Tankman's Turbo

[jbl930]

I really don't remember as it was all a bit of a blur after the power curve shot off the top of the monitor screen.

 

Anyway, with all the skepticism that the car could actually pull those figures based upon the information there is for the modifications that have been carried out on the engine, I have to assume that both the 500+ dyno runs were flawed. I have no idea how the figures on the dyno were so far removed from what seems to be a realistic output from my car. Especially as everyone else on the day had a readout which was commensurate with their expectations. I was expecting around 350BHP, bearing in mind that the last 911PW article on the car had guestimated the output of the car at 380BHP. Having spoken at length to Stuart Paterson, he thinks that 380 - 400BHP should be a realistic figure to expect from the motor when it is properly set up.

 

I wonder if Chris at Linden can explain the improbable reading from the dyno run?

 

 

I was with Chris yesterday, he remembers your car well. He thinks the run was legit, and after looking at your graph i can't see any reason it would be over 100bhp off

 

 

Usually when a dyno over reads there is a good reason, look at this graph, the intake air temp is showing 240 which will give a huge correction factor, and is totally bogus, probably reading over 100bhp too high

 

 

The barometric pressure seams a tad on the low side, you would usually expect to see between 100 to 103 so it's not unrealistic, but even if that was off by a little it would not equate to 100bhp over, maybe 30 at best. Your intake air temp may also be a tad high, but only very slightly, maybe another 10-20bhp? I would say your car was WELL over 400 based on the info, it may not hang onto all that power on a long VMax style run, it would depend on your intercooler etc.

Chris also said you had a big turbo on there from what he can remember, can you tell us which turbo it is? And do you know what boost level? You may have had a sticking wastegate and boosted higher than normal? Shame we can't see your graphs showing fuel and boost, it would tell us a lot. Chris said that dyno is now in Germany, and the runs will still be on the system, give him a call and see if he can get copies for you

Edited December 4, 2009 by jbl930

[Tankman]

Hi Jon,

 

I'm interested in exactly what spec your engine was/is in, it seams you've got head sealing rings in there, was everything in order with these when you stripped it down, did you have any broken piston rings? I'd love to know how they managed to safely fuel that engine for 1.4bar with a turbo that big. You must have had an extra fueler, either a device using the cold start injector or a 7th injector!?

 

Wish I knew! There was every chance that the car was running lean on full boost.

 

Do you have the dyno sheet that shows your fuel curve from that WRC day? Would be great if you have fuel and boost!

 

No I don't think I have and not sure that they were provided? Anyone else know? JG?

 

When i was up at WRC not long after you guys, Chris showed me your graph, in fact he printed it off for me to take back to 9M with the crappy dyno pull of my "supposed" 500bhp 930. I didn't ask too see the boost and fuel graphs. As Chris still has the same dyno up in Northampton I wouldn't be surprised if he still has the file, he went straight to it when i was there so maybe he's kept it as a reference? It's an impressive run for a CIS car!

Do you know what tubo you have? It doesn't come on boost until 4000rpm so it is bigger than a K27, my guess is a K29 but it may even be bigger than that if you are making 510bhp at less than 1.0bar?

 

I am pretty sure that it is a K27. Previous post should help calm the furore over that dyno printout.

 

Also pleased you're taking it to Stu to get set up, it'll be magic when you get it back, i wouldn't be shocked to see that turbo start spooling 500rpm sooner, and make more power! Great work so far

 

Thanks Jon.

 

What you have to bear in mind is that the car had lots of money lavished upon it when it was in a previous custodians charge. Lots of money doesn't always equate to a labour of love and some of the stuff that has been done to the car before it became mine has been of dubious and very questionable quality. That is very evident from some of the photos on this thread. Consequently, because of the number of people that have owned the car since Jeremy Wolff, some of which have obviously not been true enthusiasts and have neglected the fact that this was a supercar in it's day and needs the time, attention and money that supercars demand.

 

I think what has gone on previously should now have a line drawn underneath it and a new chapter opened. As you all know from the pictures on this thread, with a new crank, shells, piston rings etc. the car has a new bench mark to set and I will be pleased if reaches a cast iron 400+BHP when Stuart has breathed his magic on the motor.

[johndglynn]

No I don't think I have and not sure that they were provided? Anyone else know? JG?

Yes mate, we got some print outs. Pretty sure I have a pic here of us all looking at yours very carefully!

[Richard Bernau]

Tank - I wasn't really doubting anything, just not understanding it. All the other numbers were spot on that day, so no reason to doubt it.

