alang and sg72
02 January 2004, 05:59 PM
#61
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That's excellent Callum, thanks. 
Funnily enough, the best chance i get to read these threads is during working hours as well.
Always seems to be something that needs done when i'm at home and never get to divulge the info these give.
Alan
Funnily enough, the best chance i get to read these threads is during working hours as well.
Always seems to be something that needs done when i'm at home and never get to divulge the info these give.
Alan
02 January 2004, 07:15 PM
#62
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Alan
I think where Scotys source is coming from is that if you drag the handbrake (or the clutch) during the run down on the rollers, they calculate the 'drag' figure to be much higher. The high drag figure is then added to the PAW figure to give an inflated flywheel power.
The drag figure for a scoob should normally be in the region of 60-100bhp dependant on gearing. The lower geared cars having less drag than the UKs due to the lower test MPH of the rollers.
Callum
I believe even mild porting of heads/valves/manifolds can provide reasonable gains. I have only done some of the more 'obvious' points on my engine. I believe that's why it has had the highest output by over 25 bhp (on std internals 20g) This is despite having lower lift/duration cams and smaller ports than the Ph2 engines.
Andy
I think where Scotys source is coming from is that if you drag the handbrake (or the clutch) during the run down on the rollers, they calculate the 'drag' figure to be much higher. The high drag figure is then added to the PAW figure to give an inflated flywheel power.
The drag figure for a scoob should normally be in the region of 60-100bhp dependant on gearing. The lower geared cars having less drag than the UKs due to the lower test MPH of the rollers.
Callum
I believe even mild porting of heads/valves/manifolds can provide reasonable gains. I have only done some of the more 'obvious' points on my engine. I believe that's why it has had the highest output by over 25 bhp (on std internals 20g) This is despite having lower lift/duration cams and smaller ports than the Ph2 engines.
Andy
02 January 2004, 07:47 PM
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At the risk of showing my lack of Scoobynet etiquette and ruining T-uk's thread
don't be daft, I'm not one of those "thin skinned jessies" that need private threads and forums
don't be daft, I'm not one of those "thin skinned jessies" that need private threads and forums
02 January 2004, 08:54 PM
#64
T-uk
Andy,
That's very useful indeed. Now I need more knowledge. At £100/pony thats a lot of hours of fun, fun, fun
I guess it might be one of those jobs where the novelty wears off though. The first one's ok, the second one you notice the hands getting cold from the die grinder & the third one you think where the hell's my cheque book
regards,
callum
Andy,
That's very useful indeed. Now I need more knowledge. At £100/pony thats a lot of hours of fun, fun, fun
I guess it might be one of those jobs where the novelty wears off though. The first one's ok, the second one you notice the hands getting cold from the die grinder & the third one you think where the hell's my cheque book
regards,
callum
02 January 2004, 09:29 PM
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Andy
Somehow i don't think i'd like someone pulling my handbrake on at rundown... rollers or on a real road!!
On my last set of dyno runs, I felt my drag figures were quite high and wondered if it was possibly the clutch dragging slightly, but we tried runs with the car being taken out of gear and made no difference we could see.
Only explanation we could come up with was that because the car had been stood outside for so long (2 hours?), the gearbox oil hadn't heated up enough.
Or what else can cause unexplained high figures?
Alan
Somehow i don't think i'd like someone pulling my handbrake on at rundown... rollers or on a real road!!
On my last set of dyno runs, I felt my drag figures were quite high and wondered if it was possibly the clutch dragging slightly, but we tried runs with the car being taken out of gear and made no difference we could see.
Only explanation we could come up with was that because the car had been stood outside for so long (2 hours?), the gearbox oil hadn't heated up enough.
Or what else can cause unexplained high figures?
Alan
02 January 2004, 09:32 PM
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My concern (which may or may not reflect the reality of what may or may not break and in what order 
) over the 2.5 at 7000 RPM and any boost I dare to run is not the rods, the bearings or the block but the temperatures and their effect on the pistons and their tight clearances. 1.4 bar boost is sufficient on my present setup to see the EGT before the turbo at over 900C whilst maintaining an AFR in the range 10:1 to 11.7:1 and the best possible timing I can run... it always gets this hot. I am not keen on going higher, although have barely had the chance given that I only got three weeks normal use out of the car before the gearbox failed. The bore clearance has a wide range of tolerances compared to the actual clearance (factor of two or three!) it seems, but can be estimated to be about half that of a 2.0 STi forged pistons such as on the STi 5 or 6. So it is a case of how much it expands...
