Crf450r420

iTrader: (1)

The factory sock will not allow you to pull in air and his system doesn't have one. The new large socks that Holley now offers are really just a large version of the little factory socks everyone has had for years. He could add one of those and not worry about the return.

Is there a way to add a line to the current return and just move it away form the pickup? That way you don't have to drill anything and you want the return at the bottom. Fuel splashing in from the top will put air in the fuel also.

stevieturbo

I've never had a sock on mine for the last 16 years...pair of 044's and zero problems.

As long as the pumps have a good clean unrestricted supply of fuel...no problem.

And given it does run for some time without issue, the supply in that sense maybe not an issue.

Crf450r420

iTrader: (1)

True. The return being close to the inlet is only an issue if it is splashing in or is returning with air. If it has no air you could T it into the inlet line and heat would be the only issue.

Volvette

Moving the return line away from the feed line did not work. I got rid of the filter after the regulator and installed a new 10 micron after the pump where the 40 was after the pump. I also hooked up a temporary pressure gauge and it's clear as day that I lose pressure down to 35 psi under WOT. The video shows a 2nd gear roll starting at about 15 mph.

Later on I did do a 2nd gear drop at 45 with no pressure issues initially then having issues a few seconds after. I'm pretty sure its the fuel sloshing away from the pickup as I have the fittings turned toward the front of the car. Tank had 1/3 in it. So I could flip it around but wouldn't I have the same issue when you go into braking? I know the motor isnt demanding anything but wont I still be sending a bubble of air through the system dropping the pressure? If it was a quick enough brake then gas I would think it would still be an issue.

The other route is I could put foam back in it and watch is clog up my filter next year.

https://www.youtube.com/watch?v=WBmz...ature=youtu.be

G Atsma

When you brake you are off the throttle (usually...) starvation would not be an issue. Once on the pedal, it might for a bit. This is why tanks are baffled to keep the pickup in fuel.

Crf450r420

iTrader: (1)

Like I said, test with the tank full and eliminate that from the possible issues.

Good tanks will have baffles, foam, or a bucket to prevent it for short periods.

stevieturbo

With a full tank, there should never be an issue with fuel movement in the tank...because its full, so do that first.

If fuel pressure is dropping, monitor voltage to the pump, measured at the pump.

At a push logging system voltage is better than nothing, but still not a substitute for actual pump voltage. Wouldnt be the first time there has been wiring/charging issues at higher rpm's

Volvette

I'll test it tonight or tommorrow with a full tank and voltage at the pump. I didn't put a full tank in it yet since I was worried I'd have to flip it around or add my own baffeling. Draining the tank is a PITA. I have a feeling this tank is just a POS.

stevieturbo

Draining tank should be easy ?

Just pump it out or undo a fitting near the pump ?

It's handy to add a drain line or fitting somewhere down there

Volvette

The problem is more figuring out where to put 16 gallons of fuel and having to transfer 5 gallons at a time to another car which are hopefully not full. Undoing fittings makes a mess in my experience. I usually just set up a couple siphons. Either way gas seems to get everywhere.


But maybe I'm the only one whot hates getting gas all down my arm and in my clothes.

Crf450r420

iTrader: (1)

Don't take a part the line at the rear down low, just pull the line off at the rail with a rag to catch the little spill and extend that line to a tank, lawn mower, or other car.

stevieturbo

then use the pump to pump it out.

Volvette

With a full tank of fuel I had perfect fuel pressure. I also monitored voltage and above 1000 rpm I have a constant 12.7 volts. So I have a fuel pickup issue. Was thinking about getting a Holly Hydramat. I did some research and they seem to work well. Anyone have experience with them? The biggest drawback I see other than cost would be needing to replace it every so often since it is a filter. What sucks is that 100 micron filter I just bought would become useless.


Another observation from this weekend is that when I have the turn signal on my fuel pressure fluctuates about 3 psi. Other loads like lights, and heaters affect it but maybe only 1 psi or so. Voltage on the pump at idle is 12.1 and when the turn signals are on it reads 11.8 but it switches so fast I don’t think the meter is keeping up. At least this all goes away at 1000 rpm so I dont think it's a big deal. The battery is only 1 year old.

Crf450r420

iTrader: (1)

Can you tilt the fuel cell forward enough to stop the fuel at the pickup? The standard tiny fuel sock lasts the life of a fuel pump with no issue. The larger hydramat should last the life of the whole car with several motors easy unless a lot of junk gets in the tank. Maybe a different tank?

If you run the hot wire lead to the alternator post it will raise you operational voltage and keep it more steady.

stevieturbo

And whatg voltage are you seeing at the battery/alternator during these same times ?

12.7v is a little low, but not the end of the world

circa 12v at the pump I would not be overly pleased with....but if fuel pressure and tuning remains good despite this, IDC's all within safe limits, then again whilst not ideal, not the end of the world either.

At least you've established fuel supply is the problem.

Of course retaining what you have and trying to adapt it will be awkward and add costs. Hydramat does look good, just wonder if the reality of them is true, and for all pump designs.

You could move to a swirl/surge tank setup, but that would mean more pumps and wiring. 034 makes a nice compact unit designed for an 044. But by time you did that and all fittings, you're into a few hundred dollars.
There are other less neat solutions at lower cost though.

Volvette

Installed the Holly Hydramat yesterday and it works exactly as described. Car under WOT with 3-4 gallons of gas worked perfect. Even my LT fuel trims all settled down +/- 3% from the first time I tuned the car late last year. AFR under WOT was 12.6-13.1 with solid 58 psi the whole time. Car felt very responsive and put good power down.

Moral of the story;
1) Use large canister filters, disc filters are bad.
2) Spending extra money on a nice aluminum baffled tank can save money down the line.
3) Foam sucks unless you replace it every year.
4) In line fuel pumps can be more expensive and more difficult to setup than in tank pumps. (luckily most people retain stock fuel tanks)
5) Hydramats work as described.

Thank you all for your help.

Crf450r420

iTrader: (1)

Glad you got it working and thanks for the info on the Hydromat. I'll wait until it is a must because of the cost, but good to know it's there if I ever need a quick fix.