Holly mother of cow!!!
Originally posted by BadazzCR
Just curious why this setup can't hold 19psi and a number of others including myself have no problem..holding the boost all the way up.
Just curious why this setup can't hold 19psi and a number of others including myself have no problem..holding the boost all the way up.
Josh
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From: Danville/Blackhawk, California
No problem getting 20+psi of boost throughout the midrange. Above 6000rpm, however, the turbo runs out of breathe. And with the cam timing tweaks, the improved engine VE makes the turbine operate in another part of its efficiency map where it cannot support the new exhaust flow volume as well. The cam timing changes no not affect overlap, btw. Just the point in the stroke where overlap occurs.
Cheers,
shiv
PS. It is possible to run more boost in the midrange in with both the race and street gas maps. And with more boost, we can usually get one or two good dyno pulls. But they aren't consistent since the system is being pushed to operate with such little safety margin. I'd rather get 95% of max output 95% of the time than 100% of max output 20% of the time due to knock activity.
Cheers,
shiv
PS. It is possible to run more boost in the midrange in with both the race and street gas maps. And with more boost, we can usually get one or two good dyno pulls. But they aren't consistent since the system is being pushed to operate with such little safety margin. I'd rather get 95% of max output 95% of the time than 100% of max output 20% of the time due to knock activity.
Originally posted by 90GSX-03EVO
The lift of the Jeep was 5 inches. The spacers dropped the crossmember only one inch. My driveline angle before the spacers was sitting right at about 20 degrees at the front U Joint. After it was dropped, it still only brought it to about 25 degrees. When I raised it back up and added the CV driveshaft, I then had the same 20 degree angle, but it was split over the two U Joints so it was only 10 degrees at each bend. This did away with all of my vibration issues as well as snapping grade 8 bolts from excessive flex. The spacers that we are talking about are actually 1 inch thick square tubes that run about 2 feet long and have 3 holes drilled in them with reinforced internal structure. It would be the equivalent of running a tube spacer from the front crossmember on the Evo to the rear one, covering every factory contact point that is in question. They were not some cheap stacker or anything. They simply did not work right for my intentions. Here is my point. The lift kit was great, but lowering the crossmember on it was for driveline issues (to make it behave on the street better) and when taken off road, the flex was too much for it. You could chalk this up as abuse or whatever, but it would be like telling me that I couldn't take the Evo on a road course and turn hard as hell in it. As far as the overseas Evo's not having them, they are missing a lot of things that I definitely am glad that I have (stronger bumper, thicker glass, side impact beams, etc.). These cross braces were put on for a reason, and I think it is to make the car a little more rigid, either from a crash test point of view or from a road course point of view. I would tent to beleive that it was for a better crash test score. With that being said, I would hate to put something on the car that seems to be fine, but then would snap like a toothpic if I was hit from the side. Folding the car in half right along the b-pillar doesn't seem that appealing to me, since I will be right around that area.
Any ideas on this?
Josh
The lift of the Jeep was 5 inches. The spacers dropped the crossmember only one inch. My driveline angle before the spacers was sitting right at about 20 degrees at the front U Joint. After it was dropped, it still only brought it to about 25 degrees. When I raised it back up and added the CV driveshaft, I then had the same 20 degree angle, but it was split over the two U Joints so it was only 10 degrees at each bend. This did away with all of my vibration issues as well as snapping grade 8 bolts from excessive flex. The spacers that we are talking about are actually 1 inch thick square tubes that run about 2 feet long and have 3 holes drilled in them with reinforced internal structure. It would be the equivalent of running a tube spacer from the front crossmember on the Evo to the rear one, covering every factory contact point that is in question. They were not some cheap stacker or anything. They simply did not work right for my intentions. Here is my point. The lift kit was great, but lowering the crossmember on it was for driveline issues (to make it behave on the street better) and when taken off road, the flex was too much for it. You could chalk this up as abuse or whatever, but it would be like telling me that I couldn't take the Evo on a road course and turn hard as hell in it. As far as the overseas Evo's not having them, they are missing a lot of things that I definitely am glad that I have (stronger bumper, thicker glass, side impact beams, etc.). These cross braces were put on for a reason, and I think it is to make the car a little more rigid, either from a crash test point of view or from a road course point of view. I would tent to beleive that it was for a better crash test score. With that being said, I would hate to put something on the car that seems to be fine, but then would snap like a toothpic if I was hit from the side. Folding the car in half right along the b-pillar doesn't seem that appealing to me, since I will be right around that area.
Any ideas on this?
Josh
I would be surprised if the Japanese spec Evo VIIIs don't have these braces. I also doubt they are there for crash protection either. I think they are there for handling benefit. Like you, I would prefer not to have to use a spacer for something like this. But to redesign the brace would increase the price of the kit even more. Maybe a smaller downpipe (2.5") would be an acceptable trade off to some people. Lose a little power but keep your brace in its original location.
Only time will tell if the relocated brace is a problem or not.
Originally posted by shiv@vishnu
No problem getting 20+psi of boost throughout the midrange. Above 6000rpm, however, the turbo runs out of breathe.
No problem getting 20+psi of boost throughout the midrange. Above 6000rpm, however, the turbo runs out of breathe.
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