Evos also use hypereutectic pistons, as do Supras, and people are happily running these pistons at generous outputs.
It is a question of output, even with the 20G which is a little small for this sort of shenanigans but suprememly driveable, I hope to get near to 450 BHP at 1.4 bar at Star with changes to the setup in hand (freeing up intake, removal of MAF, water injection).
Personally my present feeling with the five months out of the last twelve my car has been off the road is to enjoy it at this level having hopefully finally sorted out the issues. If a piston change is forced then I will reconsider, but +50% on standard output will be a reasonably sensible test.
The prospect of much more than this output as a daily driven road car does not seem sensible to me given my circumstances. I would also hate to lose the low down torque, it makes the car what it never was as a relatively high powered 2.0.
If I break the engine, then I have the option of beefing it up (if I am happy with the rest of the car which should have had a good workout by then to iron out other issues), or buying a used Ruf.
) over the 2.5 at 7000 RPM and any boost I dare to run is not the rods, the bearings or the block but the temperatures and their effect on the pistons and their tight clearances. 1.4 bar boost is sufficient on my present setup to see the EGT before the turbo at over 900C whilst maintaining an AFR in the range 10:1 to 11.7:1 and the best possible timing I can run... it always gets this hot. I am not keen on going higher, although have barely had the chance given that I only got three weeks normal use out of the car before the gearbox failed. The bore clearance has a wide range of tolerances compared to the actual clearance (factor of two or three!) it seems, but can be estimated to be about half that of a 2.0 STi forged pistons such as on the STi 5 or 6. So it is a case of how much it expands...Evos also use hypereutectic pistons, as do Supras, and people are happily running these pistons at generous outputs.
It is a question of output, even with the 20G which is a little small for this sort of shenanigans but suprememly driveable, I hope to get near to 450 BHP at 1.4 bar at Star with changes to the setup in hand (freeing up intake, removal of MAF, water injection).
Personally my present feeling with the five months out of the last twelve my car has been off the road is to enjoy it at this level having hopefully finally sorted out the issues. If a piston change is forced then I will reconsider, but +50% on standard output will be a reasonably sensible test.
The prospect of much more than this output as a daily driven road car does not seem sensible to me given my circumstances. I would also hate to lose the low down torque, it makes the car what it never was as a relatively high powered 2.0.
If I break the engine, then I have the option of beefing it up (if I am happy with the rest of the car which should have had a good workout by then to iron out other issues), or buying a used Ruf.
03 January 2004, 01:17 AM
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Could be soft tyres but it's usually the clutch Alan, remember Sams 370+ bhp run with just an exhaust change on the std evo7 !! That was the clutch dragging.
Your drag figures should be similar to SG72's as you have the lower Sti gearing now and you both run similar wheels/tyres. Steve's last run at Star was after the car was sitting outside for a few hours too.
Your drag figures should be similar to SG72's as you have the lower Sti gearing now and you both run similar wheels/tyres. Steve's last run at Star was after the car was sitting outside for a few hours too.
03 January 2004, 07:40 PM
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Now that this thread has taken over from Drivetrain and projects forum.
(Couldn't resist Am named in the heading)Can anyone tell me the advantages of the J+S Safegard over mappable W/I.Apart from watching your injected water level?
Also is it a big deal when you can't get 5th.
apart from the embarassment of ripping away only to be caught up. As you coast along trying to find the right gear!
Would this be an expensive fix?
Steve
[Edited by sg72 - 1/3/2004 9:25:36 PM]
04 January 2004, 01:17 PM
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steve,
don't think jb is talking to you anymore, since your car scared him. I think he fears, that with the 6speed on the 1/4, you might now take him.
IMO the good thing about the J&S is when you get a bad batch of opimax, it should look after your engine. of course if you fit the J&S and then advance and push things nearer the edge you will not get the same safety.
don't think jb is talking to you anymore
, since your car scared him. I think he fears, that with the 6speed on the 1/4, you might now take him.IMO the good thing about the J&S is when you get a bad batch of opimax, it should look after your engine. of course if you fit the J&S and then advance and push things nearer the edge you will not get the same safety.
04 January 2004, 01:44 PM
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Don't think John should have much of a problem
Not now my cars basically a 4 speed with an intermitant 5th
Know what you're saying about bad fuel batches.
Made the mistake of putting BP Ultimate in the tank.
Car was Detsville.
What with the NF shortage. Tis an awfy job when you get to these states of tuning and I can understand John Bs concerns with getting it right.
