Cosworth Fuel Rails with a high power turbo setup
05-16-2009, 02:49 PM
#1
Cosworth Fuel Rails with a high power turbo setup
This question is directed to those who have Cosworth fuel rails on a turbo setup in the 700 RWHP - 850 RWHP range...
Are there any issues with the Cosworth Fuel Rails for high HP builds?
At first impressions, the Cosworth Fuel rails do not appear to be as well suited for high HP builds as the CJ Motorsports fuel rails.
The reason I am asking is that with the CJ Motorsports fuel rails and HKS injectors, I needed the Injected Performance spacer between the intake runners and the Cosworth plenum to get adequate clearence for the Cosworth plenum to fit over the fuel rails - NOTE, THE CJ MOTORSPORTS FUEL RAILS WORKED PERFECTLY FINE WITH THE STOCK PLENUM. Once we added the spacer and the Cosworth plenum, my front strut tower brace barely cleared the top of the Cosworth plenum.
I am now switching to a GTM Stage 3 turbo system, but I have been told that the system comes with 1/4" engine mount spacers that are needed to pick the engine up a little bit to get the turbo kit to fit. If I add these spacers to the motor mounts and the Injected Performance spacer to get the Cosworth intake plenum to clear the fuel rails, my front strut brace may not clear the Cosworth plenum.
It is my understanding that if I use the Cosworth fuel rails, I can eliminate the Injected Performance spacer and everything will fit. However, I want to ensure that the Cosworth fuel rails will adequately flow fuel into the fuel injectors for the HP I will be running (650-700 RWHP on 93 octane pump gas, and well north of 700 RWHP with meth injection on line).
Are there any issues with the Cosworth Fuel Rails for high HP builds?
At first impressions, the Cosworth Fuel rails do not appear to be as well suited for high HP builds as the CJ Motorsports fuel rails.
The reason I am asking is that with the CJ Motorsports fuel rails and HKS injectors, I needed the Injected Performance spacer between the intake runners and the Cosworth plenum to get adequate clearence for the Cosworth plenum to fit over the fuel rails - NOTE, THE CJ MOTORSPORTS FUEL RAILS WORKED PERFECTLY FINE WITH THE STOCK PLENUM. Once we added the spacer and the Cosworth plenum, my front strut tower brace barely cleared the top of the Cosworth plenum.
I am now switching to a GTM Stage 3 turbo system, but I have been told that the system comes with 1/4" engine mount spacers that are needed to pick the engine up a little bit to get the turbo kit to fit. If I add these spacers to the motor mounts and the Injected Performance spacer to get the Cosworth intake plenum to clear the fuel rails, my front strut brace may not clear the Cosworth plenum.
It is my understanding that if I use the Cosworth fuel rails, I can eliminate the Injected Performance spacer and everything will fit. However, I want to ensure that the Cosworth fuel rails will adequately flow fuel into the fuel injectors for the HP I will be running (650-700 RWHP on 93 octane pump gas, and well north of 700 RWHP with meth injection on line).
Last edited by ttg35fort; 05-16-2009 at 03:51 PM.
05-16-2009, 03:05 PM
#2
I am curious to this as well even tho I am no way close to that power, I noticed the ID of Cosworth rails appeared to be smaller. I do not have my fuel return all purchased yet, but I did not like the idea of adding the spacer to move the plenum up as it provided another spot for the motor to potentially leak.
05-16-2009, 03:27 PM
#3
I am curious to this as well even tho I am no way close to that power, I noticed the ID of Cosworth rails appeared to be smaller. I do not have my fuel return all purchased yet, but I did not like the idea of adding the spacer to move the plenum up as it provided another spot for the motor to potentially leak.
Also, remember that you do not need any spacer whatsoever to use the stock plenum with the CJ Motorsports fuel rails. You only need the spacer when using the Cosworth plenum with aftermarket fuel rails (other than Cosworth) and aftermarket injectors like the HKS injectors. I just don't wan't to give up the front strut tower brace!!!
