It’s common knowledge that for boosted cars 12.5 is the best a/f ratio

At 4.800 rpm it was 13.5 (to lean imo).

Now in your after dyno it shows 11.4 at that rpm level (and I don’t see it go below 11, so don’t understand why you say 11-10).

Then add a more aggressive timing, the hot boost of the eaton, and maybe there was some heat soak as well (or do you know the intercooler temperature of that run?), you increase the chances of detonation, or at least I thought that that was common knowledge as well. My experience with lean mixture showed a lower output, but all depends on many parameters…

You even yourself have observed this happening when you compared that particular base run with one where you had meth running.

Now add the odd curve and late start of the operator to add power I guess it’s clear that there were several things not right with your base run.

Its useless when you want to use this dyno as a base to compare what a stock car could gain, period.

Now does the new Gen V blower, ported TB, elbow, and intake manifolds, exhaust modification, smaller upper pulley (1.8 psi?), larger intake and last but not least the larger MAF and optimized air filter make a difference? Of course, I have no doubts there, but I can't estimate how much extra it could give on a good running car as a basis.

 

Yes, I agree with your above quoted post that the data leaves "wiggle room" to estimate higher or lower. I think my logic is sound as you think yours is sound.

I think the most honest, accurate measure will be an actual performance down the 1/4 mile, especially MPH as it cannot lie on the high side. Do you agree? If not, why- SPECIFICALLY.

I think what can be proven is that whatever times I end up getting can be duplicated by anyone doing the same list of mods to a stock XJR. This is true even if I fixed some unknown problems as you suggest is the case.

Regardless of any course of logic to explain the wiggle room plus or minus which is inherent to any dyno sheet, the actual performance numbers cannot lie on the faster side. This is indisputable. If I end up pulling a 13.42 at whatever noticeably increased mph, then anyone who duplicates my mods could expect very similar results, and it would be generally accepted that the true gain from a .4 second improvement is = to a +40 HP gain.

As you have just proven, all Dynos can ALWAYS be manipulated, always be questioned, they can read high, can be manipulated to read high intentionally too. We never even know what car made whatever dyno sheet is presented, it could have been a completely different car. My car on a dynojet would have read 365 rwhp, not the 299.4 on the dynaflow. This is why it was so good in my opinion to see Steve M's 12.28 @ 117 1/4 mile run. Anything beyond that 12.28 is theory. I do believe with his planned changes he can get into the 11s, but he has only proven a very respectable 12.28.

Actual Performance is the real deal. There are no "if i wouldas", or "if this didn't happen" etc. printed on the time sheets, just what actually happened. Time sheets cannot lie on the high side.

I have posted my before and after dynos from the same machine, under very similar conditions on the same dyno sheet.
I am going to run on the same track, under very similar conditions, and I will again post my time slips to show my improvements, whatever they may be. No excuses, no arguing, no B.S., just actual results.

 

Mmhh, thisdiscussion was already done some time ago:

https://www.jaguarforums.com/forum/jaguar-engines-47/stock-baseline-1-4-mile-times-75876/

https://www.jaguarforums.com/forum/jaguar-engines-47/stock-baseline-dyno-352-rwhp-349-torque-75435/
(Post 16has some good info).

I thought it was common knowledge that ET wasn't a good measurement for HP, and that driver skills play a huge part as well. Now I take it that over time you have learned more on how to drive, over the 1st time you did it with your car.

So many environmental parameters play a role in the engine hp output, that I am surprised you even consider 1/4 mile run as reliable way to measure HP, that is so much easier/better/controlable to do on a dyno!

And again you refer to your car with unknown condition as a base line.

I see you have edited again your posts, I am not going to re-read it all again, but do see some more assumptions again.

I give upnow, I have failed ;-) Have fun, that's what matters!

 

I've been watching this post for a while now and I think what Avos is afraid of is if you prove that people can get 50 horsepower for less than $1500.00 because that could cut into his business here.

All I'm seeing is him trying to blow lots of smoke and obfuscate the issues.

I read the posts he refers to. The end result was that

-M.P.H. was a better indicator of power than time if there was wheel spin and traction limitations. But-Waterdragon, you are correct that 1/4 mile times cannot lie on the faster side.

-Any improvement in driving ability would be limited to less wheel spin or better reaction time. You already said you had no wheel spin, so that issue is neutralized, and any improvement in reaction time is printed on the time slip and cannot be concealed. I'm surprised Avos did not know that. Maybe because he has never run his car on the track himself.

And I agree with you that ECU tunes do work. Your posts do make sense. I await your posting of the 1/4 mile time.

I would like to see what excuses Avos comes up with then as to why your car went faster.

