Scottie-GNZ

Same engine and power characteristics. TTAs had a different head because of the narrower engine bay of the Pontiac. Turns out the head flowed better than the Buick version and made more HP.

SWEET!!! Wanna play?

quote Hey AZ, little confused by the statement. To me they are one and the same . If you are shooting for the quickest 0-100, then you are drag racing and for an NA, 100mph happens to be a nice target for a 1/4-mile MPH. If you are looking for a good bang for the buck, go for a lower final drive ratio. Not sure what ratio the R-O-W 280ZXs had, but if it is 3.54, then hunt down some 3.90s.

Nice, clean setup. Good luck with it.

I concur.

Consider yourself lucky you did not pop a head gasket. If you think that quick burst of 25# of boost was a rush, imagine being able to sustain it YAHOOOOO!!!

A couple of folks have contacted me about making up a batch of the mandrel SS DPs for the L28T. I have contacted the folks that inquired but I would like to know if anyone else is interested. In case anyone is unaware, I make a 2.5" mandrel-bent SS DP for the L28T with any turbo (stock or hybrid) using the OEM wastegate. The DP fits 1st-gen Z cars, with the L28T AND the Nissan 5-spd. It does not fit 280ZXTs or the B-W T5 tranny. The DP, with a good exhaust system, will definitely help turbo performance, especially if you are trying to run more than stock boost levels. If you are looking for the 300+hp plateau, don't boost without one . Contact me by email if you need more detail.

If you are that person, please send me an email so I can get it out to you. My brand new laptop bit the dust with a corrupted BIOS and I have no access to old email.

SleeperZ hit the nail on the head. How much boost you or any engine can run depends on how well you can control detonation. The best thing to do is to find a complete L28T engine. Next best as specified before, is to run the NA block with a P90 head. I would advise against this combo if you plan to use the stock NA injs and no I/C. I do not advise anyone to run a complete stock NA engine. One of my buddies here in Orlando ran a NA block with a P90 head in a 71 for years. He kept turning up the boost and eventually got detonation at 22# on pump gas. How did he do it? T3/T04, big Spearco I/C, mandrel I/C pipes, 440cc injs, Pierburg pump, JWT setup. He abused that J/Y block with over 120 1/4-mile passes before he eventually broke the rings. Car ran a best of 12.32. Would I advise anyone else doing that? Yes, but only if you ran equivalent components and less boost on pump gas. At the track, dump in a race gas mixture of about 100-104 octane and crank up the boost. If you plan on spending $$$ on that kind of setup, spend a few extra and do it right with the turbo block.

Jim. do not have a pic of a SupraTT IRS but I studied it on a lift and it was my first choice. Just could not find one.

Difficult to answer the question not knowing exactly what that switch does. Hitting a switch that allows you to go from 10# to 15# boost means something had to increase the boost, add fuel and retard the timing. If the switch did all that, then it must be hooked into a wastegate solenoid to control boost and the ECM to control fuel and timing. Not sure I would fiddle with that w/o knowing exactly how it works. I would jump on one of the T-Bird SC or SVO forums and ask that specific question.

http://www.turbobuick.com/forums/showthread.php?threadid=20490&referrerid=1951 A 2,650lb car is just about what a race Z would weigh and I will do the math for you, 1218RWHP What would it cost to build a Big Block to match that?

Norm, are you running pump gas? If yes, you might try adding some race gas at the track, assuming you are not using an O2 sensor. Adding 1 gal of 110 leaded to 4 gals of 93 gives you 96.4 and no more worries of detonation and head gaskets. Might even be able to add a couple of degrees of timing .

Great responses, guys. To sum up, where a NA with a hot cam likes to rev quickly, a turbo performs better when it is under load and has a little more time to build boost. You cannot apply NA thinking to a turbo setup, especially when dealing with gearing and cams. When I ran the 5-spd, I used a 3.70 because I had an LSD. I know some folks are dead set against a welded rear and I am not pushing the concept or trying to sell mine. I keep tripping over the dang thing and since I will never use it again, maybe someone else can if they understand what they have.

Norm, frankly, I do not know. However, you are doing the right thing by improving the clamping force.

I have no use for it so you can have it for $50. It will cost about $50 to ship it. It is the 3.54 I used for about a year and it was welded by a driveline shop.

Yup, you have found the weak point of an open R-200 when you start making HP. Since a Quaife is out of your budget, then the only choices you have are: a) Run another open diff - cheapest option. Buy a LSD - expect to pay about $400 c) Run a welded diff - if you can live with the negatives. Whatever you do, do not run a 3.90. The LSD is 3.70 and with the HP you are starting to make, a3.54 is better for you than a 3.90 because of the turbo and stock RPM limits. If you have absolutely no choice and have to do option C, I have a 3.54 you can have cheap if you are willing to pay to ship it. However, if this your only car, then I would advise against option C.

I was told by the machinist that a little deburring might be required on the adaptor, not grinding. He preferred to make them a little tight than loose. Since they were CNC-machined, I would expect them to be consistent. Not sure I would say the same for the flange. I would debur the the pocket, see where the flange is tight an lightly file that spot.

I ran a CFDF and loved it but that is all I will say because that topic always seems to start a debate. I bought my hybrid from a guy in Miami. It was so cheap I did not care what the specs were. The "owner" did not know and even if he did he could not tell me. "no speakee the english". I just wanted to get it and get the hell outta there. For a hybrid, contact Turbo Specialties in AL. Quite a few Zers deal with them. Look them up in back of a Turbo mag.

Scotty, nice testimonial. Check is in the mail . I saw my boost increase by 2# but the proof was in the performance numbers. With the stock T3, DP and 3" exhaust, I ran 111mph in the 1/4-mile and gained 27mph in the 2nd half, after the wheels stop spinning!!! As far as I know, those numbers have never been matched by any Z running a stock T3. The more air the turbo is moving, the more benefit you will see. So, a T3 pushing a lot boost or a T3/T04 will get the best results. My buddy Patrick's car is more proof of that. 11.74 @ 119 with a T3/T04, SDS, Spearco, DP/3" mandrel exhaust, street tires. As a reminder to anyone interested, the DP was designed for a L28T with any turbo using the OEM wastegate in a 1st-gen Z with the Nissan tranny. Wheh! It does not fit a 280ZXT chassis or the T-5 tranny. The wastegate flange is CNC-machined SS, the pipe is lightly-polished 2.5" mandrel-bent SS, SS O2 bung and a standard 3-bolt exhaust flange.

Omar, go to www.gnttype.org and rifle through the Technical section.

I guess that means you like it I warned you about the boost.

I always recommend folks to work with the turbo manufacturer and let them configure the specs for you. IMO, you will be hard pressed to make 400+hp with $500 and I certainly would not recommend you try to do it with a Starion I/C. For 400+hp you will need an I/C that can flow about 600CFM w/o added pressure drop. The Starion I/C was designed to support <200hp and has about a 2.75# pressure drop with nominal boost. The more boost you try to push through it, the greatest the pressure drop, the greater the heat buildup in the turbo and whatever bosst you get through it to the engine will come with a lot of heat. In addition to the turbo and I/C, you will need bigger injs, fuel pump and an adjustable FPR and some way to manage the fuel and ignition other than the stock system. That would be an SDS like Matt, 358RWHP or a Jim Wolf setup.

I would love to, but in order to do it correctly, I would need a car for a couple of days to take to the machinist in So FL, get it up on the lift, fabricate one, then make a jig for the subsequent ones.

Does not take much at all. See the post in "Motorsports".