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This is continued from the "rev limiter" thread. I am thinking about going with the SP-66 instead of the SP-63 for a little more top end power when I get a single turbo..

Would you mind briefly comparing the turbos and your experience with them? What size A/R is SP recommending for the SP-66 and in what trim? What is the lag difference and does it produce signifigantly more power? Any info is much appreciated.
 

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Supreme said:
This is continued from the "rev limiter" thread. I am thinking about going with the SP-66 instead of the SP-63 for a little more top end power when I get a single turbo..

Would you mind briefly comparing the turbos and your experience with them? What size A/R is SP recommending for the SP-66 and in what trim? What is the lag difference and does it produce signifigantly more power? Any info is much appreciated.
If you go with a 66, make sure you get a Q trim, as I'm sure Larry will recommend taht as well. I tried the 66 P trim and it did not perform as well as the 63, even on the top end. It was also very laggy.

The 66 Q trim has quite a but more power and spools quicker than the P trim too. I still haven't had a real opportunity to track test it yet. The one time I did it to the track I was having boost problems. To little off the line, then too much once it spooled. I replaced my wastegate and that seems to have cured the problem.

I am taking the car to get dyno tuned next Friday and then plan to go straight from the dyno to the track for some real word testing. So, by next weekend I should have all kinds of good information to post.

All this being said, I still feel the 63 is a better turbo for street driving. Quick spool and plenty of power. When you have a turbo that will do 1.4 60' times and very low 10s in the 1/4 on drag radials and no NOS, it doesn't get much better than that.

I have been using a .81 A/R on both turbos.
 
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Thanks man. I have spoken with Larry and he has recommended the Q-trim-.81 A/R if I go with the 66. I realize that the 63 is probably one of if not "the" street racing turbo, but I think I want something just a tad bigger (but not much) since highway (beltway) racing is popular herealso. At the same time, I don't want something too big and laggy, that's why I am thinking/hoping the SP-66 would be the perfect compromise. It's basically down to the SP-63, SP-66, or the PHR stage 2+ kits. It'll be another 3 months at least, but I think deciding is 1/2 the fun. Thanks for you help.

Please post everything you can about your results on the dyno and at the track. I. and I'm sure others, have been waiting to see some SP-66 numbers for a while. BTW, do you have cams or the SP intake? Any other mods or just the turbo kit?
 

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Supreme said:
Thanks man. I have spoken with Larry and he has recommended the Q-trim-.81 A/R if I go with the 66. I realize that the 63 is probably one of if not "the" street racing turbo, but I think I want something just a tad bigger (but not much) since highway (beltway) racing is popular herealso. At the same time, I don't want something too big and laggy, that's why I am thinking/hoping the SP-66 would be the perfect compromise. It's basically down to the SP-63, SP-66, or the PHR stage 2+ kits. It'll be another 3 months at least, but I think deciding is 1/2 the fun. Thanks for you help.

Please post everything you can about your results on the dyno and at the track. I. and I'm sure others, have been waiting to see some SP-66 numbers for a while. BTW, do you have cams or the SP intake? Any other mods or just the turbo kit?
I do have the SP intake, but still running stock cams. No other mods to the motor. Everything else is the usual stuff, VPC, AFC, trans, converter, etc. Nothing that you haven't heard before.
 
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Discussion Starter #5
Just wondering if you have any new info, numbers, or times with the SP-66?

Decision time is getting closer.
 

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Supreme said:
Just wondering if you have any new info, numbers, or times with the SP-66?

Decision time is getting closer.
I have been able to run it a few times, but I am still having some problems with the car. Waste gate and possibly torque converter issues. But all things being equal, i got about 2 MPH more trap speed on the 66. Can't really tell which is better on et yet due to the other problems, but I suspect the 66 will turn slightly quicker times. It definitely pulls harder on the street as well, although it is about 500rpm laggier. Comes on hard at 5100.

