sparky

iTrader: (1)

Yup OP. In the lower gears the engine tends to "pull through" the turbo. Turbo shaft speed is not directly proportional to crankshaft revolutions as it would be with a supercharger setup.

Generally, in the lower gears the turbo shaft's rotational speeds can't keep pace with the crankshaft revs. So, the engine will rev out before the turbo can fully spool up in first and second gears. Sorry, I realize that this is a pretty lame explanation.

I think that what you are experiencing is normal for a turbo that hasn't had the WG preload optimized. If your turbo were configured with a 10.5 turbine housing then the slow rate of spool in the lower gears would be even more pronounced.

Evo8*

This is really brain f*****g. I was told by other tuners that an EBC would hold peak boost throughout all gears. How is this possible if the turbo can't fully spool before the engine revs out. Im with you on this one. I will see if he can preload the wg for me.

...There is more... It really seems like my Evo is the slowest one around. It doesn't seem to have the pull that the JDM verisons have, and Ive even driven a few 7s and 8s. The ADM version (like mine) claim 195kW whereas the JDM versions claim 206kW. Not really a noticable difference? I also heard that the ADMs boost 17psi while the JDMs boost 19psi. Im so lost.

I think I just need a good tune. But at $250, it's not cheap over here

sparky

iTrader: (1)

It's been a while but I once figured it out to be right on 60MPH at 3000 RPM indicated in top gear(5th). I like this box. It is a lot like the gear ratios in a German Getrag 5 speed box that I had in my old BMW 2002.

That thing had a 4:11 ring and pinion. a 1.00 5th, a 1.13 4th, and a 1.17 3rd. This Evo RS box like that Getrag box only makes the engine jump up 200 RPM on downshifts and only drops it down 200 RPM on upshifts.

Evo8*

I like the sound of it! Getrags are very popular in the UK. People used to put them in their corsa's and nova's.

sparky

iTrader: (1)

There are some options without necessarily going to an expensive EBC. You could get an Email tune from either Mellon Racing or TSCompUSA. These guys are very familiar with non USDM ECU's. They can really get a turbo to spool up via the factory ECU and a 3 port BCS.

I don't know much about EBC's as I prefer the more inexpensive and easier to use and setup MBC for adjusting boost.

When your friend adjusts the WG preload on your turbo have him first disconnect the factory boost control solenoid and cap off any open nipples or unused hose ends. Then run a length of 4mm rubber hose directly from the nipple on the compressor discharge pipe to the nipple on the WGA. Have him preload it up to about 17 or 18 PSI. This will give you an idea of how your turbo should really spool up.

sparky

iTrader: (1)

Sorry for taking your thread a bit off topic.

Evo8*

That's ok. But thank for the advice. I will get him on it this weekend and I will let you know how it goes!! Cheers!

ProPilot04

iTrader: (11)

m8.

A few things have been overlooked here...

1. Boost gauges are not the end all be all of what boost you're at. To give you an idea, I'm tuned at 24.5psi per the dynos boost gauge, and my in car boost gauge shows me hitting a hair under 27psi. Boost gauges are simply a reference. In my case, since I KNOW that my tune is setup and SAFE at 24.5psi, and I KNOW that my boost gauge is showing ~27psi, thats all there is to it. Am I actually at 24.5psi? Am I actually at 27psi? I don't know... all I know is what my gauge says and what the dyno says, and what my tuner says.

2. I'd suggest getting a tune from a reputable tuner. ALL of this will be able to be sorted out. I do NOT recommend adjusting your wastegate. If ANYTHING, you should check for boost leaks. Wastegates do come out of adjustment occasionally, but there are many more things that can cause low boost... namely, a bad gauge

3. For boost controllers, the argument between electronic and manual is endless. I suggest talking with your tuner to see what they prefer. Some tuners in my area will flat out refuse to tune any car with an EBC, and some prefer them. Some will want to use the factory boost controller, and some hate them etc.

4. If it makes you feel any better m8, my tune (including a boost leak test, MBC install, and new plugs run me about $570 AUD).

In short... there are steps that you should be going through BEFORE you even CONSIDER adjusting that wastegate... don't blow up your engine.

Evo8*

I don't have a tuner... yet

There are specific Evo tuners here that charge A$250 per hour. It's just too much but you have to pay it.

It's true what you are saying about the gauges though - It is only samping after all... But it is electronic, not mehanical, so they are meant to be more accurate anyway...

ProPilot04

iTrader: (11)

Mine is electronic as well. The only real difference in electronic vs. mechanical is the rate scaling imo. I think 99% of error can be solved with proper mounting techniques.

No worries though... I just went through much of what you're going through now. I did all of the work myself though... There's light at the end of the tunnel... I just had my tune done and am making 306 AWHP and 308 AWTQ on a mustang dyno that reads notoriously low. (I picked up 90hp fwiw). Keep at it m8!

Evo8*

This is very true. Mine boost gauge is sat it a carbon firbre a pillar mount that is just flopping about at the moment. Can bring myself to start screwing into the dash or using glue. It hasnt fallen off yet, but I think with the gauge mounted on a slight angle, this could have effects on the boost readings.

I am looking to get 300awhp to start with, maybe just over, just so I have an edge over the JDM versions. Can I achieve this with a turbo back exhaust, air filter and a tune? Or will I need a MBC/EBC?