Rain Hats vs No filters

[Jeff Alton]

Just thought I would share some dyno info about rain hats.

Yesterday we dyno tuned our latest 3.5 with 50mm PMO ITBs. We tuned it with the filters and hats as that is how it will spend its life with the owner. For kicks, we did a pull with the filters and hats off. Net gain 4whp@6800. Not much of a penalty running the filters and hats.

AFR did not seem to change at all.

Thought this may be interesting to some folks as we have read for years of far larger differences from the rain hats.

Wish we had the time to test different header and muffler combos.....

Here is a pic of the motor before it was installed.

[wildcat077]

How about more details on that great looking motor for the curious minds out there ???

Cheers
Phil

[Geneman]

thanks jeff am about a month behind you with my first engine build a 3.2-3.4 conversion with all the goodies 46mm itbs , twin plug etc, cams. would dearly love to maintain that oh so sext stack look without rain hats ..but likely not cheers frank...ps looking for a good porsche dyno guy around the philly-nj-new yor area to tune it! cheeers frank

[Jeff Alton]

Phil,

Here are the specs:

50mm PMO ITBs
Accel 36lb injectors
LN Engineering 100mm Nickies
JE 10.5 pistons
Twin Plugged 3.2 heads with guide area relief work
DRC DC60 cams
ARP Head studs and rod bolts
Bursch headers
M&K sport muffler
Vi-Pec V44 ecu
EDIS coil packs
Bosch Ignitors
NGK plugs
Turn3 Autosport custom wiring harness

Fresh motor tuned with only some break in time on dyno. Because we had not tuned the ECU we only did a cam break in prior to putting it on the dyno. Motor is still pretty tight. 305 FWHP at 6800 and torque essentially flat from 2900-6400 at 245 ft/lb. It doesn't have a torque curve, it has a torque plateau. Suspect it will loosen up and make more power once we get it fully broken in. Will dyno again in the fall.

I drove the car back from dyno to our shop and it pulls like mad. Owner will be pretty happy with it.

Video available here:

https://www.facebook.com/turn3autosport#!/photo.php?v=181112715399123&set=vb.566789893351041&type=2&theater

Just starting to assemble our next hot rod this coming week. 2.8 will feature PMO ITBs, Twin Plug, Motec M600 etc...

For what it's worth, very impressed with the Vi-Pec ecu. Vary capable and very stable. We will also be putting one on our 996 race car for giggles.....

[Jeff Alton]

Frank,

Your motor is looking good.

What cams are using?
What ECU?
My suggestion is to find a tuner who is familiar with the ECU. We have used a few different ones and always go with tuner over ECU (assuming similar ecu capabilities) We have settled on Motec and Vi-Pec. Why? Because our tuner is top notch with these products. He tunes everything from drag cars to drift cars to our Porsches. We can't be great at everything so tuning we leave to the experts. We give him our data for basics and let him do his thing while we discuss each change. We are getting there on dyno tuning but will not invest in our own dyno until we are far better. We spent about 4 hour in total tuning. I drove the car back with out a single hiccup including in traffic. He came by our facility this morning to tweek the cold start in closed loop and it is great....



Cheers

[Geneman]

Thanks jeff very helpful...
Here is my build just fyi..
Looking for mostly track car but usable on street

great advice about tuner.. Think i should have it dyno tuned before installing in car?

Je custom fit 10.6:1
ln 100 mm nickies
recon oem 3.2 rods, balanced/
394/395 webcam
twin plugged 3.2 heads port/pol. (xtreme)
arp head studs/rod bolts
race springs and lightwt valve train
sl. Larger exhaust valves
electromotive tech3r ecu
electromotive coil bank
custom clewett wires
46mm pmo/itb
injector size ?
Ngk plugs
custom clewett/isis harness
bb headers 1 5/8
supertrapp track mufflers


oem lsd 40/60
kep lightweight pp
sachs competition clutch
hargett g50 shift tower

[wayner]

Good info Jeff

Thanks for posting

[911pcars]

Originally Posted by Jeff Alton

Just thought I would share some dyno info about rain hats.

Yesterday we dyno tuned our latest 3.5 with 50mm PMO ITBs. We tuned it with the filters and hats as that is how it will spend its life with the owner. For kicks, we did a pull with the filters and hats off. Net gain 4whp@6800. Not much of a penalty running the filters and hats.

AFR did not seem to change at all.

Thought this may be interesting to some folks as we have read for years of far larger differences from the rain hats.

Wish we had the time to test different header and muffler combos.....

Here is a pic of the motor before it was installed.

Looks nice. Typically, with and without, wouldn't that just confirm that less restriction would yield more power? In some cases, the intake air path alone also has an affect. I wouldn't suggest running an engine for any length of time without filtering the air intake as an option unless it's a purpose-built track engine.

With the recent discovery of off-the-shelf pleated paper filters that fit into that same space, it would have been interesting to run an A-B comparison with the ubiquitous "K&N FilterCharger" filters.

Sherwood

[Jeff Alton]

Sherwood,

We did a single pull without filters... I agree not a great idea to run with out them. But, we have heard and read so much "info" on the web over the years about how this filter/hat combo costs big HP (far more than we saw). So, we had a chance to see for ourselves and we took it. It is fun testing the myths

For an A-B filter test, my guess is that the best filters would fall in between our results with filters and our results without filters.

More important, I would have loved to test more header and muffler combinations.....

[Jeff Alton]

Frank,

Did you mean 594/595 cams? If so you have a little more lift and duration and slightly more narrow lobe center than we have in this motor.

Can you find out your injector size?

[911pcars]

Originally Posted by Jeff Alton

Sherwood,

We did a single pull without filters... I agree not a great idea to run with out them. But, we have heard and read so much "info" on the web over the years about how this filter/hat combo costs big HP (far more than we saw). So, we had a chance to see for ourselves and we took it. It is fun testing the myths

For an A-B filter test, my guess is that the best filters would fall in between our results with filters and our results without filters.

More important, I would have loved to test more header and muffler combinations.....

I realize dyno time can consume testing dollars. Trying different header/muffler combinations would be awesome, but even more consuming of someone's resources. Hope you get to that. Your testing results would benefit a whole bunch of us forum freeloaders. :-)

Thanks for showing us what you did.

Sherwood

[Jeff Alton]

Sherwood,

Doing what we can to help build our database, and share the info we find.

The problem with testing headers/mufflers is $$$ to have a few choices available for swapping, like you said. Would love to be able to do it with lots of combos. We will dyno this car with a Dansk 2 in 1 out muffler as well to see if there is any difference.

Too bad we had just sold a different set of 1.75 headers...