[Joshinator99]

Originally Posted by musclesbmf

I'm at 855 to the wheels using a JLT intake for a point of reference. The intake tube visually matches the diameter of a Katech 103. So a "regular" intake doesn't seem to be hurting my situation.

Mark

JLT is a 5" tube just like the Big Gulp, FYI.

[LiqTenExp]

Can someone with 750+ whp look at their MAF frequency during a 4th gear full pull? What does your MAF frequency top out at, what does the data curve look like? Could you post a log, would appreciate it.

I'm in the 750-850 whp range and notice w/non big gulp my MAF frequency flat tops towards the very end of a pull. I've swapped from dry to oil filter (per the manufactures recommendation) for higher flow, it made no observable difference.

With enough data we might be able to determine if this parameter is a good measure to determine if you are in need of a big gulp or not.

[Camaro1973]

Originally Posted by LiqTenExp

Can someone with 750+ whp look at their MAF frequency during a 4th gear full pull? What does your MAF frequency top out at, what does the data curve look like? Could you post a log, would appreciate it.

I'm in the 750-850 whp range and notice w/non big gulp my MAF frequency flat tops towards the very end of a pull. I've swapped from dry to oil filter (per the manufactures recommendation) for higher flow, it made no observable difference.

With enough data we might be able to determine if this parameter is a good measure to determine if you are in need of a big gulp or not.

10,256hz (655.35 g/s)


If you already have a 103mm TB, then i would just suggest you get the big gulp. Not many people, nor shops are keeping the standard 4" past 750whp. Esp with a new blower and TB.

[LiqTenExp]

I will hit above that (but less than 11 khz) with 103MM Katech/103mm snout/TVS2300 and non-big gulp (oil filter). I think I am on the cusp of needing to go bigger, would like to see the shape of your MAF curve (RPM vs Freq) and see if it has similar behavior.

I am considering going 2650, 112 snout, 112 TB, big gulp but not sure it is really worth it except to get bigger numbers, it is hard to stick this kind of hp on the street (345/30R19 555RII), I don't do drag racing and stopped doing road course with it (too much power - not needed, above my skill). My MAT temps are reasonable due to 50/50 water/meth injection providing the cooling, 2650 would help MAT but not in a way that I would consider more timing any safer, only benefit would be CFM.

[Z OH 6]

Originally Posted by LiqTenExp

I am considering going 2650, 112 snout, 112 TB, big gulp but not sure it is really worth it except to get bigger numbers, it is hard to stick this kind of hp on the street (345/30R19 555RII), I don't do drag racing and stopped doing road course with it (too much power - not needed, above my skill).

As tempting as it was to go above 700whp, this is the exact reason I stopped there with this car. In fact, I have considered dropping mine just slightly in order to ensure I always have traction on street tires. Its right at the limit right now with the stock GYSC3 tires.

[LiqTenExp]

Originally Posted by Z OH 6

As tempting as it was to go above 700whp, this is the exact reason I stopped there with this car. In fact, I have considered dropping mine just slightly in order to ensure I always have traction on street tires. Its right at the limit right now with the stock GYSC3 tires.

I loved learning to tune GenV LT engines, much more challenging than prior LS. I'm busy/lazy and I'd have to go in and do some serious touch up, not changing parts prevents this

[SOCAL.M6.ZLE]

Originally Posted by Z OH 6

As tempting as it was to go above 700whp, this is the exact reason I stopped there with this car. In fact, I have considered dropping mine just slightly in order to ensure I always have traction on street tires. Its right at the limit right now with the stock GYSC3 tires.

I'm with you here... That is why i am only aiming for another 100rwhp now to see how that works on the street.

I figure a cam, ported blower and 103mm TB, and a 15% OD pulley will get me there, perhaps even less?
Then if i want more later, I know I will need more fuel / boost, etc...

[dbs1]

I was definitely satisfied at 688. When engine had to come apart I begrudgingly figured I might as well port the little blower and then the bigger tb and at that point the bg was part of the equation.

If I knew of someone in the Phx area I'd give them the old $50 rf.

[LiqTenExp]

Here is an example in excel from data I exported out of HP Tuners. FYI, I will hit just over 11 kHz on my MAF for some runs, it flattops right after 6900 rpm.

I noted that the calculated Mass Airflow (red curve) tops out around 10.7 kHz @ 655.4 g/s (86.69 lb/min), looks to be related to the SAE PID max value. This occurs around 6200 rpm for me. Dynamic airflow (yellow curve) appears to keep calculating and does not flatline like the MAF SAE value.

See example below, overall I think I'm not being limited harshly by not having a big gulp, maybe around 6700 you can see a little roll off in the shape of the curve:

[Z OH 6]

Originally Posted by SOCAL.M6.ZLE

I'm with you here... That is why i am only aiming for another 100rwhp now to see how that works on the street.

