260, 250, 240, 230 - wheres the power going?

[bluess57]

260, 250, 240, 230 rwkw - these are the dyno readings my car has done over time - mafless.

Are dyno runs over time a complete waste of time?
Is my engine wearing out? Dud OTRCAI? Cats blocking up?

Car Mods losing me HP?... :shock:

Maybe MPH at WSID on Sunday will reveal all...

I've trapped anything from 110-113mph at Heathcote/WSID and best ET 12.45

Background:-

260's rwkw:- original mafless tune with baby 220's camshaft .557 lift on 112LSA, tri-y paccie 1 5/8 extractors, dual 2.5 cat back ( reading on lets call it dyno 1)
(all others on dyno 2)
240-250's consistent year to two later, cat-back changed to sure-flo dual 2.5, change to pacemaker 1 3/4 4->1s, 25% UD, 7.4 hardened pushrods

230's today, OTRCAI, new tune - cold morning AT:6, IT:8

What the? I'm going backwards on the dyno....
Ok, not exactly back to back testing - granted.
But I've seen/heard of stockers doing better (and I did originally on dyno 1 - pre cam)

Original mafless tune with efilive logging showed IMO, too much knock (road logging).

Latest tune shows a lot less/little knock, but I'm reading low on the dyno.

I'm trying not to get too tied up with dyno numbers...but... 250 -> 230 is 8% loss
Is the accuracy\variables of a dyno that bad?

I have recent efilive logging and dyno sheets.

New tune - car drives great to say 3500rpm, SOTP seems like more torque,
above that hard to tell.

Opinions?
(yes its a very reputable tuner, and no I'm not bagging the tuner)

See ya's Sunday @WSID ...

[Delft Maloo]

mate if all your logs are good and the afr's are right then id say you have some form restriction there somewhere. dont take to much notice of the dynos as they will vary from one to another, day to day and setup. i know when i have found a bit more mid range it does tend to hide the top end abit. your mph on sunday will give some indication hopefully. if its down then id start looking for some form of restriction either in the intake or exhaust. collapsed cat or mufflers can be quite common. how many k's has your engine done, has it had a real hard life a compression check could reveal some answers.

see how it go's on sunday then worry about it then.

[RedVYIISS]

your valve springs going soft? (it'll effect top end only so check power v's speed on ramp up).

[bluess57]

Car now has 80,000kms. Has it had a real hard life, I wouldn't say so.
Been down the strip a few times (about 50)

I like the idea of a compression check.

Intake restriction(?) - has an OTRCAI on it
map at full throttle is 94 -> 84 kPa

Efilive log screenshot (http://home.pacific.net.au/~ijhope/dynologging.JPG)

I wouldn't say the springs are going - no characteristic uneven-ness on the power curve at the top end.
Dynosheet 2007 06 22 (http://home.pacific.net.au/~ijhope/dynosheet20070622.JPG)

Sunday will be interesting

[10sec_rx7]

84kpa is your problem, you have a restriction in the intake somewhere,

usually we will see 95+ with our OTRs on cars making 300rwkw,

[bluess57]

hmmm - filter or OTRCAI design?
Filter didn't look dirty
Track testing tommorrow...
I've packed my old gts pipe as well then

[bluess57]

84kpa is your problem, you have a restriction in the intake somewhere,

usually we will see 95+ with our OTRs on cars making 300rwkw,


Reconsidering the intake,
what about the BP on the dynosheet only being 94.7
I'm at altitude here (600+metres)...

No track test due to rain :(

[SSUte01]

Even at your altitude that is far too much of a restriction. I would've expected a loss in vicinity of ~5kPa WOT at 6000+rpm. I have done some testing on a few different OTRs on the and the results are all about the same within 1-1.5kPa at WOT max rpm.

Here is a screenshot of my OTR efficiency. Effectively what you are looking at is the difference between BARO and MAP vs RPM.

This is a PT OTRCAI with K&N filter in (take the filter out and you gain at least 1 kPa often more)

http://www.trackchat.com.au/media/data/500/Intake_Loss.JPG

[bluess57]

Ok, I'll do some testing tonight with/without OTRCAI filter and using the old combo of airbox/GTS pipe.

[OPPYLOCK]

Did you come to any conclusions about the intake???
Any big difference running OTR against GTS pipe?

