Jump to content
HybridZ

How fast will my car be?


Guest RCNSC

Recommended Posts

Guest RCNSC

Allllll right yall.

 

I'm not trying to break any records, but for the last couple of days its dawned on me my Z swap is close to happening. Now how quick will it be?

 

L28/E31/SUs/'71 4 speed/R180 diff

 

Some "source" tells me *he changed his mind and disapointed me*...... What do ya'll think?

Link to comment
Share on other sites

Guest bastaad525

That's really similiar to the last setup I was running, might be a tad bit faster for the E31 (I was running an N42) or a tad bit faster or slower from the 4 speed. Also, what is the gear ratio of the R180? That makes a huge difference... I was running a 3.9.

 

 

Well... my L28, overbored to 2850cc or 2.9, N42 head, mild cam, stainless valves, mild port and polish, rebuilt Ztherapy SU's, 5 speed, ACT clutch and lightened flywheel, headers, and 3.9's, made about 170hp at the wheels, did 0-60mph in the mid 6's, and was good for a high 14 second quarter mile. This was in my same '72 Z that weighed just under 2300lbs.

Link to comment
Share on other sites

There are just a few variables in that engine that make judging hp very difficult. Do you know what the build of this motor is like besides the e31 head?

 

Bastaad, your last post had me thinking a little. What was your 60 on the high 14s? First time I went to the track I was tried stock boost/timing/fuel pressure etc... everything and ran high 14s with a very weak clutch and 2.21-2.3 60ft on bald 215/65/15s-launching just off idle. Car probably weighed in a bit over 2700lbs.

Link to comment
Share on other sites

Guest bastaad525

my '60 sucked... it was quite a while ago but I just remember that it was pretty bad, like 2.2 or 2.5... I only got to go twice, the place was very packed (LACR/Palmdale). I actually ran a 15.3, but corrected for elevation I was told that would have been like a 14.8. The problem with that setup was that I never really learned how to launch it well without spinning the tire (open diff) thru all of first gear, causing me to shift early into second (no EFI, so no rev limiter to bounce off of... wasn't good enough to keep it from redlining myself so just shifted early) It bears mentioning that I'm a big guy, was about 300lbs at the time :oops: (no worries atkins is fixin me right up :D ), and I didn't do anything like removing my spare or any of that crap, and probably had just full tanked the gas as well (LACR quite a ways from me, I'm sure I filled up before driving there). This was on crappy $25 Just Tires all season specials, stock 195/70 14's, dumping the clutch at about 2500rpm. For what it's worth this was also running the crappy '75 5 speed that has the really close 1st and 2nd gear, and the really really big gap between 2nd and 3rd, and crossing the traps in 3rd.

 

You're not the first person to mention that my car seemed to be running slower than it should have been.... but not by much. I remember checking the common acceleration calculators and they put my trap speed at just about right, my ET only low by a tenth or two. So what can I say I wasn't doing so good that night :oops:

Link to comment
Share on other sites

A little bit of comparison:

 

L28/E31 setup, flattop pistons, .460/270cam, triple 40's with 34mm chokes, 5 speed + 3.70 gears...

 

0-60: 5.97sec

1/4: 14.5@94.8mph

G-tech info

 

This was not the best times this car was capable of. (the owner only tried 3 times) I feel that with a bit more finesse this car could be ~5.5 0-60 and in the low 14's.

Link to comment
Share on other sites

Guest bastaad525

yeah tripples would have made all the difference on my setup... it was meant to flow, with the high compression and 480 lift 270 duration cam... I don't doubt the SU's were choking off top end... with triples torque would have been probably same-ish but the car would have pulled much higher in the rev range... as it were max power peaked out at about 5500rpm... absolutely pathetic for an N/A L6.

 

My N/A motors power curve was near identical to a stock L28ET's, but at little higher... stock ET is good for 140-150rwhp, mine was putting down about 170. Torquewise my N/A was just about dead even with a stock ET. Torque in the N/A was nice and flat and came on early, just like my turbo does now.

 

In the end it was pretty sad that after spending that much cash to build that motor (est. $4k) that it just barely was above the level of a bone stock L28ET running stock boost, and on the flipside, all it took for my bone stock L28ET to make a massive leap in power was one $10 boost controller....

 

All in all though I have spent very close to the same amount on my turbo swap as I spent building the N/A motor and swapping that in to the 240... big difference is that with the N/A I was pretty much at the limit of what I could do with that particular motor, barring a second full rebuild and something like stroking... otherwise all I really could have done to it to get some more ponies would have been tripples or some kind of EFI, and some more extensive headwork.

 

With the turbo motor, I've already exceeded the power level I was at with my N/A, and have not even scratched the surface.......

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...