# Possible to build a 400whp sr that spools by 2000-3000rpm? **URL:** \ **Category:** SON240sx Automotive\ **Created:** [June 30, 2007, 7:19am UTC](https://forums.speedlife.net/t/possible-to-build-a-400whp-sr-that-spools-by-2000-3000rpm/107276 "2007-06-30T07:19:10Z")\ **Posts on this page:** 1\ **Showing post:** 42
**Author:** ![NoSkillz](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/noskillz/32/5606_2.png) [@NoSkillz](https://forums.speedlife.net/u/NoSkillz)\ **Post date:** [July 2, 2007, 7:55pm UTC](https://forums.speedlife.net/t/possible-to-build-a-400whp-sr-that-spools-by-2000-3000rpm/107276/42 "2007-07-02T19:55:38Z")
> [@What color wheels on a red car?](https://forums.speedlife.net/t/what-color-wheels-on-a-red-car/13114/11): > > Good luck with the build. I don’t know too much about turbo’s but I know there is such a thing as a variable geometry turbo that has vains that adjust to different pressures. You might be able to use this to get better boost at low rpm and still have a good turbo for high rpm as well. Here is a little bit of info I found on the VGT off wikipedia. > > Variable geometry turbochargers (VGTs) are a family of turbochargers, usually designed to allow the effective A/R ratio of the turbo to be altered as conditions change. This is done because optimum A/R at low engine speeds is very different from that at high engine speeds. If the A/R ratio is too large, the turbo will fail to create boost at low speeds; if the A/R ratio is too small, the turbo will choke the engine at high speeds, leading to large exhaust manifold pressures, high pumping losses and ultimately lower power output. By altering the geometry of the turbine housing as the engine accelerates, the turbo’s A/R ratio can be maintained at its optimum. Because of this, VGTs have a minimal amount of lag, have a low boost threshold and are very efficient at higher engine speeds. In many configurations, VGTs do not even require a wastegate, however this depends on whether the fully open position is sufficiently open to allow boost to be controlled to the desired level at all times. Some VGT implementations have been known to over-boost if a wastegate is not fitted. > > Hope this helps out. the New Acura RDX has this i believe, never seen a turbo like this for sale, what would be the price, anyone have any more info on this --- _[View the full topic](https://forums.speedlife.net/t/possible-to-build-a-400whp-sr-that-spools-by-2000-3000rpm/107276)._