Guest iskone Posted February 2, 2004 Share Posted February 2, 2004 I have been looking for a six cylinder to build and like the price to power ratio of the 7mgte. But I have always thought about the Buick GN. I've poked around but can't really find out how much is a 450-500hp GN motor going to cost. If anyone could give me a ball park figure and what mods are done or where to read about them that would be great. Thanks Isk Quote Link to comment Share on other sites More sharing options...
Clifton Posted February 2, 2004 Share Posted February 2, 2004 450-500 on a 7M is easily done with a larger turbo on a stock motor. don't know about the 3.8. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted February 2, 2004 Share Posted February 2, 2004 whats the need for 500hp GN motor? just bolt ons on that motor will give ya some crazy power. take a look at Scottie's GN-Z site, he tells what he has in his Z and that car will soon be in the 9's. a make or break deal on the GN swap is you have to go Auto with it. and a 7M to reach those numbers isnt really that hard at all but it takes some tuning and the right parts. Deff get a metal headgasket, a hybird turbo will get ya there with bigger injectors, FMIC, as well as other bolt ons. i always say go with a good engine management system as it will save you alot of problems and will allow ya to tune the car the correct way. im not sure how good the stock EFI/ECU system is on the 7M but im sure its not bad, but all stock systems have there limits. ill get ya somebody to reply to this post that has way more info to share with you then i do. mike Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted February 2, 2004 Share Posted February 2, 2004 Thanks Ididn't know you HAD to go auto with the 3.8. That about does for me and th 3.8 if thats the case. I'll look for an adaptor plate or somthing for a while before I totaly scrap that idea though. I went to scottiegnz's website but I didn't get any hp numbers off it. Altough they are clearly pretty good. I am just trying to find the least exspenive of the two. As for the 7mgte I've been spending alot of time on supraforums.com and reading alot about turbos so I now how how to get good power at a good price with that engine. Quote Link to comment Share on other sites More sharing options...
Guest Dan0myte Posted February 2, 2004 Share Posted February 2, 2004 a make or break deal on the GN swap is you have to go Auto with it That's the key right there. The engines will weigh the same, they will produce the same amount of power, they will both be fairly easy to work on, and they are both set up for RWD. The only key difference is that GN = Automatic, 7MGTE = Standard. Pick your poison. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted February 2, 2004 Share Posted February 2, 2004 well you dont HAVE to go auto but the motor wouldnt work very well with a stick.. motor wasnt designed for it. mike Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted February 2, 2004 Share Posted February 2, 2004 Why won't it work well with a stick? Sounds like I'll stick with the 7mgte Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted February 3, 2004 Share Posted February 3, 2004 Sorry about the website, I just have not been keeping it up to date. At the last SEZ I went 10.34 @ 133.94 with a lazy 1.58 60' and 26psi boost. 2,750lbs with me factors out to 501.95RWHP by my formula. Lots more left as I have not pushed it to the limit yet. I am doing some experimentation and recently went 10.31 @ 131.02 with a 1.407 60' on only 21.5psi boost!! Note: I assume you mean 500RWHP and with larger injs this combo should be good for 550-575. Having said all of that, here are my mods and some approx costs: - Stock bottom end with hyper pistons and ARP rod bolts - ported iron heads and port-matched intake - $1500 new, $? used - 62mm TB (57mm stock) - $100 - 63mm turbo with P-trim and .63 a/r exhaust - $725 new, $?? used - FMIC - ~$500 new, $? used - 57# injs - $300 new, $? used - stock ECM with custom chip - $250 - scan tool - $250 new, $? used While not an engine mod, the Art Carr 9.5" convertor and suspension is a big factor. Lots of octane allows lots of boost safely but you must tune, tune, tune, tune. Just bolting on the parts does not guarantee the power. While both engines can make the same power, they are 2 completely different animals. Call me a skeptic but I will say the 7mgte will need more than just a big turbo to make 500RWHP. Even so, the kind of turbo it will need might make it a little laggy and peaky, like the 2JZ. The 3.8L is a low-revving, torque monster that works best with an automatic and that might play into your decision as you did not say how you intend to use that 500RWHP and in the case of the 3.8, close to 600lb/ft of torque. Quote Link to comment Share on other sites More sharing options...
