cygnusx1 Posted June 24, 2005 Share Posted June 24, 2005 When the car is still warming up, like when the water temp is about 1/8 of the way up about 2 minutes after starting the engine it has MONSTER torque down in the lower RPMs. What is it exactly that causes that? I would like to somehow emulate that and keep that power even when it's warmed up. Anyone else observe this also? I know all the intake parts are still cold such as the intake manifold and intercooler plumbing. Is it that simple or is there more to it? Quote Link to comment Share on other sites More sharing options...
Phantom Posted June 24, 2005 Share Posted June 24, 2005 Do you pull your air from in front of or behind the radiator? Do you have emission controls that pulls crankcase air into the intake? As the engine warms up heat builds under the hood and the intake air becomes less dense resulting in less hp/torque. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted June 24, 2005 Share Posted June 24, 2005 I've noticed this phenomenon in every car I've owned. I always attributed it to thick oil on the cylinder walls giving a little more compression. I don't know where I got that from, or if it is correct. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 24, 2005 Author Share Posted June 24, 2005 The intake air always comes in fresh from up front on my setup. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted June 25, 2005 Share Posted June 25, 2005 or it might be you are running too lean when fully warmed up, so when it's nice and rich during warm up it makes the full power it should? Just speculation, I know that we've talked a lot about the BEGI unit, and I've always wondered how you get away with so much less fuel pressure when you're running nearly the same boost out of a much more efficient turbo than I am. Didn't you also finally find some real evidence that you were running lean? Like clean spark plugs or such? At any rate... my own car runs like crap until the temp needle gets about 1/5 of the way up.... Quote Link to comment Share on other sites More sharing options...
john kosmatka Posted June 25, 2005 Share Posted June 25, 2005 Ive noticed this also, I would think some of it could be attirbuted to heat soak. Cant see what else it would be. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 27, 2005 Author Share Posted June 27, 2005 bastaad, my car definately runs on the lean side under full boost...I had never heard ping until a few weeks ago while accelerating hard on the highway. Since that I have raised the begi fuel pressure a bit. The car has been getting 22-23 mpg mixed driving with occasional hammer downs. It definately gets enough fuel when driving casually. I don't think it's a perfect fuel curve but it's as close to factory as it can get until boost causes the fuel pressure to rise from stock. Also, my N/A motor had, and my WRX has, more power right after and during warm up. My hunch has always been that heat soak causes the loss of several foot pounds of torque. If it is mainly heat soak, too bad we can't figure out a way to keep the manifolds cold. The cold side of my intercooler is always very cold to the touch after a hard drive so I think that it's doing its job. I bet it's the intake manifold that gets hot and robs us of all that torque. Quote Link to comment Share on other sites More sharing options...
john kosmatka Posted June 27, 2005 Share Posted June 27, 2005 Im sure the intake manifold is getting pretty hot, with the exhaust manifold right under it, it probably sees some pretty high temps. Quote Link to comment Share on other sites More sharing options...
jeffp Posted June 28, 2005 Share Posted June 28, 2005 You are correct, the engine runs stronger when it is cold. All of the active components are cool and the intake air is cooler. You want a fix, do what BMW has done with their engines, go with a carbon fiber/plastic comp intake and you will get overall better performance when the engine is hot. Same thing as running on a nice 50 degree day as compared to a 90 degree day. The air is colder,denser and the engine runs better/stronger provided you can provide the additional fuel for the burn. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 28, 2005 Author Share Posted June 28, 2005 Are there any coatings for the interior of an intake manifold that will inhibit heat transfer into the airflow? So, plastic/composite intercooler pipes and intake manifolds may be the way to go. Lots of people have laid thier own fiberglass and carbon parts. Has anyone here tried to make an intake out of fiberglass or carbon fiber yet? I did see the aluminum ones with heat blankets over them. Thermal Coatings http://www.speedoptions.com/articles/1213/ What about dip coating the intake tract parts with silicone or PVC? http://www.piper-plastics.com/plastic-coating.htm Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 24, 2006 Author Share Posted July 24, 2006 Post revival. Summer is here and the intake manifolds are hot. How to keep them cool? Can we get cool airflow in between the bottom of the intake maniflod and the exhaust manifold to keep the convection heat transfer down? Quote Link to comment Share on other sites More sharing options...
dapiper Posted July 25, 2006 Share Posted July 25, 2006 I hope my larger intercooler (225 in2, up from 160 in2)will help, combined with cold air intake. I measured 100F intake charge temps last week here in SC and 75 - 85F at night with very noticable difference in torque. Heat is the enemy of turbo's. A good EFI with tuning does help alot. Quote Link to comment Share on other sites More sharing options...
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