Jump to content

dicko

Newbie
  • Content count

    19
  • Joined

  • Last visited

Community Reputation

0 Neutral

About dicko

  • Rank
    Newbie

General Info

  • Location
    Australia ACT
  • Car Type
    Nissan Silvia
  1. Useful info about the rate of change between duration and rpm of response, thank you. I've sent a request for info to a Tomei dealer about running the Poncams with hydraulic profile in a solid lifter head. For the info of others there is also a Tomei 256 duration Procam, but it is specified as lash type.
  2. Because of the duration and lift are better or at least similar, or because I don't have to convert to hydraulic head to run them? Both? Also it's been my engine builder and my decision the set the rev cut to 7000 because we didn't think sr's were reliable beyond that in terms of valve train. This particular motor and iterations thereof has had 3 previous terminal valve train failures for the previous owner. These were blamed on holding the car on the limiter for extended periods, and also when we rebuilt it we noticed some evidence of valve touching pistons, which we have corrected by flycutting pistons. I'm forming the view that the rev limit can probably be increased with a solid head and either 256's or 260's, which might also extend the powerband at the top end. This might be something like a 7500 cut which will allow revs safely to 7300 without having the limiter kick in. Again not looking to chase higher power at this rev range, and I expect the wastegate would be bleeding off boost to maintain power at around 200rwkw. Interested in feedback on that?
  3. If we can, can we direct this back to topic and a couple of technical questions which haven't been closed off - as my first post, my understanding the 'why' for me is as important as the advice so I can better understand the relationships between cams/ boost/ compression/ turbos and manifolds. Main things I'm not clear on: @as Niknuk was saying, a motor flowing 200kw should be flowing the same air, whether that's achieved by boost or static compression. I understand that the turbine and internal wastegate will struggle, but it has an external wastegate (tail 38mm I think). The situation we are looking at here is that boost will bleed off through the external wastegate probably from 5000rpm. In it's current tune it has 185rwkw (5500-7000) (Unigroup dyno) on 10psi (170rwkw at 5000). More boost wasn't applied at the last tune because the spark was blowing out (incorrect plug gap). There is no reason to suspect the turbo couldn't flow 16psi (previous owner had it running that and maybe a touch more - and I think that tune ran very rich to keep exhaust manifold temps down). At 16psi and on rule of thumb 2kw? per psi we are close enough to 200. With a tighter tune this setup is already at desired power, it's just about moving that powerband down the rev range. So with revised tune we could be hitting near enough to 200rwkw from 5000rpm, beyond that boost would be bled off by the electronic boost controller and external wastegate (I assume) and so bypassing the flow limitations of the turbine. If I have this wrong, could someone give a technical explaination - as I haven't grasped this properly from the otherwise good advice posts so far? (Thanks everyone for te posts so far and helping me with this!) @where is torque in all of this? I only have a limited understanding of relationship between torque and power, but good low down torque is also on the want list for rally. The higher static compression, in my mind, would be helping torque in the 2500-4000 rpm range and the combo of static compression and whatever boost the turbo can spool up by then should be combining to give more torque than comparing to say 9.5:1 and the T28? Or have I missed the relationship/ importance of cams in this? @the use of a hydraulic profile cam, in a solid lifter head. We all know not to do it the other way around, but is there any experience this way round? (Other than it would be a waste of money setting it up to then use a hydraulic cam, and need more maintenance) I'm listening carefully to the fix the motor vs buy a new stocker discussion. As this is competitive Motorsport with significant commitments of time and money just to turn up on the start line, bolting in secondhand motors that are untested and unproven is generally not a good way to get the best value out of Motorsport overall if you've bought a dud and it pops. The amount of testing that can be done outside of competition is very limited - it's not like you can drive around as a daily for a few weeks prior to a race and work out if anything in the second hand motor needs attention. So factoring in the turnover cost also would need to consider at least a half pull down and check, as a minimum (good to see some costs on this in posts above- thank you). Thanks again to everyone who has contributed - if we can get some more clarity around the tech questions above that would be awesome! Thank you!
