Ian C Posted August 7, 2003 Share Posted August 7, 2003 Remember my loooong old post about EGTs and taking out the restrictor ring and upping the boost and getting a marginally *slower* car? Well, I've got the next installment for you lucky people I installed HKS 256in 264ex cams just in time for 10otb2 and the car felt stronger in the upper ranges, but I felt like performing a more empirical test. Thankfully, I had my baseline setup results to compare to. The differences in the new setup compared to the baseline setup were: Higher ambient temperature by about 5 degrees Both windows down instead of one 1/4 tank of fuel instead of 3/4 Again, I had a co-pilot video the Apexi unit during all this as it's pretty damn accurate and it's a digital readout. I played the footage back on my PC in editing software so I could step through each frame and note the times, accurate to 0.04s, of each 10mph transition. It's not exactly going to qualify as NASA level science, but it's a darn sight more accurate than watching a speedo and counting in your head The results allowed me to compare full acceleration from 80mph to 130mph (obviously on a test track), with two gearchanges (3rd to 4th to 5th) between the three setups - base, base + high boost - restrictor ring, and base + cams. Base + cams got from 80mph to 130mph 0.6 seconds faster than Base. It took 9.5s rather than 10.1. Result, I think! OK, it might not sound like much but I think it takes quite a healthy power improvement to knock over half a second off that speed range. Base + high boost - restrictor ring was 2.3s slower , so those running mad high boost on stock twins may reconsider doing so, you may be stressing your engine while actually losing power. Of course, this is only my car, others may vary Conclusion - HKS cams rock, basically. I also got some other measurements during a mad moment. The margin for error may be higher for the braking results as the Apexi unit couldn't keep up - it read over 20mph by the time the car stopped but the video footage sound and motion of the poor sod holding the camera gave a very clear reference point to the stopping of the car Oh, and I wheelspan like mad through 1st gear. Anyway, enough waffle: 0 - 60 = 4.6s 0 - 100 = 9.5s 60 - 0 = 3s 100 - 0 = 5.2s 0 - 100 - 0 = 14.7s Suffice to say, I'm happy with that -Ian Quote Link to comment Share on other sites More sharing options...
Marco Posted August 7, 2003 Share Posted August 7, 2003 Look at those stats! :blink: Job's a good 'un Quote Link to comment Share on other sites More sharing options...
Sharpie Posted August 7, 2003 Share Posted August 7, 2003 Nice testing and conclusion Ian (No I'm not taking the pi$$ Terry ) I assume that you kept the stock cam gears in, right ? Quote Link to comment Share on other sites More sharing options...
dandan Posted August 7, 2003 Share Posted August 7, 2003 ian, what other mods are you running? Stock turbos and intercooler? What sort of boost did you get those results at, and are you a jap or uk owner? Sorry for the questions, just wondered how much it takes so achieve similar performance. Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted August 7, 2003 Share Posted August 7, 2003 He's got stickers... That's why his car goes well He's got 4 or 5 each side, gotta be worth 100 bhp! Sorry, couldn't resist... And jealous 'cause he beat me Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted August 7, 2003 Share Posted August 7, 2003 Nice one Ian. The underdrive pulley probably helps. I found the same cam combo delayed spool by approx 200-300 rpm. Bit like stallion spray aren't they. Stays harder for longer..... Quote Link to comment Share on other sites More sharing options...
Alex Posted August 7, 2003 Share Posted August 7, 2003 Originally posted by Terry S Nice one Ian. The underdrive pulley probably helps. I found the same cam combo delayed spool by approx 200-300 rpm. Bit like stallion spray aren't they. Stays harder for longer..... This test was after the previous baseline test with the U/D Pulley on already so the .6 sec improvement from 80-130 was entirely down to the cams as there were no other changes. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted August 7, 2003 Share Posted August 7, 2003 cool, I am surprised it made that much difference. Did you get bolted in again mate;) Quote Link to comment Share on other sites More sharing options...
Alex Posted August 7, 2003 Share Posted August 7, 2003 Originally posted by Terry S cool, I am surprised it made that much difference. Did you get bolted in again mate;) LOL - no I've been left to rot! He's got a new bolt-in passenger B@stard Quote Link to comment Share on other sites More sharing options...
dude Posted August 8, 2003 Share Posted August 8, 2003 Originally posted by Terry S Nice one Ian. The underdrive pulley probably helps. I found the same cam combo delayed spool by approx 200-300 rpm. Bit like stallion spray aren't they. Stays harder for longer..... Still buying that by the case are we dude ??????????????? John:flame Dev Quote Link to comment Share on other sites More sharing options...
Ian C Posted August 8, 2003 Author Share Posted August 8, 2003 Peter: Yes, stock cam gears in place. Terry told me he got some and found to his dismay that the optimum setting was... stock. You got increases in power *or* torque by adjusting them, yes, but only at a larger loss of the other... Dandan: I've got a mysterious set of hybrids, FMIC, uk spec injectors, walbro pump, CW set the fuelling up with an Apexi AFC, there is a lightened crank pulley in there somewhere as well. Also some ducting and heat shielding knocking around the engine bay. It's a Jspec and I run 1.2 to 1.3bar of boost, depending on atmospheric conditions and my whacky boost controller. Higher boost actually slowed the car down, probably due to it heating the intake air too much. Terry: More of a gain than I was expecting, but I'm not complaining I haven't noticed a difference in spool and I haven't yet tried wringing it's neck to see what it feels like up to 7k rpm but I'm sure I shall try, see if it does work like 'stallion spray', heh (notthatIwouldknowwhatstallionsprayislikecough). I didn't notice a low-down power loss either, which is good news, but the 1st turbo spins up a little slower now I think. Matt: You obviously don't have enough stickers Or plastic t-pieces, I believe that was your excuse on the day -Ian Quote Link to comment Share on other sites More sharing options...
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