Boost leak fixed, 12psi on 91 octane, fun filled day!
04-20-2002, 03:54 AM
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Three Wheelin'
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Boost leak fixed, 12psi on 91 octane, fun filled day!
Looks like my boost leak was from a torn rubber boot... the one between the intercooler and the pipe to the throttle body. Wow what a difference that leak made. I guess the boot was torn from the day the rebuild was completed, because my first test after replacing that boot was to turn the AVC-R down to 35% (what I set for 12psi after the rebuild) and floor it in first gear. Dear god did that scare the crap outta me, hit 20psi and the SDS fuel cutoff. After careful tweaking, the AVC-R now runs at 24% duty to give nice and stable 12psi of boost for my A pump gas setting.
Lesson learned : always replace all rubber hoses after a rebuild. I gotta stop skimping on the cheap stuff, already blew a coolant hose a while back.
The boost hits even harder now. My new tires (Kumho Ecsta Supra, 265/35-18, 235/40-18) are fairly grippy. I get "acceptable" wheelspin in 1st gear when the boost kicks in, and 2nd gear wheelspin only out of corners (I'm sure it'll be crazier with race gas...)
Driving home, get my first "race". Some dude in a 2nd gen RX7 with a nice home made hole in the hood to clear the 357 Chevy motor that's installed (yikes!). I ran even with this guy to about 160km/h, only to find out he's got 500lbs of camping equipment/kegs of beer in his trunk. I think he would've killed me if he didn't have all that crap with him... but then again, at 20psi... =)
Next, I met up with a bunch of friends. Lots of nice cars, SLK 32 AMG, Viper ACR, NSX, 911 C4 Cab, Mustang GT, and a C Coupe. We headed for the track but it was closed... the guys there said there was still frost on the track! Stupid Canadian weather... On the way to the track, we made a run from a stop. I powershifted through the gears, only to have the clutch slip badly (and really stink up the convertibles behind me). The rest of the night were just quick shifts until I can diagnose the clutch issue. It's never happened to me before, and I lost the run pretty badly because of it.
Since the track was closed, we did the next best thing, drove half way across the province and ran a few "spurts" on the 2 lane highways heading towards Saskatchewan. The roads were completely empty except for us, which was nice. The highway is completely straight, so you can see pretty much 5-10km in front of you. The first race was against the SLK 32, and I ran even with him from 80km/h to 250km/h. I DID pull about 2 car lengths from 80-100, which was very surprising. I've always bitched about turbo lag in the 951, but of the 3 races we did, the boost was instant and the car rocketed away. The SLK lagged a bit behind because it takes 1/2 second for the supercharger clutch to engage. Supercharger lag! =)
The next run was with the Viper. That thing is a monster! The Viper ACR was driven conservatively, no power shifts, but still full throttle, and it pulled about 1 carlength on me from 80-200. Every single time. I need race gas... and 20psi... =).
I made a few runs with the 911 C4 Cab, and there is no contest. Easily pulled 8 car lengths from 80-200.
Videos and pics are on the way. Stay tuned!
Lesson learned : always replace all rubber hoses after a rebuild. I gotta stop skimping on the cheap stuff, already blew a coolant hose a while back.
The boost hits even harder now. My new tires (Kumho Ecsta Supra, 265/35-18, 235/40-18) are fairly grippy. I get "acceptable" wheelspin in 1st gear when the boost kicks in, and 2nd gear wheelspin only out of corners (I'm sure it'll be crazier with race gas...)
Driving home, get my first "race". Some dude in a 2nd gen RX7 with a nice home made hole in the hood to clear the 357 Chevy motor that's installed (yikes!). I ran even with this guy to about 160km/h, only to find out he's got 500lbs of camping equipment/kegs of beer in his trunk. I think he would've killed me if he didn't have all that crap with him... but then again, at 20psi... =)
Next, I met up with a bunch of friends. Lots of nice cars, SLK 32 AMG, Viper ACR, NSX, 911 C4 Cab, Mustang GT, and a C Coupe. We headed for the track but it was closed... the guys there said there was still frost on the track! Stupid Canadian weather... On the way to the track, we made a run from a stop. I powershifted through the gears, only to have the clutch slip badly (and really stink up the convertibles behind me). The rest of the night were just quick shifts until I can diagnose the clutch issue. It's never happened to me before, and I lost the run pretty badly because of it.