[stup]

Would have been interesting to what boost pressures were run at that time when on that dyno.

Even if that figure is not far away,the fuelling in someway must have been modified or you would have ran out of fuel and detonation would have occured in my opinion..I will find out soon.

Above 400 flywheel bhp and you well and truly need to alter the fuel system to achieve enough fuel, then when you do have enough fuel, controling it all then becomes a problem,, this is where the hard work and time is spent...Finally once the fuel is correctly controlled throughout the whole rev band,these engines really do perform night and day!!

 

As we all know most bhp figures are only an estimate with some more accurate than others,, As Jon has mentioned previously, timing gear is as good as anything for power estimates, especially when you see some of the figures put about.

 

From what mods tankman has mentioned the car to have,running 1 bar boost and all depending on quality of previous work , the figure i roughly qouted to "tankman" was at the "rear wheels" which you could calculate to nearer 420-440 "flywheel" bhp....Again these are only estimates and i am sure his backside on his seat will prove the gains as good as most dynos.

Edited December 9, 2009 by stup

[jbl930]

Are you going to run 1.1bar with your engine Tank? You have the head sealing for it and you'll have the fueling set up right. Did you fit stronger rod bolts and head studs, ARP or similar? I would guess the head studs would have been upgraded when the head sealing was done by the previous owner, would be good to know what you have in there for peace of mind.

At the start of the thread you mention SC cams, were they the same as what was already in there? I believe the SC is a good all rounder, but lacks top end compared to the 964 cam, you gain in the low end though so it's a fair trade and i guess on the street you use the low end much more than the top so probably a wise choice.

I also noticed your turbo was clearly rebuilt, and the tag shows an AET job, they are pretty good with giving out info, if you call them and ask your turbo spec they will tell you, just give them the details off the tag and remind them of the job, date etc. I can't imagine it's just a stock K27/11, at the very least it'll be a hybrid, probably a K27/29 otherwise you'd have been on full boost by a little over 3k. The dyno figures may well be skewed, but where the torque starts to ramp is a dead give away of turbo size.

 

Stu, it's like getting blood from a stone gathering data-logged performance data, it's a great yard stick for power estimates. Chassis dyno's vary so much they are mostly useless! A 60-130mph run requires no skill, it's not hard on the car, and it's by far the best comparison tool.

Most of the good magazine tests do this now with modern cars, for instance the new Nissan GT-R does it in 10.69 seconds, or some of the older stuff like the Ruf 993 TurboR which does it in 9.6, or an F50 that does it in 9.6 etc... I mentioned in another thread, i have an AX22 that i'm happy to lend to turbo owners that want to log some runs, a great start would be a bone stock 930

[jevvy]

Most of the good magazine tests do this now with modern cars, for instance the new Nissan GT-R does it in 10.69 seconds, or some of the older stuff like the Ruf 993 TurboR which does it in 9.6, or an F50 that does it in 9.6 etc... I mentioned in another thread, i have an AX22 that i'm happy to lend to turbo owners that want to log some runs, a great start would be a bone stock 930

 

And what does yours do it in

[jbl930]

And what does yours do it in

 

 

Mine isn't a fair comparrison with other 930's really, being twin turbo and higher compression. The best run i've done so far was 7.53, but most come up in the higher 7's and the odd one in the low 8's. It will be slower again now with bigger wheels, probably low/mid 8's? I picked my car up yesterday after an engine rebuild, heads rebuilt and stronger rods etc, as soon as I get the chance i'll do a run and see. With the new wheels it's geared for 205mph at 7000rpm :mad jg:

 

A good comparrison was with my old engine, around 400bhp, similar weight to as it is now and with the stock wheels, it was 10.96 with the graph showing it loosing power above 120mph. The engine was running rich in the mid range and too lean at the top, i don't doubt that with the right fueling i could have run closer to 10 seconds

 

[stup]

Yeah i am also suspicious of tankmans turbo being a standard k27 going by the graph,with sc cams and standard k27 7200 i see full boost well below 3k revs in 4th gear and around 3k in 3rd gear...the more info known the better for setting up tankmans beast and if he can confirm his heads are bolted down with arp head bolts or something better than the standard headbolts, 1.1 bar boost would still be pretty safe in my opinion although for longevity i wouldnt recommend much more especially if the car is going to be tracked quite often,even though he has good head sealing i believe too high a boost pressure can still potentially shatter piston rings..

Also maybe the car has had a modified fuel head fitted..as Jon has mentioned a few quick phone calls to turbo rebuilder and maybe last owners would be helpfull....

