 4000-5000 rpm, I'm seeing in the 6-8 lbs of boost range and calling for 13-14 degrees of timing and AFR is currently at 11.1 in that range. My intercooler does seem to work well, but that might be because I haven't really been in boost for more than 1 gear at a time. It will probably never see a track, so it's not going to see 4 gears worth of boost in a row. Most of the time, I short shift first, never seeing any boost, second I might see 3-4lbs, and then roll into third for another short burst. By then I'm doing 60-80mph which is more than enough.

What I saw that day was that my IAT's went up 10-15 degrees above ambient over the course of an entire gear, so that's not bad. I ordered the autometer fuel pressure sender unit and harness, which should be here by end of the week and I can then see if my fuel pressure at the back of the rail is dropping. It might be, which would explain why the injectors are maxed, but won't know for sure till I log some data.