jgkurz
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Posts posted by jgkurz
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That is only ONE 'turbo' Isky grind. It is not the 'only' one. You need to call, talk to Ron, tell him what you want, and you will get a cam ground to YOUR specifications and intended usage.
I suggested long ago that JeffP call and talk to Ron, and NOT tell Ron what he thought about overlap, duration, lift, etc....but to just tell him what he wanted performance-wise, and see what Ron came up with. Jeff was a bit upset when Ron mentioned given his specs on the engine that he 'was down a bit on power' (which was around 500 crankshaft HP at the time...)
Jeff P thought that a bit arrogant. Until he ran it on the dyno and made 650+RWHP with the same components, save the cam change...
What one person gets from Isky will not necessarily be what someone else gets. For the same price as the others, you can get a specifically engineered camshaft solution for YOUR particular application with a specific lift, duration, split duration, and lobe center. To me it's a no-brainer...
Tony, I think there is at least a couple Isky L6 turbo cams. I'll see if I can back my claim up with some data. I run an Isky and have been very happy. Stay tuned...
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Great video of folks riding in a GT3..
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Though the irony if someone complaining that they get 'instant' boost should not be lost on the myriad of people who are continually complaining about 'lag' or 'mushy' boost characteristics.
That's what I was alluding to in my above post. I personally wouldn't want to sacrifice tire burning torque for a lesser but flat torque curve unless I did not have to make a sacrifice. I participated in a track day a while back and set the boost on "kill". The car was a handful and had huge peaky power on boost. I blew a boost pipe off during one of my sessions and the car suddenly had a flat torque curve. Not nearly as exciting.
I've tried to build a fun and fast car but there are always sacrifices when asking so much from our little Datsuns. -
Nothing like chasing a 2560 # 450HP race car with sequential shifter...That's a 2008 Cup Car with some 2010 upgrades in it... I'm still rusty from 18 months not tracking the 996TT, so my times were off slightly, but man it was fun reeling him in under braking and corner entry...
More in a few days...
Mike
Really enjoyed your video and the captions. In a way it puts the viewer in the driver seat. The GT3 had a better power to weight but it looked like you were out braking him. Are your brake upgrades superior to the GT3?
BTW, your car is amazing quiet for the power level.
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Interesting topic. My turbo L28 with a Weber 60mm TB also has a hair trigger boost response. I liken it to a two-stroke or a Porsche 930. Wait for it........wait for it........ wham! Modulating throttle on my car at peak torque is near impossible. I had RTz drive my car a while back and he had the same conclusion. I always thought these characteristics were due to having a larger turbo. My turbo is some weird custom Innovative jobby that is not ball-bearing or as efficient as a Garrett GT series but it flows well for it's size. I'd like to upgrade to a GT35R some day to see if I gain any low-end boost response. What we all really want is a nice flat torque curve. I really doubt you could make a significant improvement in throttle modulation manipulating the throttle assy. If you added an eccentric cam wouldn't you sacrifice peak torque to flatten the curve? Cool idea BTW. Adding cubic inch, improving airflow, optimizing timing and adding an efficient BB turbo are the easiest non-exotic ways in my opinion.
-John
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I have all my pipes beaded. It eliminates the hassle of pipes popping off.
Thanks for sharing!!
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I'm a Spicer fan but Neapco should be just fine, especially the Brute Force model. You will gain some strength by going to a solid non-greasable joint. Any competent local drive axle should be able to identify the correct u-joint vs. mail order from MSA. Are you running a customer driveshaft or the original? I ask because your OEM driveshaft may not be have replaceable u-joints. I might be mistaken but that's what I vaguely remember.
-John
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I have the same setup as you on my 240z and found that even with the prop valve all the way open I was always locking the fronts first. So I went with a more agressive pad in the rear (higher coefficient of friction) and now the prop valve actually makes a difference. I will say that I had always read that the fronts do most of the braking so was very pleasantly surprised how much harder I could brake when I had the rears properly set up.
The 280z weighs more than the 240 so I'm not sure how the balance f/r is affected, but once you solve the issue of the right front locking, I'd suggest you find a safe place to gradually add more rear brake and see if you can ever get the rears to lock first. I suspect you'll find that you can't.
Excellent post. Thank you. I will be switching out the front left caliper soon to fix the unequal braking behavior but the bias is also a concern. My hunch matches your suspicion. I don't think I could ever lock the rear brakes with my current setup. I use the Porterfield R4S pads which are the most aggressive street compound I know that don't require a warm-up. What pads do you use in the rear that would provide a higher coefficient of friction?
