jgkurz Posted March 30, 2003 Share Posted March 30, 2003 This email is a little premature as I've not been on the dyno yet, but I wanted to pass on my initial impressions. I went from a stock 82 turbo cam to an Isky L490/L480. First thing I noticed was the idle was a little rougher. This was expected. I actually like the sound of a cam with lope as long as the idle is stable. I set my idle to 750 rpm without much problem. A/F at idle is 14.7, but I had to retard my initial timing from the stock 20 degrees btdc to 10 before I could get it that lean. The timing change was not due to the cam change, but only to prove that the idle could be set to stoich with the new cam. My idle vacuum went from 19.5 "hg to 14.5 "hg. The car is easy to drive in normal stop and go city traffic. There is no noticable difference between the old cam and the new cam in this area. When I mildly accelerate it feels like a bit of low to midrange power is down. When put the hammer down it pulls smoothly and flat to 7000 RPMs. The power is definately improved above 4000 rpms. I'm sure it would go higher than 7K, but I'll wait for the dyno to tell me where my peak power is before I rev any higher. The old cam pulled to 5000-5500 then fell off a cliff. The new cam seems to have a very flat torque curve. Peak power well above the old cam. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted March 31, 2003 Share Posted March 31, 2003 nice! how much power are you looken to put down. mike Quote Link to comment Share on other sites More sharing options...
jgkurz Posted March 31, 2003 Author Share Posted March 31, 2003 This may sound strange, but the weakest link for BIG power in my setup is the JWT Sport 400 turbo. It's a T04E 50 trim compressor with a 3" inlet. The turbine housing is a T3 .63 a/r with a stage 5 wheel I believe. At 20psi I hope to put down 340 RWHP on a Mustang chassis dyno. It will all depend on how efficient my engine is and whether I stay well inside the 60% efficiency island on the compressor map. I don't think I will make more than 340 RWHP until I go to a bigger turbo. It sure spools quick though! Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 2, 2003 Share Posted April 2, 2003 Whats going on with your fuel injection, any upgrades there? Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 2, 2003 Share Posted April 2, 2003 Sorry I see you have a Tec II now. Quote Link to comment Share on other sites More sharing options...
jeffp Posted April 3, 2003 Share Posted April 3, 2003 >This may sound strange, but the weakest link for BIG power in my setup is the JWT Sport 400 turbo. It's a T04E 50 trim compressor with a 3" inlet. The turbine housing is a T3 .63 a/r with a stage 5 wheel I believe. At 20psi I hope to put down 340 RWHP on a Mustang chassis dyno. It will all depend on how efficient my engine is and whether I stay well inside the 60% efficiency island on the compressor map. I don't think I will make more than 340 RWHP until I go to a bigger turbo. It sure spools quick though!< I was running that turbo and I got 413 RWHP out of my car with the sport 450 turbo setup. Yes the turbo did spool up quickly. I even did a back pressure test on the system and it was excellent. Like you, I wanted a little more out of the engine, so I am in the process of upgrading the turbo again, along with an external wastegate and a .70 A/R exhaust turbine housing. I am building it for 600Hp at the crank, so that will put me right where I want to be in the torque ranges and the Hp, not that the Hp is that important to me, well not as much as the torque anyway. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 4, 2003 Share Posted April 4, 2003 You can upgrade the compressor wheel to a V. The profile I just set up for a customer has the same inducer size at a 60-1 and will flow just right. You will need to rebuild the turbo and cut the housing but not a problem for me to do. I would step up to a 60-1 if you are going to the .70 housing. I have that housing in my shop and am prepairing it for my car. The .70 is cool but you do have to "work it" a little to get a true 3" down pipe and there is some power to be made on the discharge of the down pipe. Give me a call and we can talk about your combination sounds close to what is going on with my car. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 4, 2003 Share Posted April 4, 2003 I didnt even see it was you posting that reply. May be taking my ZX to the track this weekend dude. Lets see how it all works out. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 4, 2003 Share Posted April 4, 2003 A 50 trim is a good wheel and you should be able to reach more then 340 hp. You may need to work with some tuning to pick up some power. Why did you back the timing down rather then just adjust the fuel curve? I would think you need more timing. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted April 4, 2003 Author Share Posted April 4, 2003 Regarding the 50 trim wheel, I think it's been a superb turbo. It spools much better than the factory T3 and has a large efficiency islands. I've been very happy with it so far. However I do wonder how the Sport 450 aka T04E 60 trim wheel compares lag wise. Supposedly the Sport 400 aka 50 trim is good for 400HP according to Jim Wolf Technology. I pretty sure this means 400 flywheel hp which is why I'm figuring on 340RWHP. If I get more then I'll be extremely happy. I have a very heavy stock 240mm flywheel and RPS clutch that will limit my rwhp as well as the 1977 half shafts. When I go to an aluminum flywheel and CV's I bet I'll pickup 20hp at the wheels. Someday I want to go to a larger turbo, probably a 60-1, but I don't think a larger A/R compressor housing will fit without a spacer. The current housing, which I think is .60 A/R, comes very close to the exhaust manifold. If money was no object I would go with a tuned turbo hedder with a GT58 ball bearing turbo. The timing change was the only way I could get a stable idle at 14.7 A/F ratio. When I had it at 20btdc I couldn't get better than 13 - 13.5. When I reduced the initial timing to 10 it smoothed right out. This was with both the Isky and stock cam. My Tec3 uses a wideband O2 so I'm pretty sure it's accurate. Quote Link to comment Share on other sites More sharing options...
