Mik2006

Well i finally went to get tune and the results were horrible.. i got 171whp and 158tq off of 4.4 psi.. i cant possibly understand why. they say its because of my b16 cams (stock b16 head and stock block), but ive seen plenty of these do much better. we used a boost controller to 5psi but it only gained 1 hp... heres the dyno sheet

*update
2/1/21
After changing my dump tube and trying another dyno it ended up getting 248whp and 180tq. 10 years later i miss this car lol. This was all on 4.4 psi




the blue is from it all motor before the turbo and the red is the now. compression is 180 on all 4 cyn
the afr is fine. but i got dsm 450s in there to. any one know whats wrong?? or if the tunner screwed me over?

TheShodan

iTrader: (14)

1) New tuner
2) you need to describe what turbo you're using. (saying "t3/t4" doesn't help.. get the specs of the wheels and housings
3) What engine management?
4) what fuel are you using?
5) what power are you trying to get to with a B20Vtec?
6) spark plugs?
7) any aftermarket ignition?

And the list goes on.
The more information YOU provide, the more WE can provide.

Mik2006

2)turbonetics t58 trim all i know of it.
3)crome
4)93 pump gas
5)at least 255whp
6)just regular ngk plugs
7)no..

jdm602

either somethings mechanically wrong here, or you just need a new tuner.

that graph shouldnt look like that at all.

Gunmetal_B20_Hatch

iTrader: (9)

New tuner for sure... That graph looks like ***...

boostedcivicsir

just looking at that, regular plugs, FTL. you will need 7's at that point.

C2K_TB_TEC

Which t3/t4 turbo likes 5psi on a 2lt motor?
Also check wastegate size and spring, also some boost controllers with certain wastegates dont regulate tooo well at very low boost settings..

If all is good with the motor and tuning, the "zig zags" could be caused by wastegate/boost controller trying to overcompensate... and therefore boost inconsistancy....

ATYPR

can we see the wastegate dump??

HiProfile

I dyno'd my first z6 to 160whp with stock plugs. Infact, they were the previous owner's plugs and the motor had been sitting for a year before I rebuilt it.


Looks like it's a fuel pump or FPR issue. If not that, there's a good chance the wastegate dump is too close to the turbo inlet. When exhaust comes out the WG w/o a dump, it's sucked back into the turbo inlet. Research "Direct Exhaust Injection" as to why that's not a good thing. I can't see the WG too well, but if you're using an old Delta gate, chances are it's not a baller setup...and dump tubes are commonly omitted from cheap setups.

Mik2006

well i took apart everything and found that my downpipe has a huge bend in it by the cross memeber.its like from 2.5 to 1.3 back to 2.5 piping. could this be an issue to? wana try and know cause ima go to a shop to get my dump tube and maybe downpipe redone.

0dancing_ninja

Yes, any cause of severe back pressure on a turbo system will cause substantial power loss sir.

perseverance

come back and let us know what the problem was

EsotericImage

iTrader: (8)

and with only 4 -5 PSI, you wont see much gain.. Ive been on 11psi for a year and doing just fine. And mine is a .42/48 super 60

get NGK 4091's (7's) and fix your bent exhaust and then try it.

wantboost

iTrader: (2)

if your in winder, why not make the drive to some place like Batlground or Mainstream... Bring it to a reputable shop and not some backwoods place that I've never ever heard of

sc34dc4

iTrader: (1)

Yeah fix that exhaust problem and go tune somewhere else. On my stock ls just running off the waste gate spring "5psi" I made 200whp.

boosted k20

Looks like wastegate gasses is dumping back into the turbo inlet. also that bend in ur downpipe is also killing your power. Your tuner should have pointed that out to you just by looking at the graph. def exh restrictions and/or no dumptube

wantboost

iTrader: (2)

and how can you tell he's not running a dumptube from that photo?

This guy needs to take it to a reputable shop.. I've been building cars in GA for quite some time and never once have I heard of this place he's taken his car to.

Take it a reputable shop... Batlground, Top Speed, R&D Fabrication, Mainstream... the list goes on.

Mik2006

ima bout to head out now to get my exhaust done so ill let u all know whats up. is there any way that the b16 cams can cause this to happen? thats what im also wanting to know. and no i dont have a dump tube on yet due to clearance.

TheShodan

iTrader: (14)

No. Your B16 cams won't cause this. No dumptube at all means that you're ingesting exhaust air into the compressor inlet. That is a 99% reason this car is performing so poorly.

Stop worrying about finding an excuse to get bigger cams and start fixing your general issues first. You'll be happier for it.

sneakysneaky

Nothing wrong with the tuner if thats the dyno I think it is.
Fix your problems and retune. I tuned to much higher numbers
on that dyno with a LS and a small turbo 5 years ago.

EsotericImage

iTrader: (8)

THIS!

Mik2006

well i got the dump tube on now and redyno and i made 248 whp and 178 tq on 4 psi. seems alot better now. just gotta see whats up with the tq now.. ill post pics up soon