Scottie-GNZ

300hp!!! I will take it even though it is probably not enough to kick your butt

I pulled the I/C and had a cursory glance. No oil (thats good) and no obvious leaks that could cause such a drop and thats also good . That means I can still give it to the person who's $$$ is burning a hole in their pocket. Ironically, an I/C swap was already in the works even before this discovery and it is now known that I am getting 240Z Turbo's UNDERSIZED I/C. If the NPR has no leaks when I test it, then the Z gods (you now who you are) were right and this beast is flowing more air than the NPR can move efficiently. So, whats your guess on how much HP this thing is costing me? 50? Come on, make me feel good.

Whether you use a 51" Dana44 or any other solid rear-end, all the mount pipes have to be removed and your new suspension welded on. I like the idea of using the Z strut and finding a way to attach to the solid rear. It seems on paper that even though the Dana44 would not have to be shortened, the Ford 8.8 is still the better way to go. Being 6" narrower than a Z, I would imagine you need decent sized spacers. Nothing wrong there. However, if you have to buy axles for the Dana44, that negates the cost of the axles for the Ford and the spacers negate the cost of narrowed the Ford rear-end. Other advantages that the Ford offers (for me, i.e.,) is that it comes with the ratios I need, a 3.08 or a 3.27 and the Ford, on paper, appears beefier. Dana44 - 8.5" ring gear, 1.376/26-spline pinion stem. Ford - 8.8" ring gear, 1.626/30-spline pinion stem. I would say if the initial cost of the rear-end is the same, the cost of the modifications appear to be equal with the edge, IMO, going to the Ford. You do not have to deal with spacers or finding wheels with radical positive offsets. With the Ford, you can strike up a deal for a pair of wheels with any offset, 300ZXTT, Cobra, etc and then have the rear-end narrowed to fit the wheels. Remember I need a ratio higher that 3.36 and the Corvette seems to be the only option and until I understand it better, it seems more complex and costly.

The company BLKMGK referred to is Westach, www.westach.com. The website does not have a lot so you need to get their manual. They are an aircraft gauge manufacturer that high high quality products and is right up your alley. You can even get a 4" quad-combo gauge.

Tim, you make excellent points. I plan to cap the I/C pipes, with one cap having a small hole for my air gun. I will then submerge it and pressurize it. It probably will not be air tight but it is not so much a pressure test as it is a leak test. Last visual inspection of the I/C showed nothing that would indicate such a leak. Just got back from Home Depot and $2 got me 1' of 2" sch40 PVC and 2 2" caps. The PVC has an od of 2 3/8" and with a little duct tape it will fit snugly into the silicone hose. A light bulb just went off and I have a another and more likely culprit to check, the relief valve. I am measuring boost at the compressor and before the relief valve, but the relief valve is in the boost signal line for the wastegate cannister. If the relief valve is leaking, it would also act like a bleed-off valve or more likely, it is opening at 15# but not letting enough pressure through to the cannister to overcome the shortened rod which is preloading the spring. Puck stays shut. This model NPR is proven in the import drag world. There is a local turbo-rotary Corolla that runs mid-8s @ 157+ using this I/C. His car is light and he is spraying but I still put him at 600RWHP. These guys are not going to use it if does not do the job. I do not know what the pressure drop for this I/C is (rumored at 1.5#) but if the leak/restriction was not there you can assume the boost at the compresor would be more like 22# and the temp would be substantiallly less. If we get conservative and say 30* less, you can also assume the temp at the TB would be ambient or slightly over. Cannot ask for better than that at these boost levels with an air-air I/C. Not to worry, an upgrade is in the works. [ May 12, 2001: Message edited by: Scottie-GNZ ]