Since the track was closed, we did the next best thing, drove half way across the province and ran a few "spurts" on the 2 lane highways heading towards Saskatchewan. The roads were completely empty except for us, which was nice. The highway is completely straight, so you can see pretty much 5-10km in front of you. The first race was against the SLK 32, and I ran even with him from 80km/h to 250km/h. I DID pull about 2 car lengths from 80-100, which was very surprising. I've always bitched about turbo lag in the 951, but of the 3 races we did, the boost was instant and the car rocketed away. The SLK lagged a bit behind because it takes 1/2 second for the supercharger clutch to engage. Supercharger lag! =)
The next run was with the Viper. That thing is a monster! The Viper ACR was driven conservatively, no power shifts, but still full throttle, and it pulled about 1 carlength on me from 80-200. Every single time. I need race gas... and 20psi... =).
I made a few runs with the 911 C4 Cab, and there is no contest. Easily pulled 8 car lengths from 80-200.
Videos and pics are on the way. Stay tuned!
04-23-2002, 04:09 PM
#6
Three Wheelin'
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[quote]Originally posted by Russ Murphy:
<strong>80-200? You are talking kilometers, right?
</strong><hr></blockquote>
Of course. My car tops out at 295km/h according to the speedometer. With the bigger 18" tires, I *think* I've cleared the magical 300km/h mark.
Need a radar gun to verify though... (I hope I never get a chance to have it verified!)
<strong>80-200? You are talking kilometers, right?
</strong><hr></blockquote>Of course. My car tops out at 295km/h according to the speedometer. With the bigger 18" tires, I *think* I've cleared the magical 300km/h mark.
Need a radar gun to verify though... (I hope I never get a chance to have it verified!)
04-26-2002, 03:55 AM
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Rage,
Some years back, when David Colman (from Excellence) was driving my car for an article that appeared in Excellence. The hose from the turbo to the intercooler blew apart. It was right at the turbo and I did not find it until I drove home with some light in the garage. What a time to break. Big 'Ol hole. My experience with clutches, especially hydraulically controlled ones, has taught me, that once they began to slip, it's over. You've got some real H/P and it may be difficult to find a solution. Centerforce told me they cannot help me. As I'm sure you're aware, it takes the right combination of pressure plate and disk. I have found one that works for my application, though. Let me know how you proceed. Don't let those whimppy *** ACR's get around you next time. I only run 10lbs. when I have to run that 91 octane crap. Spend the money. Get the Sunoco GT-Plus. Don't leave the H/P on the table. Might as well run nitrous. Hey, I'm looking into that blue bottle stuff. Just a small wiff.
Some years back, when David Colman (from Excellence) was driving my car for an article that appeared in Excellence. The hose from the turbo to the intercooler blew apart. It was right at the turbo and I did not find it until I drove home with some light in the garage. What a time to break. Big 'Ol hole. My experience with clutches, especially hydraulically controlled ones, has taught me, that once they began to slip, it's over. You've got some real H/P and it may be difficult to find a solution. Centerforce told me they cannot help me. As I'm sure you're aware, it takes the right combination of pressure plate and disk. I have found one that works for my application, though. Let me know how you proceed. Don't let those whimppy *** ACR's get around you next time. I only run 10lbs. when I have to run that 91 octane crap. Spend the money. Get the Sunoco GT-Plus. Don't leave the H/P on the table. Might as well run nitrous. Hey, I'm looking into that blue bottle stuff. Just a small wiff.
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04-26-2002, 01:37 PM
#8
Three Wheelin'
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[quote]Originally posted by 86944turbo:
<strong>Rage,
Some years back, when David Colman (from Excellence) was driving my car for an article that appeared in Excellence. The hose from the turbo to the intercooler blew apart. It was right at the turbo and I did not find it until I drove home with some light in the garage. What a time to break. Big 'Ol hole.</strong><hr></blockquote>
Yep, that's exactly what my hose looks like. More than 50% of it was ripped around the middle. Ouch!
[quote]Originally posted by 86944turbo:
<strong>My experience with clutches, especially hydraulically controlled ones, has taught me, that once they began to slip, it's over. You've got some real H/P and it may be difficult to find a solution. Centerforce told me they cannot help me. As I'm sure you're aware, it takes the right combination of pressure plate and disk. I have found one that works for my application, though. Let me know how you proceed.</strong><hr></blockquote>
I think I'm just going to stop power shifting. The gains in acceleration times isn't worth another $2000 to get a better clutch in there. I can't slip the clutch off the line either, when the power kicks in it's all slip if the clutch isn't fully engaged. So I either have to do a soft 2000rpm pre boost launch, or just drop the sucker at 4000rpm so it grabs, wheelspins to about 3500rpm, and rocket away when the boost kicks in. I did a few more test runs, and it looks like the clutch doesn't like the transition from no torque to large amounts of torque in a short time.
