Dyno'd streetport today.
Originally Posted by dDuB
I just want to know why exactly combining the ports is so bad? It's perfectly acceptable for people to knife edge the divider making it as thin as possible, but once you combine them this is wrong? Why? I'm just trying to understand the reasoning for this.
This is something you don't really care about on the really upper high end, but it kills a lot of power down low.
Intake velocity is very important for stock and streeted vehicles.
This is the reason for VDI and Honda's VTEC.
-Ted
it improves top end only if the whole setup works, just higging out the port in one spot will just hurt airflow. this is not the way to do it on something that gets driven on the street a lot
Yah I'm not worried with low end much, I'm working on more peak/top end power and making power past redline. But for it to be complete I need to finish other things like standalone, custom manifold and throttle body setup, etc.
I daily drive my car with porting like that, no sleeves or actuators or anyting, aluminum flywheel, solid engine/tranny mounts, bla bla... "Streetability" doesn't seem to bother me I guess.
I daily drive my car with porting like that, no sleeves or actuators or anyting, aluminum flywheel, solid engine/tranny mounts, bla bla... "Streetability" doesn't seem to bother me I guess.
yea i find the car to be streetable with this port. .it's not bad at all. almost stockish feeling, a little less low end but not much. you all saw the graph, it's not to bad. But yea that's the kind of port i have. .oh well, live and learn it still pulls pretty hard and i will be getting a standalone sometime, and making a custom intake mani, so i should be able to bring this port to life a bit more. we'll see. i may also be going over to boost with engine in the future. we'll see, it should take well to boost it would seem with a port like that. thanks for all the input
Dom
Dom
Originally Posted by Dom_C
Here is the dyno graph, you can see where i opened the VDI. I have the VDI hooked to a air pump which is hooked to a toggle. I had them open it at like 5500 rpm the first run, they do fucked up work there or soemthing cause the first run only yeilded like 120hp. it was weird. and the second run was only at 135, and this graph is the third run.
Most shops consider a pull as one cycle on the dyno and a run as 3 cycles. Any good racing shop is going to do testing in runs because the third pull will almost always make more power than the first and second. This comes from fluids still comming up to temp (even after warm up), blowing carbon out of the engine, etc.... Then they will tweak something and do another run of 3 passes.
Out of 3 weeks of dyno testing at school the only time we had a weaker number the 3 pull than the first was if there was operator error.
Wow, you're losing a lot of torque in the upper range. I'd guess air fuel ratios are off; doing porting and airflow mods to stock ECU cars poses a situation where some mean potential can be unleased with an aftermarket ems. Megasquirt in fuel mode only (stock ecu still running ignition) made a real difference in my car's case in the midrange where it was too lean. You might be able to lean out the top range and get some torque back.
haha oh man back from the dead. Yea i had planned on megasquirting this car but sold it instead. I now own an 87 t2 but thanks for all the input guys. In the future i would never port a car like this again, not unless there was a huge turbo bolted upto it or internals that could handle 10k rpms. It's not a very practical port and didn't make **** for power as you guys could see. I feel like i could have made more power on a fesh stock port engine. Oh well live and learn, then go boost :-P J/K I love n/a's but this turbo stuff is pretty cool too. haha
Dom
Dom
Dom, at least you learned something. I feel your last post should be forever etched in stone where everyone can see it and see that this style of porting in fact doesn't work well for street use. People ask about this same port style all the time and the same people keep building them for others. Prime example how bigger isn't always better and how if you aren't testing you are guessing. You've got a much more fun and drivable engine now anyways. I'll bet a TII is way more fun than that engine was.
Yea i definetly learned something. I would also never pay anyone to rebuild and engine for me agian. Not because of bad quality or anything but it's just so simple! unless I had absolutly no time and had a **** load of money to spend i owuld do it my self no doubt. And also, this port is definetly drivable on the street that's not what i was saying. . I drove this around with a 6puck clutch just fine. I just was really disapointed with the power output of this engine. Like others have said this port could be made to work if done correctly, or witha huge turbo but there are other ports out there that will make a ton more power, have a broader powerband, and just be better all around motors. And yes the T2 is a ton more fun. Boy's torque is good! It may not have a ton of really low end torque but **** i'm liking the darkside.
get a stand alone and you should be fine. stock ports can make upwards of almost 175 - 180rwhp on stock ecu's... but the ecu can actually control that. your porting ruins what the ecu understands. so get that megasquirt asap.
Thread
Thread Starter
Forum
Replies
Last Post
eddierotary
Engine Management Forum
16
Oct 4, 2016 08:22 PM
HalifaxFD
Canadian Forum
126
May 9, 2016 07:06 PM



