I'm having boost problems with my 2005 EVO MR.

Wondering what boost levels you guys are getting out of your evo's, & what mods to go with it?

With my stock turbo, but with cams, 3" exhaust, hard pipes, & intake, I'll get a max of 17psi, dropping off to 15 quickly, & to like 12 by 6000 rpm's.

Thanks

Norm Schilling - Fort Collins-Colorado

 

That seem extremely low. My best buddy Evofunk is in Colorado Spring and he is running 24PSI peak, his mods: 272/272 cams, 3"TB, LICP&UICP,ECUTEK,MBC.

I think what you need is a MBC, you haven't mentioned in your mods. I personally have driven in Colorado springsd in fact I have been in the top of Pikes Peaks but it is normal to loose some boost but you can recup the boost by turning more boost on the MBC.

Does it make sense guys?

Carlos

 

I'm pushing about 24 psi on a PnP'd head with overized valves, 3" turbo back, AFC, etc. Your boost levels seem very low. I would go as far as to say something's wrong.

 

i'd agree, that is wrong. conventional wisdom says you have a boost leak. i'd check the fitting on the hard pipes again. or could it be an improperly connected boost gauge? which bov are you using btw?

*edit* Norm, not sure if you've seen this from Al. you have to have this taken care of before the tune. heres the link

https://www.evolutionm.net/forums/sh...d.php?t=184064

 

I run 27psi tapering to 23 on 91 oct with the stock turbo. My boost is controlled by my Exede, it compensates for the altitude changes so I don't have to mess with a MBC and risk overboosting if I forget to turn it back down when I descend.

 

I'm going to weigh in my my normal conservative opinion.

if your bosst gauge is accurately showing say 22 psi, your turbo is working as hard as it does at 24 psi at sea level because of the difference in atmospheric pressure.

Many are of the opinion that 22-23 is the ceiling for the stock turbo if you plan on keeping it for a long time.

A ton of guys are running at 24 and 26 and MAY be getting away with it, but deffintely seek out 93 oct or higher (mixing race gas or alky kit)

Do a search on the varying opinions about how efficeint the stock turbo is above 23 psi.

and do check for boost leaks.

 

I am at 23-24 psi on a daily driver with 93 oct. 17 is way to low for our cars....even stock.

I agree with the rest...check for a boost leak.

 

Ok, thanks for all the input guys. I've plugged the upper ICP at the throttle-body, & plugged the inlet to the turbo, & then run the pressure up in my intake system to at least 17psi, before it blew the plug out violently.. It held that pressure withought any leaking.

I installed a 20-g-9 turbo about 3 weeks ago, & was driving it gently for 2 weeks, to not lean out the engine with the bigger turbo.

one week ago, I got the alky kit installed, & was doing a test run or 2, to see if it would give me bigger boost. That's when I found the problem of not able to go over 17psi..

SO, I just swapped in the stock turbo, to try to see if it was an issue with the 20-g, & as you guessed, the stock turbo dies at 17 to 19 also.

I'm currently using a Profec B to control boost. BUT, with my testing, I went as far as to unplug the wastegate actuator, & even wired the wastegate shut. Same problem.

The biggest problem at this point, is that if I give it about 10% throttle, it might sometimes ease up to 19psi.. If I floor it, it just goes to 15psi.. Or to 17psi & drops off. Why would throttle affect the ultimate boost level??

I just don't know what else to check at this point, so I'll still be showing up down in Denver for the tune, & maby someone will have an idea on the spot.

 

Oh yea, since I'll be doing a compression test this morning, Whats good for our cars here in Colorado? I got like 130psi with my old 100,000+ miles eagle talon, & it was a high 11 second car with a 20-g turbo, so what should I expect out of the EVO?

 

*edit* nevermind, it was the S, not the B...my bad! i'll just shut up now.*

Call Tommy @ Street Concepts in Aurora... i believe he had the EXACT same problem w/ the Profec B. pm if you need the #

 

Have you dyno'd yet? Typically, you will lose about 2-3 psi due to altitude. As others have mentioned, do you not have a boost controller?

Our Evo 9 was boosting 17.5psi and tapering to about 15psi. The car is bone stock except an Ingalls Stiffy. And our Evo 8 was boosting 18.5psi and tapering to about 16psi. Also bone stock except an Ingalls Stiffy. This was on CarZ' SuperFlow dyno.

