Eric Clements wrote:
I wouldn't put much time/$ into that build just yet, as that's not what I remembered sending to the SEB.
Glad to hear that Eric. I don't mind a little creative thinking, but promoting a 39 year old car by listing it on the same line for update/backdate as a late '80s turbocharged car doesn't seem... healthy for the class.
I can't help but wonder how excited 240Z owners are at the prospect of a 2300 lb car with that kind of power, virtually an SSM FrankenZ in BSP livery. Hopefully a correction is listed quickly...
Mike
They are not that different of cars. They have the same basic L series motor. And its early 80's not late 80's. Only difference in the years that you would want to run is 8. 1973 240Z and a 1981 280ZXT motor.
Besides since its inception there has not been a more successful car in auto racing as the 240Z, tribute to its design that people can still make it competitive when it is so long in the tooth!
And Art's smoking crack if he thinks he can get 325 whp with the stock exhaust manifold, turbo, and wastegate.
From lots of builds on HybridZ.org you're just generating heat with that little T3 at anything over 250hp and the stock wastegate is unpredictable at that power level. Don't let Art's optimistic post scare you guys. A 250hp, 2,400 lb 240Z is what's needed in BSP. Its probably the best car/engine combination to go up against the Evo.
John Coffey wrote:And Art's smoking crack if he thinks he can get 325 whp with the stock exhaust manifold, turbo, and wastegate.
From lots of builds on HybridZ.org you're just generating heat with that little T3 at anything over 250hp and the stock wastegate is unpredictable at that power level. Don't let Art's optimistic post scare you guys. A 250hp, 2,400 lb 240Z is what's needed in BSP. Its probably the best car/engine combination to go up against the Evo.
Yeah, maybe but it's also a difficult combo to put together and a difficult car to find in unmolested form, so it's unlikely the SPAC would encourage people to need to. The action committees tend to like cars people can get their hands on, just look at the Type R's plight.
Steve Ekstrand wrote:A torquey 250hp 2400lbs rwd sports car sounds like a cool car to me.
Mike Simanyi taught us a lot of about just this topic in SM this year. Its not who has the most HP, its all in how you use it.
Oh man, Mike.. are you telling people you're just making 250hp?
My information might be old, but in SP the turbo and exhaust manifold were considered one unit as far as the update/backdate rule was concerned. The issue with the T3 on the 280ZXT is on the compressor side. You can get the exhaust flow into the turbine just bitchin' but you'll still just be making heat on the intake side.
The stock turbo is a Garrett T3 with a 60 trim. Its optimized in these applications for mid-range power and is at 75% efficiency on the L28 at 3,250 rpm. Its all in at 4,500 rpm. At 16 psi of boost (the largest boost level I'm heard of on stock pistons) its at less then 50% efficiency near redline (6,500 rpm). This is not a big power turbo.
I don't know, in ST classes you can use a tubular header on a turbo car. Zs could be different. Also in SP, the turbo / engine combination needs stay as originally offered.
Rick
Last edited by Richard Jung on Tue Nov 24, 2009 12:49 pm, edited 1 time in total.
John Coffey wrote:My information might be old, but in SP the turbo and exhaust manifold were considered one unit as far as the update/backdate rule was concerned.
Eexhaust manifolds are free in SP. The Turbo and the Engine are also one unit as far as UD/BD.
Exhaust manifolds and muffler systems are free, except that they
must be quiet and terminate behind the driver. Exhaust heat
shields may be removed. Rear- and mid-engine cars without
exhaust headers/manifold systems may use any exhaust system
that meets the requirements of 3.5. This permits the removal of
“heater boxes” in order to install headers on such cars.
It came down to a debate a while ago about what a turbocharged "engine unit" is (was) in regards the update/backdate rule. The results were that the turbocharged engine unit included the exhaust manifold and turbo. It might have been changed in the interim but I don't see that reflected in the SP rule book that I have.
John Coffey wrote:It came down to a debate a while ago about what turbocharged "engine unit" is (was) in regards the update/backdate rule. The results were that the turbocharged engine unit included the exhaust manifold and turbo. I might have been changed in the interim but I don't see that reflected in the SP rule book that I have.
Nothing in the SP clarifications section about turbos, there is also nothing the automotive definitions section, so i'd say you're good swapping the manifold out, unless an immediate effect fastrack came out this year. There would also be a few cars at nationals that were very protestable if this was true.
Exhaust manifolds are free in SP, even on turbo cars.
You can also switch to forged pistons in SP provided their weight and other dimensions match the stock units.
Cylinders may be rebored to no more than .0472 in. over standard
bore and the appropriate standard oversize piston may be
substituted. This overbore dimension is an absolute limit; no
additional tolerance is permitted to accommodate wear. Cast or
forged, non-stock pistons of the same dimensions and configuration
as original equipment pistons may be used. Additionally
the replacement pistons must be of the same weight or greater as
the original equipment pistons. Replacement pistons must
match OE piston configuration exactly including quench area.