My buddy and I finally got around to doing some serious testing to find the source of my problem. We hooked up a FP gauge with a long hose that extended into the car next to the boost gauge. We also put temp probes at the compressor outlet and the TB inlet. Was hoping to have a 2nd boost gauge connected at the compressor but could not come up with one. It was cloudy with an ambient of 73*. I was driving holding the FP gauge next to the boost gauge and he was monitoring the temp gauge, the datalogger and making notes . First test was to confirm that I had the required fuel pressure at high boost and saw 60# FP at 20# boost with a base of 40.5# at idle, vacuum off. No problem there. Immediately noticed that the temps were extremely high, 300+* at the compressor and 95-100+* at the TB. This was from a short 3rd gear burst and holding 20# for a few seconds. Not good. As a side note, I was using 215/60-15 Firehawk tires and had to ease into the boost in 3rd and with my relief valve setup that just was not possible. Even trying to ease it into it, when the relief valve opened at 15# (about 50mph), it would light up the tires and put the car sideways We then moved the boost gauge to the compressor, eased into the throttle and WHAM, 27# boost. WTF!!! Tried it again, 30# boost . Conclusion: I have a massive leak somewhere between the compressor and the TB. I suspect the I/C has a decent size crack at a seam or is badly clogged. Could also be a hose as I have heard of silicone hoses having splits that were hard to see but opened up under boost. Will be a couple of days before I pull things apart and test the I/C, but I am as happy as a pig in you-know-what. Strange how bad news can make you happy. This all now makes sense as to how you could have knock despite not running lean. At the track, with the burnout, spooling up at the line and running full boost for 11-secs, I cannot imagine what the temp must have been at the TB. I would guess 50-75* above ambient. Hopefully it is something as simple as a split hose but if it is the I/C, it should be repairable. Lets get this puppy repaired and see what it will do with 24# boost.

So sorry, I am the one to be apologizing. What I meant to say was how does 51" hub-hub compare with the dimensions of a 240Z. Does that imply that the 51" unit does not require resizing and all that is needed is are wheels with the required offset and the requisite installation?

How does 51" relate to the Z?

I am not prepared to make the leap to a solid axle just yet, but I do have access to a Ford 8.8, with a 3.23(?) LSD and disc brakes. What makes this so tempting is that it would involve a deal where I would have little or no out-of-pocket expense to get it. This is so ideal and tempting, but I have 2 questions: 1. For those who have a solid axle, can you PLEASE give me an estimate (in private if you want) of what it cost to have the axle narrowed and installed in the Z. 2. To help pay for this, I would like to sell my complete rear suspension. It is obviously a proven setup but I wonder if there is any interest from folks to buy this and what do you think it is worth? Here is a component list: - 71 strut - JTR spring perch mod. Perch raised with cut-down 280ZX 2+2 spring. Allows up to 5.5" BS with tires up to 25.75" tall - Tokico Illuminas - Professionally welded R-200 with 3.54 - LSD finned cover with modified bracket for clearance - Scottie's "homemade" diff tie-down - Poly bushings with moustache bar - 280ZXT CVs with CV adaptor - 2 spare pass-side CVs - 280Z stub axles, with new bearings - 82-83 280ZX rear brakes with Maxima brackets and new KVR pads - Competition studs - Brand new 3" od driveshaft for GM trans/R-200 diff - I would also have to sell my wheels, 4 Welds Draglites with 4.5" BS. Damn, did not realize what I had until I made this list .

IMO, go with what you have. That engine has tremendous potential just waiting to be uncorked. Everyone knows the t3 turbo on the L28T is woefully small, so what does Nissan do, they design this wonderful V-6 with larger displacement and puts the same turbo on it. No wonder it only made 200hp. We have repeatedly talked about the "300-350hp recipe" for an L28T that is comprised of bolt-ons. Efficient I/C, upgraded turbo, upgraded DP and 3" exhaust, upgraded fuel system. Apply the same recipe to the V-6 and you will get stunning results because that engine has larger displacement and better breathing. How much such upgrades will cost depends on how much you can do yourself or have skilled people to do it for a reasonable price. The expensive way is to buy these "kits", like the HKS or GREEDY $1200 I/C kit or buying the turbo from Jim Wolf because he is the expert. The alternative is to work with someone like Cartech (Corky Bell) to make you an I/C and have a welder work with pre-bent mandrel pipes to do the plumbing. Work with Turbo Specialties or Majestic to build you a turbo that suits your setup, etc, etc. How would that compare with a V-8 swap? Well, for starters there are no kits that I know of. Unless you have an engine that puts out more hp than a Z-28, Trans-Am or Cobra, you are still going to get beat because you will at worse match their weight. Too many folks just refer to a V-8 and do not realize that not all V-8s are born equal. There is a current thread (several actually) about what it really cost for a SBC with the kind of power you need. Remember, the '85 is no lightweight, but the V-6 is, so you can expect a weight increase with a V-8 swap. Tough choice and your wallet will probably be the deciding factor. [ May 11, 2001: Message edited by: Scottie-GNZ ]

