Jump to content
HybridZ

Let down on the Dyno!


Recommended Posts

Hi Guys,

 

I have a a 73 240z with an older Chevy 350 which I was told has:

 

new HEI accel dist

fuelly heads with 2.02 stainless valves

HD valve springs

roller tip rockers 1:6

and some kind of 509 cam???

and was told around 10:1 compression

Edelbrock 600cfm carb

Weind "Stealth" intake

homemade looking headers (ewww)

full 3" exhaust(from collectors to a y tube all the way back to a Jones Racinf 3" straight through muffler)

It is mated to a built th350 trans

and a welded stock 73 automatic diff (not sure of the ratio but should be stock)

23" tall rear tires

shitty Eldelbrock foam air filter

 

I went to the Daft Innovations Dyno meet in Modesto this weekend and was let down to find out that I was only putting down 195hp/270ftlbs.

 

I would like to achieve 300hp to the wheels and around a 12.5-12.7 1/4 mile time. Is this not acheivable? It currently runs 13.8's due to the smaller diameter tires. The previous owner ran 13.5's on 26" tires and I have seen the timeslips.

 

 

I am wondering if anyone on here has a simalr setup in their Z and if so what kind of 1/4 mile times they are seeing. Also gas milage with a simular setup using the th400 trans or WC t5. I am going to change my transmission soon as I need an overdrive.

 

What are some suggestions to make more power? I think I may need to up the compression as I just dont think I really have 10:1 I think it is probably stock pistons. I currently run 91 octane and would like to keep it that way.

 

I am thinking:

 

new pistons

new cam and probably full roller rockers

new carb

new intake

 

What are your thoughts/suggestions? Which ones should I look into?

 

I have been using the search feature and can't seem to find what I am looking for.

 

 

THANK YOU SO MUCH FOR ANY INFO YOU CAN OFFER!!! And don't laugh at my ghetto engine and engine bay. These are the next things I am going to work on. LOL.

 

I have had the car for like 2 months and have been mainly focused on its appearence. Now I am trying to improve the performance. (see the before and after pics)

 

Josh

post-11875-12771680561923_thumb.jpg

post-11875-12771680812124_thumb.jpg

post-11875-12771681355075_thumb.jpg

post-11875-12771683044217_thumb.jpg

post-11875-12771683841855_thumb.jpg

Edited by jrb1449
Link to comment
Share on other sites

Don't pour thousands into building a new engine just yet. I've yet to see a car roll onto the dyno for a TUNING SESSION (ie: not just a baseline) that wasn't leaving horsepower untapped. In some cases with V8's like yours, their has been 50+hp untapped that could be freed up with just tuning.

 

Check out the dyno thread here:

 

Dyno Tuning Thread

 

For instance:

 

50TUN.GIF

 

351W.GIF

 

This was just jetting and timing in both cases... Buy some jets, and head back to the shop.

Link to comment
Share on other sites

Check your timing, both at idle and full advance.

 

Find out what kind of cam you have, and if it's degreed properly.

 

See what your A/F ratios were on the dyno.

 

See what mph the car ran, get it weighed and see if that agrees with the dyno, using one of the calculators.

 

That will be a good start to finding out what's up.

 

jt

Link to comment
Share on other sites

Sounds to me like your dyno numbers are not very accurate. I would think that running a 13.8 you would be making more than 195/270

 

 

Ya know, I didn't want to sound like a ***** and ask them what was up. I worked at a shop years back and we had an actual Dynojet and it was a huge above ground structure! The one at Daft is like a Dynocomp or something like that. It looked like a really small portable type unit???

 

I just didn't want to look like a poor looser asking how accurate there machine was. Either way it was only $40 for three pulls. lol.

 

At my old shop, like 5yrs ago, we charged $100 for 3-4 pulls.

 

I don't remeber seeing anyone that was really happy with their numbers.

 

In fact there was a guy with a 92-95 Honda civic with a Acura 3.2 CL tye S swap and he put down 213hp to the wheels! I was really thinking my car sucked. But after thinking about his traction issues with the 195/50 tires he was sporting I was sure I was probably faster! hahaqha

post-11875-12771707150256_thumb.jpg

Link to comment
Share on other sites

I took some pictures of the dyno print out. (crappy cellphone)

 

I really don't think it was running way rich or lean. (what the heck do I know, maybe you folks could shed some light on that)

Timming was @ 12 degrees at idle without the advance (I'm guessing about 36 degress full advance.)

