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YOUR RESEARCHTested My New 3.4/3.6 Motor Yesterday....
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With mine we just installed a 3.6 crank and rods into the existing 3.4 cases.
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Run original aos and it started throwing up white smoke
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When I first built my car 3 years ago I ran the original AOS and it started throwing up white smoke on startup almost immediately.
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The Dyno at the track was about 5% off of Dynojet used as the baseline (we tested my car too so we have the reference).
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NASA has tested all of those units pretty comprehensively.
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Suggestion
As a side note, since I own my car forever at this point some years down the road I might make a project to replace my 1999 DME with something newer, and then maybe I can bolt on some 3.6L heads to my "new" Nikied 3.6L engine.
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I suppose one advantage of doing it this way might be that you wouldn't also have to replace your DME (and immobilizer/etc.) because the 1999 3.4L DME v5.2.2 doesn't know how to deal with variocam plus in the 3.6L heads.
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In addition to already owning the heads, running the 3.4 allowed me to retain the twin chamber motorsorts AOS (with some trick plumbing by Vision) that does not fit on the 3.8, and run the IMS from my old 3.4.
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In addition to already owning the heads, running the 3.4 allowed me to retain the twin chamber motorsorts AOS (with some trick plumbing by Vision) that does not fit on the 3.8, and run the IMS from my old 3.4.
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Had a 3.4 converted to 3.6 similar to Logray's build, just not nearly as intensive. With mine we just installed a 3.6 crank and rods into the existing 3.4 cases. There's some minor machining involved, but it's really a very simple install. Cleaned up and slightly decked the OEM 3.4 heads & cams, and took it to Willow Springs. I kept out of the throttle for the first few minutes but gradually opened it up taking it higher into the rev range.
I was running with a friend in his new 3.8 Cayman S with 3.4 heads, etc. He dyno'd at 355 rwhp and I haven't dyno'd mine yet. I'm 200 lbs lighter and we were perfectly matched down the straight so I'm estimating I'm around 290 rwhp. My previous all stock 3.4 was around 270. Laps times on 6-10 HC'd slicks were in the high 1:26's, I've been to 1:25:5 on stickers so that was encouraging. I'll have dyno results Feb 11th when we have a dyno out to WS for POC's season opening race weekend. It revs up really nicely....
290? Hmmm. My math says more like 310+ RWHP. Sandbagging already?
Simply, since measured acceleration is the same, F=ma shows that the resultant force required at the wheels is proportional to the mass ratio of the two cars. So F1/F2 = m1/m2, and since m1 is 8% (measured) greater than m2 then F1 must be 8% greater. Since we know my measured TQ is (was) 287 lb-ft in the tested RPM range we know that your TQ must be ~ 287/1.08 or 265 lb-ft in that same range (assuming the same effective gearing which we also calculated to be true - using ratios and tire diameters).
Convert this Tq to HP at say 6150 RPM where your engine is likely still making max Tq and the math says 310 RWHP. Extrapolating out a bit further to say 7000 RPM and assuming a 10% drop in Tq at the higher RPM (from other data) yields a potential of 318 RWHP.
Now, my engine was tested at seal level, so we are both likely to see lower numbers at altitude, etc.
Also, I need to choke back this engine to make GT3 class weight (will probably run it at about 315 RWHP), but will hopefully be able to keep most of the tq. It now looks like you may be in that same boat my friend.
See what you get for throwing my HP numbers out in public
This should be a great season JR.
Cheers,
Sounds like a great day. Sorry I missed it. Still shaking down my new ride.
LNE 160 thermo
replaced oil plug with Mangetic plug
SS Brake lines
New 997.2 GT3 Shifter
25% from 50% Coolant ratio
Water Wetter
Replace fixed 3rd Brake light and add grounding to fixed 3rd brake light
Paint welded cage areas under the car
Off to Chuckwalla this weekend.
Need to dyno soon. Hope to run with you soon.
HAH, fun read above. LOL.
Randy: used parts probably not as much need for a break in.... but if it's
new
crank, rods, bearings, and bearing carrier, or even just new bearings yes they do have a break in. Certainly if the pistons were re-ringed they require break in.
All of the calculations are done using RW HP & TQ so the driveline losses are not relevant.
The two cars also use same tire type/width and have similar aero profiles.
Cheers,
The 3.6L crankshaft is stronger and bigger than the 3.4L, and also has a longer stroke.
I suppose one advantage of doing it this way might be that you wouldn't also have to replace your DME (and immobilizer/etc.) because the 1999 3.4L DME v5.2.2 doesn't know how to deal with variocam plus in the 3.6L heads.
As a side note, since I own my car forever at this point some years down the road I might make a project to replace my 1999 DME with something newer, and then maybe I can bolt on some 3.6L heads to my "new" Nikied 3.6L engine. :-) wait... that probably wouldn't work.
Exactly. I already have a very minimal wiring harness (5 circuits) but a complete 3.6 would provide more WHP than I can use. At 290 rwhp I can stay at my current minimum weight w/driver of 2610lbs. We'll see where it dyno's in 2 weeks; hopefully my fellow GT3 competitor's calculations are optimistic on his part (he'd just love for me to carry more weight).....