Mike, if you are still interested, I can get you an estimate. It seems the accuracy of those diagrams are in question and I apologize to whoever drew them if that statement is incorrect. I believe a couple of pics with different angles is all I would need to get an estimate.

Hey "newbies" (j/k). There is nothing that says you cannot express your opinion or even present a counter argument to someone else's opinion. What makes this board so successful and fun to be a part of is exactly that. I know I have changed my opinion on things because someone else presented an argument that proved me wrong or better yet, educated me. Welcome aboard and we look forward to hearing from you.

I thought by now there would have been a way to make those brackets available, but I guess not. Jeromio's effort must be applauded but that is not the proper to go about doing it. If there is enough interest, I can talk to my machinist about doing a CAD and stamping them out on his CNC machine. I will come right up front and say that I will help to get it going but I want no part of another group purchase . Someone else can lead that charge or better yet, some enterprising business person front the production cost and resell to members at a reasonable price. The machinist does quality work and is a personal friend. If he is involved, I will not subject him to personal contact with everyone involved. One person organizes it and works with the machinist and the machinist makes some bulk number and gets paid once. Let me know if I can help.

Boy, you are really taxing my memory here. I recall getting mine off an 86 NA but also remember pulling one off the turbo that I got my LSD from so that would make it 87+. That one I put on the Mustang 60mm TB, however, I never hooked it up. Remember the TPS is used by SDS as a signal for giving an extra squirt of fuel off-idle, sort of like an accelerator pump. I was also under the impression that all cars used the potentiometer-type after 84.

Les, I do not know the details of your 383 buildup, but take a look at this post and see what another 383 Z just accomplished, 1st time out. http://www.hybridz.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=17&t=000036 I am sure everyone has their own suspension setup so I can only tell you what works for me. My car is a 71Z, Buick GN drivetrain, with a transbrake on the 200R4. I raised my rear perch and cut down a set of 280ZX 2+2 springs. That mod allows me to run 275/50-15 BFG DRs on 15x8 Welds with 4.5" BS, but you could probably squeeze a 5.5" BS in there. I would recommend a coilover setup instead. I have Tokico Illuminas all around and at the track I set the F&R shocks to the softest setting. I also have both swaybars removed. 18# in the tires, a 3-sec burnout on a line-loc and a 5-6# boost launch on the t-brake. Nothing trick, just a lot of trial & error to come up with this combo that seems to work for my car. I am dying to see my car in action on a video because I am told it really squats, but where other cars leap of the line, mine seems to "squirt".

What in the HELL is wrong with GM? They cancel the Impala SS, plan to dump the F-body but is putting an all-aluminum, 24V, DOHC L6 in an SUV. Considering how mildly tuned that engine must be for emissions and gas mileage, the potential is staggering. However, considering the application, I wonder if we will ever see any after-market perormance parts for it?

Never thought I would ever consider having too much HP for the street. I do not think I would discourage anyone from building a 600+RWHP Z-car, but a lot of alarms would be going off. When I look at the Darius video of him spinning his tires at 60mph, I am impressed but also say I certainly hope he could on street tires. Right now I will not run anything on the back of my car but a DR because you are not always going straight at 60mph when you stomp it. Even with a DR, 1st and even 2nd gear will put a 400+hp Z sideways, with normal pressure and cold tires. I have the racing stripes in my shorts to prove it Kevin, I do not think there is an "expert" on this forum who claim they did not learn something here everyday. One thing I have learned is that when I see posts with words like "Kinematics" in the topic, I grab the Excedrin Migraine bottle before I start reading.

