Girz0r

iTrader: (1)

I learnted the other daay that 20psi does not equal 20psi

However the idea of this thing maxed out on a log manifold and a msm intercooler would be 'fun'. Or even possibly eco friendly with a similar motor build on a bp.

bcrx7

iTrader: (5)

Well since I get annoyed every time someone uses "turbo lag", here is a clarification:

Turbo lag is something from the 70's and 80's. Most turbos today will have no lag. Lag is by definition when you are at an rpm that the turbo can make 10psi of boost, you step on the throttle and it takes a certain amount of time to get to 10psi. That time is turbo lag.

Now what you are talking about is boost threshold. That's the point in the RPM range where the turbo is making usable boost pressure.

Ding ding ding, school is done!
Now go buy an EFR, run ALLOFIT and blow that bugger up!

turbofan

iTrader: (1)

^EFR Post. My car still has turbo lag. Not much, but some for sure.

bcrx7

iTrader: (5)

^Just turn that ALS on... haha

18psi

iTrader: (76)

Some people run 3071/3076/3582 turbo's on these dinky BP's, so yeah turbo lag is still there

Its more like spin lag. From the time you step on it to the time you're trying to steer the car backwards - spin lag

guttedmiata

guttedmiata

How many turbo vehicles have you owned? This is not an accurate statement at all. My compound turbo cummins diesel still had lag and that was with a stock turbo feeding the big one.

concealer404

iTrader: (3)

This thread is about to turn even more fun, isn't it?

Girz0r

iTrader: (1)

Sarcasm, see my noob post count.

bcrx7

iTrader: (5)

Diesel is a different beast! Most diesels in stock form have huge lag due to small/restrictive exhaust system. Change that and most if not all of the lag is gone.

I have owned 7 cars in different forms, most above 350hp. Built and have helped built over 30 cars in race and street mode. Don't even remember how many I have tuned (over 50).

thenuge26

iTrader: (2)

Even concealer's gt2554 car has lag. We measured it on the datalog, it was like .25 seconds

Leafy

iTrader: (1)

Yeah no, modern turbos still have lag. There's a perceivable throttle delay even on the best garrett setup I've driven (FM stroker with disco potato). Its nearly inperceivable on my car with the efr, its still there but its at about the same level as some of the more throttle laggy N/A engines. If they made a 2560 sized efr it would be so short it would not be noticeable by human beings.

concealer404

iTrader: (3)

This is also known as "an eternity" on The Internet.

Leafy

iTrader: (1)

Was that at like 2000 rpms? I would figure that little baby 2554 would at least do better than that at higher rpms.

thenuge26

iTrader: (2)

Haha I don't remember, I was a lazy POS and the logs are still sitting on my laptop. But I think it was at least above 3000rpm in 4th gear. That was from vac to the full 12psi the wastegate was set for, and remember wastegate only. It was still hauling even before it got to full boost.

concealer404

iTrader: (3)

I think it was rolling into it from coasting around 50mph in 4th.

When i'm actually driving it in the correct gear, there's pretty much no lag that is noticeable by a human. And i still have work to do optimizing it. Like Steve said, it's just on wastegate, and i have a small exhaust leak to take care of, 3" downpipe to go on, and i've been too lazy to get VICS hooked up and working.

I'll probably just chip away at it over the winter at this point. The pile of parts to install is growing.


Steve, you need to check out Keith (Twodoor)'s setup. It's hilariously gutsy in any gear. Because gearing.

thenuge26

iTrader: (2)

Haha I bet it is crazy, especially compared to the fiesta I'm DDing now, as the NYT writer said the gears are so far apart they need counseling.

bcrx7

iTrader: (5)

hahaha this is funny $hit! 0.25 seconds... haha
Maybe y'all need some VTEC! That will hit quick yo...

If you guys haven't driven an old 911 turbo, you should. Now that's lag. You get on the throttle mid corner hoping by the time you are hitting the exit you have boost!

concealer404

iTrader: (3)

Well if you were waiting for boost, wouldn't that actually be a threshold issue, not lag?

Leafy

iTrader: (1)

No for realz, 70's turbo cars, well above the boost threshold, its kind of like punch it and pray that in a couple seconds (well it feels like a couple seconds) when the turbo actually spins up that you're straight enough that it doesnt snap sideways.