If it turns out that the Cosworth fuel rails are not adequate for my fuel delivery requirements, I'll purchase another set of CJ Motorsports fuel rails exactly like the ones that came with my fuel return kit (I am selling it because I am completely re-designing my fuel system for the surge tank, etc., and will not be using much of it). If need be, I'll have a custom strut tower brace made to clear the Cosworth intake plenum when the spacer is used, but I would like to avoid yet another expense.
Last edited by ttg35fort; 05-16-2009 at 03:47 PM.
05-16-2009, 03:44 PM
#4
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Terry have you looked at the aps strut brace? That may help you since it goes in front of the plenum. If your car was at Japtrix I would pop it off for you to check the clearance. Let me know if you are intrested in doing this.
05-16-2009, 04:02 PM
#5
Ideally, I would like to even avoid using the engine mount spacers - the goal is to keep the weight of the motor as low as possible.
First, I am going to have Nate see if he can get everything installed in a suitable manner without the engine mount spacers. If so, problem solved.
If the engine mount spacers are absolutely needed, my first choice is to go with the Cosworth fuel rails IF THEY CAN SUITABLY PROVIDE MY ENGINES FUEL REQUIREMENTS.
If I end up needing the engine mount spacers and the Cosworth fuel rails are not adequate, I'll go with the CJ Motorsports fuel rails and figure out where we are on the strut brace clearence.
While I was typing this, it just occured to me that I may be able to get by by placing a washer between the strut brace and the strut tower at each of the mounting locations. That may be an easy solution.
05-16-2009, 04:26 PM
#6
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[QUOTE=ttg35fort;7334764]Thanks, Jeff.
Ideally, I would like to even avoid using the engine mount spacers - the goal is to keep the weight of the motor as low as possible.
First, I am going to have Nate see if he can get everything installed in a suitable manner without the engine mount spacers. If so, problem solved.
If the engine mount spacers are absolutely needed, my first choice is to go with the Cosworth fuel rails IF THEY CAN SUITABLY PROVIDE MY ENGINES FUEL REQUIREMENTS.
If I end up needing the engine mount spacers and the Cosworth fuel rails are not adequate, I'll go with the CJ Motorsports fuel rails and figure out where we are on the strut brace clearence.
While I was typing this, it just occured to me that I may be able to get by by placing a washer between the strut brace and the strut tower at each of the mounting locations. That may be an easy solution. :thumbup
If you do that, you may not be able to close the hood. +1 on the APS strut bar
Ideally, I would like to even avoid using the engine mount spacers - the goal is to keep the weight of the motor as low as possible.
First, I am going to have Nate see if he can get everything installed in a suitable manner without the engine mount spacers. If so, problem solved.
If the engine mount spacers are absolutely needed, my first choice is to go with the Cosworth fuel rails IF THEY CAN SUITABLY PROVIDE MY ENGINES FUEL REQUIREMENTS.
If I end up needing the engine mount spacers and the Cosworth fuel rails are not adequate, I'll go with the CJ Motorsports fuel rails and figure out where we are on the strut brace clearence.
While I was typing this, it just occured to me that I may be able to get by by placing a washer between the strut brace and the strut tower at each of the mounting locations. That may be an easy solution. :thumbup
If you do that, you may not be able to close the hood. +1 on the APS strut bar
05-17-2009, 01:59 AM
#10
Thanks, Jeff.
Ideally, I would like to even avoid using the engine mount spacers - the goal is to keep the weight of the motor as low as possible.
First, I am going to have Nate see if he can get everything installed in a suitable manner without the engine mount spacers. If so, problem solved.
If the engine mount spacers are absolutely needed, my first choice is to go with the Cosworth fuel rails IF THEY CAN SUITABLY PROVIDE MY ENGINES FUEL REQUIREMENTS.
If I end up needing the engine mount spacers and the Cosworth fuel rails are not adequate, I'll go with the CJ Motorsports fuel rails and figure out where we are on the strut brace clearence.