Clifton Posted February 3, 2004 Share Posted February 3, 2004 A thought you ment crank HP when I said larger turbo, but these are RWHP http://7mpower.com/top10.shtml. All but 1 has a stock head, a few stock blocks. Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted February 3, 2004 Share Posted February 3, 2004 I said 500hp because I want 400-450RWHP . So 500rwhp is too much(450rwhp might be too much)for me. I am only planning to drive my car hard and tack it to the track when the weather is good(I live in Washington). I just want a well rounded street machine really, but I'd still like to be able to take the guy in the other lane. Are there adaptor plates for the 3.8 or is it not worth having a manual as far as drivabilty is concerned. The guys on 7mpower know there $#!t Quote Link to comment Share on other sites More sharing options...
Guest Dan0myte Posted February 3, 2004 Share Posted February 3, 2004 You can definitely adapt a manual transmission to fit a Buick 3.8, there's no problem there. It's just the fact that all the fun is gone from the car afterwards. I was reading a post a while back from someone who had done it, and they stated that their car lost the ability to spool the turbo quickly, since the resistance of the torque converter preloads the engine and gets the large turbo spinning. He said it also lost the monsterous torque to the wheels that is the signature of the GN series. For all intents and purposes, the 3.8 should only be mated to an automatic to keep the fun level up and the speed up as well. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted February 3, 2004 Share Posted February 3, 2004 The beauty of a well setup turbo engine is that even making 500RWHP, it is still streetable and economical. I get mid-20s on the highway. For the street, turn the boost down, less timing, pump gas, putt-putt around town and still kick ass. Get to the track, add octane, more aggressive timing and crank up the boost. Instant 75-100hp at the wheels. As for the 3.8 with a manual trans, oft-discussed topic and Dan0myte summed it up nicely. No OEM 5 or 6-spd would hold up to the torque of a 450RWHP 3.8 with a hard launch. If the tranny survived the axles would not. Would anyone even consider putting a T-56 behind a hot BBC and dropping the clutch at the track? Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted February 3, 2004 Share Posted February 3, 2004 Would anyone even consider putting a T-56 behind a hot BBC and dropping the clutch at the track? That's quite a comparison.. where is the peak torque at on the GN? I am pretty sure it is at a bit higher RPM than a BBC. Also, everyone seems to be comparing the GN and the 7M as same potential power, if that is the case, then the manual behind the 7M wouldnt be likely to hold up any more than a manual behind a GN. If that is not the case, then I am sure our friend would benefit from knowing the differences between the two engines' power curves. BTW, do people really dump the clutch on high torque engines when drag racing? I slip my clutch and I dont even have high torque, I was always wondering what they were doing back there in my rear-view mirror. Quote Link to comment Share on other sites More sharing options...
Guest rxsvn Posted February 3, 2004 Share Posted February 3, 2004 Depends on the car I suppose. Granted it only has 350ish ft/lb torque, but I launch my RX7 around 5k rpm's when at the track. This way both turbo's are spooled and ready to go. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted February 3, 2004 Share Posted February 3, 2004 ...but I launch my RX7 around 5k rpm's when at the track. ... Well, there is a difference between just launching at a high RPM, and dumping the clutch. Perhaps I am using old terminology as I have always understood "dumping the clutch" to mean letting it out fully, instantly. Is it now used to just refer to any type of releasing the clutch? Quote Link to comment Share on other sites More sharing options...
Guest Zachb55 Posted February 3, 2004 Share Posted February 3, 2004 Scottie, what suspension/drivetrain mods have you done? im sure this is on your site but i cant get to it right now while im at the school, stupid restrictions. anyhow, i was just wondering if you HAD to go with a full-custom setup even with a auto trans, kinda like stony had been thinking about. if you went with an Auto trans on a RB26, would you have the same CV joint problems like he was having? or would these go away until you got up there in the 400-500 RWHP range? Quote Link to comment Share on other sites More sharing options...