Jon was nice enough to let me borrow his timing gear for testin my modified 964 turbo and i came in at 10 seconds flat 60-130 although around that time my car had slight clutch slip because of a worn wastegate valve guide which was making the boost vary...i reckon i could maybe achieve late 9's at best although that is only what i estimate..the 964 turbo also weighs slightly more than the 930 so i estimate a flywheel 500 hp 930 to be around maybe 9.5 secs..whats your opinion Jon?

 

Yeah i am also suspicious of tankmans turbo being a standard k27 going by the graph,with sc cams and standard k27 7200 i see full boost well below 3k revs in 4th gear and around 3k in 3rd gear...the more info known the better for setting up tankmans beast and he can confirm his heads are bolted down with arp head bolts or something better than standard 1.1 bar boost would still be pretty safe in my opinion although for longevity i wouldnt recommend much more especially if the car is going to be tracked quite often..maybe the car has had a modified fuel head fitted also..as jon has mentioned a few quick phone calls to turbo rebuilder and maybe last owners would be helpfull....Jon was nice enough to let me borrow his timing gear for testin my modified 964 turbo and i came in at 10 seconds flat 60-130 although around that time my car had slight clutch slip because of a worn wastegate valve guide which was making the boost vary...i reckon i could maybe achieve late 9's at best although that is only what i estimate..the 964 turbo also weighs slightly more than the 930 so i estimate a flywheel 500 hp 930 to be around maybe 9.5 secs..whats your opinion Jon?

Edited December 10, 2009 by stup

[jbl930]

The run i showed above was done with my car (a 9M special at the time ...) that was supposedly 497bhp, but on the GForce rollers posted 416bhp, and when running badly 387bhp on Weltmeisters, probably a solid 400bhp. It was in a poor state of tune to be honest, and i do think if it was set up right it would have posted 10 seconds. The car weighed 1380kgs with a full tank, the run was with half a tank and me so roughly 1420kgs all in.

Lets say i'm getting 8 seconds now, my car is producing a lot more torque than a single turbo and that's where the acceleration comes from, i would think a genuine 500bhp single turbo CIS 930 would be high 8's low 9's, anything around or under 10 seconds is bloody quick!! A lot depends on the weight of the car, Stu i bet your 964 with you and fuel is not far off 100kgs heavier than a 930?

 

Sorry for taking the thread off topic Tank. As i'm already way off topic i may as well mention this, there is a simple tool on the net that gives reasonable predictions for 60-120mph (shame it doesn't give you 60-130), you need some data from the car though. Weight, Drag Coefficient, frontal area, gear ratio's, final drive, tire size, shift speed, weight of driver, and plot your torque curve from a dyno graph. It came out with an almost perfect number for mine. Gear ratio's are easy to find data for if the box is stock, a 930 has a drag of around 4.0 (some say 3.9), frontal area is roughly 15sq ft, the rest is easy. http://vlsicad.ucsd.edu/~sharma/Potpourri/perf_est.html

It doesn't replace actually doing a proper data logged run, but it will give you an idea

 

Is this kind of stuff interesting enough for a separate thread on here, or is nobody really interested? By the way, my 60-120 with the old 930 engine was 7.35, that last 10mph takes a while....

[Jammo]

Definately good and interesting enough for a seperate thread - been following with great interest.

Good work by the way.

Regards

 

Jammo.

[Tankman]

Just so you know, it wasn't me that made the modification to the thread title.

 

AET confirm it is a K27/11 which means, although I have a dyno print which shows 510BHP, it is unlikely that this is realistic or achievable from the technical responses and information I have received and on here from Jon and Stuart.

 

Head bolts are not standard, so ARP or similar and were part of the modification upgrades carried out at the same time as the sealing rings. Depending upon your advice Stuart, what do you think to set the boost no higher than .95 for longevity?

[stup]

Just so you know, it wasn't me that made the modification to the thread title.

 

AET confirm it is a K27/11 which means, although I have a dyno print which shows 510BHP, it is unlikely that this is realistic or achievable from the technical responses and information I have received and on here from Jon and Stuart.

