High boost = moderate power?
 

Hey everyone,

First off, I'm not at all complaining. My car is completely transformed and it's incredibly fun to drive. I get out of the car with my hands shaking even after a few weeks of driving boosted.

That being said, I wanted your thoughts on potential weaknesses in my setup, and why you think I'm making LESS POWER than is typically found in my setup.
Specs:

'93 1.6L - stock internals
GT2560 from a silvia @ 16psi
2" hot side, 2.5" cold side piping w/ small-ish CX racing intercooler
RX8 420cc injectors
2.5" straight pipe exhaust w/ Begi manifold and FM elbow/downpipe.
MS2PNP w/ AEM boost solenoid and Turbosmart 10psi wastegate actuator
FM stage 1 clutch w/13lb flywheel, stock 5sp, stock open diff (:noes:)
Dynapack numbers: 182tq/180hp

If you ask me, 16psi is on the high end. I've seen setups running way less make >200hp with the same turbo. I don't have any datalogs to show at the moment, so I'll probably get flamed for asking - but if you had to guess, what's causing my conservative numbers?

Just to add a data point:

I'm running a TD04-13T which is very similar to a 2560, if not slightly smaller. @12 PSI I'm making 210whp and 190wtq, also on a dyna pack. The only real difference is that I'm running a full 3" exhaust, which at our power levels, really should only limit spool and not so much peak power.

post the tune, and check for boost leaks

boost is a measurement of the restriction of flow, it's just a number. it works with a bunch of other variables to dictate expected power output. timing, afr's, cooling, etc all contribute to power output.
elevation also plays a very big role

You're just a number....

I'm pretty much at sea level, quite humid lately though. I'll get some logs up then! Once my disaster coolant reroute install is completed that is..

Ok :(

what are your intake temps looking like? could be that you dont have near enough cooling on the charge and just blowing hot air? Posting your tune would probably help and allow those in the know to give input on fuel and timing.

Generally speaking, most motors in decent shape and with a reasonable tune will make 60-70 lb-ft of dynojet torque per liter-atmosphere. So a 1.6L running 15 psi of boost at sea level should be 190-220 or so. HP then depends on how well it breathes at higher revs, but most stock cam MIatas make 1 to 1.2x the torque in horsepower.

So yes, I agree 182/180 is low. Some possible causes are:

- dyno out of calibration.
- motor is tired. Got compression test numbers?
- tune is excessively conservative on timing

--Ian

I definitely want a compression test. It was one of the things I said "fuck it, we'll see" when doing the build (reason being I have a spare 1.6L sitting around that I would have swapped in at the first signs of trouble).

I'll definitely post my tune as well as some data logs in a few days, the car should be back on the road by tomorrow evening. Thanks for your feedback everyone

I think your cold Side at 2.5" is too big for that turbo and 1600 but I shouldn't affect peak power. I agree numbers are way down. I doubt a clean running engine has compression that bad to be that low but best check anyway....I

420cc injectors should be plenty for his power output. I installed an MS on a 1.6 with t3 running 15psi(overboost) the other day. Even on a rich base tune it wasnt maxing out the 1.8 injectors yet. It was really close but they were ok.

Timing curve retarded, boost leak on a small line, bov leak, small a/r turbine housing inflating boost numbers but hurting flow rates, timing belt off a tooth, crank pulley outer ring moved due to age and base timing is off a few degrees (common on 1.6).

Don't discount any of these without checking.

I'd be expecting closer to ~220rwhp on a dynojet. that 2.5" exhaust isn't helping, but youre WAY down on power.

post your tune file and screenshot your timing map and post here.

The last time I saw a high boost, low output situation was on a FD Rx7. It had a clogged cat. It boosted fine, everything looked and functioned fine, but it ran like ass. We took the down pipe off and chunks fell out. Check for exhaust restriction. I know you said "straight pipe" but that term varies in definition from person to person. Maybe your gasket is crooked, maybe you accidentally dropped a sybian attachment down there. Who knows? Also check timing. I have also seen proper boost with low power with the timing retarded a tooth.

like sixshooter said above, make sure you base timing is correct. It is rather common for a 1.6 crank pulley to slip and the timing marks to be off.

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