Scottie-GNZ

I am having my 4-pt rollbar welded in and sidebars added to make it a 6-pt. I ordered the swingouts from S&W and remembered thats who you ordered yours from. Luckily my rollbar was already up to spec and I am able to use it. Scottie

I agree with HPtech although my JTR had a configuration similar to Mike's except I ran 2.25" pipes and 2 small oval turbo mufflers in the stock location after "massaging" the spare tire well. There is a tendency to go overboard on pipe sizes, especially for a street car. To HPtech's point, there is a 700hp GN here running low-10s with a 3" DP and a Y into dual 2.5" with straight through mufflers. Only reason he went to duals is to have the stock appearance, else he would have ran a single 3". Bottom line is you can go a long way with a single 3" IF it is mandrel-bend and has an efficient muffler. I am running a single 3" and guesstimate 360hp when I am done tuning. Turbo upgrade and cam will have it over 400hp and I intend to stay with the single 3" and straight-thru muffler. ------------------ Scottie 71 240GN-Z http://members.xoom.com/Turbo240Z/scotties240zt.htm

When I first saw this post I was excited waiting to see the responses. Is Ron the only one that runs his Hybrid? Scottie

Scott, surprised to see you here but welcome and you will be back and often. There is a more serious technical nature to this forum. You wont find much discussion about key fobs here, hehe. BTW, are you thinking carbureted or injected? Scottie

My DP was 2.5". It fit between the bellhousing and trans tunnel and bolted up to a 3" exhaust. There is not enough room to do a 3" DP the way I routed it. I was using the stock-type wastegate housing which has only a 2 1/8" i.d. and a bolt patten that does not allow a flange larger than 2.5". With that, I just did not see a benefit expanding that to 3" especially if you had to make 2 90-degree turns. It was a tradeoff between a 3" pipe with 2 sharp 90-degree bends vs a 2.5" pipe with 2 45-degree bends. All I can tell you is that it make a big difference. The DP itself was 30" long with 2 45-degree bends and ended up close to the trans x-member. The flange for the wastegate had a 2.5" i.d. and was CNC-machined. The exhaust flange was a standard 3-bolt flange and of course it had an O2 bung. Everything was SS, except the bung and exhaust flange. Lots of pics of the DP on my page. If you are interested in one, send me email. I am in San Diego, returning late Friday night. ------------------ Scottie 71 240GN-Z http://members.xoom.com/Turbo240Z/scotties240zt.htm

If you go with the SDS and stock turbo, you will basically have the same setup I did. I did not use 550cc injs with the stock turbo, but instead used the 370cc injs from the early SVO/XR4Ti. It requires a mod which is on my page. With 50+psi, they are good for 300+hp. With that setup I went 13.02 @ 110.97 on street tires. You will go nowhere if you dont also spend some $$$ on the suspension and tires. I eventually got a 1.74 60' and that setup should also work for the GN and therefore V-8s. ------------------ Scottie 71 240GN-Z http://members.xoom.com/Turbo240Z/scotties240zt.htm

Drax, check out my site at http://members.xoom.com/Turbo240Z/scotties240zt.htm If you go with the SDS you will not regret it. The programmable system is the key to extracting the HP but you also need the right combination of parts. Get a 60mm TB from a 240SX or early-90s Mustang GT, the right size turbo, 3" mandrel exhaust, 550cc injectors with an FPR and pump, and DONT, repat DONT go cheap on the I/C. Resist the urge to go cheap with a Starion or Supra, et al. As the saying goes, "whatever blows your skirt up". It is all about pride of ownership and having fun. ------------------ Scottie 71 240GN-Z http://members.xoom.com/Turbo240Z/scotties240zt.htm

