DBeck

iTrader: (3)

I know this will be biased, but which is better? My friend tells me that a JDM engine is better than an LS1, I say the LS1 is better.

What do you think and why?

300ZX JDM ENGINE

fastest94v6

iTrader: (10)

my friend has a jdm h22 motor, he blew it about two times. Thank god i'm still on my same motor in my camaro. Our cars can really take a beating.

Chadder

iTrader: (2)

Correct me if I'm wrong.

Most JDM motors you get imported are ragged on like crazy. From what I've heard, the Japanese replace thier motors every 30,000 miles or something like that. Because of that, they tear on the motors BIGTIME. I mean, If you were gonna just replace your motor in about 2-3 years would you take it really easy on it? I wouldn't. Many of the ones you can get off of Ebay need a rebuild or are damaged to the point of just being a pricey paperweight. I was gonna build up a GS-T (no motor) with a buddy of mine, but when we looked into getting motors, the JDM ones looked trashed out, so he went with a USDM motor from a local junkyard.

But as far as brand new engines are concerned, LSx>pretty much anything JDM. Not all JDM stuff is supposed to be 'badass'. The USDM Supras are better than the JDM Supras.

NBMgreg

iTrader: (7)

thats comparing apples to oranges, way too many options, and variables to say which is better. you have to pick a specific motor from chinese land, and compare specs to specs...

in general, one will always be better than the other in a certain category, but then the other will dominate in another category, like a JDM 3sgte will be stronger than an LS1, and can hold ALOT more boost stock than an LS1 could dream of... but the LS1 could be more reliable, due to the 3sgte having cooling problems being a MR setup in the mr2's.

fastest94v6

iTrader: (10)

not necessarily, true in many cases but not all. People in the US don't drive any better. We beat on our cars just as much as they do, and we don't have any laws stating that our motors need to be replaced every 30k miles. Your chances of finding a motor with extremely low miles are rare in a junkyard, again not always true but it is in some cases.

NBMgreg

iTrader: (7)

i understand that, but im saying, compare apples to apples, a brand new ls1, vs. a brand new SPECIFIC JDM motor, in which case i chose the 3sgte, because it has its ups and downs, as does an LS1, and any motor for that matter.

fastest94v6

iTrader: (10)

agreed...

DBeck

iTrader: (3)

300zx JDM to be exact

ocshaman

Let’s clear something up first. There is no tax here that says engine done at 30K. I don’t think that there ever has been one.

There are engine taxes, but it’s more of a “your engine is this size, so give us this amount of money” tax. There is also a car tax, that is dependent on the engine size. Neither one of these would give the owner of the vehicle a reason to get a new engine.

My last car lost it’s tranny with 200K KM, or about 120K miles. Cars are taxed to death here. The country is small, and after 5 years or so, there is no reason to keep an older car if you can save $2000 by junking it. It just happens that a certain number is reached in that time.

As for which one is better, Let's clarify what JDM motor we are talking about. I have a JDM motor in my car that couldn't break 75 mph if it's heart depended on it. Saying a JDM motor is like saying a beer. There's good and bad, alot more bad than good. A 5.7 will be bigger than a 2 or 3 liter, so if room is a factor then go for a smaller engine, but if for example you drop a CA18 in your car, just make sure that you can cross reference your alternator, PS pump, etc when it goes bad. I would much rather go to Advanced Auto and ask for an LS1 PS pump than a 1992 Sil-80 PS pump.

NBMgreg

iTrader: (7)

VG30DETT or DE?

not so sure about the JDM type, but the USDM VG's are pronouned for overheating, due to the tight, extremely compact engine bay, the heat gets trapped and it melts stuff, mainly electrical stuff, resulting in alot of melted connectors etc. they also have a huge problem with turbo seals, and crank cover seals leaking, and faulty injectors... also, the 91's i believe had what they call "soft valves", and thats pretty self explanitory. i was very close to getting a TT 300z, but decided other wise because of the things i listed that i found while researching.

these are all bad things, but the motor is fairly strong, due to its FI option from the factory, they just had ALOT of minor problems, that cost ALOT of money to replace.

as for performance, a TT z usually goes mid-low 14's, just because they weigh alot, as do LS1's, but the z usually will lack just a tad in performance compared to a LS1.

RedBeauty84ZX

Actually only the first few 1990s had the "soft valve" issue, and it dosnt mean what you think. It actually means they were made too hard.

The only problem you listed that is actually frequent is the hot engine bay and some of the rubber/plastic getting brittle under the hood. Which is common in most vehicles.

As far as which is better? Well the LS1 is a little lighter then the VG30DETT, but the VG is stronger internally. The VG is good for up to 700RWHP on a fully stock block, forged crank is good for well over 1000HP, and the transmission can easily hold 800+HP(same tranny as the skyline).

As far as performance most stock TTs run in the 13.8-14.2 range, some faster and some slower. Their are also Zs with stock turbos running 10's.

98hardtopZ

iTrader: (7)

ls1=torque

RedBeauty84ZX

Actually the VG is known as a very torquey engine as well, most often the engine will produce more torque then horsepower. Heres an average dyno from a VG30DETT with smaller to medium size turbos:


If what you are referring to is low end power delivery then yes the LS1 will produce its power sooner and peak off earlier then the VG. But as far as straightline performance it is better to have torque at high RPM rather then low RPM so you can take advantage of gearing.

98hardtopZ

iTrader: (7)

i stand corrected n/a ls1=torque , n/a jdm<torque?...better?

NBMgreg

iTrader: (7)

i think the situation about having more torque vs. hp is common in alot of boosted motors, same with nitrous applications. its when you build n/a, like a h/c car, when you get far more power than torque.

NBMgreg

iTrader: (7)

and ya it was the 90's that had the soft valves, but i thought soft valves meant soft valves, kinda stupid to call it soft valves when they were too hard...

but i guess thats japan for you, everything is backwards

RedBeauty84ZX

And only a few hundred 1990 Z's were produced with the "soft valve" issue, and the ones that did are most likely all fixed by now.

http://twinturbo.net/net/viewmsg.asp...&msg_id=916703

TheBlurLS1

iTrader: (8)

That's an interesting graph. From what I understand, HP = Torque x RPM / 5250. This is why all dynographs torque/hp curves cross at 5250, and is also why you always have more tq on the bottom and more hp on the top. HP is derrived from tq numbers.

RedBeauty84ZX

Hmm im gonna ask the owner of that car why they dyno looks like that and I will get back to you. He just had it dyno'd the other day. Heres a better example:


This is a stage III car (intake,exhaust,ecu) that follows suit with most other stage III dynos.

DRSITES

iTrader: (3)

Why do people ask these type of questions on LSx sites? If you want answers to those questions, you'll need to go to much more general forum.