Just did my "after" dyno on the same machine I did my "before" dyno. Attached pic shows before and after runs. These were done on a dynaflow dyno. To get the results to match what a Dynojet would read, you would have to multiply the result by 1.22 These dynaflows read lower. I was after honest, consistent information. My final "after mods" number was 299.4 rwhp, which would be 299.4 x 1.22= 365 rwhp if read on a dynojet.

One important note. In between these two dynos I did do something that removed significant power; when I bought the car it had a very Agressive ECU lean tune that started under WOT at 13.7:1 AFR at 4000 rpm and ran down to 12.8:1 at redline. I'm sure this ECU tune also included a wicked timing advance curve. I have since had that put back to the stock tune in which the AFR is now 11.5:1 down to 10.8:1 ( I took a video of the dyno screen as it was reading AFR, and it did go as low as 10.8) at redline. While this significantly hurt power as read by the butt dyno(the car was quite a bit slower with this change), I am now on the safer side of the AFR. Obviously a more appropriate tune, keeping the AFR closer to 12.5-12.8 the whole time would get some more power back. I also noticed a decrease in my mileage too. Who does a good ECU tune these days??

Max hp gain was read at 31.9, so I'm going to add back 10 from the losses of my super agressive ECU tune that I got rid of, so I think I can reasonably then claim a gain of 31.9+10(add back losses from tune)= +42 / .83 to convert rwhp to flywheel hp=+50 Flywheel HP

Worthy of noting, before my mods the same boost gauge read 9.5 psi, and now reads 12.5, so I picked up +3 lbs of boost from a combination of the +1.8 lb pulley and reducing the vacuum of the intake track. When I switched to the new Gen V blower without the pulley, the gauge still read 9.5-10 as read from the top coming off the thing on top of the SC that says V8 on it (this is the same place where I took my reading before)

List of Mods:
$400 75->92mm Pro-M MAF
$200 3.5" intake tube
$100 75->82.5mm Maxbore TB, I port matched the elbow to 83mm (self)
$200 Gen V Eaton with +1.8lb pulley (price to just add pulley)
$ 25 ported intake manifolds (did myself. $25 for abrasives consumed)
$ 25 Denso U-groove spark plugs, 1 step colder than stock
$150 Changed my exhaust after the center muffler to go straight to rear stock mufflers (no longer over the rear end) I still have the stock cats.
$1095 for +50 HP= $21.90 per HP


I tried running on pump gas of 91 octane and then with 91 + 75% 104 octane Sunoco unleaded race fuel. No difference or benefit power wise came from the higher octane, so the stock tune/timing advance was not detonating or pulling any timing. The highest power run, the first run was with 91 octane only, and the intercoolers were already quite HOT! So, without re mapping ignition to add more timing or adding more boost, this extra octane was not beneficial other than making me feel safer running the car hard.

I am planning on running an "after" 1/4 mile in a week to get what I call the " The Real" results as to me, actual performance is what it is all about. Dynos are sources of endless bickering, especially by those who like to bicker. The gains in HP and TRQ under the curve show big improvements in mid range; approx +30-35 rwhp and rwtrq everywhere under the curve, so I am very curious to see what improvements can be made from my 13.82 @ 101.61 mph 1/4 mile baseline. I'll be running at the same track under similar conditions. It is my opinion that actual performance tells more about true gains than dynos where the car is only at WOT at 4000 rpm+ as much of the gain is before 4000 rpm.

I think the biggest improvement in real world seat of the pants racing across the intersection is the gain in how much faster the car goes from 0-30 mph and this dyno does not show that. In stock form I would floor it from a stop, wait for it, wait for it, whaaAAAAAAA ahhh boost kicks in. Now instead of waiting 2 seconds for boost and Gs, I'm only waiting 1/2 second. The difference is I'm doing 40 mph before the end of the intersection vs only 30 before. In the "Real World" this is a big difference.

I was really hoping I would be able to get a 1/4 mile time 12.99 or better, but that appears to be a big bit of a stretch, given the dyno.

2002 Jaguar XJR Dynaflow dyno - YouTube <----Here is a video of the dyno showing the AFR (lower left of screen) goes to 11.0 to 10.9

 

You need meth...

