LITE SPD

iTrader: (2)

Dynotuned my IX the other day and I noticed something slightly disturbing. I've lost 100wtq going from a FP green turbo to a FP red. The wtq loss I'm talking about is around 4200-4300rpm.

Now I knew I was going to change the powerband with this turbo, but I didn't think it would be this much. So my question is, how do I get it back without going to a 2.3 stroker or something like that.

Mods on the car with the fp green:

stock block, TBE, meth 100%, ported manifold, e-bay o2, GSC S1 cams, 27-28psi, upgraded fuel pump, 780cc injectors

Mods on ther car going to the fp red:

same as above but with EPM o2 dump, sparktech coils, 31-32psi

Are these turbos that different? The car does feel faster up top but slightly laggy in the early mid-range. I have included the graph with the fp red plot being red in color and the green being blue in color.

EVOIXreno

iTrader: (18)

not going to happen....the bigger you go the more you get a higher whp than torque! maybe with better flowing head,intake manifold and TB. you could improve it but it wont be that substantial

LITE SPD

iTrader: (2)

I understand that I will not get it all back, but some of it would help alot I think. Maybe 30wtq or something.

mrdevo

iTrader: (4)

It does seem laggy. Peak torque isn't until after 5000rpms. Should be closer to 42-4300 rpms in most cases. At 4000rpms, you are making less than 250lb ft of torque. The power up top looks strong though, it just takes some time to get there.

ev0lution9

iTrader: (3)

get some bigger cams like the S2's or something S1's work better with the green

LITE SPD

iTrader: (2)

Think this could be a boost control issue?

I was thinking cams too but everytime I read about cams, there is hardly any talk about tq. Its always about hp and how much the car gains at the end of the rev range.

I just didn't think the red was going to be so different from the green.

EvODavO

iTrader: (8)

try posting your results in this thread and ask around.

https://www.evolutionm.net/forums/ev...ts-thread.html

toverton30

iTrader: (5)

wow man thats sucks.. sounds weird tho since the red is bigger you sould make more power~~!!

LITE SPD

iTrader: (2)

Well, we did make more whp. We just feel we lost too much wtq.

cij911

iTrader: (14)

Get a different turbo or try a better O2 housing, do some porting on the turbo...

sparky

iTrader: (1)

It is possible. The low torque and laggy spool may both be symptomatic of a boost control scenario.

How are you controlling boost BTW? Are you using the stock DV? Did you run a boost leak test? Are you using the same WGA on the new turbo that you had on the Green? Are you running the same amount of WG spring pressure on the new vs. the old turbos?

LITE SPD

iTrader: (2)

I was thinking this too. The car did have a Greddy type-s EBC, but during the dyno session at AMS, the tuner found that the EBC wasn't letting the turbo hit any boost higher than 30 PSI. Then he suggested to disconnect the EBC and just run a MBC. He turned it all the way up and the turbo achieved 32 PSI. The car picked up 15-20whp up top and it held boost better.

During the red install we removed the high pressure 18 PSI actuator from the green turbo thinking it would have higher spring pressure than the one that came with the red. I called FP performance and a tech there didn't think the actuator was too much of a problem since the car was making the power up top and getting there quickly once the powerband started to climb.

We did test the actuator out running just spring pressure and you could hear the wastegate open at around 18-20 PSI (remember we have the o2 dump). Since the car is very audible now we would think we would hear the wastegate open early. And it doesn't. Well, we are pretty sure it doesn't.

So at this point we are kind of stuck. Do we replace the actuator with the one that came with the red, maybe get some kind of differnet boost control. Or do we give up and just eventually go 2.3L stroker.

If we did have a boost leak somewhere, wouldn't we not be making any power at all?

LITE SPD

iTrader: (2)

What other turbo is there to get? The o2 we are using is a EPM dump. The red is ported with the bigger compressor cover.

Evostacio

iTrader: (1)

hey when i look on fp website whats the difference between the 18psv wastegate andthe 25 psv i have no cluw what that issorry just thought i ask since you got the red???

sparky

iTrader: (1)

LITE SPD: If you've been hearing the WG opening at 17-19 PSI then you don't have enough spring pressure on the WG for running 30+ peak boost. The flapper valve can, in fact, be starting to lift off its seat(cracking) earlier than 17 PSI. It just isn't audible until it has lifted higher.

Since you are running 30+ PSI, you'll want to preload the WG up to about 25#. This should improve turbo spoolup and midrange power significantly.

Before you toss your Red away, try this....Run a length of 4mm hose from the compressor discharge pipe's nipple directly to the port on the wastegate actuator. Increase boost by rotating the turnbuckle on the threaded end of the actuator rod. Adjust boost via this method up to about 25 PSI, or so. Now reconnect the MBC and raise boost from the 25 PSI of spring controlled boost on up the rest of the way to peak boost level with your MBC.