TimZ Posted April 4, 2003 Share Posted April 4, 2003 The timing change was the only way I could get a stable idle at 14.7 A/F ratio. When I had it at 20btdc I couldn't get better than 13 - 13.5. When I reduced the initial timing to 10 it smoothed right out. This was with both the Isky and stock cam. My Tec3 uses a wideband O2 so I'm pretty sure it's accurate. I don't see any issue with this. This is exactly what you want to do to achieve a decent idle mixture, especially when your injector pulsewidths start getting close to the minimum turn-on time at idle. The idle timing has no bearing whatsoever on WOT power when you have a 16x16 timing map. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 5, 2003 Share Posted April 5, 2003 I got a sport 450, but I am not running yet. That is the turbo JeffP was running. He made 413hp with it to the wheels, and the 50 trim is good to 390 or so at the wheels on a DSM, and they say the 60 trim will go another 25 wheel hp over the 50. A 60-1 is a good wheel and it flows a lot of air and would be a good choice, and should not affect your spool up time very much if at all. It is pretty much a myth that the compressor wheel contributed much to lag, it doesn't weigh anything. The turbine wheel has the most dramatic effect. Just drop to a t3 turbine wheel and see what happens. My former turbo was at full boost by 2800 rpms, and on the dyno made boost as low as 1800 rpms. The stage 5 wheel doesn't spool that fast, and it is laggy on a 2.0 liter DSM, but it has 10 second potential. If you upgrade go to the 60-1 and don't look back, trust me you won't be disappointed. Quote Link to comment Share on other sites More sharing options...
Guest DaneL24 Posted April 10, 2003 Share Posted April 10, 2003 I'm curious about the specs of your cam. Is it just a high lift cam or does it have any extra duration too? If it does have extra duration, how did you work it into the valve timing (custom cam grind or just a regular N/A performance cam?)? I've been trying to figure out a good cam grind for a turbo motor, and I thought your cam specs could give me some ideas/insight. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted April 10, 2003 Author Share Posted April 10, 2003 Check out this link..... http://www.hybridz.org/phpBB2/viewtopic.php?t=16606&highlight= and this link.... http://www.iskycams.com/pdfcatalog_index.html Look at Datsun/Nissan My cam is the L490 on the intake and the L480 on the exhaust with a custom 114 lobe center. So far I've been happy with everything about this cam. I wouldn't recommend this profile to people who's engines aren't built for 7000 rpm's or better. Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted April 23, 2003 Share Posted April 23, 2003 Go TO4. Quote Link to comment Share on other sites More sharing options...
jgkurz Posted April 23, 2003 Author Share Posted April 23, 2003 Until I have a custom T4 flange or T4 manifold built I will need to stay with a hybrid. My next turbo upgrade will probably be to add a 60-1 wheel inside my T04E compressor housing. The only other option would be install the T04E 60 trim wheel. This would effectively make it a JWT Sport 450. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 23, 2003 Share Posted April 23, 2003 I am up and running now and the Sport 450 spools pretty good but not as fast as my Stage III turbine did. It is not bad though, probably full boost by 3200 rpms or so. Feels good at 13 psi, but need to make sure the intercooler lines stay together. Runs really good at 13 psi actually. Quote Link to comment Share on other sites More sharing options...
jeffp Posted April 24, 2003 Share Posted April 24, 2003 Hey bud, there is something wrong with your setup slightly, the turbo was into full boost 20psi @ 3000 on my car. Check out what is different from my car to your car and you will be happier with the quicker spool time. Quote Link to comment Share on other sites More sharing options...
Lockjaw Posted April 25, 2003 Share Posted April 25, 2003 You have more stroke then me (5mm right ?), I have a 280Z crank, and am only 1mm over on bore. That is likely it, although I did find a non-clamped connection, so that may have something to do with it. And I suspect my dampner is going south since I am having a hard time getting the timing adjusted without running out of room on the dizz. I was going to do a TDC check and mark the balancer and see. Retarded timing could also be an issue. I may be a little off to, I haven't really checked it good yet, that was more of an estimate. It was running pretty good when the boost was up though, and the mods Clark did really make it much nicer on the cold start and stuff. Plus I want to get my turbo XS boost controller on the top side of the WG actuator and see what it does there. I am using my old manual one on the bottom port to control boost since the bracket I made for my dual port actuator put the actuator closer to the swing valve, I am going to have to cut the rod down a little and cut new threads. Quote Link to comment Share on other sites More sharing options...
Racin_Jason Posted April 25, 2003 Share Posted April 25, 2003 Sounds great! Keep us posted Quote Link to comment Share on other sites More sharing options...
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