I have an SCCA-approved 4-pt bolt-in rollbar like Mike described. The hoop is bolted to the wheelwells and 2 bars extend toward the rear and are bolted in just in front of the spare tire well. I asked the local track what I needed to do to be approved to run high-10s and this is what I was told. I need a 6-pt cage and the 4 bolt-in points have to be welded in with larger plates and I have to add the sidebars as Mike described. The height of the sidebars must be between the shoulder and elbow and welded in at a point slightly forward of the door. I intend to put a swing-out on the driver's side for ease of entry/egress. I expect such a configuration to add stiffness but the torque in our engines still need frame rail upgrades. Scottie ------------------ Scottie 71 240GN-Z http://members.xoom.com/Turbo240Z/scotties240zt.htm

Where are you guys located? There is a real hotdog Viper here in Orlando, red with yellow wheels, that runs high-11s. I am hoping that after I get a couple of runs under my belt I get to line up with him. Thats one scalp (snake skin, hehe) I want hanging on my bumper. After you get done with Viper, you will need to give him the telephone number for Hennessy. Scottie

The welded rear is in and I am getting used to driving it. Seems to be working fine and I light up the tires even easier. The track will have to wait for a couple of weeks. Pretty busy at work next week and will be in San Diego the entire week of 5/1. Possibly the week after but I was told by the track to not try and run with only a 4-pt rollbar if the car will go quicker that 11.99, which I expect it to, even on its debut. Work and play dont mix and I cant play if I dont work, hehe. Scottie BTW, anyone in San Diego want to get together on the week of 5/1?

As far as I know, the basic engine components, i.e., block, heads and crank are identical. Obviously, things such as cam, external bolt-ons and c.r. are turbo-specific. One of the tricks is to use the 4.1L version used for larger cars and that block has even been taken out to 4.5. The later engine, labeled the 3800 is a different design and so is the pre-77 "odd-fire" design. If I was starting from scratch, I would look for a 4.1, do pistons, and then search the GN forum for GNers who have upgraded their engines and have the stock bolt-ons for sale. Not sure building a turbo-engine from a NA 3.8L is any less expensive that paying for a real turbo engine unless you can find all the needed parts in a bundle. IMO, the big advantage that the 3.8 turbo has over the Sy/Ty is that, like the SBC, they have been tweaking this thing for a long time and it is probably less expensive to extract big HP. Bone-stock engine, chip upgrade, HIGH-octane and turning up the boost yields big numbers. Scottie

Out of curiosity, for those with solids, can you give a brief description of your rear end setup and the cost, including the rear end. Scottie

Thanks. If they are not posted, please email them to me. Scottie

Pete, what you are saying conflicts with information I was given. I was told the bearings and seals can be replaced but the clutchpack was not rebuildable which is why folks opt for the more expensive unit from MSA which is rebuildable. Scottie

After inspecting the muck I found in the crevices of my finned cover, I suspect the clutches burned up. When I first installed the LSD in my 240Z, I did not have a modified rear bracket to clear the finned cover so I used the standard R-200 cover. I was only able to get less than 1qt of lube in. After I had the bracket modified, I was still concerned about the capacity even with the finned cover which is why I went with Redline MTL. Might have been too late since the used unit was probably not in the best of condition and saw its 1st lube change when I did it. I am seriously looking at a cooler but need to make sure the pump has no problem with the viscosity. I want to do it on a limited budget but still have a quality product. Looking into pumps at the local aircraft surplus store and plan to use Parker Push-Lok hose and fittings. If the GN goes as quick as I am dreaming, the LSD is short-lived anyway. Scottie

If you have to run a Nissan 6-cyl in your Z, the 300ZXTT or the Skyline RB26 is the one to get. The RB26 can easily make 400hp and anything beyond that is just a matter of $$$. It is not, however, a simple bolt in and requires the typical fabs like mounts, oil pan, exhaust, engine management, etc. I did read the article about the RB30 in Australia making 734hp but did you notice the amount of money they had into it? AD$36,000, thats, US$21,000+. Can someone say "Lingenfelter"? Scottie