100 octane.
No real advantage to the 3.4 heads other than I aready owned them. The M97 heads for the 3.4 and 3.8 are identical (same valves, cams, etc) except for the AOS ports (AOS on the 3.4 sits on the head).
In addition to already owning the heads, running the 3.4 allowed me to retain the twin chamber motorsorts AOS (with some trick plumbing by Vision) that does not fit on the 3.8, and run the IMS from my old 3.4.
Cheers,
I did, and I still do not see your point.
JR went from ~ 270 RWHP or so with the 3.4 to some new number with the 3.6. He hopes it is 290, I estimate it is closer to 310. This is a ~ 35-40 HP bump which is not unreasonable from a new engine, with 0.2 L more dispacement and decked heads (increased compression).
My engine was a 3.4 M97 and made ~305 RWHP. The new engine is a 3.8 and made 355, so ~ 50 more HP from 0.4 L displacement increase. The heads were already decked in the 3.4 so no added/similar gain there.
So I still do not see anyhting that claims 0.4 L = 85 HP.
Please help me understand.
Cheers,
I think he missed that you started with an M97 engine with dual variocam, a 7.8DME and 305HP.
thus +40HP, not +85HP (off 270HP of the 3.4L M96 w/ 5.5.2 DME)
or I'm confused .....
Mike
Doing some googling on the 3.4 power, your 270WHP looks reasonably healthy to be honest also, so I can see how you get to 29X range for the 3.6 (on the basis Porsche are reasonably honest about their ratings at the crank). I might even put my stock C4 3.4 on my flatmates dyna pac dyno to see what it does. Im am assuming mostly stock in my thoughts, increasing dynamic compression by a bit would blow it out of the water...
Different cars and different engines (and different heads, programming, etc).
355 - Cayman S with M97 - was 305 at 3.4, now 355 (+50) with 0.4 bump
270 - 996 with M96 - was 270, now 290 (+20) or 310 (+40) with 0.2 bump and shaved heads.
Comparing the 270 of the M96 to the 355 of the M97 makes no sense. I understand your math, but it is like comparing a 5.0 at 350 HP from one manufacturer and 5.0 from another and saying they should be the same. The M96 and M97, while similar are different and do make different power.
I am really not sure what you are trying to prove. Even in bold. Really, I am not trying to be a jerk, I do not get it so please explain (don't just tell me to re-read).
Which number are you suggesting is wrong? The 355 or the 270?
Cheers,
Not sure. I know it fits on some 996 years and not others. Given that your car is a X51, and both the pump and the AOS were supposedly developed for Daytona, there is a good chance I suppose.
I would stop Vision Motorsports or give Dwain Dement a call and ask him. They ran these cars in Koni GS years ago so I suspect that if anyone will know it is him.
Cheers,
I'm not sure but I honestly don't think you need it. I race with several X51 powerplants in 02' cars and they've never had a AOS issue. When I first built my car 3 years ago I ran the original AOS and it started throwing up white smoke on startup almost immediately. I changed it and it's been fine up until I built this new motor. Of course I put a new one in for this motor as they're only $110. (+/-). The motorsports version is $600....
You'll know when you need one as the white smoke on startup is highly visible. I wouldn't worry about it until then.
PS: Let the car idle a minute or 2 after a hard session to allow the vapors to make their way back thru the system to the sump....
No I am not.
I am using the physical acceleration of one car with known Tq (independent of car or engine type) to show how much Tq is required to accelerate a car of lesser mass at the same rate. This is a simple physics problem (with many assumptions on drag, shift points, etc.). Newtons 2nd Law is just that, a law.
I do not see how you have proved anything. You have only made a claim. Please explain your proof?
Nor have I proved anything for that matter. I have only calcuated what would be the required Tq match acceleration (and backed into HP). We really wont know anything until he puts the car on the dyno. My estimate is ~310 RWHP and ~ 265 RW lb-ft (the Tq is what is used for the calc and Hp will vary base on peak RPM that is currently unknown).
This all started with me taking a good natured poke at a buddy. I guess I now know why you are hidng behind the rock wall icon.
Cheers,
Yes agreed, your logic because of all those factors like drag prove you are inaccurate. Yes, all I did was make a claim, with proof, once again, evidenced in the comments made by the OP. Clearly you think you are the big tool on campus, and dont like being proved wrong, which is fine, good luck
Im not hiding, im right here... not going anywhere
You have not proved jack squat. Neither of us has. I am only doing math and you are guessing based on some assumption/expectation of performance (from experience?).
I happy to be proven wrong. Really. And the dyno may or may not do this. The math is what it is.
Tool? Interesting that you have started name calling. I was just trying to have a debate.
Cheers,
The biggest difference this combo has proven to make in my experience has been added torque and torque / throttle response from a lower RPM. These engines respond very well to added stroke, but not as much as the same displacement increases that are created by larger bores.
Of course, there are no rules and every engine assumes the character of it's designer and builder and thats what makes it fun.