The allowance for the use of aftermarket forgings vs. OE castings
does not permit alternate piston dome designs. This allowance
does not permit alternative ring configurations.
John Coffey wrote:My information might be old, but in SP the turbo and exhaust manifold were considered one unit as far as the update/backdate rule was concerned. The issue with the T3 on the 280ZXT is on the compressor side. You can get the exhaust flow into the turbine just bitchin' but you'll still just be making heat on the intake side.
Not sure about SP rules in relation to turbos but strictly engine-wise, it sounds like cold-air intake and some really efficient intercooling would be prime considerations in this case.
John Coffey wrote:The stock turbo is a Garrett T3 with a 60 trim. Its optimized in these applications for mid-range power and is at 75% efficiency on the L28 at 3,250 rpm. Its all in at 4,500 rpm. At 16 psi of boost (the largest boost level I'm heard of on stock pistons) its at less then 50% efficiency near redline (6,500 rpm). This is not a big power turbo.
I'd say for autocross, you want the faster spool-up of the smaller turbo anyway and don't care too much about the top-end. You may suffer a bit on the longer straights but make up the difference everywhere else. Like Steve said regarding Mike's SM car.
John Coffey wrote:And Art's smoking crack if he thinks he can get 325 whp with the stock exhaust manifold, turbo, and wastegate.
From lots of builds on HybridZ.org you're just generating heat with that little T3 at anything over 250hp and the stock wastegate is unpredictable at that power level. Don't let Art's optimistic post scare you guys. A 250hp, 2,400 lb 240Z is what's needed in BSP. Its probably the best car/engine combination to go up against the Evo.
wastegates are also open in SP. we can out octane and out cool pretty much any turbo outlet heat issues regardless of compressor efficiency. The power will be limited by exhaust housing and camshafts. Which model T3 turbo are on these cars? 325hp from a turbo'd 2.8L engine seems like a low ball estimate to me...whether the motor stays together is a different question though.
John Coffey wrote:And Art's smoking crack if he thinks he can get 325 whp with the stock exhaust manifold, turbo, and wastegate.
From lots of builds on HybridZ.org you're just generating heat with that little T3 at anything over 250hp and the stock wastegate is unpredictable at that power level. Don't let Art's optimistic post scare you guys. A 250hp, 2,400 lb 240Z is what's needed in BSP. Its probably the best car/engine combination to go up against the Evo.
wastegates are also open in SP. we can out octane and out cool pretty much any turbo outlet heat issues regardless of compressor efficiency. The power will be limited by exhaust housing and camshafts. Which model T3 turbo are on these cars? 325hp from a turbo'd 2.8L engine seems like a low ball estimate to me...whether the motor stays together is a different question though.
No John's right, you have to remember this is a 40 year old design on the motor. Single cam two valves per cylinder and it is not a cross flow head, have lots of problems with heat in the intake. Also stock injectors are only 180cc and the stock throttle body is 53mm.
Art Rinner wrote: Also stock injectors are only 180cc and the stock throttle body is 53mm.
both are free in SP. It's pretty much anything you can do by changing a or tuning a carb you're allowed to do to a fuel injected motor, so AEM computer and 700cc injectors with E85 or MS109.
Art Rinner wrote:
No John's right, you have to remember this is a 40 year old design on the motor. Single cam two valves per cylinder and it is not a cross flow head, have lots of problems with heat in the intake. Also stock injectors are only 180cc and the stock throttle body is 53mm.
nothing an intercooler and e85 and more boost can't fix. custom intake with 75mm TB, water injection, some ID1000 injectors. the only thing you need to keep is the long block and turbo
The guys on HybridZ.org have done all the upgrades listed above and more (cams, headwork, higher compression forged pistons) and the horsepower numbers stall at around 250. A couple have gone to around 275 but have had detonation issues even with 24 x 12 x 3 IC cores and methanol injection.
John Coffey wrote:The guys on HybridZ.org have done all the upgrades listed above and more (cams, headwork, higher compression forged pistons) and the horsepower numbers stall at around 250. A couple have gone to around 275 but have had detonation issues even with 24 x 12 x 3 IC cores and methanol injection.
it's a 35lb/min turbo looking at that compressor map, so it should make 350hp with SP allowable mods. My guess is the forums don't have anybody dropping the kind of money on stock turbo builds that they do on turbo swaps, at least that's how it is on the evo forums.
Absolutely. You can 300+ on stock internals (for a little while) with a different turbo. Electramotive pulled 700+ in race trim and over 800+ in qualifying trim with lots of extra work and OS Giken made over 1,000hp on some of their drag cars in Japan. None of that has ever happened with the TB03.
BTW.... Bo's car (the example cited above) was a T3/T04E that did a theoretical 45 lbs. min. @ 20psi which is about 30% more then the TB03.
BTW... I just looked in the 2011 rule book and the 240Z and 280ZXT are still on the same line. Sent a letter to the SEB to see if they screwed up again.
