chunkyda

Not quite Lavrishevo. The vert line shows peak HP after modification at 5,782 RPM and specifically calls out the plotted numbers at that same RPM. HP increased from 224 to 246 with the headers. Torque went up at the same RPM from 203 to 223.
If my LS ever sees that RPM I am running away from Godzilla, not very practical for a street luxury mobile.

SQuester

Yeah, you're reading the dyno incorrectly.

And of course tuning will make an improvement, even with a bone stock car.

I plan to grab the headers and maybe fab up a different intake, and speak to my tuner about piggyback options. I've been down this road before though and don't have a good feeling when it comes to the stock ECU throwing the tune out the window as it relearns. I've fought that for years with my old boosted is300. The only thing that makes me think it'll work okay is there won't be a need for larger than stock injectors, so the two ecu's may just play nicely together.

I won't have true baseline power numbers though, since I've already had a full exhaust fabbed up after the stock y-pipe.

SQuester

Here's some more discussion, and I still stand by my opinion from my posts in that thread.

https://www.clublexus.com/forums/ls4...ore-hp-tq.html

Lavrishevo

iTrader: (1)

How am I reading the dyno incorrect? It's obvious the peak HP and torque are about 20 more then stock about 5800 rpms but the difference at 5000 rpms is only about 5 in torque. Notice how they don't point out that the max torque at 5000 rpms on the stock motor. I mean really... Not to mention that the stock setup outperforms the header setup all the way till 5k. At 4500 rpms the stock motor is making 40 more lbs of torque vs with headers. I am willing to bet the LS430 maybe even slower in the 1/4 mile or to 60 based on this dyno. Would be nice to see someone actually test this on a track. In reality, you only gain 4 lbs of torque and you loose 2 hp over the stock motor peak output. A 20 lbs difference at 5800 rpms for a fraction of a second before it shifts means very little in real world numbers. The stock motor actually puts out more peak HP then with headers... lol.

Stock max output:
Toque - 242
HP - 228

Headers max output:
Torque - 246
HP - 226

SQuester

Just using that dyno plot, which doesn't show the true gains across the board since they started so high in the rpm range...

Look at the vertical black line, they chose 5782rpms to illustrate the gains over stock.

Torque: 203.63 stock, 223.60 with headers.
Horsepower: 224.19 stock, 246.17 with headers.

On that dyno graph:
Thin blue line=stock torque
Thin green line=torque w/headers

Bold blue line=stock horsepower
Bold green line=horsepower w/headers


There isn't a single loss in power or torque after the header install.

The dyno would look a bit different had they done a true run and started below 2krpms. I'd bet you'd see torque peak in the 275ft.lb area. We're looking at a dyno graph that plots 1700rpms worth of range, and it doesn't show peak torque in that high of a region.

Lavrishevo

iTrader: (1)

I really think you are reading the graph wrong. The thin lighter lines are stock. Green is torque, purple is hp. The bold lines are with headers. I'll give them a call and see if I can find out. But this is the only way the 20 lbs of difference at 5800 rpms makes any sense. The dots pointing out the peak are also in bold. This implies the bold refers to the headers.

SQuester

Not possible. HP is derived through equation by measuring TQ, and the two dyno plot lines will cross at 5252rpms.

Look at the dyno again, if what you said is true, where is the point that HP and TQ cross? There isn't one.

Lavrishevo

iTrader: (1)

I see what you mean. Hmmm, I guess was misreading the damn thing the whole time... SOB....

If that's the case, I'm totally wrong. I understood it as I mentioned.

SQuester

It happens, just an "oops" moment really and they did make the dyno chart a bit difficult to read with their color/line thickness choices. And really, that dyno being started so high in the rpm range really only makes it good to see the HP.

Lavrishevo

iTrader: (1)

Just talked Eric at PPE. If you guys are interested they are willing to do a group buy. They want $888 without the group buy discount he mentioned free ceramic coating was on special for this week. Sounds like we need at least 5 people to commit to get a discount.

http://ppeengineering.com/products/lexus/gsscandls.php

Marklouis

oh so tempting

Lavrishevo

iTrader: (1)

If you guys are interested message me. I have been thinking about this mod for a while and now that I understand the torque and hp curve I am more interested in doing this upgrade. They are a sponsor of the forum but cannot initiate a group buy directly. 10 - 15% off the listed price is most likely what the discount would be.