[NKY ZL1]

Hey Guys,
I am just finishing up a cam swap and adding long tubes to my 2018 ZL1. Looking to re-pulley the car so I am at ~14lbs of boost. I've done some searching on here and it looks like a stock lower and 70mm upper would get me in that range. I have talked to a few of you and seen in posts that belt slip with the 70mm can be an issue because of losing belt wrap.
I am wondering if anyone can recommend a set of pulleys with a larger than stock crank pulley so I don't have to go all the way down to 70mm to get to that boost level. Heres the full setup
2018 ZL1 LT4
Stock heads
TVS 2300
BTR Stage 2 cam
2" long tube headers with no cats
Roto fab intake

Looking for ~ 14lbs of boost

Let me know what you guys have tried,
Thanks in advance

[TMS]

I run a Maggie 2300 at 14 lbs peak boost on the money. I run the stock pulley that came with the Supercharger (I think it’s 80mm) along with a 9.17” lower.

[laynlo15]

I work for Magnuson and I've been thru lots of pulley changes on both my 2300 Maggie which I had over the last 3 years and now my 2650 Heartbreaker. You should be able to get very close with the 75 mm pulley. I had a similar setup with my 2300 earlier in the year and I was at 16 lbs with the 70mm, however I do have a stock lower. Do you know the size of lower you'll be running? TMS has a good starting point if your running that large of lower. The Griptec pulleys are a little more expensive but I haven't had one slip yet, but to be fair I didn't have one of our Magnuson pulleys slip either and that's all I ran on my 2300. I didn't start running the Griptec until I installed my 2650 as the smallest pulley we had at that time was an 80mm. Glad you chose the Magnuson, you'll love it.

[LiqTenExp]

I am running stock upper on my 2300 with 9.17 lower and hit ~ 14psi. Ported stock heads, cam, 1 7/8" ARH headers through full 3" borla sport.

I am moving down to a couple sizes to a 3" pulley shooting for 16psi

[laynlo15]

The 3" should be the 75mm and if the 80mm is the stock upper you should be there at 15.5 to 16 psi.

[L78toLT1]

You guys keep referring to "stock" 80mm upper pulleys. Greg, correct me if I'm wrong, but aren't 2300 Maggie's shipped with 98mm pulleys, which are good for maybe 5 - 6psi with stock lower.

[laynlo15]

Jim, his is a zl1 and I believe they come with an 85 or 80mm. The SS is a 98 with the factory tune.

[NKY ZL1]

I would like to thank all of you for taking the time to reply. We've all got stuff to do during the holiday so I really appreciate it.
You guys combined with Ted from Jannety Racing helped me out and I'd like to send a special thanks to him for spending the time on the phone with me today.
I settled on an 85mm upper and 15% lower
Thanks to all of you guys !!!!

[laynlo15]

Good to go and I'm sure that Ted discussed the issues you can run into running higher boost levels and having the fuel system keep up with the boost your trying to achieve but boost is based off restriction and headers, ported heads, compression, larger displacement all factor in to how much boost you can make. I should have mentioned in our discussion that I was running race fuel on 16 psi and spraying a little meth/water at the track. On the street I was running an 80 mm upper with stock lower and on 93 octane/meth/water. I think that was about 11-12 psi which was very safe for me on the street. Have some fun and take Ted's advice and you'll have a safe, fast fun ride.