I figure a cam, ported blower and 103mm TB, and a 15% OD pulley will get me there, perhaps even less?
Then if i want more later, I know I will need more fuel / boost, etc...

I feel like 650whp is probably a safe target if you want good traction out of the stock tires. Every amount above that gets really borderline with 700whp really pushing the limits. I can hook when its really hot outside 80F+ and the tires are still somewhat new and warmed up, but temps below that starts to get some wheelspin. I could use a Nitto 555R2 on the back and it would hook more consistently.

[radz28]

Originally Posted by LiqTenExp

Here is an example in excel from data I exported out of HP Tuners. FYI, I will hit just over 11 kHz on my MAF for some runs, it flattops right after 6900 rpm.

I noted that the calculated Mass Airflow (red curve) tops out around 10.7 kHz @ 655.4 g/s (86.69 lb/min), looks to be related to the SAE PID max value. This occurs around 6200 rpm for me. Dynamic airflow (yellow curve) appears to keep calculating and does not flatline like the MAF SAE value.

See example below, overall I think I'm not being limited harshly by not having a big gulp, maybe around 6700 you can see a little roll off in the shape of the curve:

I have to go look at some current logs to be sure, but I know I've seen the limit of the MAF PID of , something like 655.35g/s, around 10,100hz (this is a car with only a 2650, 103, and BG), at around 6000 RPMs or so. My Dynamic Airflow tops-out around at my shifts (around 6700-6800 or so) at something like 670-680g/s. I think I'm getting all the lingo right...

I don't believe Dyn-af has a limit like MAF. GMVE-af reaches it's limit even earlier, like 512g/s. I've been using another Math that I think either Higgs Boson, hjturbo, or GHuggins to extrapolate GMVE, and through much of the runs I have, I have all of these matching-up quite well, and the curves are all pretty close, so when the MAF PID flatlines (and the Dyn_af continues), I feel like the Dyn_af should be relatively close. I'm only showing, a lot of the time, a couple percent correction way up there. I'm still trying to clean it up though.

I have logs from before the ported-LT5 TB/ported snout, but the tune was at the very beginning. I was getting A LOT of weirdness. I'm not sure how useful that might be for this comparison. If it seems like it might, I'll update.

And I'm not saying anyone SHOULD get a BG or ANYTHING - I'm just posting what I'm seeing and what I understand of what I'm seeing.

Originally Posted by Z OH 6

I feel like 650whp is probably a safe target if you want good traction out of the stock tires. Every amount above that gets really borderline with 700whp really pushing the limits. I can hook when its really hot outside 80F+ and the tires are still somewhat new and warmed up, but temps below that starts to get some wheelspin. I could use a Nitto 555R2 on the back and it would hook more consistently.

In my experience - I think you're right. We're still on stock tires (with plenty of tread) and even on hot days (warmer than yours even), a 4th Gear pull gets very sketchy and the 4-5-shift will spin the tires pretty hard at around 105 (the logs show near a 10-MPH difference between front and rear tire speeds). I can't imagine a lot of your guys combinations making hundreds more HP on street tires, lol. WHEW!!! I think those 555R2s are on the list for replacing these SC3s.

[SOCAL.M6.ZLE]

Originally Posted by Z OH 6

I feel like 650whp is probably a safe target if you want good traction out of the stock tires. Every amount above that gets really borderline with 700whp really pushing the limits. I can hook when its really hot outside 80F+ and the tires are still somewhat new and warmed up, but temps below that starts to get some wheelspin. I could use a Nitto 555R2 on the back and it would hook more consistently.

Great points everyone... this conversation is very helpful for me. bottom line, i really miss my cammed LS1 and want a cam in this car also, and i know the fuel lobe bump should allow me to hit 700rwhp due to bumping my ceiling for E content correct?


The choice to add the ported blower, TB, ATI, BG was all good measure, and wanting to see the limits of stock fueling with JMS only. With the engine out, it seemed like a no brainer. But costs are not only rising, but i am worried that with the current mod list, i will shoot past the limits of my fueling, and will have overspent on mods... so, if the target is 725rwhp +/- or 850 at the fly... what is the minimum i need to add?


Perhaps just the cam, which will allow for more E and an ATI with 15% OD?
Is the ported blower, TB and BG even needed?

[SOCAL.M6.ZLE]

Budget is now a concern because of all of the EXTRA (non-power adders) I wanted to add like... Banks Gauge, Synergy Tank, Catch Can, Katech VVT Delete, Oil Pump, Valve Covers, Coil Relocation, C5R Chain.... etc...

[AZIROC]

Imo, if you are getting the blower ported to take a 103 t.b. then you might as well get the big gulp