I ran a 4.90 with only 750'ish rwhp.

 

Very encouraging Scott! I'll have some numbers by monday hopefully. Dyno'ing in about half an hour I'll update later.

 

Ok when are you coming to Toronto and driving my car?

 

LOL....after my broken wrist heals, buy me a plane ticket.

 

At the Mile, I had a brief discussion with Todd K. and he did mention that you can drive buddy Get those wrists healed brother.

 

Not going to ask about the broken wrist LOL

But your on!

hope we have a dry winter!

 

i want the first set, flash can be 2nd in line...

 

You are correct, there is no debate. The question was whether 4's has been achieved on a stock motor set up. I simply answered it. No reason to be so defensive. 997's are not totally different animals, more efficient yes, but not night and day. If someone wanted a stock 996 set-up to run 4.90's, Tym would get it done. He's just never been asked to build that set-up yet.

As for Switzer's standalones, they are all running well, at least the last time I spoke with Tym. He is using his own flash programming on lesser hp kits, but if someone wants the control the standalone offers for custom high hp builds, that's still the best solution out there. As I'm sure you are aware, Tym made over 800whp on a stock 997 motor without a standalone awhile back.

There is no "you guys" here....I'm not part of his shop. Just one of his many satisfied customers.

 

Good talking to you today Tony!

I'll throw this out for those reading who haven't spent any time tuning... Peak cylinder pressure is what you shoot for when tuning, that gives peak torque and thus peak power. If you put an engine under load on a dyno and diddle timing up and down you will see torque go up, up, up, level off, then drop, then detonation begins. That's IF you have enough octane to hit peak torque\pressure before detonation - boost and compression. Different fuels will work best at different ignition timing levels, nature of the beast. Peak torque is best BSFC BTW and if memory serves is also least timing. Timing is higher before peak torque, lowest at peak torque, then rises again after peak torque - part of that being because RPMs give less time for fuel to burn. All of this jacking with timing is to get the fuel to fully burn\expand at the "right" time to give peak cylinder pressure without having put so much pressure to it that it ignites on it's own like a diesel and creates detonation. If you retard timing too much and fire it way late the stuff is still burning going out the exhaust - hence Tony's comment about EGT. This is also GREAT fun for pre-spooling a turbo aka anti-lag. I've used this, nothing like having a W/G crack open to atmo at the starting line. Poor starter guy and the guy in the next lane both nearly crapped their pants - starter guy especially! This happens because the exhaust expands in the exhaust header instead of cylinder - it's like nitrous for the turbo. You can easily imagine the downsides however...

So what does this all mean? For starters if the biggest difference between one motor and the next is good rods\pistons and each are equally tuned well, and the stock one isn't pushed past it's parts capacity to withstand the forces, then NEITHER ought to make more power than the other or be less durable. Stronger parts don't mean more power, and if they're heavier it might mean less power. I say less because honestly I'm not sure, might just change the curve is all Anyone know for sure?

Frankly, from what I have seen and others have intimated here, "built" motors tend to have more issues. Clearances are sometimes wonky, rings might not seat, funky things like head studs have to be torqued, copper gaskets leak, blah blah. Within reason a good overbuilt stock motor is the way to go. If it's a crap design like say many Hondas then yeah it will die at lowish power but come on - just how poorly built is THIS motor? I've seen what the cranks on some of these beasts look like - works of art. The pistons are likely forged (okay not researched that). Rods, now there Porsche might have tried to save some money. So at what level do these parts really fail on a decent tune and not stupid boost? The number seems to be rising...

P.S. I mainly talked about timing. I would point out that diddling timing ALSO moves A/F some as the burn is more or less effecient. For fun put the motor the dyno under load and move A/F all around - surprise torque doesn't change NEARLY as much as it did with timing. "Lean" might be "mean" but I'll take timing over A/F any day and run my motor a little rich where it's a little cooler\less likely to detonate...

 

Thanks for clearing it up Jamie... and my point and only point is that I have not seen a 996tt run 4s...
As far as the 997s they are way more efficient... thus more power as same boost.... They already come with a fuel system stock for almost 800 rwhp... all it needs is a 5 bar...

If I was going to do it again I would do rods, some good working studs and a good install of the motor... thats it... leave everything else alone... then run 1.7 bar on 30rs and call it a day....
just my opinion...
mark

 

Mark, would you not at least consider some cams?

 

no because now your getting into heads... then maybe a port... some steel liners... bigger valves etc etc... where does it end...

rods+ good tune and 30rs with supporting mods= 800rwhp..

is extra 40K worth the extra 100 to 150 hp? look at recent texas mile results... the built motors are running 5 to 15mph more only... and some are $100K builds..

 

This thread is excellent. Think I might be selling some freshly rebuilt GT28s and ordering a set of 30s & water/meth kit!

 

I know it can be a slippery slope but is it not possible to simply swap cams and show restraint on the other things? Apples to oranges but on the Supra a cam swap when the airflow limit of the OEM cam was reached was 100WHP by itself! And not a nasty race cam either I will admit when I was preparing to do mine I bought a brand new head, had a brand new valvetrain built, and even had it ported so I understand the temptation - succumbed to it too! Wish I'd gotten to put it on, I was VERY curious to see how much more than 100WHP I'd get

Anyway, I'd agree that if the stock motor can make "enough" power that going crazy isn't warranted. Driving a beast that can't pass a gas pump, requires race gas, and wants to buck and snort sucks. Reasonable upgrades that don't result in peaky power curves and have good manners are worth something for mot folks. These turbos sound interesting for those reasons alone even if in the end they aren't at the tippy top. Makes for fun bench racing debating all the options though and it's nice to see more parts become available...

 

Ha I wish bro! Not quite there yet... but put me on the list.

What a great thread... and a big money saver for those that want and now can apparently have (safely) big power. Good shiat.