After installing a boost gauge last weekend, I have been able to see what my boost is up to.

I am guess all turbo cars will have a controller of sorts...

...Anyway here is what I get

1st Gear - 15psi peak then drop
2nd Gear - 15-16psi peak then slight drop
3rd Gear - 22psi peak and hold
4th Gear - 23psi peak then drop to 20-22psi
5th Gear - Haven't really tried...

I asked the question on another forum and I got told my 3" turbo back exhaust could even mess with my boost levels.

I suspected a dodgy actuator or wastegate...

Can someone please shed some light on these weird happenings? I do plan on getting a HKS boost controller in the future, but is there anything I should be replacing before hand?

Thanks in advance!

 

is that a full pull in each gear or while ripping through them?

 

No pretty much full pull every gear, I make sure im sitting on about 2000rpm in each gear so I can get the correct boost levels... Just seems a bit strange to me... Any ideas?

 

At what RPM are you seeing peak boost level in 4th gear? What model Evo do you have(RS, GSR, etc.)?

 

If I am being honest, I don't know the answer to either of them question. I THINK it peaks at 4000rpm or somewhere around there.

All I know, it is a ADM Evo VIII CZ With the VIN starting with JMASNCT9A4U...

Here in Australia, I think it's just the jap imports that are called the GSR. I've never hear of the RS. Noob.

 

Each market has their own GSR. I'm guessing you have 5 speed since you only stated 5 gears. Most likely you have a GSR.

 

Personally I know that due my tune and the fact the gears are shorter I usually only hit 19psi in first, 20-21 in second and 22 in 3rd-5th. It always finishes at about 19-20 in 3rd-5th.

Sounds like you need a tune?

Do you datalog to find peak and drop off? My 1st and 2nd goes by so fast I wouldn't be able to just "eye" the gauges to find my peak boost.

 

OP...The above is more or less what I am getting at. If the WG is not properly preloaded then you'll have a hard time seeing peak boost in 1st through third gears. With my old TME turbo I never saw over 18 PSI in 1st through third. And the standard VIII turbo spool up a bit slower than a TME turbo.

With a standard VIII turbo that is not properly preloaded you'll probably never see over 19 in 1st through 3rd gears. I think that from what you say that your WG is not preloaded. Because peak boost by 4000 RPM is very lethargic spool up.

You should be seeing 20 PSI by 3000 to 3200 RPM with the standard VIII turbo. Especially with the 9.8 housing in 4th gear.

It sounds like NorCalEvo415's turbo is set up about right. You have to preload the hell out of the WG to see over 18 PSI in first before shifting into second. The engine in the lower two gears tends to rev out faster than in 4th and fifth. I know that I never saw peak boost in the lower gears with the TME turbo and the short RS gears.

 

Just read the above post and, I don't want to jack this at all, but you mentioned the "shorter gearing" of the RS. I have a US spec RS and I definitely don't have shorter gearing than any other GSR. I noticed you're in Central America, so is your RS different somehow? I THINK the JDM base RS might've had shorter gearing-not sure though.

 

Thanks for the detailed reply!

So are you saying I need to adjust the wastegate arm as tight as it will go? It might be worth mentioning that my car is under warranty, and will probably get it all done for free. From day 1, I knew something wasn't right with the wastegate!

 

You'll probably have to preload the WG yourself as the factory dealerships don't like the turbo to spool up too fast as it brings torque in at a lower RPM which is hard on the clutch etc. It will make the turbo spool up faster in all gears though. So, you should see higher boost at lower engine RPM's even in the lower gears.

 

Right I think I am with you now. So what you are saying is there is nothing wrong. The turbo doesn't have time to fully spool up because you run out of first gear

I might have to get my mate who is a qualified car nut to do it. I am really "scared" of doing those things myself

Thanks for your help, I really appreciate it.

 

Yeah, no problem. I don't think that there ever was a specific Central American Market version of Evo. There just were not very many sold down here through the local dealerships.

To the best of my knowledge, the Evos sold new in Central American dealerships were pretty much JDM spec but with left hand drive. The ECU's were detuned for the local pizztane gasoline which is about 89 octane on a good day.There is only one Honduran Mitsu dealership and he only ever sold two new Evos.

The interesting thing to me is that a customer that orders an Evo here gets to option it out via a "build list" and order his Evo straight from the factory just as in the States you can or could order an American car exactly as you wanted it. You order your Evo and wait three months for the factory to assemble it to your requested specs.

So, no two RS's here are the same as far as factory equipment is concerned. Mine for example had the Recaro seats deleted as well as the roof antenna, but it was ordered with electric windows. At least down here, when ordering your Evo everything was optional more or less. You just payed half up front and ordered it as you wanted it and then waited three months for the factory to build and deliver it.

Getting back to your question....The JDM RS's had three available gear set options(short, medium, or long). I am pretty sure that my Evo has the shortest gear set available although it may be the medium. Definitely not the long cogs though. I see 100 KPH at 3200 RPM in 5th gear with standard height tires.

I really ought to drive my car more often though. It's been sitting in the garage for 5 months at least. So, I hope that the above road speed in 5th gear info that I gave you is in fact accurate to the best of my knowledge. Sorry, if I couldn't be more helpful.

 

Sure thing! See what your mate advises about adjusting the WG preload. If you should have any questions about the SOP feel free to shoot me a PM and I'll be more than happy to help.

 

Lucky bast'd....and HOLY CRAP. I'm turning about that many revs at 70 mph, so I've got about 8-9 more mph than you in the same gear at the same revs.