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good luck should be pretty easy.... i ran 11.1 @ 127 using BFG DR 680 cc injectors, 15PSI on stock turbos and stock GTR intercooler
I ran 11.3 @ 124 with a 1.725 60ft on Bridgestone RE750's. They work well on a superbly prepared track but are useless if the track surface is marginal. Since the car is never driven in the rain I might go to a DOT competition tire. I'd like a tire that would work well for autocross and the occasional trip to the drag strip.
I'm considering Proxes RA1.
Side note: You probably know this but NHRA will boot you off the track if you don't have the necessary safety equipment when going faster than 11.49.
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Yes, but I'm lazy and will likely just replace the suspect caliper under warranty so I don't have to bleed twice. : )
Correction: my calipers cannot be moved between sides. They are left/right specific... Not sure why I thought they were interchangeable.
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Its tiny...
The stock T3 is tiny. The T3/4 hybrid that 1979280zx mentions is a decent upgrade that should get him to 400crank HP if all the other supporting parts are in place. Personally I'd say the smaller 50 trim T04E compressor wheel is a better fit for the L28. The compressor map for the 50 wheel is superior is most every way as compared to the 57. The setup he mentions will bolt in to the stock location with the .50 A/R housing. Anything larger will hit the exhaust manifold unless a spacer is used.
So my answer to his question is yes but with a 50 compressor wheel and a stage 3 turbine T3 wheel. The T4 57 or 50 compressor wheel will outflow what a stock T3 turbine wheel can handle.
If he wants a slightly larger turbo over stock then go to a T3 Super 60 compressor or maybe even a T04E 46 trim with the stock turbine.
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I've got 2 CLSD's for sale, will PM with prices and info.
Thanks.
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I know this is probably the most sought after item in the Z community but I thought I would start here just in case. I'm looking for an 1988 or 1989 300ZXT R200 differential with the clutch LSD and 3.7 gears. I cannot use a viscous R200 from the 1987 300ZXT SS. I'm not looking to low ball so please contact me if you have a working unit for sale. I have cash ready.
Let me know.
Thanks!
jgkurz1 at gmail
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I have run R4S pads (S-Street...) for years without issue. You run the R4 compound and you will have exaggerated issues. But R4S's on the street dust a bit and squeal under light braking, but under panic situations, they bite just fine.
My immediate thought was either sticking caliper and weight differential.
The TUV inspection in Europe does a test and the braking force applied has to be within 3% side-to-side or they won't let you register the vehicle. If the thing is still locking when there's a 200# passenger, and a 160# driver, I'd lean more towards a caliper sticking. It is common enough. If the pads have been on there any length of time, you should see a difference in the wear side-to-side. My last set of R4S's on the Blue Turd went out due to a stuck caliper, so I can see that happening. One side was almost metal-to-metal while the other side still had a good 3mm left on the pads.
Make sure the pivot pin is lubed...
Thanks Mark and Tony. My next step is to pull the front wheels off and check the pad wear between sides. The right side should have more wear if our assumptions are correct. I'll likely replace the LF caliper regardless. I do use R4S pads not the R4. One the street I'd hardly ever get the R4 pads heated up safely. I also am looking for some corner scales to test weight differential and weight jacking.
BTW, shouldn't my rear brakes have locked also if the car was setup correctly? My assumption is that the rear brake bias should be slightly less than the front. Correct?
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I can't find the instructions on the MM site.
If the original valve is retained (it would be mounted on the firewall in your year of Z, to the left of where you have your adj. valve from the picture), do you recall if the instructions advised you to gut the original proportioning valve? If so, you've connected the rear brake line to the front right caliper!
Nigel
Here's how my adj valve is installed. The stock proportioning valve is removed. Both front brake lines are routed to the brake indicator switch in the stock locations with no connection to a valve. The one rear line coming out of the brake indicator switch has the adj valve inline before it goes to the rear of the car. It looks like I connected all this up properly back in the day. My next step is to replace the left front caliper. Stay tuned...
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Go to the drop down menu on your username up in the top right corner. In there you will find my settings, click that then it will take you to a page with 7 tabs. You will want to click on the one that says Forum and then below it there should be a list of things, Select Manage Watched Topics. After you click on Manage Watched Topics it show a list of all the threads you have posted in and what specific forum they're in. Sadly there is no quick button like in the old software.