But really, you wouldn't imagine the difference it makes when things get hot

 

If you use meth and then re-map your ignition advance, then you can see some serious gains from it, but you are then reliant on that system always working correctly and never running out of meth or water.

I want to be able to always run 91 octane pump gas, so any tune I may get in the future will be for 91 octane.

I imagine if I get a "tune" and change my fuel ratio from the 11.0:1 to 12.5-12.8:1, and get a more aggressive timing advance curve, I would see maybe another +10 hp.

 

Most probably a 13.2-13.4 car now - depending on your 60ft.

 

I'm hoping for 13.2 or better
I should know weds May 22nd, cuz that is when the drag strip opens and I'm going racing!

The boost comes on quite a bit sooner and stronger, so the total gain in area under the curve will determine the faster time, not only the top/max hp number.

If you look at the dyno, at 4300 rpm the mods give +35 RWHP /.83=+42 estimated overall Flywheel HP, this is NOT factoring in the the losses from de-tuning the ECU. I'm pretty happy with this gain, given the mods were pretty mild and pretty cheap.

We will see. As I said before, the actual 1/4 mile performance cannot lie on the fast side. None of this armchair warrior chest beating. I'll try and get a video of the best run to post.

 

Good luck

 

Quote:

Originally Posted by WaterDragon

If you look at the dyno, at 4300 rpm the mods give +45 RWHP /.83=+54 estimated Flywheel HP. I'm pretty happy with this gain, given the mods were pretty mild and pretty cheap.

Don't look to much at rpms below 5000, as the power can be different pending on how you bring the engine up to speed and floor it (which you must do with care otherwise you get a down shift).

I do find it odd though that your pressure on the original car was only 9.5 psi. That could explain maybe the lower readings you got in the 1st place.

Something like Below ?
Scaling was off, and this wasn't even my best run which was 525 rwhp, and I think before twin-screw (red) this was even with a larger lower pully. Blue was 506.3 (610hp) and red was 312.9 (376hp), so a total gain there of 234hp.

 

Good luck at the track!

Cheap maybe, but not small labor. It's a lot of work to change the blower and do intake work on that motor, so kudos.

Though, Avos could probably do it eyes closed and with one hand by now.

 

Ya I mainly use meth to keep the car running cool, not to advance the timing (no one tunes the STRs).

I keep going back and forth with nitrous. I am worried about the zf box in my car because it does odd things at random times.

 

Exactly!


The power of the original set-up (with lean tune) ran a 13.8 at 101 mph, so it was about stock rated power.
On both before and after dyno runs they rolled into the power the same at 4000 rpm almost identically, so the mid range power gain shown on the dyno I think is accurate. On the dyno, the top # gains are generally what is referred to, but from stoplight to stoplight, or at the drag strip, all the area under the curve is muy importante. The fact that the car comes on boost much faster I think will make a huge difference at the drag strip. We will see next Weds.

I'm pretty happy with my results, as I could probably duplicate this +50 mid range flywheel HP gain for about $1300-1400 USD
+ my own labor to port the parts if I had to do it all over again.

 

No the part where you measure the difference between the pre and after one isn't correct, there is a un natural dip in the pre one which I have never seen on any other car, there should be a normal curve just as with the after dyno. So the change there is somewhat calculating yourself richer...

Personally I am not in favor of NOS or Water/Meth for a couple of reasons.

I can understand the NOS issue with regards to the gearbox, as that one is sending torque reduction requests (based on air flow/rpm) to the ECU which reduces it via the TB. This would already require a smart system that could take this into consideration, if that is there then NOS could be an option (best to go for a WET system).

A less intrusive option is the Water/Meth setup, I like it for its cleaning capabilities, and its anti-knock effect, so you get the ability to run with a hotter/higher boost setup (specifically of interest for Eaton users, but also twin-screw setups).

But once you start to have to depend on either NOS to be there or the Water/Meth it gets to be a more complicated system, so chances of issues (i.e. not running properly for whatever reason) do raise, so not an option for everyone. Also not for me as I don’t like change more than just normal fuel (it doesn’t feel too jaguarish to fill up meth bottles or nos bottles, but that is personal). But I have to admit I am charmed by the cleaning capabilities of the water/meth kits, and that they do allow for more power at higher boost/heat setups.

So whereas on your stock (something wrong situation) water/meth has only given 7 hp, it may give more with your higher boost(/heat) now.