Guest iskone Posted February 3, 2004 Share Posted February 3, 2004 I won't be dropping the clutch and even if I do my tranny won't blow the clutch will just slip, worst case would be fring the clutch. I don't intended to do much drag racing, Just enough to tune the car. I want to do autocross. The 7m makes good torque numbers but I don't think it is quite as much as the GN.The power curves with the 7m's are very respectable but of course all the power comes on at or around 3,000rpm. If a manual will make the engine less desirable (such as turbo lag) I won't bother. If it makes less torque down low it might not be so bad, If the numbers are still comprable to the 7m. I guess I'll have to find someone with a manual GN and ask them about their powerband and turbo lag. As far as being able to kick on the boost when it is time to race, thats why I want a turbo. I just don't want 5 little gauges/lcd's or knobs to turn every time I want more extra power. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted February 4, 2004 Share Posted February 4, 2004 iskone, if the primary use of the car is autocrossing, then the 3.8 is probably not a consideration. A 450hp turbo Z-car will be a handful in autocross and the most HP does not necessarily make the quickest car. A 350hp L28ET with the balance of your money in the suspension and tires sounds like the ticket to me Nic-Rebel450CA, the peak torque on a 3.8 is rated at about 4400 and with the stock cam it is pointless to push the revs much 5500. I do not get caught up too much in dyno/HP numbers, etc, but my guess, based on what similar spec'd 3.8s have done is at 575 and probably closer to 600lb/ft torque. As a comparison, one of the popular crate 502ci BBCs is rated at 502hp and 565ft/lbs torque but those are at the flywheel. Zach, apologize again for the web page but I am just not inspired to maintain it but plan to one of these days. My front suspension is typical Z with hi-po springs, Tokico Illuminas, but with the swaybar removed and C4 Vette 12" brakes. The rear suspension is a complete C4 IRS that I modified to fit the Z. I eliminated the monoleaf spring and tube shock and replaced them with a coilover setup, custom toe-rod that also adjusts bumpsteer. Sounds like a road race setup, eh? Well, if I was road racing, the same setup with the proper adjustments would work equally well, but that is another discussion. I recently found a DANA44 diff and swapped that in. The Vette used 3" aluminum driveshaft and 3.5" aluminum halfshafts but I replaced them with 3" steel for the abuse I had planned. Couple weeks ago I tested the IRS to its limit and cut a 1.393 60' and since then have a couple of 1.40s and low-1.40s. The tranny will probably now break before the rear-end. I broke a 280ZXT CV on a hard launch but the main reason I switched was gearing. I am now running 3.08 and was not willing to pay the big $$$ to get NISMO stuff. If I did, I am sure I would probably eventually break the stub axle. I would go out on a limb and say if Stony was running an automatic, not only would his R200 setup hold up, the car would be quicker in the 1/4 with the right gearing and convertor. Watch and see what 240Z Turbo does when he puts the P-Glide behind his 3.1 TT. Yikes, I am rambling Quote Link to comment Share on other sites More sharing options...
majik16106 Posted February 4, 2004 Share Posted February 4, 2004 . I guess I'll have to find someone with a manual GN and ask them about their powerband and turbo lag. You know there is no such thing? No 3.8 turbo was ever mated to a manual, i hope it has been done, for a long time i looked into seeing if it could be put to a t56, but all KINDS of custom work would need be made.. unless like i said.. its been done and now i sound like an idiot, but no turbo trans am or gn or regal t-type came with a manual trans. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted February 4, 2004 Share Posted February 4, 2004 I had considered the idea of swapping a GN into a Jeep with a manual transmission, but, Sottie was nice enough to inform me about how a GN works so much better with an auto as he pointed out here. I would check with the Jeep crowd about swapping Buicks with manual transmissions. Quote Link to comment Share on other sites More sharing options...
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