What a find
#16
Instructor
Join Date: Jun 2002
Location: Seattle, WA.
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Geoffry--what results do you expect, or have you gotten, from the extrude honing? What variations in airflow? I've heard the stock 930 manifold has pretty wide ones....
#17
Nordschleife Master
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Bruce,
I have not yet flowed the intake manifold because I've been busy with work etc. In fact, I still haven't put my engine the rest of the way together. I'm hoping that after my trip this week, I'll be able to complete all of this this weekend. I'll definately post my numbers. I too had heard that the intake runners of the 3.2 Carrera manifold and the 930 manifold for that matter varied as much as 20% from runner to runner. I flowed the 4-5-6 side before I sent it out to Extrude hone and they all flowed within 1cfm of each other at 221cfm at 28 inches. So my particular manifold appeared to flow quite evenly although I didn't do the other side. I'd have to flow a few more before I said I disagreed with the 20% variance statement.
Extrude hone indicated to me that they exprience a 40cfm increase per runner on the 3.2 Carrera manifold after their process. We'll have to see how accurate that statement is because a 240cfm overall increase is pretty large.
I also considered having the throttle body enalrged by 3mm, but at this point, I've changed so much from the original configuration I just need to stop and see where I'm at.
I have some fuel issues that I'm still working out since my 55lb injectors were at 74% duty cycle with the old engine which is fine, but I don't want to go over 80% which is what I think is going to happen. I'm also considering replacing the rear fuel pump with a Bosch 044 pump and running a larger line from the front pump to the rear, but that is another story altogether.
I have not yet flowed the intake manifold because I've been busy with work etc. In fact, I still haven't put my engine the rest of the way together. I'm hoping that after my trip this week, I'll be able to complete all of this this weekend. I'll definately post my numbers. I too had heard that the intake runners of the 3.2 Carrera manifold and the 930 manifold for that matter varied as much as 20% from runner to runner. I flowed the 4-5-6 side before I sent it out to Extrude hone and they all flowed within 1cfm of each other at 221cfm at 28 inches. So my particular manifold appeared to flow quite evenly although I didn't do the other side. I'd have to flow a few more before I said I disagreed with the 20% variance statement.
Extrude hone indicated to me that they exprience a 40cfm increase per runner on the 3.2 Carrera manifold after their process. We'll have to see how accurate that statement is because a 240cfm overall increase is pretty large.
I also considered having the throttle body enalrged by 3mm, but at this point, I've changed so much from the original configuration I just need to stop and see where I'm at.
I have some fuel issues that I'm still working out since my 55lb injectors were at 74% duty cycle with the old engine which is fine, but I don't want to go over 80% which is what I think is going to happen. I'm also considering replacing the rear fuel pump with a Bosch 044 pump and running a larger line from the front pump to the rear, but that is another story altogether.
#20
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M,
I am very intereted in your project and had the same thought for a long time. Have you ever tried to push down the CIS metering plate with the air cleaner off. Even without the 50 lbs of control presure trying to close it, it is hard to push the plate down. Getting rid of this and adding corect mapping of fuel and ignition should help a bunch.
Have you seen:
<a href="http://www.pem.com.au/porsche.htm" target="_blank">http://www.pem.com.au/porsche.htm</a>
They did what you are thinking of. Got about 10% more top end but a lot more low & mid range. I think this was with out playing with the ignition where there is more off boost to be picked up.
Lead the way... this could be very cost efective and eliminate most of the fab work of the typical conversion. I am suprized someone has not come up with a kit to do this yet.
I think injectors from a MBZ are .oo2 inch off from the existing CIS holes. Thus, it might not even be necessary to even change our the injector blocks just ream what we have a very small amount.
Are you going to leave your air filter & tract intact?
Can't wate for your report.
I am very intereted in your project and had the same thought for a long time. Have you ever tried to push down the CIS metering plate with the air cleaner off. Even without the 50 lbs of control presure trying to close it, it is hard to push the plate down. Getting rid of this and adding corect mapping of fuel and ignition should help a bunch.
Have you seen:
<a href="http://www.pem.com.au/porsche.htm" target="_blank">http://www.pem.com.au/porsche.htm</a>
They did what you are thinking of. Got about 10% more top end but a lot more low & mid range. I think this was with out playing with the ignition where there is more off boost to be picked up.
Lead the way... this could be very cost efective and eliminate most of the fab work of the typical conversion. I am suprized someone has not come up with a kit to do this yet.
I think injectors from a MBZ are .oo2 inch off from the existing CIS holes. Thus, it might not even be necessary to even change our the injector blocks just ream what we have a very small amount.
Are you going to leave your air filter & tract intact?
Can't wate for your report.
#21
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Keith,
I looked at the webb site. Thanks for the info. as soon as I can borrow a Digital Camera I will post pics. I did forget to say that the original purpose of the PD Injector blocks was to add additional Injectors to the CIS system for higher power. My kit comes with those holes plugged and I use bigger injectors. The electronic Injectors are in the place where the original mechanical Injector would be and the holes for the Mechanical Injectors are moved around to the side.
Engine is almost finished.
I looked at the webb site. Thanks for the info. as soon as I can borrow a Digital Camera I will post pics. I did forget to say that the original purpose of the PD Injector blocks was to add additional Injectors to the CIS system for higher power. My kit comes with those holes plugged and I use bigger injectors. The electronic Injectors are in the place where the original mechanical Injector would be and the holes for the Mechanical Injectors are moved around to the side.
