New numbers on Vortech Cobra after adding CXracing intercooler

[black4vcobra]

Just got my 99 Cobra retuned yesterday after running a non-intercooled Vortech kit for the last 2 years. Car previously made 415/376 at 6.8 lbs of boost but was much slower on a hot day as the tune would pull timing to preserve the motor.

Yesterday the car made 456/386 at 6.8 lbs of boost, 11.3 A/F ratio and 18 degrees of total timing. The temperature in the shop was 96 degrees so I'm pretty impressed with a 16 year old can with 75k miles on it and the tuner said it makes right what should based on the mods. He also said there is plenty more in it with more timing and a smaller blower pulley but of course the stock shortblock is at it's limit with 456 rwhp.

I also added a FGT fuel pump and KB BAP, 3.12" pulley (from 3.48"), a Vortech mini race BPV (vented to atmosphere) and a PMAS HPX MAF sensor. The car drives much smoother too as the previous bypass valve was kinda junky.

Dyno graph below, other mods in sig. Anyone think the boost is a little low or is that just a byproduct of an efficient motor? I'm pleased with the CXracing intercooler, when cruising the IAT's are only a degree or 2 above ambient and only a couple more degrees above ambient when getting on it.

Couple pics of the install -

 

[ZeroDCX]

Nice numbers!

From my research, it seems that the CXRacing intercooler isn't very efficient as far as inhibiting air flow. A couple people have picked up boost, just from swapping from the CXRacing intercooler to a Treadstone intercooler with no other changes. However, I haven't found any validated data between the differing brands of the same respective thickness intercoolers. Most swap from the 3''/3.5'' thickness CXRacing intercooler to the 4.5'' thickness Treadstone TR1245 or similar intercooler. Then post claims that they've picked up 5-8psi without pulley changes. (Of course the larger intercooler would flow better than the smaller intercooler). I've also came across that the flow rate of the 3'' CXRacing intercooler is also 700cfm, but again no valid data to back up that claim. But take it for what its worth.

 

[Brutal Metal]

Congrats BUT going from a 3.48 to a 3.12 and you didn't pick up any boost?

 

[Mach828]

Boost is low, but numbers are strong for the boost level. Mine hits 8lbs with the 3.12" pulley and an S trim, my DA here is 7,500. I have the Treadstone 1045.

The CXRacing unit is probably a restriction. I'd have expected closer to 10 with the 3.48 pulley non intercooled, and more like 13 with the 3.12".

Any belt slip?

 

[black4vcobra]

Nice numbers!

From my research, it seems that the CXRacing intercooler isn't very efficient as far as inhibiting air flow. A couple people have picked up boost, just from swapping from the CXRacing intercooler to a Treadstone intercooler with no other changes. However, I haven't found any validated data between the differing brands of the same respective thickness intercoolers. Most swap from the 3''/3.5'' thickness CXRacing intercooler to the 4.5'' thickness Treadstone TR1245 or similar intercooler. Then post claims that they've picked up 5-8psi without pulley changes. (Of course the larger intercooler would flow better than the smaller intercooler). I've also came across that the flow rate of the 3'' CXRacing intercooler is also 700cfm, but again no valid data to back up that claim. But take it for what its worth.

People bash the CXracing intercooler but given the smaller supercharger and the relatively low amount of power I'm making, I just can't see it holding me back that much considering the tuner had to pull some timing just to prevent the engine from making more power than it can handle.

Congrats BUT going from a 3.48 to a 3.12 and you didn't pick up any boost?

Shockingly yes, the 2 setups each produced 6.8 lbs of boost. This is the old dyno graph -

There is some evidence that one of the couplers wasn't holding all the boost though. Prior to the install, I didn't realize that I needed a 3.5" to 3" silicone reducing coupler so we had to make a rubber plumbing coupler work for the dyno since a 3.5" to 3" coupler is not available locally. I already ordered the correct coupler and will have to monitor boost levels to see if anything changes with that.

Also the tuner did say that he usually doesn't see huge boost numbers, with smaller blowers, on the long runner intakes on the 4V's and that the long tube headers on the car probably lowered the boost

 

[black4vcobra]

Boost is low, but numbers are strong for the boost level. Mine hits 8lbs with the 3.12" pulley and an S trim, my DA here is 7,500. I have the Treadstone 1045.

The CXRacing unit is probably a restriction. I'd have expected closer to 10 with the 3.48 pulley non intercooled, and more like 13 with the 3.12".

Any belt slip?

Tuner didn't mention any belt slip and I don't see any evidence of it. I did spring for the Thump RRR tensioner so I hope there won't be any.

One thing to consider too is that I have an E-trim blower which supposedly has different gearing that was made for the high RPM 4V's. There isn't much info on it but from what I understand it needed a smaller pulley to match the boost of the S or Si trim blowers.