[quote]Originally posted by 86944turbo:
<strong>Don't let those whimppy *** ACR's get around you next time. I only run 10lbs. when I have to run that 91 octane crap. Spend the money. Get the Sunoco GT-Plus. Don't leave the H/P on the table. Might as well run nitrous. Hey, I'm looking into that blue bottle stuff. Just a small wiff.</strong><hr></blockquote>
I won't next time. Just have to fill up with 103 Octane. Might even wire in my scramble boost setup to give me a short burst of 25psi to seriously kick some *** in 3rd and 4th gear. There's no Sunoco here, it's either 91 octane, or 103 octane race gas. The run at 12psi was pretty quick, the week before (when the hose was still ripped) I could only push 10psi, and I lost pretty bad to the SLK 32. 2psi makes a huge difference... 8psi (when I run 20psi on race) will be more than enough to beat the ACR.
NOS? No thanks... I've driven a few NOS cars, it's embarassing when you run out =).
<strong>Rage,
Some years back, when David Colman (from Excellence) was driving my car for an article that appeared in Excellence. The hose from the turbo to the intercooler blew apart. It was right at the turbo and I did not find it until I drove home with some light in the garage. What a time to break. Big 'Ol hole.</strong><hr></blockquote>
Yep, that's exactly what my hose looks like. More than 50% of it was ripped around the middle. Ouch!
[quote]Originally posted by 86944turbo:
<strong>My experience with clutches, especially hydraulically controlled ones, has taught me, that once they began to slip, it's over. You've got some real H/P and it may be difficult to find a solution. Centerforce told me they cannot help me. As I'm sure you're aware, it takes the right combination of pressure plate and disk. I have found one that works for my application, though. Let me know how you proceed.</strong><hr></blockquote>
I think I'm just going to stop power shifting. The gains in acceleration times isn't worth another $2000 to get a better clutch in there. I can't slip the clutch off the line either, when the power kicks in it's all slip if the clutch isn't fully engaged. So I either have to do a soft 2000rpm pre boost launch, or just drop the sucker at 4000rpm so it grabs, wheelspins to about 3500rpm, and rocket away when the boost kicks in. I did a few more test runs, and it looks like the clutch doesn't like the transition from no torque to large amounts of torque in a short time.
[quote]Originally posted by 86944turbo:
<strong>Don't let those whimppy *** ACR's get around you next time. I only run 10lbs. when I have to run that 91 octane crap. Spend the money. Get the Sunoco GT-Plus. Don't leave the H/P on the table. Might as well run nitrous. Hey, I'm looking into that blue bottle stuff. Just a small wiff.</strong><hr></blockquote>
I won't next time. Just have to fill up with 103 Octane. Might even wire in my scramble boost setup to give me a short burst of 25psi to seriously kick some *** in 3rd and 4th gear. There's no Sunoco here, it's either 91 octane, or 103 octane race gas. The run at 12psi was pretty quick, the week before (when the hose was still ripped) I could only push 10psi, and I lost pretty bad to the SLK 32. 2psi makes a huge difference... 8psi (when I run 20psi on race) will be more than enough to beat the ACR.
NOS? No thanks... I've driven a few NOS cars, it's embarassing when you run out =).
04-26-2002, 02:53 PM
#9
Nordschleife Master
WHere can I find this Excellence article!!!!! I have been looking for articles on modded turbo cars. I can't ever find a good 930 or 951 article in those mags n/e more 
\
doesn't 103 have lead in it? There is 110 over hear. I ran it on my oe wastegate and I think I made too much boost for it. I beleive that's when I punctured the diaphragm.
\doesn't 103 have lead in it? There is 110 over hear. I ran it on my oe wastegate and I think I made too much boost for it. I beleive that's when I punctured the diaphragm.
04-26-2002, 02:57 PM
#10
Three Wheelin'
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[quote]Originally posted by Luke:
<strong>doesn't 103 have lead in it? There is 110 over hear. I ran it on my oe wastegate and I think I made too much boost for it. I beleive that's when I punctured the diaphragm. </strong><hr></blockquote>
103 is unleaded. 110 and higher is leaded. BP Racing Fuels is what I get up here.
<strong>doesn't 103 have lead in it? There is 110 over hear. I ran it on my oe wastegate and I think I made too much boost for it. I beleive that's when I punctured the diaphragm.
</strong><hr></blockquote>103 is unleaded. 110 and higher is leaded. BP Racing Fuels is what I get up here.
