shaunv74

Right. But it's comparing stock to: porting+intake+optimized exhaust+reflash tune.

I'm not sure how much the porting contributes alone. It would be nice to see an optimized tuned motor before and after porting comparison

EG: intake+reflash tune+optimized exhaust vs. porting+intake+reflash tune+optimized exhaust.

That would be the most valuable comparison to me.

edit: paging through their site they do have one showing the engine hitting 225bhp fully modified vs. their ~245bhp or so with the porting. That's a nice bump.

Nemesis8

iTrader: (3)

bingo

EricMeyer

Our professionally built motor with about 100% new parts runs 270 peak flywheel hp ran on Motec at .90 Lambda, 90 psi oil, 185 water and oil T F. On good high octane pump gas. Header, stock intake, -11 plugs, aftermarket ignition which allows for nuts on tuning.

This same motor makes approx 219 rwhp on a dynojet when drivetrain is fully warmed. 5th gear. This equates to approx 19% para drag and/or drivetrain loss.

I would kill to see any details about a ported motor. Everything I've heard is that it's trouble and all you get is 5-7 hp max with less reliability. Please advise otherwise is someone has facts/data.


Engine dyno: http://gallery.me.com/meyermotorspor...&bgcolor=black

EricMeyer

If it's the black plastic upper intake there is very little opportunity that I can see. These motors do not like VOLUMES of air. They like VELOCITY of air.

EricMeyer

It is unfortunate they are so many new variables added in this comparison. You could make an argument that the exhaust made the additional power.

Not a apples and apples test.

Geeshh---can't anybody share some before and after ported motor info????

Mazmart

iTrader: (12)

I agree:A lot of people don't realize how much port timing and volume the stock renesis has. 220 flywheel hp was possible with street port 13Bs back in the day (Maybe 10-20 more occasionally). 270 flywheel is like bridgeport territory.

Monkeying around with the ports is not nearly as good an idea as many of the other things that you have done. It is not hard to make ports that will have adverse effects on side seals, especially on the renesis.

Paul.

Nemesis8

iTrader: (3)

Hey Paul, I would like to investigate the RB templates for our project. I would love to see the side seals given a break from the constant hammering they have been taking.

blackenedwings

For what it's worth I will have a dyno comparison between a stock turbo Renesis with my current mod list and a half-bridge Renny with Esmeril seals. The only things I will be changing initially are the motor itself and upgrading the clutch. That should give a decent enough idea of what porting actually does for a FI car anyway.

EricMeyer

Excellent. Do we believe that the BEFORE motor status had good compression, low miles, etc., etc., etc.? I guess what I'm asking is are we comparing a turbo so-so motor with a 1/2 bridge turbo rebuild using new components, seals/better compression, etc., etc.,???

I'd be interested to know more about any of this 1/2 bridge stuff if you'd like to share and keep it confidential (or not):

meyermotorsports@mac.com

olddragger

iTrader: (3)

you going to measure the egt's doing this?
lets see if the porting can have any affect?
OD

PhillipM

Damn, I'm going to have to go looking for another 3bhp now

blackenedwings

Eric, thats a really good point actually. I do have compression numbers for the motor I have now and they aren't bad, but doubtfully up to the compression of a newly built motor. Truthfully its going to be very hard to get an apples to apples comparison between a half-bridge and a stock motor both freshly rebuilt with close to identical compression.

No worries about confidential secret stuff... I'm just learning as much about this stuff as I can. The modifications on the motor are largely coming from recommendations by Brian@BDC who is building the motor. We've discussed a lot of potential changes to the motor, especially various apex seal options and I've settled on the Esmeril seals despite some reservations about lack of long term wear data etc. The intake/exhaust porting on the motor will be relatively mild, mostly cleanup work from what I understand, but the half-bridge is something Brian has done on a couple of other Renny motors now and was comfortable doing for mine. If you need the exact specifications on how he is doing the porting I would recommend dropping him a PM.

Brettus

iTrader: (2)

I might be able to do an apples for apples dyno comparison on my partially ported motor .
I only cleaned up the intakes but did do some massaging of the side exhaust ports ....

The one thing I've noticed so far is a nicer exhaust tone at high rpm . I originally thought the motor was flowing more air but I eventually traced that back to an intake leak at the turbo that I must have had pre rebuild .