As a few of you saw, I did a WHOLE bunch of porting on my TPI intake, siamesing the SLP runners and almost 3 inches into the stock base. The car is VERY tame down low (obvious but not excessive torque loss below 3000 rpm) making it exceptionally streetable for a change. Past 3000 rpm, all hell brakes loose right into the 6200rpm rev limiter. I welcome the change. (Before, the range was 2000-4500rpm).

I got the chance to take the car to the track this weekend. The only difference between my previous best and the new one is the ported TPI intake (no new parts). Keep in mind this was all done on $70 225/60ZR16 Road Hugger street tires.

Previous best: 13.18 @ 105.1 mph

New:

R/T: 0.565 (best ever)
60': 1.974 (best ever)
1/8 mile: 8.24 (best ever)
1/4 mile: 12.74 (best ever)
1/4 mph: 109.75 (best ever)

I was very happy with this run. Based on weight and mph, I calculated a 44hp gain from the intake work. Not too shabby for $40 in parts.

 

Your engine must've been starving for breathment! Nice results! What are you running (give me the big picture) cause I doubt gains like that are typical on a mildly modded engine.

 

350 block
GM 1011034 race castings ported and decked for near 11:1 compression (not sure of valve job)
282/288 roller cam, 230/236 @ .050, 110LSA, .510/.520 lift
Block hugger headers
Stock TB
Ported stock plenum
Ported/siamesed SLP runners
Siamesed base
24# Accel injectors
Holley Commander 950 programmable computer
Dual 2.5" into single 3" exhaust, no cat, back to a Dynomax Super Turbo

Sam

EDIT: Oh, my car weighs 2870lbs with me in it and a full tank, ready to race. I calculate just shy of 360hp.

 

Ah now things are a bit more clear. Well - nice engine you have there, and now I am seeing why your port work freed up so much!

Eh, good job!

Oh... how did you manage to get your body down to 2800 pounds (WITH YOU IN IT)?

 

 

well that pretty much explains the weight and your screen name

 

I love your car (except for the fender flares).

Tim

 

Yes things are much clearer now...

Cool of you to do so (put a tpi 350 into a nissan)
Very cool as a matter of fact! Nice looking vehicle to boot.

 

thats a nice z

 

Very cool sleeper there. It looks so.........tame. Nice job! I always dug those 280Z's.

 

Hey nice Z :hail: :hail:

Very cool little car to put a powerful motor in. I always liked the way they looked.

 

That's a bad *** car you got! Do they make conversion kits to drop a SBC into a 280Z?

 

very cool little Z, have u ever seen the supercharged LT1 280z? all i can say is SICK!

alot of people talk about using the TPI for what it is (lowend and midrange power) was ur motor just starving for air or did u need to compliment the cams power band? what did it do at the track with out the siamesing work?

 

Well - I read that the stock L98 cam has alot to do with the choke that the LTR's get discredited for! TPIS (I know many do not like them, but they are TPI pros) Anyway they say that GM has something designed into the L98 cam called "roll off". Supposedly the cam is equally responsible (as the LTRs) for the engine face planting at 5,000RPM. I think your cam is a huge player in why you're pulling so hard all the way to 6,000. Man, you have such an awesome car!

He was running 13.1s before.

 

does the LT1 cam have this roll off designed into it to? if not what would the TPI engine pull to with it installed

 

I do not know. I am a cam newb TPiS was very vague... surprise. All they said was that GMs L98 cam has this "roll off" design, and their L98 cam (the super profile) does not, so it makes useable power after 5000 RPM. I too would like to hear more about this. I wish they would have explained exactly what the hell "roll off" is and why it tires after 5000 RPM but go figure - they're TPiS.

 

Nice car 280Z28. How about a picture of under the hood?

 

TPIS will say anything if it gives them a chance to hype a product. I don't know what they mean by "roll off" in the stock cam, but to me it boils down to an even simpler concept: It's a GM stock cam

And long runners are absolutely a hindrance at high RPMs. All you need to do is compare the dyno charts of say a LTR car with say AL L98s and an Lt4 hot cam ,and an LT1 car with the same cam and you'll see a very different shaped curve. TPI basically pitches a tent pole in your torque curve and then you'll notice a flat HP line off the top as it chokes the engine for air. LT1 will be a flatter TQ curve with a nicely peaked HP curve

 

Thanks for the compliments guys.

It's not a sleeper once you hear it. Sometimes I wish it was! Sound clip (2 full 6K rpm revs)

Regarding conversions in the Z cars: it's a pretty easy and straightforward (and common) swap. Tons of info here

Someone mentioned cam roll-off and intake roll-off. When I went heads/cam from stock, my power went up, but the engine still rolled off at nearly the same point. Before heads/cam, I shifted at 5000rpm. After heads/cam, I shifted at 5200rpm. Now I shift at 6000rpm (waiting on more tuning and a rev-limiter bump now). Until you get a cam and intake that breathe TOGETHER, you'll always be hindering yourself.

As for the cam I'm running: it's about at the limit for a stock TPI intake. You shouldn't get this cam unless you have heads, exhaust, and programming, and are SERIOUSLY thinking of going to at least a siamesed stock intake. I wouldn't expect to use this cam in a heavy car either: lack of torque below 1500rpm would get annoying fast. My heads cam package was absolutely suffocating under the restriction of the (near) stock TPI (only SLP runners).

Under hood 1

Under hood 2

Front of car with tint (dirty )