racerx260 Posted January 23, 2006 Share Posted January 23, 2006 I Am Currently Running A Stock 83 Turbo Motor And Ecu In A 260. Boost Is A10 Lbs. Power Is Good. However I Dearly Miss The Low End Tourqe I Had With A N/a Motor With Flat Tops P90 Head And Su's.where I Live In The Mountains There Is More Use For Tourqe Than High End Hp.i Am Thinking Of Putting Flat Top Pistons In The Turbo And Running Lower Boost.will This Give Me The Tourqe Below 3000 And Some Better Than N/a Punch On Top?how Much Boost And What Hp?will Compression Alone With The Turbo Ecu Give Me N/a Tourqe?how Much Top End Hp Without An Intercooler At What Boost?need Your Imput. ? Quote Link to comment Share on other sites More sharing options...
Garrett76Zt Posted January 23, 2006 Share Posted January 23, 2006 well i've never had any issues with torque in my turbo motor. When i was still running the stock electronics, stock t3, etc. i ran 15psi everyday with 370cc injectors and it made 274hp and 326ft lbs torque. And the t3 is very peaky/torquey, so i was getting full 15psi by like 3000-3100rpms. Quote Link to comment Share on other sites More sharing options...
SHO-Z Posted January 23, 2006 Share Posted January 23, 2006 For low end torque you need a supercharger so boost comes in at a lower RPM. A supercharger has a real flat torque curve. A smaller Turbo that boosts up at a lower RPM will also add lower end torque, but you will lose upper end boost and power. Nothing comes for Free! Quote Link to comment Share on other sites More sharing options...
GrayZee Posted January 23, 2006 Share Posted January 23, 2006 Try advancing the timing. I'm not sure how much you can get away with on a stock ecu, I'm using a z31 ecu and have the timing marks advanced right off the scale. Still no ping and man, did it ever make a difference in the off idle response! If I were to just let the clutch out and hammer on the gas yes, it would be mushy.. for about .2 seconds, the next thing to happen is it wants to tear the tires off. That is why a little bit of lag can be a good thing. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted January 23, 2006 Share Posted January 23, 2006 For low end torque you need a supercharger so boost comes in at a lower RPM. A supercharger has a real flat torque curve. A smaller Turbo that boosts up at a lower RPM will also add lower end torque' date=' but you will lose upper end boost and power. Nothing comes for Free![/quote'] HUH? Hard to go smaller that the L28ET T3. He has tuning issues. Get those addressed and you should have the opposite problem like Garrett and GrayZee said. Quote Link to comment Share on other sites More sharing options...
racerx260 Posted January 24, 2006 Author Share Posted January 24, 2006 Boost is positive by 2300 and full 10lbs by 3000.lots of tourqe by then. Its just a dog below 3000 compared to a 8.8 compression motor that n/a.In first or second its hits hard at 3000rpm and makes it hard to drive casually in town.If i'm at 2400 in forth and give it some gas it struggles untill about 3000 and takes off.Gts like a small bore two-stoke motorcycle.on or off.Great if you want to play boy racer all the time, but not if you are just driving around in the mountains.I was hopeing that if I ran a higher compression motor I would get better power and response from 1500 to 3000. I would need to lower the boost to keep from knocking of course and loose high rpm power . I' m willing to loose some peak hoursepower to make it driveable when driving casually.How much unintercooled boost can I run at 8.8 compression? I saw the mention of the timing, I have the stock setup from an 83 turbo. I thought it controlled the timing.with the ecu. How much advance should I set it at? / Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted January 24, 2006 Share Posted January 24, 2006 Unintercooled, I'd stick w/stock boost levels. If you had a hybrid turboyou could go to 6-10. I think you are better off getting a MS unit and programming it - driveability will be much better. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted January 24, 2006 Share Posted January 24, 2006 I would suggest that you could happily run 10psi through a 8.8:1 CR engine WITH intercooling and good engine management. I may well be wrong but newer engines like the RB25DET are 9:1 and seem to get away with it. Dave Quote Link to comment Share on other sites More sharing options...
racerx260 Posted January 24, 2006 Author Share Posted January 24, 2006 Scottie=gnz You Get The Brownie Points.tuneing Was The Issue. I Have A Haynes Manual For Zx's Up To 82. Its Says Timeing Is Stock At 20 Btdc.i Have A 83 Turbo.i Did A Search And Found That An 83 Is Stock At 24 Btdc. After Changeing It To About 24-25 Btdc It Made Drastic Improvements In Response , Power When Off Boost And Much More Tourqe In Mid Range.the Transition From Off Boost To Boost Is Smoother.driveability Is Way Better.how Much Advance Can I Run? 93 Octaine, 10lbs Of Boost, No I/c.i'm At About 3000 Ft Above Sea Level.i Have Positive Boost At 2300 Rpm And A Full 10 Lbs At 2700 Rpm Now.can't Stop Smile'in.thanks For The Suggestions. Quote Link to comment Share on other sites More sharing options...
