Jump to content
The mkiv Supra Owners Club

More power gained


Paul Whiffin

Recommended Posts

Alright chaps,

 

Went back to G-force rolling road yesterday, managed to coax another 67bhp at the flywheel out of it! Now got 587bhp & 543lbft torque, messed around with cam timing and a bit of ignition, nice. Also found some nice gains in the mid range as well. More power to come soon...

 

Big thanks to Chris at G-force, nice geezer and most helpful.

 

 

Paul

Link to comment
Share on other sites

Boost peaked at 1.95 bar but still dropping off to about 1.76 which would suggest the turbo can't handle it or may be need a higher pressure wastegate spring. Ran on Optimax 98, no additives. Added 3 degree of advance in certain areas, also put cam timing to zero, couldn't believe it but my pulleys had moved, I originally set them about 1 1/2 years ago approx to ex -3 and in +1, when I looked yesterday they were ex+1 and in 0! Not good, I'm going to be checking that a bit more often from now on me thinks...Annoying thing was one of the pulley bolts rounded off so I couldn't try retarding the ex cam anymore, I gained around 10bhp at the wheels from putting it back from +1 to 0, I reckon there's another easy 10-15hp from retarding it a couple of degrees so that should see over 600 flywheel me thinks. More power to come though soon...

Link to comment
Share on other sites

Guest Terry S

Nice one mate. I have said before, but we found the best combination of BHP or Torque was the stock settings. We could get more peak bhp or torque by altering them but the affects were negative elswhere, i.e we'd gain say 30bhp but lose 40 ft lb of torque & visa versa. How many degrees timing are you running now??

Link to comment
Share on other sites

Originally posted by Terry S

Nice one mate. I have said before, but we found the best combination of BHP or Torque was the stock settings. We could get more peak bhp or torque by altering them but the affects were negative elswhere, i.e we'd gain say 30bhp but lose 40 ft lb of torque & visa versa.

 

Agreed. Stock settings are pretty good for the majority of inlet cams for road use. OK, 272's can be played with a little but like you say you do have a bit of a trade-off at other points.

 

We nearly always run between 2 and 3 degrees advance on the exhaust with 264's though- it gets on the boost earlier but you have to be careful and watch EGT's....

 

Nice figures Paul. Only thing I would mention is that 1.75 bar seems a little high though- I'm sure with some further tweaking you could make the same power with less boost. Do you have forged pistons and rods?

 

Cheers,

 

Nathan.

Link to comment
Share on other sites

Guest Terry S
Originally posted by Nathan

Nice figures Paul. Only thing I would mention is that 1.75 bar seems a little high though- I'm sure with some further tweaking you could make the same power with less boost. Do you have forged pistons and rods?

 

Cheers,

 

Nathan.

 

Paul is actually running 1.95 bar around 28 psi. He previously had the timing backed off so that was OK. Must be very near the limit of det now though I would have thought. Weather is probably helping though.

Link to comment
Share on other sites

Guest Terry S
Originally posted by Paul Whiffin

I'll show you my ignition map at Santa Pod in a couple of weeks if you like, as long as the weather is ok of course....Wouldn't mind having a butchers at yours as well, I'll show you mine if you show me yours and all that!

 

Deal.

Link to comment
Share on other sites

Nope, std engine, I wont be running that boost all the time, only on the odd occation for drag racing, most of the time it will be 1.5bar max. If it does blow though its a good excuse for a fully sorted bottom end! I think its the turbo limiting the power, but then I originally bought that particular kit for good driveability and not outright power. I could get a bigger turbo and run less boost and have the same amount of power or more perhaps but then the power will come in 500rpm or so later, can't have everything I suppose. I may go down this route when I get bored with what I have though....

Link to comment
Share on other sites

Originally posted by Paul Whiffin

Nope, std engine, I wont be running that boost all the time, only on the odd occation for drag racing, most of the time it will be 1.5bar max.

 

Ah...thats better....you know it makes sense ;-)

 

I must admit- I take my hat off to you for being able to hit 1.95 bar on pump fuel without EGT's going crazy from loads of ign retard.

 

I do see your logic with regards to using an engine blow-up as an excuse for going forged though...honestly I do...;-)

 

Cheers

 

Nathan

TDI PLC

Link to comment
Share on other sites

Guest Martin F

Paul - would you care to share the make of your pulleys that have slipped. I think most of us have heard that some are worse than others. I guess you torqued them up properly when you originall fitted them, perhaps medium threadlock may be an idea.