[Delft Maloo]

i would also be keen to know how things are going with this.

[bluess57]

Sorry guys, its been too bloody wet (for a change)...
My rear tyres are a little down/slippery and WOT = wheelspin
I have a KN filter replacement which I'll pickup Monday, and it'll go on the dyno next Sat for giggles (at Gentech for the LS1 dyno day)
I'll log the runs there again as well.

[bluess57]

Got a quick filter test in today.
Reveals the filter is not a free flowing product (its blue and I don't know the brand).

Map is 94-95kpa today

With filter, map bleeds away down to 84kpa

OTRCAI With Filter (http://home.pacific.net.au/~ijhope/ls1/OTRCAI_WithFilter.JPG)

Without filter holds 92-94kpa

OTRCAI Without Filter (http://home.pacific.net.au/~ijhope/ls1/OTRCAI_WithoutFilter.JPG)

All testing done on private roads and in controlled circumstances :up2sum:

[bluess57]

K&N Filter wins the day/night folks...
OTRCAI KNFilter (http://home.pacific.net.au/~ijhope/ls1/OTRCAI_KNFilter.JPG)

Tonight Map 95-96Kpa
Worst Map at WOT is 92Kpa

One crappy airfilter into the bin...

[bluess57]

Spun up the dyno at Gentech for the LS1 dyno day, 262rwkw reported.
All good.

[BOMI]

Spun up the dyno at Gentech for the LS1 dyno day, 262rwkw reported.
All good.

Thats good that its all fixed up mate :thumbs:

Troy :)

[Delft Maloo]

good result mate. i think the problem might have been in your bum, getting to used to the power you have. try another mod, a few more kw's should tie you over for awhile.

[Hazza]

Yeah ya bugger... All this complaining and you hose me by 15rwkw. After going through all the results every car we had a benchmark for lost 10rwkw due to conditions. So yours is more like 270rwkw. Another example was John's Dutton Ute pulling only 3 more than you.

That touch up tuning has made the difference. Remember in the previous dyno comps when you reckoned I was cheating and had a baby cam in it cause I beat you LOL, and I said its all in the tune, proven to be correct now.

PS - Was that blue filter that stole your power a UniFilter brand one? Just remembered the 2nd hand OTR I am using has a blue UniFilter LOL. Might have to log it and see.

Spun up the dyno at Gentech for the LS1 dyno day, 262rwkw reported.
All good.

[bluess57]

Lol, hazza... baby cam hehehe, I only asked, you sure they didn't sneak one in, coz stockers shouldn't do 255 ;)
Yep tune touchup has made a good difference.
Big thanks to Dan (aka Chipmaster/ Delco) :bravo:

The blue filter supplied in OTRCAI, no idea of brand. You want it? Have I got a deal for you :)
(guaranteed to lose at least 20kw)

Comparing filters to the K&N, the blue one would have half the surface area of a K&N.
(There are significantly less "W" shapes/vanes across it, so less surface area)

Yep Hazza, definitely log what MAP is being held with/without your filter at WOT.

What gives with John's Dutton ute?
(I went back thru threads and see it spun up 290+ at Sonnys)

[Hazza]

Chuck the blue one up on eBay. You might get 20 bucks :lmao:

Yeah Marcus' ute (GTS Cam/GTS Heads, 2 Hole Mod) pulled 290 last time it was on, but did 275rwkw yesterday. So if you up John's by 15 also then it would be 280. The GenTech dyno seems to be 10 less than most others so that would account for it. Makes yours pretty impressive if you up it by 15+ also!!! And would bring me up to 260 where it should be.

[10sec_rx7]

here is something i did a few months back
http://www.castlehillexhaust.com.au/files/airfilterdyno.jpg
run 008, EBAY Holley filter 219.1
run 009, No filter at all, 227.5
run 010, JR, 226.7
run 011, BMC 222.6
run 012, K&N 227.1

pics of filters
http://www.castlehillexhaust.com.au/files/airfilters.JPG

the cheap shit blue ebay (come supplied in the capa OTR's) are a piece of shit, the JR brand blue ones work a treat as do the K&N's

[BOMI]

Thats interesting mate, cheers for posting that up :yep: :cheers:


Troy :)