Z54 Tuning
 

I've been reading that people are getting the 6758 to fully spool by around 3k rpms. I realize the Z54 will not spool quite as fast, but I have some questions regarding the tuning necessary to get something similar. With the Z54 I feel like I'm driving an NA car until after 3500rpm or so. The turbo doesn't seem to want to build boost in the low RPMs. I have also never driven a stock K04 car so I'm not familiar with how the stock turbo spooled or how soon. Currently my tune is set for 25.5 PSI, which it hits no problem by 4200rpm or so if I floor it after 3500rpm.. My MALT table is ramped from about 93% at the lowest to 100% by 3000rpm.

1. What gear are people achieving this in?
2. Coming from a stock tune, how high are your DALS and WGDC at those RPMS to achieve those boost levels on the 6758?
3. At what RPM "should" the Z54 begin building boost and when should it be at full boost? I've played around with bumping up the WGDC at lower RPMs which has helped start building positive pressure earlier.

I guess my main question is, should I be able to floor it in second gear at 2500rpm and be at full boost by 3000-3500rpm? If so, what is the best way to achieve this?

Cant answer the tuning question, but I can say you dont want to be flooring it or boosting that much below 3500 RPM. The sudden torque spike down low is what kills our transmissions.

Yup ^

Just because he wants some power down low doesnt mean hes asking for 25psi at 2k RPM. :lol:

Are you guys forgetting that a stock LNF can make peak torque under 2k rpm?

OP, for best results, zzp might be the best tuning option for you since its their turbo.

better keep it under 24 psi or it will blow up

armcclure on here knows what hes doing with the z54

It's not just a single table adjustment, they all play together and cam adjustments can affect boost build also. The turbo should build some boost below 3000rpm not problem. I'll have to check the logs I have of a local guy with a z54, but from memory it spools pretty damn quick and certainly doesn't feel NA below 3000rpm.

Going through zzp or another remote tuner is likely your best option.

I completely understand what tables do what. My problem is I have no frame of reference to compare to. I've never driven a stock LNF, and I've also never driven a EFR LNF. As a matter of fact, this is the first turbocharged car I've owned/driven, and it was far from stock when I bought it (20g). I owned an LSJ for several years and tuned that as well, but that's a different beast altogether. I'm not asking for maximum boost at some ridiculously low RPM. What I'm looking for is some kind of reference as to how it "should" behave when properly tuned. I also realize this is a very subjective thing as people prefer different performance outcomes.

I appreciate all the replies, but I'm not looking for someone to do the work for me.

I understand this. There should be some positive pressure before 3500 RPM though. My question is how much?

If it's driving like an NA car below 3500rpm something isn't right in the tables. Start making adjustments and see what happens.

it should not be that laggy

on my EFR Cobalt on pump gas I could make 20 psi before 3500 RPMs. it spooled so fast my tuner at the time had to make it spool slower so it didn't surge.

I'd like to see the tune so I could see what the values were for DAL and WGDC.

You won't be able to just copy those numbers.

Start experimenting or pay someone.

I don't have the tunes anymore, havent had my LNF in almost 4 years now.

A stock turbo car can spool pretty quick. I never started to get on mine below 3,000 because of all the trans failures, especially 3rd gear. I can imagine by 3800 on a stock turbo with no ramp you would be 25psi by 3800. Part throttle with some load they can start to spool at 2,000 or so if that's what you are asking.