Any 2.5 owners willing to post and share your power plots. Ideally ones showing boost and AFR so G Force or equilevant plots.

Had another dyno day after fitting STI8 TMIC and another map tweak and considering the boost on the rollers and the slightly rich fueling at the top I am pleased with results.

I am now thinking only way to get some good paper numbers is to crank the boost on the rollers to acheive 1.35bar on the rollers, and run it leaner at the top end. But would probably have to then pull boost back and richen it up once back on the road under full load conditions to avoid melting something.

But would be keen to see some plots and specs if anyone else is willing to share.

Will scan and post up my results tonight.

Very interested to here what AFR people are running on full chat, as I have heard that the 2.5's like to run leaner, but is this a myth.?

 

what were the results if you dont mind me asking?

Also, do i remember rightly that your usinga VF series turbo?

 

My specification has moved on a little since buying the car.

Its 2.5ltr bottom end, running standard UK Heads.
Tubular nearly equal headers.
20g Turbo
ITG Panel Filter in Standard Airbox
Standard Dump Valve
Full2.5" decat - TSL Group 'N'
Uppipe
740cc injectors
STI8 TMIC
FPR
Walbro pump.
Apexi power FC

Figures on the day were 334bhp and 362ft/lb torque at about 1.2bar. First run before we logged it on the rollers was 346bhp but it got warm after 2nd run.

However if I had thought to increase the boost duty to get 1.35bar on the rollers in 3rd/4th gear I would have had a double benefit on the day of increase boost for paper figures and it would have leaned it out at the top giving better results due to boost and fueling. And would have probably seen figues a lot higher. perhaps even the 380/380.!

 

Tubular nearly equal headers.


sorry Rob, couldnt resist

 

that sounds really cool I really dont knwo what to expect from mine, but to see you achieve that with a standard airbox and 2.5" exhaust is encouraging.

My turbo is slightly smaller, an MD195 VF22 hybrid, P20 housing and garrett wheel but i would hope to be running nearer 1.6bar, id be happy with those figures though, given the other bits im using. will be interested to see the graph

 

Mine was 434 BHP and 395 lbft on Maha dyno running 3" exhaust, headers, FMIC, 20G at 1.4 bar midrange, 1.27 bar at the top. Optimax with 10% methanol. Running 0.80 lambda, but I would richen it without methanol. It held together in this spec run daily until I got greedy.

At 0.78 lambda with methanol injection at similar boost it ran 403 BHP and 395 lbft at Dastek.

Leaning it at the top won't give you much power and seriously risks overheating. Running too much boost at the top loses power unless on silly octane - 1.27 bar with methanol was optimum, less would be optimum without methanol.

 

I am really not big into noise.! - This is my daily driver as well as hobby car. hence happy to loose a little from panel filter and standard airbox, standard DV and 2.5" zorst with the quiet TSL group 'N' zorst.

If they done a quite 3" sytem I would think about it one day.

I will probably do another run sometime in the summer, but next time make sure the boost is cranked a little for the rollers.

Will post up graphs later. Torque starts falling away a little up the top, but the power and torque comes in nice and early and all over by 6K.

 

sounds excellent Rob, think about the revolution system though, mine is quieter than stock with tubbed headers

 

oh dont worry im not big on noise either....(he says putting a 3.5" exhaust on) ill probably get it chopped in half and a big resonator put in!!

 

I went to G force Yesterday with my Brother and his Porchse 911(930) turbo who happens to have a scoob as a works hack (alright for some) with a full 3" nurspec exhaust which he hates, I could be tempted to swap with him if it wern't so damn noisey.

p.s He got some massive results on the 911 (930) turbo he got 476bhp and 500fl/lb torque. Not bad from a 1981 car. It certainly impressed G force.!

 

Lets start the ball rolling

 

[quote=john banks]Mine was 434 BHP and 395 lbft on Maha dyno running 3" exhaust, headers, FMIC, 20G at 1.4 bar midrange, 1.27 bar at the top. Optimax with 10% methanol. Running 0.80 lambda, but I would richen it without methanol. It held together in this spec run daily until I got greedy.quote]

Was that on std internals John? I'll be running a very similar spec for going up the hills but running with uprated pistons/rods/bolts/bearings. Just wandering if i could push it a bit more ......(no methanol)

 

John also had the benefit of ported Sti5 heads which will definitely make a difference on a 2.5.

The above graphs show it's running on the conservative side, but really the power is low for the combinations of bolt ons. The problem is likely to lay with the available ignition timing at the top end, although you need to look at all the variables. Fuel, compression, breathing, intercooling, spark quality, ignition timing fueling, heat management and more.

 

"John also had the benefit of ported Sti5 heads which will definitely make a difference on a 2.5."

I take it that would also reduce the issue of head/gasket related problems on the 2.5 as John had later on??

Who should i speak to about getting headwork done?. Or better still, could anyone advise on porting them myself? I've done a few 'A' series heads before but don't really want to end up buggering my ver.6 heads...slightly more expensive to replace if it goes **** up!

(sorry to jump on the thread!)

 

I cracked a ring land with what I think was a single red knocklink flash at 1.7 bar on a bolt on Garrett doing a top speed run.

Subsequently the pistons held well running up to 1.6 bar on rotated Garrett on Optimax with careful timing and running richer.