Engine is almost finished.
#23
AutoX
Join Date: Feb 2003
Location: London, United Kingdom
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Dear All
Apologies for joining the thread late but I wanted to share what I am doing with a 3.3L. The bottom end has been nicely prepped in a previous life and we've just freshened it up with new bearing etc. But for the top end we have: ported the heads some more, added a 964 3.8RSR black plastic intake manifold (with injectors and rails etc) and twin throttle body, made alu CNC machined injector blocks, real factory 935 headers (which ARE a work of art), two Garrett T28s with integral wastegate, 993 CBVs on each side, fabricated twin sided intercooler as big as we could fit in, 993 GT2 EVO profile cams and its all on DTA engine management with mapped wastegate control. The garretts are scavenged by a new GT2 racecar pump driven by an intergear drive off the block just like a GT2 racecar.
It's going together now and should get mapped on the engine dyno in about a month.
I expect it should make 550-600 fwhp at 1.3 bar but I believe that's way to much sustained heat for the 3.3L cylinders so I suspect we will run it on track at 0.8-1.0 bar at 450-500 fwhp and save the boost for qualifying!
I changed the intake manifold because its an obvious source of poor flow (along with the ports, headers, etc.) and I think you should always aim for as little boost as possible!
Apologies for joining the thread late but I wanted to share what I am doing with a 3.3L. The bottom end has been nicely prepped in a previous life and we've just freshened it up with new bearing etc. But for the top end we have: ported the heads some more, added a 964 3.8RSR black plastic intake manifold (with injectors and rails etc) and twin throttle body, made alu CNC machined injector blocks, real factory 935 headers (which ARE a work of art), two Garrett T28s with integral wastegate, 993 CBVs on each side, fabricated twin sided intercooler as big as we could fit in, 993 GT2 EVO profile cams and its all on DTA engine management with mapped wastegate control. The garretts are scavenged by a new GT2 racecar pump driven by an intergear drive off the block just like a GT2 racecar.
It's going together now and should get mapped on the engine dyno in about a month.
I expect it should make 550-600 fwhp at 1.3 bar but I believe that's way to much sustained heat for the 3.3L cylinders so I suspect we will run it on track at 0.8-1.0 bar at 450-500 fwhp and save the boost for qualifying!
I changed the intake manifold because its an obvious source of poor flow (along with the ports, headers, etc.) and I think you should always aim for as little boost as possible!
#24
Nordschleife Master
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AG,
That sounds like a cool project. I think you'll find you don't really like the GT2 Evo cams with the 3.3l engine. They really hamper the turbos from spooling up and you get only power from 5k and up in a single turbo application. I'll be interested to see how they work in the twin turbo application.
That sounds like a cool project. I think you'll find you don't really like the GT2 Evo cams with the 3.3l engine. They really hamper the turbos from spooling up and you get only power from 5k and up in a single turbo application. I'll be interested to see how they work in the twin turbo application.
#25
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M42racer,
Back to your original post of your conversion to EFI using the "stock manifold".
No, it is not the ultimate HP project but for the limited investment you should gain much better gas milage and drivability!
Look forward to your pics.
Back to your original post of your conversion to EFI using the "stock manifold".
No, it is not the ultimate HP project but for the limited investment you should gain much better gas milage and drivability!
Look forward to your pics.
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#26
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To many things happening at once. My 951 lost its Head Gasket. My daily driver. had to concentrate on fixing that. Have got together pics of all parts, invoice totals etc, as promised and finished engine. Engine will dyno again tomorrow. This will put money where mouth is.
#27
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AG Racing,
Why do you have to go so far? We dont have to convert fuel rails, manifold etc etc to get 450-500 fwhp at 0.9 bar with our 930's. You can get 450-500fwhp with cams,turbos,3.4 litres, headers,manifold,muffler,intercooler.
Why do you have to go so far? We dont have to convert fuel rails, manifold etc etc to get 450-500 fwhp at 0.9 bar with our 930's. You can get 450-500fwhp with cams,turbos,3.4 litres, headers,manifold,muffler,intercooler.
#29
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M,
Sorry to hear about the 951. You sound like a boost junky!
Am wondering if you are just removing the Fuel-distributor & flapper valve (adding a block off plate) and keeping the original intake system from the stock air-cleaner assambely through to the throtle plate???
Keith
Sorry to hear about the 951. You sound like a boost junky!
Am wondering if you are just removing the Fuel-distributor & flapper valve (adding a block off plate) and keeping the original intake system from the stock air-cleaner assambely through to the throtle plate???
Keith
#30
Intermediate
Join Date: Sep 2001
Location: Richmond Hill, Ontario
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Keith,
M is completely removing CIS injection system and replacing the stock injector blocks with ones that are machined with the correct EFI injector bung and retaining his intake manifold. These blocks also have the cis injector port but M is blocking these off. Blocks were originally designed to add supplementary fuel using additional efi injectors controller by an external injector driver, such as Link, HKS, Rebic, etc. I guess that a connecting pipe and KN filter will be used to replace stock filter.
M is completely removing CIS injection system and replacing the stock injector blocks with ones that are machined with the correct EFI injector bung and retaining his intake manifold. These blocks also have the cis injector port but M is blocking these off. Blocks were originally designed to add supplementary fuel using additional efi injectors controller by an external injector driver, such as Link, HKS, Rebic, etc. I guess that a connecting pipe and KN filter will be used to replace stock filter.