I don't say this all to sell you a kit, as said earlier I don't think you will ever do, as why would you want to waist your time otherwise?

 

"No the part where you measure the difference between the pre and after one isn't correct, there is a un natural dip in the pre one which I have never seen on any other car, there should be a normal curve just as with the after dyno. So the change there is somewhat calculating yourself richer..."

Your right, I changed the photo in my original post and added dotted lines to correct that error and remeasured the gains. Still a screaming deal for the money though, if one only wants approx 50 flywheel hp.

 

Mmmh, the boost still got started later on the pre version, and that does make a difference as mentioned earlier, so even the dotted lines may not as you thinnk they are now. But thats all nitty gritty, 25 or 30 rwhp is an increase which is nice, assuming that all the changes you performend didn't correct an ealrier fault as to why you didn't get 11.6 PSI in the 1st place.

Don't get me wrong, what you did is the way to go, ie minimize the vacuum in the intake as much as possible, and than also the boring out etc.

I understand/apreciate the relativly easy power you can get form NOS systems, I mean I drive a 250 shot more or less ;-), but it also requires some carefull setup I guess, especially as shift points are relative pending on different parameters. But that is not my area, so can't help there.

 

I've not heard of any stock Eaton powered 1998-2002 XJR or XKR reading more than 10 lbs of boost on a guage. Everyone I've asked has said theirs read 9.5- 10 psi too.


My 1/4 mile time and mph will tell all

The mph IS reliable evidence of power, much more so than time. At least to those in the know.

 

Yes you do have an increase in power, but the results will not tell if you have corrected the earlier issue I’m afraid if you want to compare pre and after runs. Nevertheless it would be interesting to see what the trap speed will be now, as some improvement should be there.

 

Avos,

It is worthy of pointing out again that when the previous owner's very aggressive ECU tune was removed there was a significant loss in power. Other board members have told me they got +18 RWHP on the dyno from their tune, so the -10 HP from the loss of my tune I think is being quite conservative.

Whatever extra power the very aggressive tune gave likely 10-15 HP MUST be added back in the equation to make a fair assessment of the gains of my mods. These losses should be estimable from the AFR and guestimateable for the ignition advance too.

How much power, in your opinion, on my motor, given the information from my car that the dynos give, is gained or lost from going to and from a 13.2-12.8 AFR to a 11.5-10 AFR? and, then one must guess how much power was also lost from extra timing advance curves...

Here is the video of my Dyno showing the 11.0-10.9 AFR at above 5000 rpm: 2002 Jaguar XJR Dynaflow dyno - YouTube

The top end max gain was 31.9 rwhp. Would it not be correct then to say that we should add a minimum of 10 rwhp because of the AFR losses.

So is it not fair to say that my mods added at least 42 RWHP? I think, given the dyno, and the removal of a very aggressive tune, that I can reasonably claim a gain of of 42 RWHP / .83= +50 Flywheel HP gain

The way I see it +50 Flywheel HP, as PROVEN on the same dyno with the same operator, before and after under the same atmospheric conditions for a total of less than $1,100 means that I did pretty well for myself.

Sure, these results are nothing as huge as compared to a twin screw, obviously....but if one only wants to spend less than $1100 and actually get 50 flywheel HP, this list of mods is a good way to go.

 

I'll give up, I'll bet you can find even more assumptions to safely say these mods actually bring 75 HP extra more ;-)

PS, Some dynos I've done with lean 13 a/f measurements gave me even less power, go figure.

 

What I am asking for is your much more knowledgeable opinion about what are the true correct gains from my mods. I admit you know better than I ever will, how to estimate my total gain, and I am, I truely believe, lowballing the estimate from that tune at no less than 10 rwhp, but I would defer to your, again more knowledgeable, opinion. Removing the tune removed significant power, without a doubt, so there was the timing advance curve and the AFR changes that would have to be accounted for, not just the AFR. We all know ECU tunes, especially aggressive ones like my car had, add significant power, or do you now say AFR and timing settings do not matter?

I am only looking for the truth, and it would be very incorrect, and dis-honest to not re-add at least some of the losses from that tune.

I am not looking to deal with any other assumptions which is why I did not add anything back for the intercooler coolant being far hotter than it would have been on the road, under "more normal" driving conditions, nor did I go us a Dyno jet dyno as they read about 1.22 times higher than this dynaflow does. I am after honest numbers. I used the same dyno.