  4. Johnillite - nice Vid. The power graph looks very good for rally, assuming the tail off in the upper end isnt the setup stopped breathing and is fuel pump as you say. 90-ish rwkw by 3200, 150-ish rwkw by 4000, and near flat around 180-200rwkw from 4500-redline. Was this ever converted to E85, or could anyone point to a similar spec car on E85 dyno graph?
  5. Lots more great advice - thank you everyone. Yes selling the motor and going back to stock is controversial but I understand the logic. Money in the pocket (tits and rack LoL) and closer to the powerband desired. It is controversial but good advice. I think that the high static compression / E85 setup that I currently have, once tuned for smaller cams, stock inlet manifold and the T28 SHOULD have benefits in the low and mid range area compared to the stock compression ratio. It should help spool and low end torque. For this reason i'll do cams/ inlet manifold/ turbo and a tune first, then consider selling second if the benefits over a stock mid/ low end response are only marginal or none. Would I do a built motor if it was me starting from scratch - no, but since it is already in the car it seems more PITA to start over than bolt a few more mild bits on. To confirm a few of the questions asked: *Gearboxes are open - the car runs a Z32 box with Giken close ratio gearset *It is supposed to be standard turbo's. *Management is a Link G4 *Car already has a 4.6 diff The HyperGear thread was very useful - thanks Skepticism. Good dyno comparisons between different mods and turbos. Assadd11 and others - we know you shouldn't use solid profile cams with hydraulic lifters due to valve float etc, but does anyone conclusively know that you shouldn't use hydraulic profile cams with solid lifters? Since the hassle of converting to solid is already done, (and the rally car doesn't do many kilometres that maintenance of lash is a real problem), I am considering retaining the solid setup but with a hydraulic profile cam. I have been running the BC272 which is a hydraulic profile for circa 2500km of which 1000k's was competitive racing so far, and there doesn't seem to be a issue wrt mismatch of solid lifters on the hydraulic profile (although I haven't pulled it down to check lobe wear/ etc yet). There is conflicting info on the web about the duration of stock cams, but my summary of the best low range cams is as follows: Stock S13 DET - 240 duration with 9mm lift Stock DE - 248 inlet with10mm lift, 246 exhaust with 9mm lift, Poncams - 256 with 11.5mm lift. Its a hydraulic profile but I'm yet to see anything that says you cant run hydraulic on solid lifters (but you don't want to do it the other way around) . Procams 260 with 12mm lift - smallest profile solid lifter cam So that gives me a good range of cams to consider. If stock isn't breathing above 6000, the rest probably would. Poncams seem the pick duration and lift wise. I'm keen to understand more about why the high static compression ratio is considered outside the range of the t28. Remembering its running a external wastegate and electronic boost controller, when the motor is higher in the rev range, and given only 200rwkw target, excess exhaust manifold pressure will be bled off instead of having to pass through the turbine. So my understanding of turbo theory must be missing something? Thanks again everyone
  6. The engine builder set it up for me using a dial gauge and experience. He never did tell me what it was set at, so sorry I cant pass this info along. It ran untuned for a couple of races, then got a tune but not a proper one and cam timing was not examined. 180rwkw at 8psi, 160rwkw at 5krpm. T25G turbo. Of interest on strip down my motor which had 272's in it had piston damage from valve strike, we flycut the (flat top) pistons on rebuild to be safe. Phone BC in the States would be my advice.