Hope you're right Jake. I only want 280-285 whp but loads of torque. It felt really good off the corners on it's test day, I'll post the dyno results when completed in 2 weeks.....
So true... "Horsepower sells cars, torque wins races"
My track car, the AE86 in the avatar only makes 175WHP (from a 1.6 though), but have to rev it to 9,500 to get much out of it!
Road Racing is about getting off the corners more than anything else. Many times I have upped torque, or moved torque around within the RPM range and have gone faster, even when some of those changes made less peak HP. Throttle response is key to getting off the corners which always increases trap speeds on the straights following those corners. Having a super responsive, predictable engine is what separates the men for them boys.
If I see a peak HP gain, I also demand that that gain increase the average power under the curve all the way up to peak, else I don't consider a change to be a success. I also want to see a torque increase across the board.
Too many people over rate HP and don't understand that it is merely a formula that uses TORQUE and RPM to be calculated. Without TORQUE, HP Can't exist.
If I hand someone a dyno graph and I see their eyes wander to the peak HP number, I immediately shake my head and know that I am wasting my time dealing with them.
I think you will see positive benefits on the track from this, because these cars are heavy and their gearing also demands torque. Just remember, the 3.6 cranks are the weakest of the bunch. I hope you had it magna fluxed :-) (I even magna flux brand new Porsche cranks!)
Yes crank was magna fluxed, knife edged, and polished.
BTW my plan for restricting in the unlikey event I do have 300or more rwhp is to use a Boxster 2.5 throttle body which as you know steps or tunnels inward. I've never measured and compared the inner diameters so I don't know how much of a restriction it is actually is, but significant I'm sure.....
Dyno'd this weekend at 302 rwhp with 285 lbs. of torque so my geeky Cayman friend was correct (or damn close). i restricted the intake with duct tape until we got it down to 292 rwhp which is where it will stay for the year. I won't have the torque numbers for the lower, restricted settings for a few days as his printer went down at the end of the day but I don't think it was significantly less.....
This was on a Dyno Dynamics 4500, on a Dyno Jet it would be higher....
If you are taking a shot a me, have at it, but the calculations were correct.
The Dyno at the track was about 5% off of Dynojet used as the baseline (we tested my car too so we have the reference). So, if adjusted for testing delta the math was nearly dead on (302*1.05=317).
There were a couple of other cars that we know about what they should make (other 3.8s) and they came in right where they should (340 unrestricted, so 340*1.05= 357 and equal to my engine)
We jokingly estimated 310 just to throw in some fudge factor for assumptions, etc. Considering the power bands are a bit different and RPM used were estimate I am very surprised it was that close.
JR, is that 285 right? If so, and the 302 is right, is says the engine is making peak HP at 5560 RPM, which seems low. Please take a look at the chart again and verify the axis.
In the end we made the necessary adjustments to HP and weight of various cars and had some great racing. On Sunday, positions 1,2,3 in GT3 (where we run) came across the line nose to tail (maybe closer) after 15 laps. Other than one questionable pass attempt/alleged door close in T1 the racing was quite pleasant ;-) We can look at the video from my rear facing camera and discuss.
Cheers,
Will they should be for all the work you've invested. Also remember that this was on a Dyno Dynamics machine. NASA adds 10% to their results to equal the results on a Dynojet. Let me know the numbers when you dyno please....
It's all black science anyway.....
NASA has tested all of those units pretty comprehensively. They came to the conclusion that the Dynojet was the most prevelent unit across the country and made that their standard. They have added 10% premiums to the Mustang and Dyno Dynamics units as they've proved to provide lower results. The Dyno Dynamic operator we have out for our POC event last weekend says he's more like 15% lower than a Dynojet. YMMV....
When we race dynos the numbers will really matter. A dyno is a tool, but it cannot be used solely for comparing performance. A dyno cannot measure throttle response and many other aspects of engine performance experienced at less than wide open throttle, where the engine will spend the majority of its time. The only motorsport that I have experienced that only uses WOT for the entire duration of the competition is drag racing. How many 911s do we see at the drag strip? When I go with my sponsored drag car (620HP aircooled VW) I generally never see a single one, even at the local track for test and tune or Friday night grudge matches.
I have effectively tuned an engine for my Wife's Land Speed car and lost 6HP at WOT on my dynojet chassis dyno. The result was a car that picked up 6 MPH and set 4 records in a single weekend. Prior to this the car made more HP and even more peak torque, but we were .5MPH from even setting a single record on THREE previous attempts at different events earlier in the year.
Peak numbers don't mean anything to the guy that wears a hat like mine. Where the concentration of power is means everything.
Peak HP numbers are only good for selling engines
to people that don't understand that peak numbers mean very little and further most of those people also don't understand that HP is achieved through torque multiplied by engine RPM. If I hand a dyno graph to someone and they look at the peak numbers first I usually just give up.
yup... most guys don't get it... peak torque and hp are all they look for... when people look at say Cayman R and comment it's only 10hp more it make me chuckle... that engine has more under the curve and hp is only one metric that makes a car go fast
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