-Tailwind
-Change of gravity
-other

 

Hello Baloo,

While I appreciate the support, I do want to keep it friendly here. I think Avos has plenty of business these days with his TS kit, lots of good reports of successful installations and happy buyers, and I think his kit is for a different audience, that of people wanting to completely transform their jag to supercar power and speed who are willing to spend the $7000-$10,000 for a kit professionally installed. +250 HP / $8000ish if you do the kit yourself = $32 per HP, still not a bad deal at all, especially considering those last hp are usually exponentially expensive.

His kit offers the ability to buy a $12-13,000 XJR, add a Kenne Bell twin screw, and for a total investment of around only $20K, one now has the ability to completely smoke almost any $120,000 MBZ, BMW, etc.

I also think it needs to be said that no one is, has been, or will be, more helpful on this board than Avos.

That being said, my agenda is this:

Try stuff, see what works and doesn't work for me, then post the results here so people can, for the first time, have honest, unbiased, trustworthy information about what mods produce what results and what mods are only snake oil. When I first came to this board it was not clear to me which products really delivered what was promised. As I have no intention of selling any products, I have "no dog in this fight" and no reason to project intentionally erroneous information. My goal is only to make it easier for the next guy to have better information as to what to do to improve performance. If someone is looking for the fastest they can safely make their car then the Kenne bell twin screw is the best there is, as far as max gain, and bang for the buck at those power levels. But if someone, like me, wants to go slowly at first, and test the waters, then I hope I can contribute to this board by posting what I think I have learned from my experiences of trial and error.

While I disagree with Avos to the point of what my hp gains will be proven to be, I cannot discount his arguments. They do have merit. I do, however, believe that the 1/4 mile time and mph gains will prove unquestionably no less than a 40 horse power gain. I have received several pms of support, and I do thank you for publicly supporting me, but this is not a me against him scenario. I think we are both searching for the truth and both come here to have a good time.

 

@Baloo

And another one that is not trying to comprehend what I am trying to say here.

Yes you are fully right, I am afraid. Oh boy what comes the world to if you could get 50 HP (or more) with the eaton, no one would be interested anymore in 150 to 250 HP more. Man you have uncovered me here, Hats off. Its probably all my fault, I should have never given all the tips/products you eaton guys can now all make use of, so please also don't thank me for the efforts.


I've nothing to prove here, and if you prefer assumptions over hard data than go ahead many do (even I did here based on the limited data, but more to prove a point). I know how hard it is to get repeatable dyno results to get good hard data, but with good preparations, knowledge about your car and knowing what to check, it as far as I am concerned the only way to give some creditable HP predictions.

There is one thing though that you are right in, I don't have any 1/4 mile experience, and can only look at what others are saying/doing, and until now my opinion is that it would be harder to get good creditable and comparable HP data with a 1/4 mile than with a dyno.

For both methods counts that you do at least a couple of runs (pre and after) to be able to give some sort of estimate (i.e. gains over a base line), and that is as far as I am concerned totally missing here. And that doesn't even include the unknown/bad setup Waterdragon started with.

 

It sounds to me like there is an almost orthogonal argument here. Avos is arguing the technical correctness of the dyno runs, and WD is arguing the real world usefulness of modifications.

If 1/4 mile is your game then that's the measuring stick you should use. Sure it includes the driver, and tires and lots of other things that aren't strictly power, but if the mods result in a time slip that is three 10ths faster, then it was worthwhile.

If, on the other hand, you are interested in comparing absolute power, then you need a metrology. A dyno is really not a very good metrology, in fact by the statistical definition it probably isn't a metrology at all because it has so many noise factors. As such, to get comparable data you have to be very careful about planning and running the experiment.

I like WDs experimental approach of trying things and tinkering with the car for fun, just to see what works. I am a similar experimentalist but one notch crazier so I bought a twin screw, to install myself, just to see what would happen.

Having bought a twin screw kit from Avos, I can safely say he is not making a living off of them. Having done lots of custom engineering and fabrication I can tell that the price is little more than cost when you consider all of the custom, low volume parts that are included. Not to mention the technical support. After all the questions I've asked, he probably wishes I'd never bought it.

Like was said before, this is all supposed to be in good fun, so just use whatever measuring stick you like.

 

Regardless of the questions concerning the baseline, I have no doubt your mods made 40-50 bhp more.
Based on your first runs, I'm guessing 13.4 ET @ 106 mph. Although there's no reason you can't run 12.99 when it's colder. I did, with less mods too.

 

So what did happen? I'm sure you are loving it. Have you had yours on the dyno or 1/4 mile?