This is about the most "reliable" info I can find on the E-trim - http://www.alternativeauto.com/Vortech_Supercharger_Kit.html

"Vortech has done a superb job of making the Mach-1 scoop fit nicely around their supercharger package. One new and very noticeable feature with the Mach-1 Vortech blower is that they’ve gone back to the “SC”-Trim for this blower kit, not the “E”-trim that was used on the ’99 and ’01 Cobra’s. The SC-trim was first used exclusively on the ’96 thru ’98 cobras and is nothing more the tried and true “S”-trim with a slightly reduced impeller outer diameter that kept the blower from over boosting on the 7000+ rpm capable 4-valve engines. The E-trim was a good unit but only made about 7 psi of boost with stock pulleys and was limited to about 10 when over spun as far as you could go with the typical 6-rib Cobra pulley combination. When over-spun, the SC-trim can produce as much as 12-14psi on a typical 32 valve that sees 7000+ rpm’s."

 

[Mach828]

Good to know. Vortechs site said it flowed more cfm than the s trim. But I don't see a compressor map available for it to compare. Your tuner wouldn't have happened to send you the winpep file? I was going to overlay it against my 6lb graph to see the differences in the blower dynamics.

 

[Brutal Metal]

Boost is low, but numbers are strong for the boost level. Mine hits 8lbs with the 3.12" pulley and an S trim, my DA here is 7,500. I have the Treadstone 1045.

The CXRacing unit is probably a restriction. I'd have expected closer to 10 with the 3.48 pulley non intercooled, and more like 13 with the 3.12".

Any belt slip?

I'm at about 14 with a 3.1 Reichard with a 6.75" ATI damper with an E-Trim! E's can make 17 without overspinning

 

[Mach828]

Cool! Thanks for posting the two graphs. Here is what mine looked like. The red line is 6lbs and 16 degrees of timing. It looks very similar to yours, and I have 96 cobra cams. Yours seems to carry a steeper trend at red line.

 

[black4vcobra]

Good to know. Vortechs site said it flowed more cfm than the s trim. But I don't see a compressor map available for it to compare. Your tuner wouldn't have happened to send you the winpep file? I was going to overlay it against my 6lb graph to see the differences in the blower dynamics.

He did not send that file. Ya, it's such a rare blower that Vortech doesn't even put the compressor map up yet for some reason they have a compressor map of an ancient "F trim" blower lol.

I'm sure there is more power to be had by spinning the blower harder and with a Treadstone intercooler but considering I'd need an engine rebuild to take advantage of that power I'll probably stick with this setup until I can swing the $$$ for a rebuild.

 

[Brutal Metal]

This is about the most "reliable" info I can find on the E-trim - http://www.alternativeauto.com/Vortech_Supercharger_Kit.html

"Vortech has done a superb job of making the Mach-1 scoop fit nicely around their supercharger package. One new and very noticeable feature with the Mach-1 Vortech blower is that they’ve gone back to the “SC”-Trim for this blower kit, not the “E”-trim that was used on the ’99 and ’01 Cobra’s. The SC-trim was first used exclusively on the ’96 thru ’98 cobras and is nothing more the tried and true “S”-trim with a slightly reduced impeller outer diameter that kept the blower from over boosting on the 7000+ rpm capable 4-valve engines. The E-trim was a good unit but only made about 7 psi of boost with stock pulleys and was limited to about 10 when over spun as far as you could go with the typical 6-rib Cobra pulley combination. When over-spun, the SC-trim can produce as much as 12-14psi on a typical 32 valve that sees 7000+ rpm’s."

That's some good fiction right there? An E-Trim is only capable of 7-10lbs? haha!

 

[black4vcobra]

Cool! Thanks for posting the two graphs. Here is what mine looked like. The red line is 6lbs and 16 degrees of timing. It looks very similar to yours, and I have 96 cobra cams. Yours seems to carry a steeper trend at red line.

What size pulley were you running on the red line? 3.12"?

 

[Brutal Metal]

The E-Trim flows 1150 cfm just like the Si AND it has a bigger inlet, it's only downfall is a less aggressive impeller, nothing wrong with the E...

http://www.vortechsuperchargers.com/page.php?id=30008

 

[black4vcobra]

I'm at about 14 with a 3.1 Reichard with a 6.75" ATI damper with an E-Trim! E's can make 17 without overspinning

That's some good fiction right there? An E-Trim is only capable of 7-10lbs? haha!

Glad to hear there is more in it when I can swing a rebuild. Vortech's website does say it will flow 1150 cfm which matches the Si blower and exceeds the S and SC blowers

 

[Mach828]

What size pulley were you running on the red line? 3.12"?

Red line is 3.40", blue line is the 3.12".

.....

And here is how the 3.12" responded to 23 degrees of timing on e85 (blue). Stock engine with 115k. If you feel like you need more power, e85 is awesome!

 

[black4vcobra]

Red line is 3.40", blue line is the 3.12".

.....

And here is how the 3.12" responded to 23 degrees of timing on e85 (blue). Stock engine with 115k. If you feel like you need more power, e85 is awesome!

You must be a gambling man! I would be so bummed to blow my engine and have to scrimp for a year or pull out retirement funds to afford to get it rebuilt. Glad to see it will hold together (for awhile at least) at that power level!

The differences in blowers and the intercoolers must account for the power differences between my car with the 3.12" and yours.