I just changed out my HE pump with a Johnson pump. Even though I thought I had no problem with my old one. Just doing some upgrades right now. Let me tell you, this car feels like it picked up a few horses. It takes off alot stronger than it did before.Its a whole lot more responsive. And the traction control lights up like crazy now. I know some of you are waiting for your factory pump to go out fiirst, but let me just say, don't wait. I think this single mod/upgrade is the difference between cars that run high 12's and those that run low 13's stock. I truly believe that the stock for stock the reason why some people are running fast and others are running slower all depends on the state of their respective HE pumps. I just went to the track this weekend and my best time was a 12.89 at 109 and I swear by my butt dyno I could smoke that time now, no doubt.

 

Jerry at LET told me that the car starts pulling timing depending on the inlet air temp to the motor to prevent timing. This is a temperature effect, while the pump is still functional, thus it makes sense, Woody

 

Mine has been steady as a rock since the Johnson pump swap. I think my factory pump was good too... not to mention the mild temperatures here.

I plan on adding about a 2 gallon reservior later this year to expand the capacity of the Air Charge Cooler system. Hopefully that will lower my IATs as well.

 

I agree Waldig - here is a good read on engine cooling from Stewart-Warner components - the same principle can be used for the intercooler coolant.

http://www.stewartcomponents.com/tec...ech_Tips_1.htm

When SpeedInnovation was tuning my SRT - I was told that heat soak was preventing me from a MAX HP dyno run.

There is much I plan to do, Expanded HE - High Pressure Pump (Johnson) , Dual Reservior Tanks, Lower Temp Thermostat, High Tech Heat Wrap for the Intercooler.....

I just recieved my IAT gauge & sending unit today and have a custom aluminum dual gauge pod (IAT and Boost) that just shipped out today (no more plastic gauge cup).

 

Brian, Do you have phenolic spacers on your intake? I sure like the looks of the Code3 spacers. I have the TVT thermostat to put in. If I had known what the mod was I would have done my own in the shop. It's just 4 holes in the plate.

MikeR

 

MikeR,

Thanks for the pictures, that is TRUELY an easy mod we can all do for the stock themostat.

Cheers!

 

The proper mod (from what I read on the MB forum) is to replace the wax pellet in the T-Stat with a 170Deg F (vice a 195Deg F). This allows the engine to get beyond cold start mode faster.

Along with the T-stat mod is to have the radiator fan programmed turn on 25 deg sooner. Both of these mods should have the engine running a lot cooler and helping to reduce heat soak.

I have not installed my spacers yet - I am going to be removing the SC and pleniums - for polishing and to get to the intercooler. I will install when I re-assemble.

Of course this mod is not emissions friendly - but it is performance friendly.

 

Well, I will still have my stock thermostat if I want to do the MB mod on it. Then I will have a backup. I guess I could get InMotion to program the lower fan turn on during the re-flash too.

MikeR

 

umm yeah, how do you program the fan to come on at a lower temp?

 

In a typical OE setup, the Johnson CM30 pump will lower IATs ~10 degrees Fahrenheit.

Reputable source…http://www.mbworld.org/forums/showpost.php?p=2376178

When getting after ‘em on a road course, or especially before fitting an aftermarket pulley, upgrading one’s heat exchanger is imperative for best performance. The DME will retard spark timing significantly, and dump fuel, once the 140 degree threshold is breached and continue to do so as temperatures increase. Properly controlling heat soak, high IATs, and their attendant ‘dialing back’ from ideal spark timing and mixture strength parameters will measurably increase performance.

Congratulations on becoming a member of the 12 second club!

 

Please post pics when you receive.

 

Just wanted to mention that I was experiencing my S/C not working properly. Ironically on my way to LET Motorsports today, it was really acting up on the very trip I planned to have it changed out with the LET HE as well as the Johnson Pump. I have to say, I was very impressed with Erick at LET and he did a great job. Super guy and I am sure many of satisfied customers will be on ther way or on-line purchasing his top quality offerings. The car has a lot more power. In fact, more power than it ever had since I've owned it. My car has 23,000 miles on it and the more I learn about these motors and the particulars as to how the temps effect the power output and how much more it has now, I am sure the pump was working intermittently at best the whole time I have owned it. Not having anything to compare it to, I thought what I had before the swap was the normal expected performance. I am very gald I swapped these parts out. The original HE and pump are far inferior compared to the new ones.

Steve

 

I honestly think I can beat that 12.89 now with just the changing of the pump. The car is so much more responsive and oddly it gets to the magic 3000 mark faster now. I know the SC doesn't come on till that rpm so why its faster to 3000 now is a mystery to me. It revs much better and more consistently. Like I said before to those who haven't done this upgrade "I thought my pump was just fine before."

 

Where would anyone with the johnson pump suggest buying it?

 

www.letmotorsports.com

 

Hi MikeR What size holes are drilled in the plate? looks to be 1/8 or 3/16. i'm going to be installing the johnson H E pump soon and i'll modify my stat at the same time. thanks for the information. ILLCYA

 

The SC does come on before 3000; it wont engage after 3000, but it will STAY on past then.

 

+2, someone please measure the holes. If its this simple we should all be doing this ourselves.

 

Wow, I'm confused then. It was my understanding that below 3000 the supercharger is not engaged. Around 3000 is when I feel the kick of the SC.

 

There is a thread floating around the srt-6 section that addresses this. I cant remember what the title of it is but someone included a passage from an article that stated if the SC were to kick on after 3000 that the load on the belt could be to high resulting to breakage.

However, the way the artilce reads makes it sound exactly the opposite...the way you described it. Upon me pointing this out some members helped clear this up and when i re-read it i understood it.