Inquiring minds want to know

 

Im going to give you the number I just got on mine yesturday on my 05 Nissan Frontier truck that I put a Ken Bell twin screw on and took the Eaton off of(it was normally aspirated from the factory )
All my dyno are on the same dyno dynamics(aka Mustang or the Heartbreaker)
stock in 07 ......192rwhp
CAI, cat back, 2* timing advance......199rwhp
Stillen Eaton unit 10psi boost, cams, ported heads, headers and full stainless exhaust no cats, dropped compression from NA 9.7to1 down to 9to1 with forged pistons and billet rods. dyno'd ......257rwhp
since last year when I spun a rod bearing and broke a ring. Ive bored .020, new crank, Total seal ring "gapless" rings, and dropped compression down 8to1. Custom installed a 2.6l Ken Bell Twin Screw(like Avos but he run the H, higher boost unit)
So lets look at changes
compression lower =hp loss
gapless rings and overbore=hp increase
The KB gives 12.5psi instead of the Eatons 10 but is WAYYY more efficient and boost is instant and it does NOT drop like the Eaton. at 6800rpm rev limited it was actually still building boost and HP

RWHP now 337 80hp more to the wheels.
Now for you math gurus
I run 1000cc injectors (95.24lb/hr)
tuner said at full tilt the injectors were running 70%duty cycle, and 43psi fuel pressure. if you plug those number in using .6 for BSFC for a blown app. = 111(crank HP) per cylinder X6 cylinder engine=666crank hp. yes that alot more drive train loss than ya'll will ever see from your cars.
But remember, Im a 4X4, w transfere case, big heavy drive shaft, 4.56 gears, locker, the mud tires and beedlock wheels are about 125#each and you get an idea of where my consumptions are
Moral of the Story.
I modded the Eaton, the motor, the exhaust etc and got basically 60rwhp.
Added a more efficient KB twin screw with only 2 psi more boost but yet 80rwhp more. Forget all the rest and just buy a Avos kit if your serious, otherwise quit burning those $100 bills up and send me some...
Great thread H2Odragon

 

Nice one Brutal

My 2 cents, a 1/4 mile is a good indicator for HP gains, but only the trap speed, as the ET is dependant on traction & gearing, as well as HP & weight. The mph through the trap is pretty consistent for just HP & weight.

At least that's how I see it.

There are several online calculators that have been pretty accurate for whp, based on vehicle weight & mph through the traps.

 

13.387 @ 104.51

No mufflers and an intake tube

 

Yep cambo youre correct, funny how a top fuel car can get out of the throttle and still almost run 300mph at 11 seconds or 300 at sub 5
it doesnt take in to account better air, temps etc and their affects on hp, but mph is a very close indicator of more or less hp regardless of wether from the car or environment.

Water dragon i applaud you and the work you do and ive been there done that to see how much i could tweek from waterever i have. As we're always discussing the eaton does have limits. When i when from 5psi to 10psi on the eaton i got minimal gains since it turns faster=more power consumption, and heat both killing psi gains. And i remember my dyno always showed the eaton dropping boost before rpm limits of motor, something the kb just never did.

 

As it is right now, the Jag is my daily comfortable driver/sleeper/toy. At first I was thinking the Jag would be my only toy car, but the more I think about it, if I want a track toy, then I want a track toy, and a 4000 lb street car is not built for that purpose.

I am considering getting a modified Lotus Elise or Exige Turbo with 300-340 hp at less than 2000 lbs as my "fast" toy car.

At the moment I still want to see what additional power I can get for low dollars, and I think there are lots of other people who want something in between the stock or full out twin screw configurations.

I have a few more small mods to make. I think I have found a place where I can get a good tune, as I do believe they work, and I need to make some cooling system improvements. Just as a benchmark, I want to get my Jag to pull a 12.99 or faster before I stop with the small mods. The track nearest to me opens May 22, so we'll see what my times and speeds are.

The thing that I am thinking is that the Jag is 4050 lbs, and is a very decent car for the money as a daily driver, but if I'm looking for a racier car, for a more thrilling ride, then I should buy a racier car as my full on toy. The supercharged Lotus on the track is hard to beat , just as the Jag for cruising around town is hard to beat.

 

Since I did the work myself I spent about 2 months with the car scattered around the garage doing a little here and there on weekends and in between the day job. I wasn't in a hurry and got all the exposed aluminum parts polished while it was apart.

I just got it back together with all the polished aluminum bits and it feels stronger for sure but I need to sort out a high fuel trim problem before I will be comfortable getting on it really hard.

I don't have any quarter mile numbers but did get a before dyno as a baseline and do plan to get an after done. To be completely fair, I will have to wait for fall when the air temps are back around 60F to get a comparable dyno pull but I might not be able to wait that long.

 

2002 Jaguar XJR quarter Mile 13.233 105.34 mph - YouTube

.606 second improvement, 13.233 @ 105.34 MPH.

That about sums it up. I'm pretty content.

 

Without trying to find it....what was your mph improvement

 

+3.91 mph

Before and after times given here, and video of the run too https://www.jaguarforums.com/forum/j...results-95807/

 

Well that a hp increase and notable

 

and cheap

One thing that was nice to see was that the power did not fade from heat soak at the end of the run, even though I'm running more boost and more power.