Headgaskets still snuffed it though then I went to BMW land. Now I'm bored but reliable

I don't know if it would be a solution, but if I did a 2.5 Scooby again (unlikely) it would have factory 2.5 head castings, ideally on a factory fresh engine.

 

Robevo5, sorry to butt in on your thread,

I just need to ask a relevant question to everyone,

I also have the 2.5 engine and have developed a problem over the last couple of days......................my car stalled on me out of the blue yesterday whilst driving along, and after getting it going again, it stalled again, so I limped it to work.

What I noticed on restart was a big cloud of white smoke, now how do I find out if the seals on my turbo have gone OR reading this could this be my headgaskets that everyone says are a weak point.

I'm running 1.4 bar (or I was)

Kev

 

Mate sorry to here you might have a potentially nasty problem. Take the hose of the turbo, if its really oiled up it could be the seals. Failing that pop the plugs out and get a compression tester to check for equal compression across the cylinders.

 

Trying to get my head round my map, and went to the trouble of printing off a exel spread sheet of 20x20 grid, so I could then read and write down the ignition map on this spread sheet. On first glance it would appear the timing is fairly flat at the top.

My knock count is mouse quite so might get adventourous with the timing, but think I will wait until I have a wideband fitted.

 

Timing can appear flat at the top, but unless you have a very large turbo, and wild cams, the load will drop with increasing RPM for a given boost level. Usually this will mean the timing increases assuming that it increases generally as you go to lower load zones. You need to look at the map tracer to see what is going on. Sounds like it was mapped on the hand controller, was that the case?

Paul

 

Not mapped on hand controller (best left at that), I don't envy any mappers job. They don't really know how the client will drive a car all the time, and whilst they want to please the client with great paper results, in the same token they don't want to potentially melt the customers car. Its difficult to read each other as to what each other percieve's as on the edge.!. Apart from paper numbers I am very pleased with how quick the car feels. But I can't help but think it could be quicker.

If your willing to give any freebie advice/input on the ignition map I could ping you over an exel spread sheet of the iginition map. But in isolation if wouldn't give ou the ful picture.

 

Drove this car Friday and it defo matches the RR plot above i.e little point in hanging on beyond 5500rpm.

Rob, I've finished building my New set of Detcan's, so give us a shout if needed. Even better if/when you get the wideband installed.

 

Cheers mate, you worked wonders on my 95WRX at the time all those cars back, so think from here on in, I'll give you a shout at the tittle and see what magic we can do with the handcontroller, a wideband and a set of DIY detcans, and a lot of knowledge mapping early scoobs.

 

Rob

I can't always keep track of all my customers S/net names so "IF" ? I mapped this car for you, let me know and I'll check the files on it. It certainly looks like it flattens off timing or struggles to breath from circa 5200 rpm.

If I didn't map it then I'll just breath a sigh of relief

Andy

 

Dont be concerned, its not you. This thread wasn't started to question the map/mapper but seems to have gone this way unfortunately. But it is helping me to target the area where there could be more.

Not so sure the timing is flat at the top now, and will do a run and monitor timing on handtroller and see whats going on.

Beginning to think that maybe the panel filter in amongst other things is strangling the car, and its not all down to the map.

 

Rob,

I think you are confused. At no point did I question the mapping, it was yourself that started the mapping thread with a question about AFR.

Just because the a map doesn't have additional timing with increasing RPM on a row by row basis, that doesn't mean it isn't appropriate. Some cars need timing removing at the top simply because they are sensitive to det. That is a problem I come across on many UK cars of a certain vintage. Add the 2.5 bottom end and you can run into serious problems trying to get the power you wish.

Some cars just behave nicely and power is easy to get, other can be a pain.

 

Fair play.!

Not having a pop at anyone, including the person who mapped my car who wasn't you. Initially I thought that possibly the 2.5 could run leaner and therefore see another 20-30bhp, but this theory has been pretty much knocked on the head unless I want to run on Methanol. Hence the post.

I am grateful for all the constructive advice from the best in the business. I have spent a lot of time, effort and money in a very short space of time to get a high BHP/torque car and currently feel like I am on a mission, and just want to be sure I am getting the very best from my specification.

They should put a warning sign on rolling roads ... They are bad for your health and sanity.

Going back to my ported bid valve pinto days, I can imagine ported STI heads would make a big difference. IMHO not convinced about the difference a larger exhaust would make, and panel filters are not great for big BHP either. Its possible I could gain a few more degrees more timing at the top.

I would say considering UK heads panel filter, exhaust, that a bhp of around 360 and a torque of 370 would be a great result.

First run before it was hot and got logged was 346bhp and 360ft/lb. So I am probably only chasing 20/20 but it all counts.

 

heres mine,i would like the boost to come in slightly lower,but as i have the standard type R gear box im normaly ubove 3500 rpm anyway.

 

On the road I should think the boost will come in at least 500rpm lower

 

yep,on the road i only notice a small amount of lag if im in top gear at around 60mph.im normaly at around 70mph and dont notice any lag.i suppose theres not much wrong with the driving of the car but the map would look better if it was boosting earlier.

 

Nice graph. Somehow I have just got to find away to keep the graph climing above 5250, and possibly ramping up quicker in the mid range as well. Do you know what you timing your was doing between 5-6K. ?