  7. Awesome responses thank you everyone. To clarify a couple of things: Yes, have to retain the original motor, so only sr20. I think the regs may also prohibit the VCT as well, which is a bummer. My bad on the direction the internal wastegate is lock wired - it is indeed wired shut. It didn't make sense after I wrote it and I double checked on a spare turbo today. The high static compression (and as a result E85) is all about helping off boost power and building boost quickly. In theory I assume the E85 also allows more timing as well as boost, but with the choice of either a T25G or T28 it may not be too critical as I understand neither of those turbos can really achieve very high boost levels anyway. Yes the BC cams are a hydraulic profile. Probably not the best and regardless we all agree the wrong duration and lift choice for this application. So is it a definate that the S14 inlet manifold won't fit on the S13 redtop? Keeping in mind there is no emissions controls or anything similar left in the engine bay to worry about. Or are the differences between the S14 and S13 inlet manifolds in terms of powerband benefit so slight it isn't a big deal? Longer runners improve low down torque by 'straightening' the air removing small pockets of turbulence and getting better flow over the valves and into the cylinders, or so the theory goes. Probably less important with turbo applications but certainly that's what happens in NA. I'm sure Nissan didn't do it like that for no reason, as shorter would have been cheaper to produce. Seems like no love for the T25G. I'm guessing the 0.64 turbine version of the T28 would be the pick then? Any further advice around that? A few cam suggestions - HKS264's, and procam 260's and avoid stockers. Any love for the Unigroup stage 1 cams? Do they even do them anymore? The BC264's sound too big if they aren't working below 3000rpm. The NA cams sound like they might be worth a look if they are going to continue to breathe after 6k. Dialling back the existing BC272 cams would help and save cash, but it seems like a long way to dial and may end up causing other issues, compared to buying new cams that are the right ones? Selling the motor for a stocker is probably a logical choice, but given it's all done already I'll see how much of a difference the high comp/ E85 makes to early rpm powerband, and if it is nil or marginal then consider selling it. Thanks everyone who's contributed so far, great tips and much appreciated.
  8. I have a highly modded RWD SR20DET (red top), but it isn’t performing as I would like. Basically the powerband is too narrow and high in the rev range. I’m fairly new to SR20’s and turbo cars in general. Can anyone help me out? The motor is in a gravel rally car. The ideal attributes of a 2WD gravel rally car are: No lag A fairly progressive (i.e. linear) power curve (to limit uncontrolled wheelspin) No need for more than 185-200rwkw (as you can’t put that power to the ground on gravel in a 2WD car) On boost as early as possible in the rev range Big torque down as low as possible. Targeting 150rwkw by 3500rpm (earlier if possible), max power in by 4500rpm (earlier if possible) Motor shouldn’t need to spin over 7000rpm Reliable (Fairly similar to a good/basic street setup?) The motor already has had a fair bit of coin spent by previous owner, and currently has: E85 setup (1000cc injectors/ fuel rail/ pumps/ surge tank/ etc) 11.4:1 static compression Billet crank, forged rods and CP pistons Custom exhaust manifold, similar to a twin scroll/ scavenging setup, very professional External Tial wastegate plumbed back into dump pipe (feeds primarily from cylinders 2/4 on header manifold but is fairly close to collector) Custom dump pipe and 3’ exhaust, no cat, very minimal muffler BC Stage 3 cams – 272 degree with 12.5mm lift Solid lifters, Tomei rocker stoppers, BC retainers and springs, adjustable cam gears T25G turbo? I'm guessing its a T25G, it has 0.86 turbine housing and a 0.8 compressor housing and looks (to me being a noob) like the stock S13 turbo. Internal wastegate is currently lock wired full open(?) Electronic boost controller Inlet manifold of unknown origin (single plenum and throttle body, with short/straight inlet runners), all vac lines disconnected/plugged (external oil catch can) Unknown Nissan throttle body Runs a Link G4 Stock intercooler/ water spray bar/ 2 ¼ inch inlet piping Pod filter At this stage, I am looking primarily for advice around the following as I think these are the areas where I can most easily achieve my goals: Which stock SR20 turbo would be the best for this application – i.e. T25G or T28XXXX, and what trim/ wheel size combo etc. The rules permit only OEM Nissan stock SR20 turbos to be used - nothing else. Is lock wiring the internal wastegate full open and relying on the external electronic boost controller a smart move? Surely with the wastegate open all the time this is slowing the build of boost? For the target power and revs, could that be accommodated by the turbine alone and the internal wastegate lock wired full shut, or do I need something to control the internal wastegate so it’s switchable? Which inlet manifold to use. I’m thinking S14 or S13 would be better than the large plenum type, given the longer intake runners to bring the mid-range torque up, and of the two I am thinking that the S14 one has longer runners and should be better? Are they bolt up to the S13 head? Would a throttle body setup be of any benefit (i.e. the EFI concepts ones)? What throttle body would best suit (does it need to be a larger one than stock if I am only chasing less than 200rwkw)? Which cams would work best for this desired powerband? With the minimum of compatibility conflicts with the rest of what is in the head already? Is there anything else I should be doing to make it better? I’m interested in the ‘why’ as much as the recommendation. All advice greatly appreciated – as I am fairly noob at SR20! Thank you!
