Bad numbers

[LowDog]

Hi

Got my car dynoed the other day. It made 207hp with 8psi tuned on chrome. 2 days later i tryed to turn the boost up 24-25psi. Then it made 247hp ?? I was counting on +280hp at min. with my GT2860R. Do you think i can hit those numbers when i get it tuned to 25psi?

[mikeD16Z6]

somethings definately not right... I'd like to say its too much fuel, not enough timing, but I doubt it.

You sure that GT28 is efficient at those boost levels? and not just blowing hot air?

[LowDog]

Dont know its efficient levels. But as i wrote, its only tuned for 8psi, so must be the lack of tuning that results in those numbers. We tryed to meassure AFR but it kept falling out of my exhaust, so only got a log from 1400rpm-4500 where it shows that its a bit to rich.

[lsturbohatch10]

well i pretty much guarantee that you have your timing and A/Fs way off at those boost levels if your only tuned for 8psi.

[BLK92_D16]

Something is very wrong there! Definitely get that thing tuned right...

[Rexinre]

GT28 efficiency level is about 16-18 psi.

25 psi is too much = blow dryer.

[ralph12sec]

there is engine problem there. compression loss? really bad airflow? if tuning is bad, your engine should have blown up

[LowDog]

Well, gonna take it slow on the throttle until i get it retuned again.

So i should just get it tuned to 16-18psi, got any sites where you got that from? Thanks

[Green 91]

usually, you tell the tuner what HP goals you want, and they tune up to it, dont tell them you want to run XXpsi, beocuse that psi on one turbo could equal low, or really high power numbers.

so tell them how much HP you want.

[LowDog]

Just took a pic of the powerband

http://bilgalleri.dk/uploads_large/804600.jpg

[LowDog]

usually, you tell the tuner what HP goals you want, and they tune up to it, dont tell them you want to run XXpsi, beocuse that psi on one turbo could equal low, or really high power numbers.

so tell them how much HP you want.

I know, but dont know how much my setup is worth

[boostdeliquent]

Invest in a wideband. You're never going to get it tuned right until you have an exact reading of your A/F ratio's. Even if your tuner has one, it is doing you absolutely no good if it keeps falling out of the muffler.

[LowDog]

My tuner got a decent wideband to mount in my downpipe. The powerband just comes from a random shop who had a dyno and a old afr reader.

[EGhatchintheham]

Well, at 11.5 AFR, and assuming your putting out 300whp you would be at about 31.625 lb./min. of airflow. At 25 psig (a 2.7 pressure ratio assuming no pressure loss before the compressor) you can see that is well outside the efficiency for this turbo.

http://www.turbobygarrett.com/turbobygarrett/images/catalog/Turbochargers/gt28_images/GT2860R_707160_7_comp_e.gif

[gpny]

1) you are outside the efficiency of the turbo.
2) Where are you taking your pressure reading from. Could be that a coupler is blowing off... That's what doomed the pink civic on pinks...

[Rexinre]

I got the info off of garrets site. I have the same turbo in my civic and the most I was able to squeeze out of it was a little over 270. I also have a big cam and higher compression pistons (10.5:1) in mine.

[mikeD16Z6]

The larger GT2871R should suit your goals

[98_4drCivic]

boost leak?

[99EJ6T]

But as i wrote, its only tuned for 8psi,
well i pretty much guarantee that you have your timing and A/Fs way off at those boost levels if your only tuned for 8psi. bam, the key to it all. btw i'd have to agree with Rexinre 18 psi at most.

[Rexinre]

The larger GT2871R should suit your goals

Mike when are you and Jeff coming over? We got to build a tranny. :0

[hatchnthoughts]

^^ all of you are forgetting the different trim gt2860r. the 62 trim is rated higher than the 55 trim. he never said which he has. the ones you guys are all talking about seems to be the 55 trim... rated at 150-310hp while the 62 trim is rated 250-360. as for the gt2871r, there are five different options on the page. if it was me id go with a gt2876r :) haha one of my favorite sites to drool over http://www.turbobygarrett.com/turbobygarrett/products/turbochargers.html

[BOYURLAZY]

Mike when are you and Jeff coming over? We got to build a tranny. :0
Can I join too?

[mikeD16Z6]

Mike when are you and Jeff coming over? We got to build a tranny. :0


this weekend I'm going to an engagment party. the weekend after that I'm going camping. After that I'm free. I'll let you know so we can work out the details. Jimmy, you willing to trek out to Penn?

[BOYURLAZY]

not sure if my sol can make it w/ the HG and clutch lol, but i can carpool w/ u ;)

spoke to Geoff, trying to do HG and clutch 7/14 tentatively

[gpny]

not sure if my sol can make it w/ the HG and clutch lol, but i can carpool w/ u ;)

spoke to Geoff, trying to do HG and clutch 7/14 tentatively

Yeah, that's the 1st weekend I'll have free... engagement party, then camping or autox, then france...
Mitch, if you want to throw the tranny in the back of the STI and bring it up on the 14th, we can try to do everything in 1 shot... I probably have the most shop equipment handy at my parents place and it we're 4 who know it might go faster... I personally suck at trannies but would love to learn about them because a higher FD or new gearset is definitely a possibility for me in the future.

[Rexinre]

The 14th I was supposed to go to the rally race in Maine. What about the 21st?

[LowDog]

Dont want to ruin your fun... but could you please use som IM for private chat?

[mikeD16Z6]

we thought you were done with this thread and came to the consensus that you need a bigger t28...so we were just whoring it up a bit lol

[99EJ6T]

we thought you were done with this thread and came to the consensus that you need a bigger t28...so we were just whoring it up a bit lol

Oh, I'm a dick.

[mikeD16Z6]

How the hell is that being a dick?

[H2Bcivic]

idk im confused about that too! lol

[Rexinre]

How the hell is that being a dick?

Fixed.