I have done what I set out to do: Post accurate before and after dynos, from the same machine, under the same conditions, without any B.S. or trickery for the benefit of people to be able to get unbiased, reliable information about what actual gains they can expect from a set of mods. I think it would be untruthful to not add back the losses from the tune. Anyone disagree with my methods here or philosophy? If so, please do set me straight if you think I have made any mistakes here. Again, you must address the specifics above; 1: timing advance would add power in the condition of no detonation, and 2: An AFR of 12.5-12.8 makes more power than 11.5 to 10.8

And...I believe the 1/4 mile times and mph will add even more compelling evidence of true gains.

 

All I’m fighting here is the amount of assumptions on top of little data where we even don’t know all the circumstances of, other than for instance a fact that we do know that your car wasn’t operating stock (i.e. 2 psi low for instance with the lean mixture), and we don’t know if the boost issue might have been fixed by all the work you have done so far.

So how can you (or anyone) seriously claim a 50 (or whatever) hp gain?

That almost becomes xjr-0220 stuff ;-)

 

That almost becomes xjr-0220 stuff ;-)[/QUOTE] <--OUCH! Easy on the hand grenades! The point of my post is to share actual results, not for any other reason.

As to the boost change: What I do know is that the same gauge, reading from the same place, read:
9.5 with my original blower
9.5-10 with the new Gen V blower and ported TB, elbow, and intake manifolds
12.5 with the new GenV with smaller upper pulley (no grinding, just heat and slip on pulley) and larger intake track, and slightly freer flowing exhaust
-So that answers the boost question-

As to the tune, when it was removed, the car was noticeably slower, by a lot. All things being equal, it is common knowledge that an AFR of 13.2-12.8 makes more power than 10.8-11.5 (look at the graph, the AFR dips below 11.0)

To Avos: An AFR of 12.5 may be the best "overall", when you take engine safety margins into the equation, but are you arguing that an AFR of 11.5 makes more POWER than 12.8-13.2?? It was my understanding that max power for a forced induction motor was 13.2, (maybe too hot, and cooler/safer at 12.5) and 13.7 for naturally aspirated, and that the desire for running a AFR of 12.5 over 13.2 was for a margin of safety. Are those who say this incorrect? Please answer this question.

The ECU tune likely also had a much more aggressive timing advance curve, as most tunes do. The timing advances MUST also be considered as they absolutely, definitely add to power when there is no detonation happening. And as said before, given there was no gain with the higher octane, I'd like to hear a specific argument that for this specific example, that a performance ECU tune would not add at least 10 hp that I'm claiming I felt the loss of when the tune was removed. Again, as a reference, I have credible reports from a board member who said he got +18 RWHP from his tune.

As shown that the higher octane did not produce more power, I take that as evidencial proof that there was no detonation/nor timing being pulled in this specific instance, even though the inter cooler fluid was as hot as I've ever felt it. Yes running hotter increases the "chances" of detonation, but clearly this is evidence that this was not happening at this time.

Let us just see what the 1/4 mile time and mph says then.

The "after" 1/4 mile times and mph will remove all conjecture. If the car only pulls a 13.6 I'll then admit the evidence shows a gain of only 25-30 HP. But if I prove a .4 second gain, then my argument will be evidently proven, no if's ands or butts. What will really prove my point will be when I re-dyno and run the 1/4 mile after I get another tune. Then we will see what the truth really is.

It is generally accepted that .1 second faster in the 1/4 mile is roughly = to +10 HP, so I will use the actual performance as my proof. I expect the mph (the more reliable measure of HP) to be considerably higher.

As the great Foghorn Leghorn used to say "You can argue with me, but you can't argue with figures!"

Stock best was 13.82 @ 101 mph with zero wheel spin with and without traction control. So then, again with zero wheel spin:
If I run a 13.62, then, as general knowledge goes, it would be said that there was an approximately gain of no less than 20 HP
If I run a 13.32, then, as general knowledge goes, it would be said that there was an approximately gain of no less than 50 HP
This is not counting the losses from removing the tune, which some correction must be added for an honest calculation.

I will post my results no matter what.

The drag strip near me opens May 22, I plan on being there early to get a spot. Only the first 300 cars are admitted.