260DET Posted January 24, 2006 Share Posted January 24, 2006 I would suggest that you could happily run 10psi through a 8.8:1 CR engine WITH intercooling and good engine management. I may well be wrong but newer engines like the RB25DET are 9:1 and seem to get away with it. Dave 'With good engine management' being the key. Which means a decent aftermarket ECU using MAP, TP, temp etc sensors and properly dyno tuned. Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted January 25, 2006 Share Posted January 25, 2006 Good to hear mate. I give it 3 weeks and you'll be wanting more. Dave Quote Link to comment Share on other sites More sharing options...
racerx260 Posted January 25, 2006 Author Share Posted January 25, 2006 Got That Right; Never Enough.also True About Money, Never Enough. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted January 25, 2006 Share Posted January 25, 2006 Scottie=gnz You Get The Brownie Points.tuneing Was The Issue. I Have A Haynes Manual For Zx's Up To 82. Its Says Timeing Is Stock At 20 Btdc.i Have A 83 Turbo.i Did A Search And Found That An 83 Is Stock At 24 Btdc. After Changeing It To About 24-25 Btdc It Made Drastic Improvements In Response , Power When Off Boost And Much More Tourqe In Mid Range.the Transition From Off Boost To Boost Is Smoother.driveability Is Way Better.how Much Advance Can I Run? 93 Octaine, 10lbs Of Boost, No I/c.i'm At About 3000 Ft Above Sea Level.i Have Positive Boost At 2300 Rpm And A Full 10 Lbs At 2700 Rpm Now.can't Stop Smile'in.thanks For The Suggestions. Dude, I'm the one who said to play with your timing. Start advancing it slowly.. say a couple of degrees then take it for a drive. If after alot of abuse it still does not ping, go for a couple more.. and so on. Once is does ping turn it back to where it does not. Too many factors come into play to be able to say how much YOU can get away with. Even outside air temp plays a factor. Another thing you may want to consider.. I don't know what you are running for exhaust, but a really nice system will cut down on turbo lag considerably! On a turbo car, don't go cheap on a exhaust system. BTW, I guess you're not complaining anymore about the L28et's "lack of torque" Ha ha ha... Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted January 25, 2006 Share Posted January 25, 2006 ignition timing makes a HUGE difference on the stock turbo L28, as far as off boost torque and throttle response goes. I've owned many cars and have always advanced the timing on them 2-3 degrees over stock to try to gain some 'free hp' on them, but generally I never really felt much of a difference. With my turbo 240z I notice a HUGE difference in seat of the pants from a couple degrees of timing one way or the other. From day one I've actually had my timing set 2* more advanced than stock on this car... it makes such an improvement in the driveability and low end response. I even had it advance dlike this when I was running 10psi with no I/C on bone stock EFI (well, not 100% stock I did have an upgraded fuel pump but that was it). And still now at 14psi I run 22* advance. Just suggesting that if you wanted to you could advance to 25-26* and should be okay. Keep in mine I'm in SoCal so only get 91 octane as well, if you're in a state with 93-94 octane you would be even better off. Been driving it this way for 3 years, get on it every time I drive it, also had several dyno pulls, and never ONCE heard any sign of ping, nor saw any on the dyno, so it's no problem running the bit of advance. Quote Link to comment Share on other sites More sharing options...
racerx260 Posted January 27, 2006 Author Share Posted January 27, 2006 Sorry Grayzee, You Were Correct , Timeing Did Wonders. I Am At About 26 Advanced And Lov,in It.without An I/c Thats About High As I Dare Go.off Boost Is Much Better And It Jumps When The Boost Hits.i,m Runnin 2 1/2 Back To A Magnaflow .not The Best But It Flows All Good.full Boost 10 Lbs At 2700. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.