  9. I had the same problem with mine. Cam card was useless. Stage 3 BC0206 cam into a S13 SR20. BC were also unable assist much from memory (purchased direct) - the guy I spoke to on the phone in the US did try to help, but when I relayed the information received to my engine builder he said that the advice made no sense. In the end we dialled it in on first principals and the adjustable cam gears. Cant remember settings sorry, and I have never been that happy with how high the powerband is (might still not be dialled in right- haven't revisited it since initial build. Following
  10. Further research on this is that the Bosch injectors have a circa 7-10micron filter basket in the injector. It makes sense to have an inline filter of 10 micron to make sure that gunk is filtered prior to starting to clog the injector basket filter which is harder to service. Also in reference to e85 keeping the system clean further internet reading indicates that seems reasonable except for some overseas reports of black goo accumulating on the injector tip, which was blamed on poor quality petrol comprising the circa 15% content of the E85 - under atomisation additives in the petrol were crashing out leaving behind a deposit that could be dissolved by using a full tank of petrol or using an in tank injector cleaner. So on the assumption is a dumb idea to remove the injector filter baskets, the 10 micron filter just prior to the fuel rail stays (may make it a bigger surface area filter), put in a new 100 micron filter prior to the fuel pump and consider a circa 30-40 micron filter somewhere in between. A fuel system flush is also required - I'll try to 'wash' the drained fuel through the 10micron filter and reuse it.
  11. That is very interesting if true. GM essentially saying the reliability of clogged filters is more of an issue than putting dirty fuel through the injectors. Perhaps the E85 has an ability to keep injectors clean in much the same way as it will strip gunk from anywhere else it comes into contact.
  12. S13 Track only car running dedicated E85. The fuel system currently is as follows: Stock fuel tank with stock in tank fuel pump, via Speedflow inline micro filter 45micron, to auxiliary tank, Bosch 040 pump to engine bay, Speedflow 10micron filter prior to the fuel rail. Exit fuel via regulator back to auxiliary tank and another 45micron inline Speedflow micro filter. The fuel rail is an EFI Concepts rail and uses 1000cc Bosch Motorsport injectors. Now the issues with this setup is that the fuel filters clog really fast - like I get 8km of race or so before the fuel pump starts squeeling, I then have to pull the 10micron filter out and scrub all the cap out of it with a toothbrush and fuel. If not, it won't rev over 5000rpm and worse when its under load, down on power and clearly starving for fuel. No questions I have bad fuel onboard which is highly contaminated (my fault I filled up once using an old metal jerry can) but before that even with using drum only E85 the same issues existed only got 200km or so on a filter. So questions: Given the massive injectors, what micron would be appropriate for final pre-injector filtration? Assuming that micron is used pre fuel rail, what size micron filter would you use pre main fuel pump? I've been thinking about using a large canister size 100micron filter to capture most of the junk pre main pump, then a smaller canister size 45micron before the rail. 10micron seems excessive for such large injectors, although I have no idea reasons for wanting such clean fuel wrt injectors. Thanks for any tips!
  13. Looking for an (ideally aftermarket) quad throttle body / individual throttle body (ITB) setup to suit an RWD SR20 (S13 Silvia). My preference is not to use GTIR's, but may consider if the price is right. Ideally looking for a complete setup ready to bolt up but will consider whatever you're got. PM me please.
  14. Wtb Silvia s13 bonnet stock. Condition and colour not important so long as it's reasonably straight. $150. Pm me please. I'll pickup between canberra and sydney. Also looking for a stock front bar and/ or bumper reo.
×