Who here really knows how to make BOOST?
Who here really knows how to make BOOST?
(OP)
Here is my question. For a high horsepower drag racing application, using a manual transmission what are the best ways to make boost?
I have heard of several different techniques and do not know who to believe.
One school of thought says reduce timing down to a minimum - say 5-6 deg and pull fuel out of the map, this will cause lean popping in the exhaust thus allowing the turbo to create boost.
Then I heard the opposite, pull timing out and add a lot of fuel, the intent here is to force fuel into the exhaust so it burns there and spools the turbo.
Assuming we can make boost, how about controlling it?
I hear some guys use a waste gate on the exhaust and also the intake side to control the boost instead of just using an exhaust side gate. Does anyone have some ideas here of the best way to do it?
So what is the best way to make boost at the starting line with a stick?
I have heard of several different techniques and do not know who to believe.
One school of thought says reduce timing down to a minimum - say 5-6 deg and pull fuel out of the map, this will cause lean popping in the exhaust thus allowing the turbo to create boost.
Then I heard the opposite, pull timing out and add a lot of fuel, the intent here is to force fuel into the exhaust so it burns there and spools the turbo.
Assuming we can make boost, how about controlling it?
I hear some guys use a waste gate on the exhaust and also the intake side to control the boost instead of just using an exhaust side gate. Does anyone have some ideas here of the best way to do it?
So what is the best way to make boost at the starting line with a stick?





RE: Who here really knows how to make BOOST?
Another way of building boost of the line is to completely cut fuel to one cylinder (or I suppose two on an 8 cylinder?). The system I am aware of that does this builds about 6 or 7 psi doing that. You could also cut the ignition to that cylinder, but then you are dumping lots of unburned fuel.
-Mike
RE: Who here really knows how to make BOOST?
Regards
pat pprimmer@acay.com.au
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RE: Who here really knows how to make BOOST?
21 PSI, what size turbo?
patprimer: NOs does work wonder but is illegal in the racing I do. So we have to make as much boost as possible and control it so we can tune the clutch for consistency.
RE: Who here really knows how to make BOOST?
"Another way of building boost of the line is to completely cut fuel to one cylinder (or I suppose two on an 8 cylinder?). The system I am aware of that does this builds about 6 or 7 psi doing that. You could also cut the ignition to that cylinder, but then you are dumping lots of unburned fuel."
????????????????????????????
Well, I'm not into racing, but I've never heard of anything like this -- and I'm mystified as to why it would work.
Otherwise I agree with Pat. . . .A Short Shot of NOs works wonders.
RE: Who here really knows how to make BOOST?
RE: Who here really knows how to make BOOST?
My friend does not change his a/f ratio. Some people like to make it run rich, but since he has been able to create 21 psi off the line there has been no need to. The turbo is a 16G. The motor is a 4g63. And yes, 21 psi is really pushing that turbo. He is upgrading right now.
-Mike
RE: Who here really knows how to make BOOST?
in my opinion, traction would be a bigger obstacle to overcome..once the tires break lose, boost or no boost, your waisting time..
automotive imagineer--making the stuff is the hard part- thinking of the stuff to make is the fun part..watching it work is the best part..chrisman2
RE: Who here really knows how to make BOOST?
Are we better off lean popping in the exhaust or pumping more fuel in there?
Traction has never been an obstacle, making enough power at the line is the problem. We are trying to get our 60' times down under 1.1 sec, 1.01 is our goal. Running a 94mm turbo.
RE: Who here really knows how to make BOOST?
This setup with our 2600lb pro mod should run around 6.7 sec in the 1/4. We have been 7.0 but our short times are off because of spooling issues, hence the reason I am asking the question.
RE: Who here really knows how to make BOOST?
RE: Who here really knows how to make BOOST?
If you can add an injector ( in the rules) before the turbo, on the exhaust side, you can add fuel and spool up the turbo. This is the method used in the WRC cars someone already mentioned to prevent turbo lag. You may want to look at Greddy for a controller for the injector. I am quite sure if you get this thing to make boost traction will become a new problem on your way to a 1.01 60 foot.
I know of a turbo leaving the lights at 25 lbs boost and builds to 32 in .1 seconds on the data aq box using an aux injector. This keeps your mix and timing good and may keep all your pistons in tact.
Good luck.
PFM
RE: Who here really knows how to make BOOST?
could you just use compressed air and fuel instead of nitrous and fuel?how much pressure can be developed in the exhaust before the turbo.?---all in the name of boost..
automotive imagineer--making the stuff is the hard part- thinking of the stuff to make is the fun part..watching it work is the best part..chrisman2
RE: Who here really knows how to make BOOST?
RE: Who here really knows how to make BOOST?
I am in the same school of thought with you. I believe that Rich is the way to go. Although I have been told by some other racers that "lean" is the way to go.
I am just trying to get an engineering explanation as too which way is the correct way to operate.
RE: Who here really knows how to make BOOST?
It is not an either/or situation. There are tradeoffs to be made. Real engineering is not rules of thumb, it is understanding the reasoning behind complex phenomena.
In this case you are trading off the temperature limits of the materials, against the ideal burn characteristics of the mixture, against the operating characteristics of your particular setup.
As such there is no one size fits all solution.
Cheers
Greg Locock
RE: Who here really knows how to make BOOST?
RE: Who here really knows how to make BOOST?
Btw what sort of specs on the 302, heads, port work, manifolding, intercooler design if you don’t mind sharing? Also what boost pressure at what manifold temp was the 100mm build at for 1850hp and what was the max torque at this output?
RE: Who here really knows how to make BOOST?