[JSH]

Originally Posted by radz28

You'll need a meth pump and run lines to the intake and some tuning to compensate for the added fuel in the ECM. It'll spray right into the intake.

Joe knows the car well and will opine, but that sounds doable. I feel like I'm going down a road previously traveled by many.

[EDFHOBBIES]

What combo you running. And I would assume any setup brand will have same issue.

[JSH]

Originally Posted by EDFHOBBIES

What combo you running. And I would assume any setup brand will have same issue.

Combo of what?

[radz28]

Originally Posted by JSH

Joe knows the car well and will opine, but that sounds doable. I feel like I'm going down a road previously traveled by many.

I think there are many opinions on this road.

Some people love and swear by meth. It's a useful fueling source, and does well at what it seems like you need it for.

Others don't have a high opinion of it. Some don't like it as a fueling crutch, and don't like the maintenance aspect of it.

It seems like for you, a supplemental cooling source makes the most sense. You can bring your MATs down, and help control timing with the stock IAT table. You are good on fueling, so an argument about safety (from it clogging and failing or whatever) is something you wouldn't have to worry about.

I wouldn't know from personal experience, but from things I've come across, it seems like a better flowing top end might be necessary. I watched a video where one of the guys, talking about 2650s in general, mentioned if you want the most, a big cam is key to getting the most efficiency out of them. I don't remember if you're still running the Hennessey cam, nor what the specs are, and what a big cam should be (240-250@.050"?), but that's what a pretty successful LT4-guy has said. That might be a lot of cam for the street, but that might be the choice you have to make.

JMO...

[JSH]

Joe hasn't really recommended meth to me, so I've assumed he's not wild about the idea.

But we have discussed a bigger cam. My thinking is that, although HPE will not disclose its specs, the current cam is their 850 cam which made 723 wheel, w/o touching either the TB or SC. To do that, it must be a high rpm cam with at least 32% lobe and intermediate lift/duration along the lines you suggest. In terms of its drive-ability, it's the lumpiest cam I've ever driven on the street.

This reminds me to comment on plug gap, which I reduced from .028 to .022 a few weeks ago. I believe the smaller gap makes the car run even rougher than before.

Originally Posted by radz28

I think there are many opinions on this road.

Some people love and swear by meth. It's a useful fueling source, and does well at what it seems like you need it for.

Others don't have a high opinion of it. Some don't like it as a fueling crutch, and don't like the maintenance aspect of it.

It seems like for you, a supplemental cooling source makes the most sense. You can bring your MATs down, and help control timing with the stock IAT table. You are good on fueling, so an argument about safety (from it clogging and failing or whatever) is something you wouldn't have to worry about.

I wouldn't know from personal experience, but from things I've come across, it seems like a better flowing top end might be necessary. I watched a video where one of the guys, talking about 2650s in general, mentioned if you want the most, a big cam is key to getting the most efficiency out of them. I don't remember if you're still running the Hennessey cam, nor what the specs are, and what a big cam should be (240-250@.050"?), but that's what a pretty successful LT4-guy has said. That might be a lot of cam for the street, but that might be the choice you have to make.

JMO...

[KingLT1]

Originally Posted by radz28

So, if we accept around 3% power loss, per thousand feet of elevation, he's probably making closer to 1100 to the tire at an air density of around sea level?

Maybe there isn't much to be done outside of adding meth, unless he changes the VE of the engine.

I would say at seal level with a DA of 0 it would definitely be in-between 1k-1100whp.

As of right now I think he could get through the 1/4mi with no timing pull in 60-70 degree weather. So it's likely fine as is. I might even be able to raise the IAT spark correction table to not pull timing until a little higher temp with race fuel. It's currently set to not start pulling timing until 154 MAT's. Won't really know how far I can stretch it out until we get some warmer temp logs. But yeah, meth could help with cooling as well if need be. I don't have a problem with it if it's used for cooling and not a fuel source.

Originally Posted by JSH

I could also run it as-is with the 2.75 and wait until March T&T's to determine whether I need to put the 3" upper back on it. I'm trying to prepare now for racing next year at 8000-9000 ft. DA with much higher ambient and MAT.

That's what I would do. I don't really see any issues with your setup tbh.

[wnta1ss]

Originally Posted by ZL1Atlanta

This was only at 19.5 psi, but it's the pass in my signature (tire size messes with the MPH).

While your speedo calibration might not be set correctly for the tall drag tire, the reason that your speedo reading is pegging out at 158 in the log is a known problem with that channel in HPT. However, if you want to track speeds above 158, the 'Driven Wheel Speed' and 'Undriven Wheel Speed' channels do indeed keep reading above 158.

[ZL1Atlanta]

Originally Posted by wnta1ss

While your speedo calibration might not be set correctly for the tall drag tire, the reason that your speedo reading is pegging out at 158 in the log is a known problem with that channel in HPT. However, if you want to track speeds above 158, the 'Driven Wheel Speed' and 'Undriven Wheel Speed' channels do indeed keep reading above 158.

Good info! I just always accepted it for what it was, but I just recently started trapping this high so it'll be worth looking into that as it gets faster. We should just calibrate it as well since the car will never see regular wheels/tires again.

[JSH]

Originally Posted by wnta1ss

While your speedo calibration might not be set correctly for the tall drag tire, the reason that your speedo reading is pegging out at 158 in the log is a known problem with that channel in HPT. However, if you want to track speeds above 158, the 'Driven Wheel Speed' and 'Undriven Wheel Speed' channels do indeed keep reading above 158.

Good info right there, thanks

[CamOnlyJabroni]

Originally Posted by wnta1ss

While your speedo calibration might not be set correctly for the tall drag tire, the reason that your speedo reading is pegging out at 158 in the log is a known problem with that channel in HPT. However, if you want to track speeds above 158, the 'Driven Wheel Speed' and 'Undriven Wheel Speed' channels do indeed keep reading above 158.

Interesting. Wondered why when I logged the C7Z to around 170 it quit reading at 158.

[radz28]

Maybe JSH needs a 3100 if he wants to let the smoke out at that elevation.

[JSH]

Originally Posted by radz28

Maybe JSH needs a 3100 if he wants to let the smoke out at that elevation.

LOL, it would be like me to order the largest available, but I'll try to enjoy this one for a while first.

[EDFHOBBIES]

Let me know if you need a log to compare Eddie's. My car is over at Matt's.

[JSH]

Originally Posted by EDFHOBBIES

Let me know if you need a log to compare Eddie's. My car is over at Matt's.

Sure, let's swap logs. I'm going to dyno on 104 octane and 2.75 pulley in the next week or so and will log it. Do you want to exchange files here or via email?