400 RWHP out of the 951
11-29-2011, 11:01 AM
#46
11-30-2011, 12:49 AM
#49
Rennlist Member
This is exactly what I've been preaching for years. I know my car is fast, I've proven it on many levels even with crappy clutches. I for one can't see a justification for a 3.0 for a fast street car. I would really like to compare my new setup to a well sorted 3.0. Maybe I'll drive it to our next bike race in Utah and meet up with Darwin, I think that'd be fun!! I'm not taking anything away from any of the big engine builds as I'll be building a stroker myself, but I'll be after WELL over 400hp.
11-30-2011, 02:07 AM
#52
Race Car
To be honest Tom, I don't know what that means??
I will reiterate though that I have great respect for those who have built bigger engines. I will be building one.
However, my point was that for a street car, I'm not sure how much more power is needed over 25-28psi on E85?? With this I was seeing 4.7v (around 500hp)out of my maf whereas at the tracks elevation I only saw 4.3 and trapped 118(true 400+) . Personally I have always pushed the boundaries (driving an 8 second street car to work BITD). If I were concerned with better low rpm performance rather than using anti lag I'd put on a gt30r and gain low rpm torque.
So I just don't really get it.......there is a point where too much is just too much (tirespin), and is it worth the expense?...I truly am not sure.
11-30-2011, 04:11 AM
#53
Rennlist Member
Sid, in regards to those sort of psi levels you have seen some need for clutch upgrade (eventually), but what about head gaskets? How long do yours last at those boost levels? You running a metal h/g, O ringed?
11-30-2011, 05:04 AM
#54
Three Wheelin'
It's not about boost levels, but cyinder pressures and these are related more to head flow not boost pressure.
If Sid would run such levels on 16v head, cylinder pressures would be much higher and that would cause issues.
And I can't stress enough, good tune is vital, no head gasket (or other engine component) can withstand bad tune for long, especially turbocharged engine.
Regarding my own project, at the moment I am again in confusion: whether to go twin smaller ball-bearing turbos (I have those in front of me, ~300 hp per turbo) or get HE341VE from a friend which is much more interesting to mess with and results will be incredible but it weighs quite a bit more (18 kg's vs 2x 3,2 kg of the twins) and requires much more work.
The twins would spool up very well and have effectively split-pulse design (1+4 to one turbo, 2+3 to other)....Decisions, decisions.....
If Sid would run such levels on 16v head, cylinder pressures would be much higher and that would cause issues.
And I can't stress enough, good tune is vital, no head gasket (or other engine component) can withstand bad tune for long, especially turbocharged engine.
Regarding my own project, at the moment I am again in confusion: whether to go twin smaller ball-bearing turbos (I have those in front of me, ~300 hp per turbo) or get HE341VE from a friend which is much more interesting to mess with and results will be incredible but it weighs quite a bit more (18 kg's vs 2x 3,2 kg of the twins) and requires much more work.
The twins would spool up very well and have effectively split-pulse design (1+4 to one turbo, 2+3 to other)....Decisions, decisions.....
11-30-2011, 11:40 AM
#56
Race Car
Don't get me wrong I've went through a few parts over the years running high boost. It had been poor tunes or part failures previosly.
Fortunately for me I have Josh close by to keep my tune up to date and safe. I think he fibs to me a little regarding my timing
. I always want to maximize it and he keeps it safe. It's fine with me.I have orings on the new engines head. And I will oring the 16v as well.
11-30-2011, 05:47 PM
#57
Rennlist Member
To be honest Tom, I don't know what that means??
I will reiterate though that I have great respect for those who have built bigger engines. I will be building one.
However, my point was that for a street car, I'm not sure how much more power is needed over 25-28psi on E85?? With this I was seeing 4.7v (around 500hp)out of my maf whereas at the tracks elevation I only saw 4.3 and trapped 118(true 400+) . Personally I have always pushed the boundaries (driving an 8 second street car to work BITD). If I were concerned with better low rpm performance rather than using anti lag I'd put on a gt30r and gain low rpm torque.
So I just don't really get it.......there is a point where too much is just too much (tirespin), and is it worth the expense?...I truly am not sure.
I will reiterate though that I have great respect for those who have built bigger engines. I will be building one.
However, my point was that for a street car, I'm not sure how much more power is needed over 25-28psi on E85?? With this I was seeing 4.7v (around 500hp)out of my maf whereas at the tracks elevation I only saw 4.3 and trapped 118(true 400+) . Personally I have always pushed the boundaries (driving an 8 second street car to work BITD). If I were concerned with better low rpm performance rather than using anti lag I'd put on a gt30r and gain low rpm torque.
So I just don't really get it.......there is a point where too much is just too much (tirespin), and is it worth the expense?...I truly am not sure.
While I do think your particular results are uncommon, I fully agree there is no rational justification for building a 3 liter for a street car. I suspect many folks who say they want X horsepower have not actually been in a 951 making even 300 or so to the wheels. My old 2.5 made over 350, and had more power than the car could handle really, with a great sling shot power delivery. Of course, rational thinking is not the benchmark here, which is why I'm currently assembling another 3+ liter with significantly more ambitious goals than my current 3 liter.
11-30-2011, 06:00 PM
#58
Race Car
I can't wait to see what you are brewing up. Watching your 3l build was like watching a concourse resto (just bigger).
I'm not sure if I'll ever be driving out to California but I'd love to meet up sometime.
I'm not sure if I'll ever be driving out to California but I'd love to meet up sometime.
11-30-2011, 07:06 PM
#59
Rennlist Member
@blown 944
Have you ever had any HG issues with those pressures and are there really any evidence that shows that ORING \head work against it . We just took out my widefire gasket that looked almost new even after 2 months abuse at 26psi "nurburgring,autobahn,DD,etc."
Have you ever had any HG issues with those pressures and are there really any evidence that shows that ORING \head work against it . We just took out my widefire gasket that looked almost new even after 2 months abuse at 26psi "nurburgring,autobahn,DD,etc."
11-30-2011, 08:29 PM
#60
Race Car
Well, I've had a total of 3 hg issues since cranking up the boost really high. 2 of which were the gaskets that were on each car when purchased. The third was after approximate 2 years of abuse. All three times what I saw was deterioration of the composite material and that allowed the fire rings to slide past the top of the cylinders.
In regards to the o ring in conjuction with the widefire is that it will stabilize the sealing area witting the o ring preventing it from sliding. In addition I'm experimenting with the BMW blue coolant to see if it helps to retain the integrity of the composite material.
The reason I'm putting this effort into using the composite gaskets is from past experience with copper and mms gaskets on my old sbc race engines. I made good power and had far less issues with coolant leaks in comparison to my counter parts. These were detonation prone nitrous engines
In regards to the o ring in conjuction with the widefire is that it will stabilize the sealing area witting the o ring preventing it from sliding. In addition I'm experimenting with the BMW blue coolant to see if it helps to retain the integrity of the composite material.
The reason I'm putting this effort into using the composite gaskets is from past experience with copper and mms gaskets on my old sbc race engines. I made good power and had far less issues with coolant leaks in comparison to my counter parts. These were detonation prone nitrous engines