 

It will be dyno'd & tuned tomorrow, which is why I'm in such a rush to get all this figured out...

My question stands still.. Has anyone done a compression test on their evo, here in Colorado? What were the numbers?

I have a profec B boost controller. I also have a Hallman boost controller. I have also tried wiring the wastegate shut, to force it to give me the maximum boost possible. All these have given me the same results. If I floor it, it bounces off 17psi, & drops as rpm's go up. If I just barely ease on the gas, letting it spool with light pedal pressure, it might make it to 19psi, but still drop back down again.

I have no re-done my pressure test, to enclude the entire engine. I did find some more air leaks, including a hose behind the engine that goes to the EGR valve, & that's now attached. Basically, I plugged the turbo's inlet, & plugged the exhaust where the o2 housing meets the downpipe, so the intake manifold & exhaust manifold, & turbo's hotside are all pressurised now. I got it up to 25psi on the system now, & there were some very minor leaks I attended to, but as much air as a 20-g moves, I find it hard to believe that it couldn't get up to pressure because of those little leaks. We'll see after another test drive.

Grabbing for any possible issues, I checked my timing gears, & the timing is right on also.. (But, on a side note, haha, this car has unorthodox pulley's on the crank, alternator, & water pump.. The seller forgot to mention that..)

Thanks for all the input guys.

Norm

 

Sounds like the same problem I had when I tried to bolt on an AMS upper intercooler pipe with a Tial BOV that VTA. The Tial BOV was leaking boost and only giving me 14-15 pounds of boost. The engine would not run worth a **** under 100% throttle. Sounds like you may have a boost leak. The 05's and 06's MAF's are VERY sensitive to incorrect airflow. I scrapped the AMS system and went with the Injen intake system with upper intercooler pipe the used the stock BOV (MR in my case since it is a IX) that uses recirculation and the engine ran flawless. Even picked up an additional 10whp from stock. Very nice system Injen has provided us. I do have two of them in stock and stand behind their product as it has treated me well.

Norm, your lucky though. You can bolt in a AEM ECU in 30minutes (I have one in stock also) with you EVO VIII MR and solve many problems and gain HP easily. I on the other hand am waiting for an AEM ECU for my IX. Some good but expensive news. MoTeC just released an 880 ECU for the Evo IX. Bad news... I am sure it is going to cost anywhere from $6000.00 to $8,000.00. I have searched and NOBODY gets deals on MoTeC. But feel free to correct me if I am wrong here.

If you need any help Norm feel free to call me or Don at the shop tomorrow. 720-214-5095

 

The '05 and '06's use the same MAF as the '03 and '04 cars.

MR578399

 

I'm assuming this is Lucas?? (Dude, you need to make a shorty profile or something.. I had to look all over CRN to find your name, haha)

I still do have the stock MR BOV in my parts pile.. I could try that I guess. It's wierd though, cause I installed the Greddy type S about 2 months ago, & it IMPROVED the car's spool, & just seemed to seal better than the stocker.

I did pressure test the entire system up to 31psi yesterday. THat's all I did yesterday is swap turbo's, & go for test drives, & look for boost leaks.

The pressure test that I did included the ENTIRE system. I plugged the turbo's inlet by using a coupling & a HOME DEPOT 2.5" PVC cap. I then wraped a piece of clearbra over the inlet to the downpipe, & bolted the down pipe back on. SO, the turbo, intercooler pipes, intercooler, BOV, throttle body, intake manifold, exhaust manifold, hot-side, and o2 housing, were ALL tested at the same time, up to 31psi. I could hear the very slight blow-by that the rings were allowing, & found that vac line that goes to the EGR was not connected, & even the tiney little bit of air that leaks by the wastegate flapper's arm, where it goes through the housing to the actuator arm. Anyways, after pressureising the entier system, it holds boost quite well. From the 31 to 20 psi leakdown, it takes about 10 seconds, which is pretty darn good, considering the vehicles rings were included.

I was slowly building up the boost though, so I'll try the stock BOV again.

By the way Lucas, I will be at your shop today to drop off that upper ICP for Luke, so you can try to sell me an AEM then...

Norm