79 RX7 LS 5.3 Turbo. (8.93 @ 153mph)
#342
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
Got to play a little this weekend. First run out was a 9.1x @ 153.9. 15lbs of boost creeping to 16. 1.5x 60'
Wasn't able to get the boost by speed working as it should and still have issues blowing the tires off with any kind of boost. Leaving off the TB at 3500 and 2-3lbs of boost was the only thing that netted me any kind of traction. Launching this way at 19 lbs creeping to 20 it went 8.9x @ 158.2. 1.51 60'. Several more passes spent trying to figure out the launch.
Last pass I was pulling 15* of timing at the TB release and ramping it back in over 4 seconds. This resulted in a wheels up 1.38 60' that I carried a good 100' and unloaded the tires hard when the nose came back down.
Got some footage of the rear suspension. These were both mild 1.5x launches 3-4lbs and 3500 rpm. Any higher on teh 2-step 3800-4000 boost just takes off and is uncontrollable. I'd see 12-16lbs instantly.
Power is there just need to iron out this damn launch!
Side view of the first video.
Wasn't able to get the boost by speed working as it should and still have issues blowing the tires off with any kind of boost. Leaving off the TB at 3500 and 2-3lbs of boost was the only thing that netted me any kind of traction. Launching this way at 19 lbs creeping to 20 it went 8.9x @ 158.2. 1.51 60'. Several more passes spent trying to figure out the launch.
Last pass I was pulling 15* of timing at the TB release and ramping it back in over 4 seconds. This resulted in a wheels up 1.38 60' that I carried a good 100' and unloaded the tires hard when the nose came back down.
Got some footage of the rear suspension. These were both mild 1.5x launches 3-4lbs and 3500 rpm. Any higher on teh 2-step 3800-4000 boost just takes off and is uncontrollable. I'd see 12-16lbs instantly.
Power is there just need to iron out this damn launch!
Side view of the first video.
Last edited by Forcefed86; 09-14-2015 at 03:02 PM.
#343
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
Ran into some more bad luck. Out testing my new boost control setup and my crank pulley exploded. I ordered it new less than 2 years ago. This motors never seen much over 6500rpm either.
When the pulley let go it knocked a hole in my oil pan, bent my crossover and damaged the steering link.
This is all I could find when I went back to look for it.
No idea how I’m gonna pull whats left of it off…
When the pulley let go it knocked a hole in my oil pan, bent my crossover and damaged the steering link.
This is all I could find when I went back to look for it.
No idea how I’m gonna pull whats left of it off…
#344
Ran into some more bad luck. Out testing my new boost control setup and my crank pulley exploded. I ordered it new less than 2 years ago. This motors never seen much over 6500rpm either.
When the pulley let go it knocked a hole in my oil pan, bent my crossover and damaged the steering link.
This is all I could find when I went back to look for it.
No idea how I’m gonna pull whats left of it off…
When the pulley let go it knocked a hole in my oil pan, bent my crossover and damaged the steering link.
This is all I could find when I went back to look for it.
No idea how I’m gonna pull whats left of it off…
#345
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
Think I’m going to try and weld a cheapo HF 3 jaw puller to it. A cutoff wheel scares me a bit. Also looks like I could file down flats on the back with a lot of time and effort. Hoping to avoid that.
On a side not I just looked at my daily driver C5. The pulley on it is wobbling too, WTF!
On a side not I just looked at my daily driver C5. The pulley on it is wobbling too, WTF!
#348
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
It does have a few 8 second runs on it… I was under the impression RPM was the killer though, not power in general. This engine doesn’t see over 6500rpm, so I thought I’d be fine. I’m assuming it was a flaw in the casting. Hard to tell at this point.
#350
keep working on it! It's getting closer to running well into the 8's!
Bummer about the balancer. Even a cheap SFi balancer is better than stock. Or get an ATi and it'll be the last one you ever buy. They sell blemished ones on eBay all the time. Go to their website and then the bottom left hand side and click on ebay auctions. Early Xmas present to yourself.
Bummer about the balancer. Even a cheap SFi balancer is better than stock. Or get an ATi and it'll be the last one you ever buy. They sell blemished ones on eBay all the time. Go to their website and then the bottom left hand side and click on ebay auctions. Early Xmas present to yourself.