Thank you.
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Can you switch the calipers side to side and see if the problem follows the caliper?
jt
Yes, but I'm lazy and will likely just replace the suspect caliper under warranty so I don't have to bleed twice. : )
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I can't find the instructions on the MM site. If the original valve is retained (it would be mounted on the firewall in your year of Z, to the left of where you have your adj. valve from the picture), do you recall if the instructions advised you to gut the original proportioning valve? If so, you've connected the rear brake line to the front right caliper! Nigel
That would suck. The 4x4 brake upgrade has been an improvement over stock but not the night and day that I hoped for. I have put the brakes through some serious abuse so it seems to me that if I connected the adj. valve incorrectly I would have symptoms noticeable under all braking conditions. I will check when I get home. If you are right I'll be happy because it's an easy fix. Thanks for the suggestion.
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Where did you find the Z specific instructions, and what did they tell you to do with the original valve?
Nigel
The instructions came with the valve from Ross @ Modern Motorsports. http://www.modern-mo...&products_id=53
I don't have access to the car right now but I know the original valve is retained. I believe the instructions had me put adj valve is installed inline with the back brakes.
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Imagine a bar stool or four legged table with one leg that is a little long or little short. Cross weights, (X-weight), not being equal causing weight jacking.
Cross weights could easily be way off, especially with coil-overs being as they allow so much adjustment. Left to right vehicle weight or front to rear can't really be adjusted, even thought he car can be titled left or right or front to rear with coil-overs. But what if one corner is adjusted tall or it and the opposite corner are adjust tall, (or short, same thing applies). Back to the bar stool weight one or two legs at opposite corners that longer or shorter than the rest, the longer ones are bearing more of the weight.
Back to your car, lets say the left front and right rear were adjusted tall, (or just the left front). This would cause the Left front wheel to be loaded considerably more than the right front and with good brakes that apply equal pressures, the front wheels would end up with the skid pattern you pictured.
Cut springs, same thing could happen.
A car body that is the twisted from a previous accident, same thing.
Using corner scales with coil-overs, you can fine tune the "X" weights to counter any body twist issues, long-short struts, etc.
Grass Roots article on this subject;
http://grassrootsmot...corner-weights/
Excellent post. Thanks for taking the time Paul. Looks like I will get the car on corner weights... : )
I might also replace the front left caliper since it's under warranty.
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Where did you install the adj. proportioning valve, and what did you do with the stock valve?
Nigel
'73 240ZT
Here a pic of the mounting location. I purchased the valve from Modern Motorsports and followed the Z specific installation instructions.
http://www.modern-motorsports.com/catalog/product_info.php?cPath=60_61&products_id=53
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Is there a shortcut to My Posts or My Subscriptions?The old forum software had this feature but I haven't been able to find the option since the upgrade.
Thanks!
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Possibly weight jacking due to spring positions?
Cut springs not cut/seated perfectly even frt-bck-lft-rght, or coil-overs installed and when adjusted was not done with corner scales with the drivers weight in the seat...
My springs are cut but they were all cut so they seated perfectly in the original location. The spring rate at each corner should be close to identical. Obviously this isn't ideal but I needed to lower the car on a limited budget so I went the "cut spring route". My future goal is to install coilovers with new springs that have rates for my specific application. I also need to swap to shortened struts vs my standard Tokico Illuminas. Rtz has told me this on more than one occasion..
With that said, is it still plausible that the front left caliper is contributing to the issue? It's under warranty so the part is free.
BTW, How do coilovers change weight reading on a corner scale?
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Or the driver is pretty heavy and loads the left side front wheel more then the right.
Hmmm, never thought of that. I'm about 200lbs. I did have a friend that weighs about 165lbs drive the car with me in the passenger seat and it still locked the front right.
I've tried to build a fun and fast car but there are always sacrifices when asking so much from our little Datsuns.
MSA "Performance" turbo camshafts
in Nissan L6 Forum
Posted · Edited by jgkurz
Here are some Isky cam cards for reference. The first is my cam and the others are from folks I've run across over the years. Notice the cam timing on my cam vs the other 7181 is different. Very odd. Maybe 7181 is for drilled cams and 7151 is for external oiled cams. L490 grind number also doesn't seem to be a consistent grind either if you look at the catalog and other cam cards.
My Isky 7181
Another Isky 7181
Isky 7151