While I was typing this, it just occured to me that I may be able to get by by placing a washer between the strut brace and the strut tower at each of the mounting locations. That may be an easy solution.
Ideally, I would like to even avoid using the engine mount spacers - the goal is to keep the weight of the motor as low as possible.
First, I am going to have Nate see if he can get everything installed in a suitable manner without the engine mount spacers. If so, problem solved.
If the engine mount spacers are absolutely needed, my first choice is to go with the Cosworth fuel rails IF THEY CAN SUITABLY PROVIDE MY ENGINES FUEL REQUIREMENTS.
If I end up needing the engine mount spacers and the Cosworth fuel rails are not adequate, I'll go with the CJ Motorsports fuel rails and figure out where we are on the strut brace clearence.
While I was typing this, it just occured to me that I may be able to get by by placing a washer between the strut brace and the strut tower at each of the mounting locations. That may be an easy solution.
JETPILOT found that the 1/4" spacers were absolutely necessary for clearance of the kit on his GTM TT install. Check his SAA3 thread.
FWIW, you might be better off going back to the stock plenum with a spacer. Intense found out on the twin GT37R Z that the Cosworth intake manifold was restrictive and was hindering their efforts to go beyond 1,000whp. Once they took the Cosworth intake manifold off and put the stock plenum with a PowerLab 3/8" spacer on (without any other changes to the setup or tune) they made the 1,013whp number. I'm just not convinced that the Cosworth plenum is worth the hype or is optimum for true high horsepower FI setups. It's a beautiful piece for a show car, but it's performance worth is questionable at best IMO given Intense's experience with it.
IMO you should look into CJM's intake manifold if the stock plenum + spacer option doesn't sound appealing. The CJM intake manifold has proven itself on the SP shop Z and seems truly suited for high power setups. I wish phunk would hurry up and get this thing into production.
Last edited by RudeG_v2.0; 05-17-2009 at 02:13 AM.
05-17-2009, 08:52 AM
#11
possible solution.. swap injectors? i am pretty sure that DW has something that they can set you up with... i could be wrong, but for some reason i thought i heard they do have a 1000cc or something around there that is still in a shorter casing. if that were true, you could possibly ditch the intake spacer?
Rude: ill have something to show you with the intake shortly
they are available if anyone wanted one, we just havent yet got to the point where there is an abundance of them for everyone to play with and test etc. however, there will be a couple more pretty soon here
Rude: ill have something to show you with the intake shortly
they are available if anyone wanted one, we just havent yet got to the point where there is an abundance of them for everyone to play with and test etc. however, there will be a couple more pretty soon here
05-17-2009, 02:09 PM
#12
JetPilot needed the engine mount spacers, but his car is a 350Z.
Mine is a G35, which has a little bit different engine compartment. Do I also need engine mount spacers???
The turbo kit I have is a GTM Stage 3 with 0.64 A/R turbine housings.
Please let me now.
05-18-2009, 08:26 AM
#16
Terry,
JETPILOT found that the 1/4" spacers were absolutely necessary for clearance of the kit on his GTM TT install. Check his SAA3 thread.
FWIW, you might be better off going back to the stock plenum with a spacer. Intense found out on the twin GT37R Z that the Cosworth intake manifold was restrictive and was hindering their efforts to go beyond 1,000whp. Once they took the Cosworth intake manifold off and put the stock plenum with a PowerLab 3/8" spacer on (without any other changes to the setup or tune) they made the 1,013whp number. I'm just not convinced that the Cosworth plenum is worth the hype or is optimum for true high horsepower FI setups. It's a beautiful piece for a show car, but it's performance worth is questionable at best IMO given Intense's experience with it.
IMO you should look into CJM's intake manifold if the stock plenum + spacer option doesn't sound appealing. The CJM intake manifold has proven itself on the SP shop Z and seems truly suited for high power setups. I wish phunk would hurry up and get this thing into production.
