[AMOR]

Originally Posted by clg82

I have a 2650 on my ZL1, I run it in so-cal heat track and the canyons with 0 issues. I dynod at 725 to the wheels with stock exhaust.

Hi, thanks for the feedback! What fuel and pulley it dynoed at 720 whp? From what Magnuson advertises 2650 should give you like 730 at the crank, granted all other components are stock?

[Blackdevil77]

Originally Posted by NG329

Honestly, heat isn't the real issue with the stock blower unless you start spinning it faster. I've already debunked that myth with a 40minute session on a 90*F day at advanced pace. Emptied the gas tank in 63 miles and never saw any problems with heatsoak.

I was literally just chatting with another forum member over text about this yesterday. Personally, the biggest issue with me not going faster isn't a lack of power but fast left-to-right transitions. The rear end of the car can feel unstable on the limit and the front is actually soft-ish. Adding more power without fixing that issue will just exacerbate it. I get pulled off the corners all the time by Porsche GT3s which make at least 150hp less than me right now.

A 2650 is truly overkill in my humble opinion and I track very very often. If you're truly a track rat your priority should be tidying up the rear and eliminating any wheel hop etc. The car needs to feel as flat as possible in the turns.

In full transparency, I also considered a 2650 and one day I may still do it. Maybe over the winter. However, I've prioritized putting the power to the ground over all else. The 7:16 Nurburgring run has left me puzzled because Chevy never released their setup info. The car wasn't truly stock on that run. The passenger seat was removed. Bill also used a racing seat. The car had a roll cage and the interior looked to be stripped down. Who knows what else was done to the car. Whatever the case was, his car hooked up nicely and that is what I personally am aiming for.

If you look in the track pics I posted in the other thread, you can see the front end of the car compressing in those corners and the front end is not even lowered the last 10mm. The stock setup is probably the best setup for a wide range of conditions, including damp and wet roads. But to get the best performance in the dry I think the chassis needs considerable attention. Particularly from the rear.

My $0.02

I read in a few places that these cars have a problem with heat soak after staying WOT for a long period of time. Ever race on a track with long straights where you kept your foot down for 15-20+ seconds? If so, what did the temps look like?

[AMOR]

Originally Posted by Blackdevil77

I read in a few places that these cars have a problem with heat soak after staying WOT for a long period of time. Ever race on a track with long straights where you kept your foot down for 15-20+ seconds? If so, what did the temps look like?

Any forced induction car will heat soak, especially with a supercharger that is spinning 20K RPM. That’s why Porsche GT cars are NA.

[Blackdevil77]

Originally Posted by AMOR

Any forced induction car will heat soak, especially with a supercharger that is spinning 20K RPM. That’s why Porsche GT cars are NA.

Yes of course, but I’m wondering if the ZL1 does it more so than other supercharged cars, like the GT500 or the Hellcat. That’s the claim I was reading

[clg82]

Originally Posted by AMOR

Hi, thanks for the feedback! What fuel and pulley it dynoed at 720 whp? From what Magnuson advertises 2650 should give you like 730 at the crank, granted all other components are stock?

It has the stock (Magnuson) pulley, and it dynod with that number with shitty california 91 and a full can or Torco.

[AMOR]

Originally Posted by Blackdevil77

Yes of course, but I’m wondering if the ZL1 does it more so than other supercharged cars, like the GT500 or the Hellcat. That’s the claim I was reading

I personally feel like the car is loosing like 50-70 hp at the mid-end of a 20 min track session. But that is in Florida heat though. For a large V8 it’s actually doing pretty well I would say. How about GT500 ?

[clg82]

Originally Posted by NG329

your priority should be tidying up the rear and eliminating any wheel hop etc. The car needs to feel as flat as possible in the turns.

He can do both....tidy up the rear as well as adding more power. OP if you haven't tracked your car yet...I'd say do that first....get a feel for it after some sessions and figure out what you want the car to do and how.....

[clg82]

Originally Posted by AMOR

I personally feel like the car is loosing like 50-70 hp at the mid-end of a 20 min track session. But that is in Florida heat though. For a large V8 it’s actually doing pretty well I would say. How about GT500 ?

you'll feel like that with any supercharged vehicle in the heat....I can speak from experience (i go with my neighbor who owns a 2020 GT500) and he has considerably worse IAT on his 500 than i do with my ZL1.

[Camaro1973]

Originally Posted by Blackdevil77

Yes of course, but I’m wondering if the ZL1 does it more so than other supercharged cars, like the GT500 or the Hellcat. That’s the claim I was reading

Yes, the cooling bricks in the blower are just too small. While the heat exchangers themselves are fine stock, the problem is the cooling bricks aren't large enough to pull the heat from the blower even with the water being cooled by the exchangers. The 2650 bricks are just massive and are able to get that cooler water to air into the blower.



You should see a 20-40F difference in MAT temps on a track session from the stock blower to a 2650.



A nice sized expansion tank is also a good idea on the road course as well.

[clg82]

Originally Posted by Camaro1973

Yes, the cooling bricks in the blower are just too small. While the heat exchangers themselves are fine stock, the problem is the cooling bricks aren't large enough to pull the heat from the blower even with the water being cooled by the exchangers. The 2650 bricks are just massive and are able to get that cooler water to air into the blower.



You should see a 20-40F difference in MAT temps on a track session from the stock blower to a 2650.



A nice sized expansion tank is also a good idea on the road course as well.

spot on^ i believe i was seeing a difference of 38*

[20Bluezl1]

I track my ZL1 all the time and have no problem with the JRE125 package. Making like 650 - 680 whp on E60 no issues what's so ever, and have plenty of traction with the SC3R.

[Camaro1973]

Originally Posted by 20Bluezl1

I track my ZL1 all the time and have no problem with the JRE125 package. Making like 650 - 680 whp on E60 no issues what's so ever, and have plenty of traction with the SC3R.

If your Manifold temps start approaching 145F, guess what happens. Timing starts to be pulled. Besides that, simply running hotter you lose power.


Granted teds package is on ethanol, so your already at an advantage, but do you ever monitor IAT3 AKA MAT temps?


Alot of people say they have no problems on the track, that doesn't necessarily mean you aren't losing power.

[AMOR]

Originally Posted by 20Bluezl1

I track my ZL1 all the time and have no problem with the JRE125 package. Making like 650 - 680 whp on E60 no issues what's so ever, and have plenty of traction with the SC3R.

The problem with that package is that you need to change headers and that is something I do not want to do. Also the price of that package is practically the same as getting a 2650...

your priority should be tidying up the rear

Could you please elaborate what exactly you mean by "tidying up the rear"? I have factory recommended track alignment and the SPL titanium rear toe arms with eccentric lockout. Other than that, this car already has steel ball joints instead of rubber bushings and brilliant Multimatic shocks as standard, so what else would you do?

Yes, the cooling bricks in the blower are just too small. While the heat exchangers themselves are fine stock, the problem is the cooling bricks aren't large enough to pull the heat from the blower even with the water being cooled by the exchangers. The 2650 bricks are just massive and are able to get that cooler water to air into the blower.

This is exactly why I am considering the 2650 upgrade! It can run cooler and at a lower boost/less stress than factory LT4 blower. Good point, thanks!

It has the stock (Magnuson) pulley, and it dynod with that number with shitty california 91 and a full can or Torco.

Did you have it custom tuned or using the stock (provided by Magnuson) calibration for 2650 ?

[NG329]

If you're not logging then you're just guessing. OP should post a log of a track run.

I sent one to Jannetty earlier in the year and no timing was pulled on a stock setup with TC off in warm conditions after a 20 minute session.