Link to comment
Share on other sites

Originally posted by Martin F

Paul - would you care to share the make of your pulleys that have slipped. I think most of us have heard that some are worse than others. I guess you torqued them up properly when you originall fitted them, perhaps medium threadlock may be an idea.

 

IMO adjustable pulleys, unless really well made and with some positive locking device, should be considered development aids only, after a cam offset is decided a stock pulley should be returned with offset key or dowel, made to achieve the desired timing change. Probably a bit OTT for a slow revving road engine, but I wouldn't trust a vernier pulley that just relied on friction clamping the 2 halves together. Multiple hole with peg vernier ones are fine though, but never seen any *S-GTE ones.

Link to comment
Share on other sites

Originally posted by Paul Whiffin

Alright chaps,

 

Went back to G-force rolling road yesterday, managed to coax another 67bhp at the flywheel out of it! Now got 587bhp & 543lbft torque, messed around with cam timing and a bit of ignition, nice. Also found some nice gains in the mid range as well. More power to come soon...

 

Big thanks to Chris at G-force, nice geezer and most helpful.

 

 

Paul

 

Good figures, nice amount of torque! Still feel you are pushing your luck with that much boost on pump fuel, probably OK for short rolling road pulls, wouldn't want to do 12 laps of a circuit in the summer with that much boost and pump fuel though. Not for me to interfere, but why not try 5 gallons of race fuel, and see what she can REALLY do. Adding some advance and pulling some excess fuel really wakes a turbo engine up :-)

Link to comment
Share on other sites

I've got HKS ones on my car, I used to use those dowel type vernier's back in my mini days, £50 for a complete adjustable timing gear kit, used to leak like a bitch though.

 

Dont worry I'm not going to bomb round a track all day with that sort of boost, no way jose.

 

I was going to try some race fuel at some point to see what the difference is like but then I wanted a real world power figure, can't see the point unless your going to run the stuff all the time.

 

 

Paul

Link to comment
Share on other sites

I asked which fuel would be best for me using on track with a non-mappable ECU.

 

******************************

 

Thank you for your mail. It is difficult to say which of our fuels

that will give most power as you do not want to map the car

exclusively for your engine as you then would have a problem with running it on the street (cost that is). I would always recommend to run it neat as that is how the fuel is designed. However, you would improve the optimax by mixing it 50% with either the competition 100 or the RFT (this fuel is specifically designed for turbo applications). I know that properly mapped the RFT is the more powerful but in a case where you have to rely on a previous map the difference might not be huge between these two fuels - the improvement over what you have today should be quite

a lot. the comp 100 meets the British Standards for super unleaded as the oxygen content is 2.7% which is the maximum for BS 7800. RFT has

got 3.6%.

 

 

**********************************

 

Not sure of the actual Octane ratings but I can find out. I think its the chemicals themselves which make the fuel technically more powerful rather than just allowing for more boost. IYSWIM.

Link to comment
Share on other sites

From their website http://www.nutidltd.co.uk/ Order on-line!

 

76 Competition 100 (106RON, 96MON, 2.7% oxygen) - Unleaded

 

A fuel designed for the performance enthusiast who wants a high-octane extremely clean burning fuel. This is the control fuel for Grand AM (Rolex Daytona 24 Hours). It conforms to the BS 7800 (Super Unleaded) and BS EN228 (Premium Unleaded). It is suitable for racing purposes and high performance street vehicles, powerboats, jetskis, motorcycles etc. In fact, engines with compression ratios as high as 14 to 1 will benefit greatly from this powerful clean burning fuel. It is oxygenated to improve engine breathing to improve power in engines with air fuel restrictors. It blends with any pump fuel (for those who wants to boost the octane) and provides great protection for knock (pinking or detonation). It contains no lead or alkohol.

 

------------------------------

 

R FT (102RON, 88MON, 3.6% oxygen) - Unleaded

 

The RFT is specially formulated to provide maximum power for Turbo charged engines conforming to the current FIA Appendix J regulation for petrol. This fuel is developed and blended by a world leader in Formula 1 race fuel technology in conjunction with one of the leading world rally team’s engine department with the aim to develop the most powerful turbo fuel on the market. The high oxygen content of 3.6% combined with special high octane power enhancing 'turbo' chemicals results in improved responsiveness, mid-range torque and power output. Already proven a winner both in Group C turbo engines and in rally turbo engines.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.