Lowest upper with a 6 lb lower

[jhwalker]

I have the Apten blower mod, and have been running the 2.80 upper pulley. I'm adding the 6 lb lower.

I think the 'pre-Apten mod' standard was 2.93 upper with the 6 lb lower.
Anyone gone smaller with the 6 lb lower? Comments in general...

James

 

[JPKII]

At 6500 RPM and a 2.8/6lbs Combo you'll be spinning your blower at 21125 RPM

At 6500 RPM and a 2.93/6lbs Combo you'll be spinning your blower at 20187 RPM.

IMHO the 2.93 and 6 lbs is as aggressive as you may want to get. Brian from Apten may recommend something different though.

 

[jhwalker]

Thanks --

Who did your Predator Custom tune? Love those torque numbers. Do you remember your torque max rpm? Pretty mild slope downward from the max?
James

 

[JPKII]

Shawn at SoCal Diablo did the tune. I'll have to check the dyno sheet tonight to see where the TQ peaks at.

 

[jhwalker]

Originally posted by JPKII
Shawn at SoCal Diablo did the tune. I'll have to check the dyno sheet tonight to see where the TQ peaks at.

thanks
J

 

[IronTerp]

Wow, that is really spinning the Eaton. Have heard on this forum that 18,000 is maximal rpm for efficient power production. Is this true?

 

[jhwalker]

Originally posted by IronTerp
Wow, that is really spinning the Eaton. Have heard on this forum that 18,000 is maximal rpm for efficient power production. Is this true?

I heard that for the stock Eaton. I don't know what that number is for the Apton mod Eaton.

:idea:
Brian at Apton can probably tell me, but that would be too easy and no fun...

:mj: 'don't quit on me now, damn you' will be the sound heard in a couple of days.

God bless the dynos.

:smmon:
James

 

[sambandit]

You know what, I, of all people, am beginning to realize the diminishing returns of spinning the blower too fast. You can see my combo in my sig, but I am seriously considering a 4 lb lower instead. I'm gonna experiment like a mofo at the track this spring and find out just what the limit is. The Apten mod and an aftermarket HE have raised the bar a little though. JPKII, what are those rpms numbers at 6000 rpms? That is where I shift anyway. I personally wouldn't go smaller than a 2.93 upper to to try to battle belt slip a little better.

 

[jhwalker]

sambandit


Your input is appreciated.
This will be my first experience with a lower, and I plan to start where I am on the upper and work my way to the right balance on a dyno. I have the 6/8 lb Metco and am prepared to condense some serious screwing around into a single tuning session if I can get the proper amount of time and help.

We, of the noble order of Eaton, must fight :bash: :mj: the infidel KB legions, and they are very very strong and fast (when their horses are not slipping ha ha).

Waiter, more wine please!


:rockon:
James

 

[Cobra10thaniv]

8lb lower what are you spinning the eaton off hand

Originally posted by JPKII
At 6500 RPM and a 2.8/6lbs Combo you'll be spinning your blower at 21125 RPM

At 6500 RPM and a 2.93/6lbs Combo you'll be spinning your blower at 20187 RPM.

IMHO the 2.93 and 6 lbs is as aggressive as you may want to get. Brian from Apten may recommend something different though.

I see your running the 8lb lower so what is your eaton speed.

 

[IronTerp]

Originally posted by jhwalker
I heard that for the stock Eaton. I don't know what that number is for the Apton mod Eaton.

Would the Apten porting actually affect the heat produced by the Eaton? Or does it just improve the efficiency of the Eaton's flow characteristics? But, can see how an upgraded HE could help with negative heat affects at high blower rpm.

 

[jhwalker]

I'm also running Earl's Super Chiller which drastically lower's the temperature of the Intercooler fluid.
After a couple of full-bore runs at the strip, the fluid temp is up to, maybe, 70 degrees f. Cool to the touch when you stick the pinkie in...
I will go silent until I do my dyno thang -- hopefully this Thursday or Friday.
(exception -- if you actually grenaded your car screwing around like I plan to, please PM me :lol1: :lol1: )
James

Originally posted by IronTerp

Originally posted by jhwalker
I heard that for the stock Eaton. I don't know what that number is for the Apton mod Eaton.

Would the Apten porting actually affect the heat produced by the Eaton? Or does it just improve the efficiency of the Eaton's flow characteristics? But, can see how an upgraded HE could help with negative heat affects at high blower rpm.

:lol1:

 

[redaddiction]

I'll be running a 2.76 w/ 6lb lower. Got boost ?

 

[onerichrunner]

Originally posted by jhwalker
I have the Apten blower mod, and have been running the 2.80 upper pulley. I'm adding the 6 lb lower.

I think the 'pre-Apten mod' standard was 2.93 upper with the 6 lb lower.
Anyone gone smaller with the 6 lb lower? Comments in general...

James

Hey James

In the last 2 weeks I have seen 2 guys come in with pulley combos that didn't generate the power up top they thought they would get.

The 1st guy had a 8# lower with a 2.80 upper and we only got 440 rw tops. Since then he has changed his catted pipe and felt an improvement which may or may not have been the cause of lost power. It was his first time with me so I didn't have any prior data but the power looks good down low but falls off like a bug getting sprayed with RAID at 5500 rpm.

The 2nd guy I had previously tuned to 507 rwhp with the 8# lower, stock upper with the Apten. The only change he made was the stock upper to a 3.10 upper and we lost 40 rwhp. The power loss was indentical to the 1st guy with it diving off at 5500. Trq was up and power was up to about 4000 rpm but then its...see ya later. Nose dive city.

Air fuel and timing targets were met with both guys so IMO I felt that was the limit of the Eaton SC. i would highly suggest to anyone wanting to spin the eaton faster and faster to reconsider. If anyone would like to call and ask me any questions feel free. I'm the first guy that loves to raise the bar but hate to see wasted dyno money.

Shawn

 

[trey193]

Shawn that is awesome info and props to ya!!!!! Thats telling it like it is!

 

[jhwalker]

Shawn,
Good input. Damn I hate the laws of physics...
We still have a couple of variables to play with. I'll bring down a couple of pulleys and we will play. If the overspinning is generating heat, my additional chilling may make a difference.
We will find out
see you soon,
James

 

[xVENOMx]

you would probably be better of with a 4lb lower and trying it with the 2.80

James>> how do you like Earls Super Chiller, how does it work, where did you pick yours up?

 

[IronTerp]

I'm currently running a 3.10 upper and HBH recommended stay with that and go with 4 lb lower. I believe Amazon Racing has been going with the same philosophy. This is fairly consistent with Shawn's info from above post.

 

[jhwalker]

Originally posted by xVENOMx
you would probably be better of with a 4lb lower and trying it with the 2.80

James>> how do you like Earls Super Chiller, how does it work, where did you pick yours up?

4 lb? Maybe so, but too late now! The 6/8 kit is on. ha ha I am going up in size on the upper pulley after reading the recent experiences.

B&D Racing (Canoga Park) installed the chiller. I like it, but have not had a chance to really quantify it's value. (dyno time has been scarce for me lately, so dynoing with it off and then on has not happened). Right after I had it installed, the weather turned cool out here and has never been hot since. I also have Gordsfords HE. My son and I both drive the car at the drags so we are trying a way to keep it cool enough that we don't always hate each other when we are running in two brackets.
James

 

[JPKII]

Re: 8lb lower what are you spinning the eaton off hand

Originally posted by Cobra10thaniv
I see your running the 8lb lower so what is your eaton speed.

With just an 8 lbs lower (and stock 3.65 upper) I am spinning 17007 RPM @ 6500 crank RPM.