#351
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
If the steering can be fixed I hope to have it patched up this weekend. Picked up an SFI balancer. I know it's still china junk, but better than what I had.
http://www.summitracing.com/parts/pfs-90032
Ran a few 8’s last weekend. Leaving at no boost with a 1.5x 60’ it will do a 8.9X @ 158-159 @ 19-20lbs. With any kind of boost on the launch it usually insta-spins. Right after a decent prep it pulls the front wheels and unloads/spins. That’s pulling timing down to 4* on the launch and ramping it back in over 5 seconds! It’s a light switch with this 370/T4 combo. I miss the nice progressive power band of my 8.6:1 5.3 with the Zr1 cam! That combo would pull solid 1.3x 60’s every time with no drama.
http://www.summitracing.com/parts/pfs-90032
Ran a few 8’s last weekend. Leaving at no boost with a 1.5x 60’ it will do a 8.9X @ 158-159 @ 19-20lbs. With any kind of boost on the launch it usually insta-spins. Right after a decent prep it pulls the front wheels and unloads/spins. That’s pulling timing down to 4* on the launch and ramping it back in over 5 seconds! It’s a light switch with this 370/T4 combo. I miss the nice progressive power band of my 8.6:1 5.3 with the Zr1 cam! That combo would pull solid 1.3x 60’s every time with no drama.
Last edited by Forcefed86; 02-23-2017 at 09:00 PM.
#353
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
Welding the the crappy cast pulley was a nightmare. Every weld I made it would break off a little more of the pulley when I tried to pull it. 3 hours later....
Pan was gouged up pretty good but the hole/crack is only on the far LH side of the damage. About the size of a pen head.
Put the shop vac on the crank case to pull vacuum and hosed it down with brake clean. You could easily see it was sucking the brake clean into the pan. Used Some JB quick weld then, which also sucked in the crack. Hoping this doesn't leak...
Pan was gouged up pretty good but the hole/crack is only on the far LH side of the damage. About the size of a pen head.
Put the shop vac on the crank case to pull vacuum and hosed it down with brake clean. You could easily see it was sucking the brake clean into the pan. Used Some JB quick weld then, which also sucked in the crack. Hoping this doesn't leak...
#355
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
Drove the car quite a bit this weekend, no leaks so far.
Beat the steering rod back into shape and did a quick and dirty DIY alignment to get ready for the track Saturday. Ended up turned away at the gates for a "Pontiac Only" event. One that I raced T/O in the past 2 years...
Cruised by the dump to get it weighed again since adding the new cage. This was with 5 gallons of gas, filled it right after. With 7 more gallons of fuel, my tools, and chute I'm sure it sits damn near 3000lbs. I shuda bought a stinkn mustang at that weight...
Beat the steering rod back into shape and did a quick and dirty DIY alignment to get ready for the track Saturday. Ended up turned away at the gates for a "Pontiac Only" event. One that I raced T/O in the past 2 years...
Cruised by the dump to get it weighed again since adding the new cage. This was with 5 gallons of gas, filled it right after. With 7 more gallons of fuel, my tools, and chute I'm sure it sits damn near 3000lbs. I shuda bought a stinkn mustang at that weight...
Last edited by Forcefed86; 10-05-2015 at 02:07 PM.
#357
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
#359
Thread Starter
Joined: May 2011
Posts: 8,047
Likes: 778
From: Wichita, KS
That’s with me in the car as well. I’m 200 lbs, so the chassis is 2740. Still I’ve seen notchback mustangs weigh in quite a bit less. 9” rear and all the additional cage and support tubing is kill’n me. Still has steel bumpers and glass all around. In factory trim these cars are 2200lbs stripped.
#360
Yeah I've seen fox bodies get to 27xx with lexan, carbon body parts.
I'm about finished with my 5th gen, my 2016 goal is single turbo combo project in something else. I never ran 8's though my old turbo kit did 8.8's in my buddy's car. haha.
I'm about finished with my 5th gen, my 2016 goal is single turbo combo project in something else. I never ran 8's though my old turbo kit did 8.8's in my buddy's car. haha.