I understand the risks involved but the welded rear is only temporary until I can get a replacement as I doubt mine is salvageable. I cannot go through the agony of seeing the car on jackstands for another couple of weeks and running this setup with an open rear is pointless. I pulled the LSD out today and pulled the cover and there was up to 1/8" buildup of "muck" in the crevices in the finned cover. I assume thats metal shavings as the lube is fresh Redline MTL. I would be very upset if the lube was the cause because I contacted Redline to confirm it was OK to use it in the LSD. I got great results using it in my Z 5-spd. Despite all the negatives on a welded rear, my best friend here in Orlando runs one in a Mazda RX-3. It has run a best of 9.9 @ 135 with 1.42 60' using a powerglide and 6000RPM stall. Ironically it is a Datsun pickup rear end and he has been using it for over 2 years. Dont know how much torque that engine has but we estimate 500hp and it is a full-bodied car. If anyone has been to the SDS site, that car is featured there. I did not take it to BillyBob to be welded, but instead took it a driveline shop that specializes in building narrowed rears and do this for living. Hopefully it will work out OK for a while. Scottie

Ironic that we had a post just a few days ago about broken R200s. I recently started to hear a noise I was hoping was something touching and creating harmonics, but confirmed today that my LSD is toast. Looks like I am going to have to go the cheap route and weld up a 3.90 R200 just to get the car to the track until I can figure out what to do ($$$, i.e.). Anyone have any serious negatives on temporarily running a welded diff for the track with limited street driving? Scottie

Big Ed, funny you should ask this question. One of the kids I am coaching ran his 83 for the 1st time yesterday and after getting over the butterflies, he ran a 1/4-mile of 15.4 @ 91 with an 1/8-mile of 9.82 at 71.5. He tweaked the boost to 10psi which accounts for the almost 20mph gain in the 2nd 1/8-mile. His car is heavy with t-tops and boom box and with a little more practice it could run 15.1. BTW, a fairly accurate way to convert 1/8-mile to projected 1/4-mile ET is multiply the 1/8-mile ET by 1.57. You can do a lot with the ZXT engine but it depends on how fast you want to go and how much you want to spend. I previously ran a ZXT engine in my 240Z and wanted to see how far I could go with the stock engine and turbo and was able to get 13.02 @ 110.97 with 17psi. That equates to about 280hp at the wheels. That is not normal for the stock engine and I had FMIC, K&N, 3" exhaust, 300ZX TB (55mm), Ford SVO injectors and the key upgrade, an SDS programmable system. 400+hp can be squeezed from this engine but then it gets expensive. I have since swapped that setup to a Buick GN, but having previously had 2 V-8 Z-cars, I feel I give an opinion from experience. I still do not have my GN swap fully sorted, but it is hands-down the sweetest of the 3 setups. Not everyone wants to be that different, so if you have an oppurtunity to do a V-8 Z-car, go for it. However, if you are going to do one, do it right or you will regret it. If you decide to do it, also budget for suspension and brake upgrade to really take advantage of the new found power. First piece of advice is to buy the JTR manual, study it and query this forum on any questions that come up. Next, get someone with a well setup V-8 Z-car to let you drive it and if possible, dont drive a 500hp SBC if that is not what you plan. Good Luck, Scottie

Johnnydinx, we race at Orlando SpeedWorld on SR50 East. Wednesdays and Fridays is test and tune, $10 and run all night. There is an import meet at the track tomorrow and some very quick cars should be there. I will be there but not racing. Hope you can make it despite the short notice. I dont have an email for Derek and he does not have a page but one of the turboZ guys put some pics and info about his car here: http://www.eng.fsu.edu/~jthagard/otherzs/Derek/derekGN.html. Put a post on Zcar.com, he might see it. The other 10-sec GNZ is owned by Keith Olsen, turbozv6@aol.com. Scottie

