I've conquered all the little gremlins and actually got a little seat time this weekend. I've burned ~10 chips so far, concentrating on getting the part throttle BLM's on and the hesitation problems. I've had to max the lower accelerator enrichment tables to address the "tip in" problem. It's still not as crisp as I would like. In my opinion, the low end torque loss is huge compared to my previous Accel LTR setup. The ZZ4 is known for being a torque monster anyway. Keep in mind, I've still got many hours of tuning to do, so the low end (2500-4000rpm) may get a little better. As I expected, this is a good thing. I can actually flash the convertor on take off, then nail it without totally blowing the tires away all through first gear. For the first time, with some practice, and on these Nittos, I can imagine perfecting a very hard launch. Guys, my biggest dilemma now is how high to rev it. It's pulling so hard at 6000 you don't want to shift there. I called the techline at Scoggin-Dickey and they said the ZZ4 was good to 6000, but couldn't recommend any higher. I've still got a lot of prom work to do before it's running to it's potential. Mainly, without a WB sensor, it's hard to tune the "PE %F/A ratio vs rpm" tables and know that your not lean. Once I have some confidence in holding it to the floor for a 1/4 mile, I'll put the G-tech on it and see if the extra revs has overcome the low end torque loss.

 

Did you buy the LT1 moddified or did you do it yourself? So far do you think it was worth the swap? How long did the actual swap take? Do you have any dyno or 1/4mi #'s before the swap, can you still burnout if you want to with such a low rpm torque loss?

 

CAuse we all know thats the TRUE measure of performance!

 

I bought it from John Millican already modded. Yes, it was worth it. Don't use me as a measure of how long it will take. I took ~3weeks to do it. I like to take my time, since I don't drive the car much anyway. I took this opportunity to remove everthing but the essentials from the engine bay, and put things back together where they look good. I bet I've removed at least 45lbs. from the front of the car. My last G-tech run before the swap was 13.25 @108. Of course I can still roast the tires if I want to. I'm not sure if you have experienced extreme traction problems, but before on street tires, 1st and part of second gear was useless. With drag radials I started finding a little traction with practice. Now, the couple of times I've tried launching with this new setup, I felt the rear grab and the front rise more than ever. At ~4000rpm and up it feels like a nitrous shot. I had said (to the wife)that I wouldn't do any more mods for awhile, but more gear and a 3000 stall would do wonders.

 

ive got the lt1 intake installed i have about 1500 miles on it no probs at all i cant tell any differences in the torque i thought id loose alot but i cant tell the diff between this and tpi until i get above 4500 it pulls like mad all the way to 6000 "thats where my rev limiter comes in" i hit the rev limiter alot now never did with tpi 6000 comes so fast now im trying to get to the track this sat but theyre saying rain for sat i got my intake from john its any easy install i love it its staying later

 

Thanks for the info Steve10. I do have a big traction problem with my 383 stroker, so I can afford to lose some lowend torque. I can't wait to see what you do in the 1/4mi now with the LT1.

 

SMKNGTA...what's your setup? If you're doing the swap, I think you're 383 will respond much better than my 350.

 

I think most of us with modded engines will welcome a loss of low end torque.... I know I would!! This having to roll into the throttle and pedal it all the time crap when 'playin around' is for the birds..... not to mention the falling on its face on the top end . But I have to assume that some tuning will give you back some of that low end power. I mean how many regular LT1 cars can't smoke the tires or don't have any guts on the low end???? Nice work Steve .

 

Steve10

My setup is in my sig, and I plan on running AFR 190 or 195's when I do the swap with a better cam, 58mm TB, and Headers.

 

Remember torque is what you "FEEL" But HP is what gets you to the traps sooner.


TPI feels great compaired to an LT1 car (both stock) but the lt1 will run you down in a quarter even though the TPI has you grin'n on launch

Long live the butt dyno

 

The loss of low end torque compared to an L98 is welcomed. Do you ever hear of fourthgenners crying over not being able to roast their tires, or that their cars don't run fast compared to thirdgens? LT1's spin to 6000+ RPM and continue to make power (not stock LT1's, but with a good cam like an LT4 HOT cam). I bet most of you guys would trade away your torque TPI for a nice high revving LT1 intake. I know I would/have (well I did the whole motor). You don't have to play with the gas teaching yourself how to launch with little wheelspin, only to have to shift at 4500. There's a reason LT1 4th gens ran 13.8 in the quarter stock, that's almost a full second faster than the '91-'92 L98's, and let me tell you, it wasn't because the LT1 ONLY had 30 more flywheel HP. It's cuz they could stretch out the power band much further. You guys are fortunate enough to be able to use an LT1 intake on an SBC without having to buy an expensive miniram. The LT1 intake is essentially a miniram in design. There's a reason why there are NO commercial aftermarket intakes for the LT1, and 3 for the TPI.

 

Preach it brother!

If you're straight up crazy you can port the lt1 intake and you've got more flow than you can ever use, it'd take a 406 before you'd even need to do it.

 

Very good observation!

 

I'm swapping to the LT1 intake also. Can't hook up to save my life with drag radials and the superram. I guess too much of a good thing can be bad for you.

 

Well, TPIS did try and market an intake for the LT1, for a very limited time cause they couldn't sell it, it's just not where the engine needs improvement. Basically it's a small tunnel ram intake, hard to improve on.

 

I am pretty sure edelbrock made an intake for the lt1. Am I wrong??

 

Its discontinued

 

Ummm, don't get me wrong, I like the LT1 and all, but I'm curious as to where this statement came from:
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There's a reason LT1 4th gens ran 13.8 in the quarter stock, that's almost a full second faster than the '91-'92 L98's, and let me tell you, it wasn't because the LT1 ONLY had 30 more flywheel HP. It's cuz they could stretch out the power band much further
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When many L98s pulled low 14s and I believe a guy on here hit a 13.9, Also the trap speeds are with 1-2 mph of each other, especially if it's auto vs. auto. The Lt1s that run 13.80s are probably more to do with Manual vs. automatic, in which case it's a drivetrain issue.

Judge engines by trap speeds, judge cars by E.T.

 

Because nobody would buy it . LT1/4 intake is proven to 155 mph in the 1/4 and at least 1200 hp . Don't believe me , search the net for George Baxter .

Nice job on coverting the intake for the gen1 engine , imo best thing a TPI guy could do

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Derek
92 Z28 - soon to have a VERY nasty LT4