I am sure the temp leaving the turbo is higher but the volume is so miniscule relative to the cooling system as a whole, it is not even worth worrying about. I plumbed from the thermostat housing to the turbo and then from the turbo housing to the hose leading into the heater core so that water runs through the heater core before going back into the engine.

Paul, I want to make sure I understand that you are saying you paid $14,900 for a mint 87 GN with 50K miles. Even if you overpaid, you have a rare beast and should hold on to it. It will not depreciate. If you are concerned about cars challenging you, I can tell you that with minor tweaks, your GN can comfortably run mid-12s on pump gas and short of hopped-up Vipers and all-out race cars, nothing will hang with you. I am into the Buick drivetrain, not necessarily the cars and so cannot answer your question. If you like, I can post the question on the Buick forums and link you to the responses. MOF, you probably should start lurking on those boards.

11.56 @ 148 in a 2600lb car is about 550RWHP and an indication of SERIOUS traction problems. It is pointless running with that much power w/o slicks. Assuming traction is there, a 660RWHP, 2600lb Z should be running 9.50 @ 148. Even if that is 660FWHP, it should still run 10.20s @ 137ish.

Randy's opening sentence sums it up well. I hope my post does not scare anyone away from the OEM pieces. I also hate to see anyone spending an inordinate sum of money for an alternative when it is probably not necessary. The R200/CV pieces are readily available and comparitively cheap so I would encourage folks to go that route until it proves it cannot handle the task.

I am very interested in this topic but have a concern about the overall cost. I think most of you know I am big advocate of the R200/CV setup, but I am beginning to have some 2nd thoughts on my specific application based on where I expect to be in a couple of months from now. I have never had my engine dyno'ed but I do believe in the industry formulas and my projection is 440RWHP(@4250) soon. Applying the formula to calculate torque (see below), I come up with 543lb-ft . I think the R200/CV combo can handle that torque in a street car or one doing auto-x or road racing. Where my concern is in launching a 2800lb Z-car off a t-brake with sticky tires and getting full boost before the car has rolled a couple of feet. I am beginning to think that is asking too much. I certainly intend to continue using my setup but just thinking out loud. Is there anyone here running a solid rear end that is willing to reveal the actual cost so we can understand the alternatives? Is the T-Bird the same as the Mustang Cobra? Those Cobras are snapping CVs like twigs and they are nowhere close to having the low-end grunt of a prepped SBC or V-6 turbo. mep = hp x 792,000 / displacement x rpm torque = mep x displacement / 150.8 [ May 07, 2001: Message edited by: Scottie-GNZ ]

Mike, how high a speed did you have the car up to before taking it apart and did you sense any vibration at all? I understand the concerns considering the speeds you expect to hit, but I would hate to see you chasing a problem that might not be there.

That is a nice package you have listed but if you want 350RWHP, do not even consider the stock t3. Call Turbo Specialties or Majestic and work with them to come up with the correct turbo for your use. The difference in cost between a rebuilt t3 and a hybrid is well worth it. Zs SQUAT, LIVE WITH IT. The more you try to do to eliminate it, the worse it will be if you try to drag race the car. I have about 200# rear springs and Tokico Illuminas. At the track I set the shocks to the softest setting and it squats like no tomorrow but rockets off the line. The car can live a dual life, but the only caution is having a spring too stiff that will cause wheelhop at the strip. The adjustable shocks are highly reommended.

GRAB IT! The GN engine uses a 200R trans and converter designed specifically for it and your best bet for finding one is to check the Buick forums classifieds everyday and be prepared to act quickly. If you could have gotten the I/C, that would have been good to get the project going but you probably want to go with an FMIC eventually. You could not have used the radiator. http://www.turbobuick.com http://www.turbobuicks.com http://www.gnttype.org (all the technical details you could ever want)