The other GM V-6 is the Buick 3.8L turbocharged engine that came in Regals between 84-87. In 86-87 there was the Grand National and GNX, the pinnacle of the turbo Buicks. There are 2 other Z-cars with GN engines that I know of and both are running mid-10s with mild (by GN standards) upgrades. My engine is bone stock except for ARP studs when I put the heads back on and larger injectors. The trans is a TH-200R4 with a 2800RPM stall speed converter and B&M Pro-Stick. My diff is a 3.70 LSD. The turbo is stock with some mild porting on the compressor housing but it has a 3" DP and exhaust with an Ultraflow. I have a 3" elbow for the turbine housing to eliminate a bad restriction on the stock setup. Immediate plans, as we speak, call for a 62mm TB (57 stock), a turbo upgrade and a transbrake to allow as much boost as my tires can take off the line. With a very agressive chip requiring at least 108-octane, 22psi boost and lots of tuning, the engine should approach 400hp at the wheels. Larger turbo, headwork, larger valves, cam upgrade and now you are getting serious. The front mount bracket, like the 4.3 is home made but the JTR trans mount could be used and everything else is basically the same as a V-8 swap. My car gained about 60lbs with this swap. Scottie

I have some pics (now a little dated) at http://www.mindspring.com/~vscott911/gnz.html and if you are interested in more details about the car and the old L28T setup, that is at http://members.xoom.com/Turbo240Z/scotties240zt.htm. This drivetrain was already in a Z when I found it and the owner wanted to go back to a L28T/5-spd to road race, so we made an even swap. I included the SDS programmable system I had since I felt the stock GN ECM and chips would suffice. The brackets for the mounts are welded on the cross-member and has the engine as low and as far back as it can go. It is not as far back as your setup because the GN's DP sits high then needs clearance by the firewall. Still the entire engine sits behind the axis of the front wheels. All of the above can be seen in the pics. The FMIC and plumbing are all part of what I did for the swap. With the L28T I used an Isuzu NPR truck FMIC, a very good and cost-effective unit. The L28T was stock with the stock t3 turbo and SDS and I squeezed 110.97mph out of it. For the GN, I found another NPR I/C that is even larger than the old one. Dont know how far I can go with it but there are several 450+hp imports running it so I think it is good for quite a while. Lots of pics and details on this I/C on my page. Dont know enough about the different V-6s to have an opinion. My goal for this car is to break into the 10s by the end of the year w/o touching the bottom-end and I would really like to do it w/o touching the head or cam. I figure I need about 430hp (at the wheels) to run 10.95 assuming I have traction. With the L28T, I cut a 1.78 60' with a 5-spd and street tires, so with the transbrake, 10psi off the line and sticky tires I expect the car to hook up. Ambitious goal but I believe the right bolt-ons and tune, tune, tune, is what makes the GN run hard and I am learning this engine fast. The car only has a 4-point rollbar so I expect it wont be long before they boot me off the track and I have to get a proper cage. Scottie

Ironically, there is a '86 300ZXT here in Orlando that runs 10.0 @ 140 (est 700hp) with the stock suspension and 3.70 LSD. The car weighs in at 3200lbs and uses 11.5" ET Streets. He does experience breakage if he does not slip the clutch off the line, but what he breaks are the stub axles. Then there is Derek Grubb, a 10-sec GNZ from PA running halfshafts w/solid joints with his LSD and cutting 1.48 60' with 6" motorcycle tires (how does he do that??). My point is that there are some extreme horsepower cars using the stock setup and having success. Its a mystery why some folks experience that breakage. Sadly there are probably too many 20+ yr old R200s that still have the original fluid from the factory. Scottie

I am "2" short of a V-8 (Buick GN), hehe, but having previously built a 75/JTR/350/5-spd and a 73/Scarab/350/4-spd I have a soft spot for the V-8 Z. Hopefully you will all let me play in your sandbox, albeit being a black sheep. Is'nt that a bit of irony for you V-8ers? Scottie

John, the GM V-6 engines are one of the best kept secrets. Have a friend here in Orlando with an 87 GN full body/interior, a/c weighing 3700 w/driver and it runs 10.3 @ 135. Do the math and its 700+hp and very mild-mannered. Myron, the 10-sec GN-Z is not mine but it wont be long before I am there. I just swapped out a L28T. The GN engine is basically stock but I expect about 360+hp now and 450+ with a turbo upgrade, headwork and mild cam. That should put it in the high-10s with good traction. The car gained a little over 60lbs. I plan to updates my pictures this weekend with the Griffin installed. Scottie