Question for Scottie about his motors

[clint78z]

I always liked how you gave people your honest opinion everything . I would like to know how the 3.8l compares to the old L28ET, obviously it has greater HP potential and better low end torque from displacement . Can you give a comparison, sound, smoothness, overall impressions of the 2 motors .

 

It is hard to get a good comparision, most of time it is Chev sux, or Nissan is a wuss motor . You having owned so many different vehicles porsche, talon, V8 .

[Scottie-GNZ]

Thanks Clint. Hope you all do not mind if I ramble a bit

 

Boy, where do I start? The Buick V-6, by todays standards is a crude SOB, from the infamous odd-fire version up to the GNX. I do not think GM knew what they originally designed had such potential. In '86, the sophistication of the engine management system in the GN matched anything available. Once the engineering hot rods got hold of it, the sky was the limit. Actually, the limit is about 600hp on the stock block before it needs a girdle and the StageII motor you know from the Indy Car program.

 

My L28 turbo had a slight rod knock and needed guides and I considered building it up, or swapping to a 3.0L single turbo or twin-turbo or GN. I ended up picking the crudest of the choices because I thought it had the most potential for the buck. The 3.8T was rated at 247hp stock. For a minimal investment of about $600, some diligent tuning and a little race gas at the track, 350hp is at your command. Thats right, folks, 40% increase for about $600 To date, here is my investment in hop-up parts that directly contribute to the engine's performance: $120 for a 3" wastegate elbow including getting it repaired, $275 for a 3" DP and exhaust, $80 for a slightly larger TB, $45 for SS I/C plumbing, $125 for used injectors, $50 for a race chip, $45 for a K&N. Not everything I did was necessary but I was positioning myself for a lot more horsies. I truly believe this setup will run 11.30s and that should be around 375hp AT THE WHEELS and torque well into the mid-400s. This is still the stock turbo. BTW, on a recent trip back from Tallhassee, I clocked 27mpg on the highway on a 245-mile trip. The Z equipment is so inaccurate that I might have been off a little but even 25 is great.

 

Having done the SBC, L6 turbo and GN swaps in the Zs, my favorite is the GN, but only from a drag racing standpoint. Both my Scarab and JTR V-8s were not top-notch engines. The JTR was a standard 350 with 1.94 heads, Edelbrock intake and carb and T-5. Given a choice between MY, repeat, MY V-8 setup and my L6 turbo, I would choose the L6. An L6 turbo, when properly tuned, is one sweet engine, and that sound! Despite running the stock t3 turbo, mine was tuned to the max with an SDS and ran 110.97mph in the 1/4-mile. Loved it until until I costed out a buildup

 

Does that make the SBC worst? Absolutely not!! A buddy in Denver has a C-5 and I have driven it and if one of those was available for a reasonable price, it would be my #1 choice for an all-around Z-car. However, since my primary focus with my Z is drag racing, NOTHING beats the GN for price/performance.

 

If you are looking for a lot of HP and driveability (sometimes mutually exclusive) you cannot beat a turbo or supercharger. Remember that a forced induction engine running at 1-bar boost is capable of ingesting twice its displacement. So, when I run 22psi, I am capable of ingesting the equivalent of 570+ c.i. Since the cylinder volume at TDC is unchanged, that is one massive explosion and explains the incredible HP and torque numbers. The trick is doing it without detonation.

 

I have given you my opinions from personal experience, so please, no flames

 

------------------

Scottie

71 240GN-Z

http://www.mindspring.com/~vscott911/gnz.html

[Guest Fast Frog]

Scottie:

 

Great Post!! You make me nostalgic about my former mini GN setup I had before my V8 conversion (sniff sniff). It was a nice setup-only problem was bottom end sucked. But I didn't want to loose any top end to gain bottom end. It was a great Interstate rocket!! Keep up the good work! You're what we're about!!

 

Rick

[clint78z]

Well I don't imagine the low off boost torque won't suffer all that badly compared to the old L28 . The compression dropped a full point . I personally thought the motor had decent low end torque (no V8) . It will hopefulley have a little more jam down low than my brothers DSM . I guess pick a motor that suites you, more importantly your budget .

I should offer to store Jame's spare parts in my car .