All and all, I would say get the 63 if most of your driving will be street. Get the 66 if you will be racing a lot or are into open highway racing. From a roll, there is not much difference in lag, but off the line, the 63 comes on noticeably quicker. You won't be dissapointed with either.
 

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5100???

Wow, 5100 seems a bit late...have you ever driven a T78 car by any chance?? I thought even the T78 kicked in hard by around 4500. Maybe I'm mistaking. I do like to interstate race too, thats why I'm looking at something a bit larger than the SP63. I also have a 6spd. Do autos kick in later than 6spd or would my 6spd possibly come on hard before 5100?? Soory for all the questions, but I need to decide soon on a kit. Thanks for the info! Peace!
 
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Re: 5100???

n disgii said:
Wow, 5100 seems a bit late...have you ever driven a T78 car by any chance?? I thought even the T78 kicked in hard by around 4500. Maybe I'm mistaking. I do like to interstate race too, thats why I'm looking at something a bit larger than the SP63. I also have a 6spd. Do autos kick in later than 6spd or would my 6spd possibly come on hard before 5100?? Soory for all the questions, but I need to decide soon on a kit. Thanks for the info! Peace!
I agree. 5100 does seem a bit late doesn't it? Given that an SP-66, to my knowledge, is loosely based upon a T-66 in size, 5100rpm would be way late. I was thinking that it would be laggier, but now we are talking about getting into the 5000rpm range which is would probably seem laggy for a street car.

Any chances it's kicking in later than it should due to other issues with the car? Just asking because a wastegate issue will almost certainly affect the turbo's output and characteristics, and a converter issue could possibly make it seem later as well.

Either way, a good, honest SP-66 dyno graph should clear this up pretty well...:)
 

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Remember he has a 4000 stall converter on an auto. The motor does not see much load until 4000 so it is not fair to compare these spool #s to a 6 spd. The turbo starts making positive boost in the 3000-3500 range. Just take a T78 6 spd car and race Mark..... you'll see!!


Lar
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LOL, no way.....

I'll pass on racing Mark..lol...I know better! I figured it had something to do with the auto, I just wasnt sure! Hey Larry, thats why I am very interested in seeing the performance of your SP66 -or- 70 compared to the T78, as far as lag goes, on a 6spd. I think the lag will be very similar on your larger kit (hopefully less lag), but at the same time, produce much more power. You mentioned in my other post that you are testing SP70 now, so I cant wait to see the results!! Take it easy!
 
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Sound Performance said:
Remember he has a 4000 stall converter on an auto. The motor does not see much load until 4000 so it is not fair to compare these spool #s to a 6 spd. The turbo starts making positive boost in the 3000-3500 range. Just take a T78 6 spd car and race Mark..... you'll see!!


Lar
SP
Oh, so it starts making boost in the low 3000rpm range. That's plenty early for my tastes. I'd still like to see a dyno graph but now I'm leaning towards going with the SP-66.
 

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Re: 5100???

n disgii said:
Wow, 5100 seems a bit late...have you ever driven a T78 car by any chance?? I thought even the T78 kicked in hard by around 4500. Maybe I'm mistaking. I do like to interstate race too, thats why I'm looking at something a bit larger than the SP63. I also have a 6spd. Do autos kick in later than 6spd or would my 6spd possibly come on hard before 5100?? Soory for all the questions, but I need to decide soon on a kit. Thanks for the info! Peace!
I have never drivien a T-78, but the basic laws of physics still apply. The larger the turbo, the longer it will take to spool.

On an auto with a high stall, it's not quite as bad as it sounds. Kind of frustrating off the line unless you do a big power brake, but from a roll it hits almost instantly.

A six speed would probably kick in a little sooner since it doesn't experience any slippage from a converter and also has a closer gear ratio (six speeds as compared to 4). But any 3 liter engine is going to be laggy with a turbo that size.

From what you are saying, the 66 might be a better choice for you.
 
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