Maleficio

With that tubing broken open like that, it seems the fuel would simply be pumped back into the tank instead of through the lines to the main pump?

AO

I have a new specially designed strainer for the 044 pump that eliminates any restrictions. I'm one of ten beta testers for this and I'm sure you will be hearing more about it very soon.

AO

I've been given permission to post a pic...

Speedtoys

..it was in your first pic too.

ROG100

OK I will bite - looks no different to the current strainer?? Cheaper maybe - is that the bonus?
Compared to the current strainer it looks restrictive.

BC

The current strainer is different in that it just has a mesh over a plastic frame. That medium/filter in he pic is different.

AO

Here's a side by side photo of the in-tank pump, Porsche strainer, and the 044 strainer. Doesn't look like much, but the minimum I.d. Hose Spec for the 044 pump is 5/8". This new strainer is the only one of the three to meet this spec...

Another factor that came up is that the thread length of the in-tank pump fitting is SIGNIFICANTLY shorter than the thread length of the porsche strainer fitting. We experienced where this caused an incompatibility between the stock strainer thread length and the threaded tank insert. Basically, on my car which had an in-tank pump, we could not thread a stock Porsche strainer in all the way without it binding because the threads were too long.

The new strainers will fit with all 928s and possibly other cars, has a stainless steel strainer vs. Nylon, and has the same micron level of filtration with more flow and additional dirt holding capacity.

Remember, this is designed for the high output 044 pumps.

And no, it isn't less expensive.

jcorenman

Andrew, that hose that split looks like the molded factory hose-- What are you thinking??

When we replaced ours, I disassembled the brand-new internal pump and replaced that molded hose with some braid-reinforced 1/2" fuel hose, rated for ethanol on the inside at least... That is coming up on two years ago, time to pull it out and have a look... Anytime in the next four weeks...

borland

AO,

The in-tank pump only serves to develop a positive pressure to the external pump in the rare case of when the fuel tank is under negative pressure.

Can you post a picture of the internals of the in-tank pump? I cut one open, but never pictures of the insides.

If you find time to take a look at the insides, you'll see how the motor's carbon brushes are down stream of the screen, such that brush wear products end up getting eaten by the main fuel pump. Also, the two small side holes suck up fuel by the impeller, bipassing the strainer. And also take a look at how small the impeller actually is.

AO

Nothing like fixing a factory part before service...

Also take a look at those inside diameter of those various fittings.

928mac

AO, any idea aprox how much they will be asking for it and when can one be ordered?

Brad

FredR

Andrew,

An interesting development and look forward to reading about how well the system performs in day to day use. As you can appreciate, over here our fuel can get rather hot and of course that increases the vapour pressure. High vapour pressure [not low vapour pressure] reduces the nett positive suction head to the pump and ultimately induces cavitation and no pump will last too long under such conditions before the impeller gets chewed out.

When the in tank hose ruptures, my experience is the car runs more or less OK mid range etc but top end is compromised. A more serious consequence is that the main pump suction is then exposed to crap in the tank/fuel and all it takes is one particle just slightly bigger than the casing to impeller clearance and your pump gets jammed [big bits simply cannot get through to cause jamming].

When one fits the Bosch 044 pump in this system has anyone every analysed whether the delivery capacity of the stock in tank pump matches the 044 capacity or have you also purchased a capacity matching unit- assuming such a thing exists? If they are not adequately matched that may well induce cavitation in the main pump.

I do not understand Roger's comment about your new unit looking more restrictive- to me it clearly has much more surface area than stock strainer on the in tank pump setup unless comparing to the size of the strainer fitted on cars without in tank pump- clearly something does not quite add up.

I have seen a few in tanks pumps that were "hose broken" but never seen a problem with the strainer element blocked up.

It would be interesting to see the results of a dyno test with this strainer element fitted and evaluate whether it causes any restriction on power delivery top end when the fuel tank level is relatively low. Ideally you would need a before and after.

My experience is that with the stock system in perfect working order, hard acceleration from rest troubles the fuel delivery when the tank level is down to about 10% to 15% capacity, the problem being exacerbated in a hard charge round a right hand bend if my memory serves me correctly. It would interesting to know if the in tank pump delete improves or exacerbates this observation.

I look forward to reading about your experience with this mod.

Regards

hacker-pschorr

The idea behind this new setup is properly feeding an 044 pump (or any larger pump) in non-stock configurations. It's not for simply replacing the stock strainer, the outlet is also larger.

We have experienced cavitation with 044 pumps using the stock tank fitting, which led to the development of this piece. Doing a before / after on a stock car isn't going to gain anything, neither is installing an 044 pump on a stock car with the stock strainer / in tank pump.
That's not what this is for.
Same as installing larger injectors or fuel pressure regulator on a stock car.

Those familiar with Todd's red car, he modified the tank fitting on his red car quite a while ago and has been the driving force behind this project. He helped design & machine the first prototype pieces last winter that were installed in my 81.

Andrew only showed the first half of this setup, there is also a new piece that fits into the 044 pump with the same size fitting. Yes there are adapters that can be used to turn the inlet size of an 044 pump to a 5/8's or larger barb. That is not an ideal setup so we have also machines a 5/8" fitting to the 044 pumps inlet that will be part of this kit.

Todd is very concerned with safety and wanted to minimize the amount of hardware between the pump and the tank. Too many adapters and fittings greatly reduces the amount of hose being used. In the event of an accident, one of these metal fitting could become damaged causing a fuel leak. Todd's #1 goal of this setup was to keep the amount of rubber line as close to stock as possible which can flex in the event of a collision.

SeanR

What is the new strainer made out of? The filament looks to be a filter type paper. my thought when looking at it was it would be more restrictive also.

hacker-pschorr

It's stainless - very similar to the strainer on the inlet of the in-tank pump.