haulin79

Has anybody here tried the Greddy V-manage to tune their vvti?

http://www.greddy.com/products/displ...SubCategory=72

Are there any other recommended ecu tuning solutions for our 1998+ LS400's?

S30ZG

iTrader: (5)

piggy backs =

PureDrifter

iTrader: (10)

constructive
do you even know what it is? it isnt a normal fuel/timing piggyback

all this does is alter the point at which the VVT-i engages, but honestly you're going to see a TINY improvement across the lower part of the rev-range.

for the price, you're better off getting a real piggyback, the Apex'i SAFC Neo/SAFC II is popular, i'm a fan of the SMT6/7/8, or countless others. you'll see better gains given your mods.

what engine related modifications do you already have? if the answer is "uhhh" or "none" then a piggyback isnt worth it for you.

haulin79

Do you have a recommended PC customizable ECUs for our LS? Are there any that are easy? Something like Cobbtuning's Accessport for Subarus /Mits /Nissan /Mazda /Honda?

I thought that VVTi offers "continuously" variable intake valve timing (i.e. not engaged/disengaged like Honda's low-tech vtec).

No mods yet, I just bought my LS last week. First engine mods will be:
-modified intake box
-headers
-rpm and throttle activated e-cutout (something like http://atpturbo.com/root/releases/release091004.htm )

PureDrifter

iTrader: (10)

the cutout wont be worth it for you. plus its illegal in cali.

haulin79

Thanks for your input.

To avoid being illegal, I will have the e-cutout dump into a straight through muffler system.

Essentially, the idea is to have two exhaust system modes:
Mode 1 (quiet): exhaust flows through one pathway that is nearly as quiet as stock.
Mode 2 (loud but legal): e-cutout opens and allows exhaust to flow through the "straight through" pathway.

My friend owns an eddy current dynamometer so I will dyno my car with the stock exhaust system. I will then remove the stock rear half of the exhaust system and dyno again. If I find that the upper rpm range hp and tq benefits from this less restriction, then I will go forward with the above 2 mode plan. If there is no difference in hp and tq, then I will retain the stock exhaust system.

fourthmeal

I think you'll find that the factory ECU needs time to learn what it can do with less restriction in the exhaust. I imagine what you'd find is that you'd need to do many pulls (after resetting the ecu back to factory unlearned params) and you might see subtle changes each time. I may be wrong, but I believe the adaptation built into the ECU will skew your results too much otherwise.

Thoughts from anyone who's been able to confirm this ECU does this? I know some do.

haulin79

Thanks for the heads up on the ECU issue.

I will be monitoring the air/fuel ratio during the testing, if the AF remains within a narrow window between the different pulls, then I can be confident that the ECU is doing its job properly. Perhaps I would also need to plot ignition timing too.

damon

I would also consult the Lextreme forum which would go into much more detail concerning non oem ECU's for vvti engines.