 

Head bolts are not standard, so ARP or similar and were part of the modification upgrades carried out at the same time as the sealing rings. Depending upon your advice Stuart, what do you think to set the boost no higher than .95 for longevity?

it is common practice to run 1 bar boost on our engines without head sealing so 'with' your head sealing i see absolutely no reason why not to run 1 bar....yo possibly could run slighty more however i reckon due to the turbo you have it may drop to 1 bar up top revs anyway as that turbo usually runs out of puff combined with your other mods...Another issue is what clutch you have?..As much as 1.1 bar in my car with the standard clutch fitted,i start to see slippage......responding from mobile phone so excuse spelling errors

[Tankman]

Clutch is modified too. It is a race type clutch to go with the Patrick Motorsports gearbox fitted to the car. However, whilst out in it this week, I think I had some slippage. Don't think it was the tyres spinning up although it was very greasy. Having done 650 miles since the rebuild, was in the process of gradually incrasing maximum revs up to 4500-5000 which means the turbo was spooling up and I had an indicated 0.7 on the VDO gauge.

 

So, clutch aside, let's go 1.1 and see where that gets us.

[jbl930]

That's the spirit Tank... I would be very careful with that motor until you get the fuel sorted out, i melted a piston in a nice fresh rebuilt engine down to going lean on one cylinder, it's a tough pill to swallow as you can imagine!

I'm not sure a standard K27/11 will hold 1.1bar to the red line, but it'll give you plenty enough through the mid range. You'd be better served with a K27HFS to hold 1.1bar, in fact with a K27HFS you could run less boost for the same result which would keep IAT down and keep the turbo well within it's operating range. It would be a direct bolt on and you could off set the cost by selling yours, i know it's more outlay but that engine deserves a HFS...

[MrPerkles]

That's the spirit Tank... I would be very careful with that motor until you get the fuel sorted out, i melted a piston in a nice fresh rebuilt engine down to going lean on one cylinder, it's a tough pill to swallow as you can imagine!

I'm not sure a standard K27/11 will hold 1.1bar to the red line, but it'll give you plenty enough through the mid range. You'd be better served with a K27HFS to hold 1.1bar, in fact with a K27HFS you could run less boost for the same result which would keep IAT down and keep the turbo well within it's operating range. It would be a direct bolt on and you could off set the cost by selling yours, i know it's more outlay but that engine deserves a HFS...

JBL we require some videos of your car playing at VMax and generally going fast being as its Friday

Keep up the good work Tank looking forward to a spin in it sometime soon

Edited December 18, 2009 by MrPerkles

[Bertroex]

I mentioned in another thread, i have an AX22 that i'm happy to lend to turbo owners that want to log some runs, a great start would be a bone stock 930

 

I'm just catching up with this. Its cold outside, bit snowy, loads of cold air feeding turbo engines..... I have such a stock 930. Would it be interesting to see what these cars like stock, twinny's Tankmans, JBL930 etc can do?

 

Btw tankman, whoo mucho respect for bringing back that car to that specification!

 

Bert

[jbl930]

I'm happy to lend the AX22 to anyone who wants to borrow it, if you have a stock 4 speed and stock wheels 133mph is possible in 3rd, so just crawl along in 2nd at about 30mph or so, then when you're ready just floor it right up to near the red line, then change to 3rd and hold it up to the rev limiter. Will be great info to know what a bone stock 930 does it in I'm off to Thailand at the weekend so it'll have to be in Jan when i send it out, PM me your address or email me at jon@kigi.co.uk

 

HERE'S A VID of a run up to 183, you can see the AX22 on the windscreen. This was my first run so i let the 430 scud go as we went round the bottom corner so i had plenty of room if something went amiss. The car was stable all the way up to 187+, it's now geared for 205 with the bigger wheels. I bought a G50/50 yesterday, will have that on in the new year

 

We must start a 60-130 thread, can someone do that in the appropriate section, i'm not sure where to do it

[johndglynn]

HERE'S A VID

Hahahahahahahaaaaaa, that is totally awesome!

[REX]

Awesome

 

Calling VT, lets get a comparison

Edited December 18, 2009 by REX

[Tankman]

Primer

 

 

 

 

 

 

 

 

 

 

[Nige]

Exciting stuff, are you going for the same colours and appearance?

Edited January 25, 2010 by Nige

[Von Twinzig]

Awesome

 

Calling VT, lets get a comparison

Sorry chaps, missed this one.

 

Can't think mine will be anywhere near 180. My rev limit, final drive and rolling wheel circumference are all about as was so can't see my V- Max being any higher than stock, just my acceleration through the gears is faster than a NA 3.2 and Stock 930. Am I missing something?

[johndglynn]

They are painting all the front suspension blue? Would have been easy to drop the legs and mask the rest?

 

What is the final colour? Gulf?

 

Sorry for all the question marks, birthday boy

[jbl930]

Tank, hasn't your car already been resprayed? Or are these pics from a while ago?