Won't be expecting to get my car any further on until the Spring.(That's if it's still here. I am getting big pressure to stop feeding the beast and set it free.)
We'll see.
Steve.
Not now my cars basically a 4 speed with an intermitant 5th
Know what you're saying about bad fuel batches.
Made the mistake of putting BP Ultimate in the tank.
Car was Detsville.
What with the NF shortage. Tis an awfy job when you get to these states of tuning and I can understand John Bs concerns with getting it right.
Won't be expecting to get my car any further on until the Spring.(That's if it's still here. I am getting big pressure to stop feeding the beast and set it free.)
We'll see.
Steve.
04 January 2004, 06:00 PM
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Bob I am using an RS51 meter and K type 3mm probe at the top of the uppipe. It is a new probe, but previously running them over 900C never gave a problem, althoug Harvey mentioned he has moved onto 5mm probes because of losing them. I suppose the present probe could be over-reading as it is the only one I've tried on this setup, but I would be surprised.
sg72 I think the J&S and the water injection should be considered separately although I suppose they can both protect your engine and possibly enhance performance. As per Andy's suggestion I am going to just inject neat methanol from a separate tank on a boost switch I think.
sg72 I think the J&S and the water injection should be considered separately although I suppose they can both protect your engine and possibly enhance performance. As per Andy's suggestion I am going to just inject neat methanol from a separate tank on a boost switch I think.
05 January 2004, 12:17 PM
#76
John: YHM.
The probe you showed me is thinner than 3mm from memory. Originally I used a thinner probe as supplied with the guage from SPA. After going through two or three of the thinner ones I went to 3mm of which I have lost the tip on one now I have looked in my folder. It may be to do with rapid heat and cooling, expansion and contraction. The probe in the headers is O.K. but the down pipe one has gone frequently so now I carry a spare.
RS 228-7489 Thermocouple type K MI, St.St. sheath 3mm x 250mm
Gland 158-610 s/s 3mm bore 1/8 BSP.
Hope this helps.
The probe you showed me is thinner than 3mm from memory. Originally I used a thinner probe as supplied with the guage from SPA. After going through two or three of the thinner ones I went to 3mm of which I have lost the tip on one now I have looked in my folder. It may be to do with rapid heat and cooling, expansion and contraction. The probe in the headers is O.K. but the down pipe one has gone frequently so now I carry a spare.
RS 228-7489 Thermocouple type K MI, St.St. sheath 3mm x 250mm
Gland 158-610 s/s 3mm bore 1/8 BSP.
Hope this helps.
05 January 2004, 02:25 PM
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397-1264 
is actually what I've been using, still 3.0 mm but different to the one you mentioned. I'll compare the specs of both.
Mineral insulated J & K thermocouples
Very rugged and flexible
Particularly suitable for high pressure, high vacuum or high vibration applications
Max temperature of probe 1100°C (K) 760°C (J)
Plain pot seal (max temp 180°C)
It is a few pounds more and not stainless steel based. I wonder which is more rugged? None of these ones I have used have failed, although they've not been beyond 930C.
[Edited by john banks - 1/5/2004 2:28:11 PM]
is actually what I've been using, still 3.0 mm but different to the one you mentioned. I'll compare the specs of both.
Mineral insulated J & K thermocouples
Very rugged and flexible
Particularly suitable for high pressure, high vacuum or high vibration applications
Max temperature of probe 1100°C (K) 760°C (J)
Plain pot seal (max temp 180°C)
It is a few pounds more and not stainless steel based. I wonder which is more rugged? None of these ones I have used have failed, although they've not been beyond 930C.
[Edited by john banks - 1/5/2004 2:28:11 PM]
06 January 2004, 02:26 PM
#79
OK John, the man who Bob knows who I know he say Evos with these cast pistons with the fancy name have bore clearance .8 to 1.6 thou.
Now that has to be good news for you because although it is a lot more than the U.S. 2.5litre it is also a lot less than you would run with forged pistons so I conclude the manufacturers have a lot of faith in the expansion or non expansion properties of these high silicone content pistons. I just hope that they can handle the heat when you run lots of power as I expect you will, with EGTs in the 920-940 deg C range.
Now that has to be good news for you because although it is a lot more than the U.S. 2.5litre it is also a lot less than you would run with forged pistons so I conclude the manufacturers have a lot of faith in the expansion or non expansion properties of these high silicone content pistons. I just hope that they can handle the heat when you run lots of power as I expect you will, with EGTs in the 920-940 deg C range.