A question to the critiques out there, have you guys ever actually tested these things on the level that you are suggesting? Honestly, it appears otherwise.

Pressure sensors are not just for "shitty" setups, they are an integral part of tuning a turbocharged system. Would you run your turbocharged system without knowing the intake manifold pressure? I'll tell you right now that knowing the exhaust pressure is just as important, knowing the drive pressure at all times will give you needed information to finely tune in cam, iginition, fueling and turbine size.

The reason as I stated earlier for not running 4 or 8 pyrometers was an issue of cost, and drawing the line at a certain point. Because I have tested many manifolds using pressure and temp sensors on each primary with a set at the head flange and the collector, I have learned what my temp drop through out my manifolds tend to be. Realize that the manifolds I build, and including this honda manifold have a double insulating coat of ceramic coating on both the outside and especially the inside (the inside is without a doubt the most important place to coat) and are also completely header wrapped. Without giving away some proprietary race information that does not technically belong to I will say that temperature drop I have found on approx 20" primaries with the above mentioned heat retaining capabilities the drop is actually hard to measure as it is so minimal (yes I am talking less than 50* fahrenheit).
So based on these things I am sure you can understand why I am ok with having done what I have with this turbo system.

As for the megaphones, if you don't believe me try it yourself. It does in fact work, and the reason why is because the exhaust venting from the gate does not like to be just dumped from a 1.5" tube into the atmosphere. The transition helps the high pressure head expand which ultimately makes it accelerate, this acceleration allows more volume to to exit and thus you get better boost control because the gas can get out faster.
To put that into easier to understand terms it makes a smaller gate work like a larger gate. We all know you will get boost creep with a gate that is too small, and a larger one would give you better control, this works on the same principal.

It all matter much to me even if its just for rippers

 

Fred's good with microcontrollers, and riddling ppl with questions to get in depth answers. He could care less if you think he's rude as long as you keep talking. :P


Actually, the angle of your wastegate exits from the collector is the #1 factor in boost control. You can call up Full-Race, who has shitty exit angles in their collectors, and they will tell you that you need dual 50mm gates for a 4-1 collector running a GT40 or larger Garrett due to their low backpressure design. However, the BRMS car runs a single 44 on an intelligently designed Love-fab and has rock solid boost control @ 11 psi wastegate with their GT40. It's pretty obvious when you compare manifolds, one company cuts an arbitrary hole because it's easier and the other angles theirs a few degrees to help flow out the wastegate.

I'm not saying the wastegate megaphones don't work as advertised, mind; I can see why creating a low pressure pocket at the dumptube exit would be a great aid to a mix of differential + pulse flow. What I am saying is that I think your collector's wastegate exit is the larger part of the mojo.

 

Dont tell that to our new Mazda buddy... Wastegate placement doesnt matter... According to him...

 

JD, you are absolutely right, I never said that the megaphone were the key to boost control, they are just merely an extra improvement, wastegate angle is without an doubt the most important thing to boost control. If there was more room in this chassis the gates would have been mount in the flow stream of the turbine housing itself. THAT is the best, but there wasn't room so a compromise was necessary.

 

If it makes a noticeable improvement, it is worth doing. Large turbine modern turbos are really twitchy, especially if you are trying for a streetable low boost setting you can launch hard with on treet tires in a FWD.

 

Hey, I'd love to have pressure sensors back there. It would make for a very accurate tune if the ECU actually knew what was happening in the exhaust runners. I've seen the affects of a closed gate still spooling on AFR with all other parameters the same. Pressure is certainly important. Which tuning tool do you use that has access to this data though? Or is it just so you can say "oh, it's not too high, sweet". If the latter, it still falls under "nice thing to have" not "essential tuning tool". The secondary point was that you aren't measuring it in the right place really as it will almost certainly read some small amount higher there than it would where the gates exit from. The gate exit point is the useful pressure number for several reasons. I'm coding EMS software every day and making sure all sorts of things that don't really matter are spot on and 100% right. Anyway, it will be interesting to see what sort of pressures you are seeing relative to boost. I calculated mine based on a semi accurate measurement of spring rate in the gate and some accurate dimensions and logging data. I made 3.5psi with my gate spring in backwards and wide open and 17.5 from an 18.2psi spring. I think it meant about 20psi in the exhaust stream from memory, so not too bad. A pressure sensor sure is easier though :-)

+1 on the exit angle. It's a compromise between allowing it in smoothly and allowing it out easily though. Pretty difficult to have both! Mines slightly backwards, that combined with the ram mani is what allowed the 3.5psi with the gaping hole.

 

hey *******.

sorry i couldnt come help. wish i coulda been there for the good times. hope everything is working out!!
did a few turbo swaps myself this week. but on shitty locomotives

 

Well after hrs and hrs, of searching, and replacing, and testing idea's as to why it wouldn't idle properly. It all came down to my EPIC FAIL of putting the vtec solenoid back together incorrectly. In my only defense I had never seen the inside of one before that point, and couldn't find it in the service manual, but at the end of the day that was it. Switched it around, and now finally after 4hrs+ of changing things to try and get it sorted out, we finally did. Now it is on to some tuning. I have a feeling as it is 95PM local time, that we will be here all night again.

I will post our progress as we go, and hopefully some one will add pics and video tomorrow.

 

WHERE ARE THE PIC'S!!!!!!!!!!!!!

 

im still waiting on nudies!