JETPILOT found that the 1/4" spacers were absolutely necessary for clearance of the kit on his GTM TT install. Check his SAA3 thread.
FWIW, you might be better off going back to the stock plenum with a spacer. Intense found out on the twin GT37R Z that the Cosworth intake manifold was restrictive and was hindering their efforts to go beyond 1,000whp. Once they took the Cosworth intake manifold off and put the stock plenum with a PowerLab 3/8" spacer on (without any other changes to the setup or tune) they made the 1,013whp number. I'm just not convinced that the Cosworth plenum is worth the hype or is optimum for true high horsepower FI setups. It's a beautiful piece for a show car, but it's performance worth is questionable at best IMO given Intense's experience with it.
IMO you should look into CJM's intake manifold if the stock plenum + spacer option doesn't sound appealing. The CJM intake manifold has proven itself on the SP shop Z and seems truly suited for high power setups. I wish phunk would hurry up and get this thing into production.
Thank you for the information. Do you know what RPM they were pushing it to?
On my last build, we picked up quite a bit of torque/HP throughout the RPM band by adding the Cosworth Intake Plenum and Turbo Blankets. The most notable improvement was in the mid-range torque, however.
On this build, I am going with larger turbos (Garret 3071's vs. Greddy 18G's), and larger cams (JWT C8's vs C2's). Both the larger turbos and cams are going to adversely affect the mid-range torque. Also, I am only running to about 7500 rpm. I think I would rather sacrifice losing a little bit of HP at the very top end in order to ensure I have sufficient mid-range torque rather than doing the opposite.
Anyway, I already have the Cosworth, so I want to give it a try. Morevover, given that the Cosworth Plenums are no longer in short supply, I'm sure I will take a significant loss on it if I sell it (much like everything else I have sold or am currently selling
).
Last edited by ttg35fort; 05-18-2009 at 08:29 AM.
05-18-2009, 10:42 AM
#17
I don't recall specifically. But that car is a 4.2L stroker, so they probably didn't rev it above 7500RPM. I don't remember what cams are in that motor either. It seems that experiences with the Cosworth vary across the board.
Glad to hear that it has performed well for you.
Glad to hear that it has performed well for you.
05-18-2009, 02:58 PM
#18
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intense is going to give another crack at it with the cosworth on my car...ill switch to pl spacer+oe plenum in the high psi pulls. Different engine than chris car, different turbo setup, and ill test the 8000-9000rpm area and see where it goes....worst case its a quality show piece, and i give charles a call
Last edited by IIQuickSilverII; 05-18-2009 at 03:01 PM.
05-18-2009, 04:41 PM
#19
intense is going to give another crack at it with the cosworth on my car...ill switch to pl spacer+oe plenum in the high psi pulls. Different engine than chris car, different turbo setup, and ill test the 8000-9000rpm area and see where it goes....worst case its a quality show piece, and i give charles a call
If my understanding is correct (I have not seen the latest version, only pics of earlier prototypes), Charles's intake plenum is better optimized to achieve maximum HP at high RPMs. Of course, with most things, there is a trade off. In this case, it is the trade off between mid-RPM torque/hp and high-RPM torque/hp.
Given the RPM range you are shooting for, IMO it's a waste of time to even try the Cosworth because it just isn't designed to maximize HP in the upper RPM range. With the Cosworth, the torque is going to start falling off after about 5000 RPM. Based on old pictures I saw of Charles's plenum, this is just when his will be getting started.
Last edited by ttg35fort; 05-18-2009 at 08:24 PM.
05-18-2009, 08:29 PM
#20
^^^^^
If anyone knows of a plenum that will outperfrom the Cosworth from about 3000 rpm up to 7500 rpm, I would certainly like to know and will look further into it!!! There is always room for improvement.
If anyone knows of a plenum that will outperfrom the Cosworth from about 3000 rpm up to 7500 rpm, I would certainly like to know and will look further into it!!! There is always room for improvement.
Last edited by ttg35fort; 05-18-2009 at 08:31 PM.