944Hybrids: 924/944/968 and 928 V8 Conversions
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HOW TO DO AN ADVANCED SEARCH.

Mon Jul 08, 2013 3:56 pm by Admin


For the benefit of 944Hybrids users there are two search functions available for you to use.
The purpose of this sticky is to explain the "Advanced Search" function because it is much more powerful and is the best choice when researching information.

When you log on to the site a list of options is shown in a line at the top of the page. One option is labelled "Search", use this option (NOT the search box lower down on the right).

After you click on the upper search option, a drop down box appears. At the bottom of this box is a radio button marked "Advanced …

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L59 5.3 Flex-Fuel Injectors...

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L59 5.3 Flex-Fuel Injectors... Empty L59 5.3 Flex-Fuel Injectors...

Post  erioshi Wed Oct 21, 2015 3:29 am

As I've been working through my parts list, I've reached the point were I need to think about getting air and fuel into the engine. For an intake manifold, I'm thinking I'll go with the Dorman LS6 OEM replacement part (Dorman PN: 615-900), and perhaps hand port it a bit if needed. At under $300 from Rock Auto, it seems hard to beat for the price.

I've already sourced a set of ebay fuel rails and combination of AN fittings from Speedway and Summit that should handle getting enough fuel to the engine. The rails were about $75 with shipping, and the total cost for of all of the AN connectors added up to about the same. That makes it about $150 for fuel rails and fittings. Ouch .. at least their not red, blue, purple or some combination of those three colors combined, lol.

Next up is fuel injectors. According to the math I've done, it looks like my OEM L33 injectors will not meet my fueling needs with the cam I've ordered and the other changes I'm making to help increase the volume of air moving through the engine. Most of the common upgrade choices I've seen are LS1/LS2/LS6 car injectors .. which seem pricey and require different electrical connectors, SHO Fuel Injectors .. which are less expensive, but again require different electrical connectors, and aftermarket injectors .. which again seem pricey, and many require car electrical connectors. None of those options seemed to be what I was looking for.

A bit more research turned up an interesting OEM GM truck alternative. It turns out that the 5.3 L59 flex-fuel engine has injectors share the same electrical connectors as other trucks but are designed to flow about 37% more fuel than my OEM L33 injectors (33 lbs/min vs. 24 lbs/min). This flow rate should easily support over 400 whp and keep the injector duty cycle below 90%. I've also read that the tips on the flex fuel injectors are supposedly compatible with LS1/LS6 intakes. Additionally it looks like these injectors were used with both return style and return-less fuel systems. It does look like I may need to make up some shorter L brackets to lower the height of my fuel rails from car length to truck length.

So now my plan is to order up a used set from car-part (about $75 with rail, plus shipping) to test fit and see how they work out. Rebuilt injectors start at about $28 (plus a $10 core) on Rock Auto, so even going all rebuilt wouldn't be outrageous if the used ones are questionable.

Has anyone else tried these?
erioshi
erioshi

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Post  FrostedFlakeJake Wed Oct 21, 2015 8:05 am

(33 lbs/min vs. 24 lbs/min). This flow rate should easily support over 400 whp and keep the injector duty cycle below 90%.

Just went through injector selection myself. A lot of TBSS guys (33 lb-hr injectors) are at 85-95% duty cycle with minimal mods and ~400 whp. Just saying that you might end up with a higher duty cycle than planned... hopefully not!


FrostedFlakeJake

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Post  erioshi Wed Oct 21, 2015 1:27 pm

You're right .. my saying "easily support over 400 whp" is a bit over the top.  I've been using 400 whp as a cap for my calculations, so that's were these look to sit at about 80% with a 54 psi returnless fuel system.

I'm realistically expecting to land somewhere between 350 and 400 whp so these should work well on my car.  I was not aware that the TBSS injectors were 33/lb as well; makes me wonder if they might be the same part number.

Regardless, I should have a set of these on my doorstep in a couple of days.  I ended up at $85 shipped for a full set with rail off car-part.
erioshi
erioshi

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Post  FrostedFlakeJake Wed Oct 21, 2015 1:45 pm

I was not aware that the TBSS injectors were 33/lb as well; makes me wonder if they might be the same part number.

They have the car electrical connector on them so they wouldn't be plug n'play for you anyways.

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Post  superman22x Sat Nov 14, 2015 1:16 pm

Have you checked LS1tech? They generally sell OEM LS1 injectors pretty cheap. $20-30 for a set is what I've seen before. Maybe a bit more if you needed them in a hurry. But you would need a different style connector though. Also, I thought these engines needed a little more fuel pressure than that? 58psi is what is listed for an LC9 according to the swap guide on GMPP. If you increase your fuel pressure a bit closer to 60psi, you will get more fuel through the injectors. The guys running higher duty cycles with the 33lb injectors may have had lower fuel pressures?

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Post  lsporsche Sat Nov 14, 2015 3:37 pm

I have a set of flex fuel injectors. Supposedly theyre a little shorter than ls1/6 injectors, requiring spacers. They also use an ev6 connector instead of the ls1/6 ev1 connector. I didnt want to bother with spacers so Im using the ls6 injectors i have

lsporsche

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