 

I ran a 13.895 at 94 mph on 23" tires

 

I weighed it at the local truck scale and was 2700lbs with me in the car (I am about 270lbs)

post-11875-12771714406109_thumb.jpg

post-11875-12771714602416_thumb.jpg

Link to comment
Share on other sites

Don't pour thousands into building a new engine just yet. I've yet to see a car roll onto the dyno for a TUNING SESSION (ie: not just a baseline) that wasn't leaving horsepower untapped. In some cases with V8's like yours, their has been 50+hp untapped that could be freed up with just tuning.

 

Check out the dyno thread here:

 

Dyno Tuning Thread

 

For instance:

 

50TUN.GIF

 

351W.GIF

 

This was just jetting and timing in both cases... Buy some jets, and head back to the shop.

 

THANK YOU SO MUCH FOR THAT LINK!! It was super informative!!!

 

I am going to go back to my old shop here in town with the Dynojet and get a couple of baselines to see what the difference is. The only problem is that my old shop is now under new ownership and just because someone owns a dyno does not mean they know how to tune!!!!!! Trust me!!! My old boss acted like he knew what was up but sometimes I could tell he really didn't!! I guess I need to ask some oldschool hotrod guys here locally for good places that have a dyno and REALLY KNOW how to tune!!

Link to comment
Share on other sites

It looks like it's leaning out above 4K rpm. A good baseline AF to shoot for is 12.5:1. Making peak hp in the mid 4K range would indicate a pretty mild cam if everything else is right. Check your timing at full advance, that's a key part of your tune.

 

jt

Link to comment
Share on other sites

my GF has a 2003 Acura CL Type S 6spd. I am very aware of the power! lol

 

Its a 2003 and has 190k on the clock and still is a blast to drive!!

 

I replaced the timming belt and water pump a while back and thats it! (other than several sets of tires)

 

Still on the stock clutch even! (knock on wood) and she drives all over the San Francisco Bay. She commutes to Sacramneto regularly as well.

Link to comment
Share on other sites

THANK YOU SO MUCH FOR THAT LINK!! It was super informative!!!

 

I am going to go back to my old shop here in town with the Dynojet and get a couple of baselines to see what the difference is. The only problem is that my old shop is now under new ownership and just because someone owns a dyno does not mean they know how to tune!!!!!! Trust me!!! My old boss acted like he knew what was up but sometimes I could tell he really didn't!! I guess I need to ask some oldschool hotrod guys here locally for good places that have a dyno and REALLY KNOW how to tune!!

 

I think you missed part of the point of my linked thread. A dyno is best used as a comparative tool, not a meter to tell you absolute HP measurements. Switching dyno's to get a bigger number doesn't make your car any faster, does it? ;)

Link to comment
Share on other sites

I think you missed part of the point of my linked thread. A dyno is best used as a comparative tool, not a meter to tell you absolute HP measurements. Switching dyno's to get a bigger number doesn't make your car any faster, does it? ;)

 

 

I am purely interested in the differnt readings of the two brands of machines. I am looking for an actual increase in power. I would just rather use a machine local to me. I live in Sacramento,CA and the shop I went to was over 70 miles away. I totally get what you are saying.

Link to comment
Share on other sites

By checking it I should be at full 32 degrees at 3k rpm correct?

 

With your timing light hooked up, start at idle and increase the rpm while watching the timing advance. You will reach a rpm where it stops advancing and stays steady. You want to set the total advance with the engine about 500 rpm above the rpm where the advance stops increasing. 32 is pretty conservative. Usually the fuelie style heads will like 35 or 36.

 

jt

Link to comment
Share on other sites

THANK YOU SO MUCH FOR THAT LINK!! It was super informative!!!

 

I am going to go back to my old shop here in town with the Dynojet and get a couple of baselines to see what the difference is. The only problem is that my old shop is now under new ownership and just because someone owns a dyno does not mean they know how to tune!!!!!! Trust me!!! My old boss acted like he knew what was up but sometimes I could tell he really didn't!! I guess I need to ask some oldschool hotrod guys here locally for good places that have a dyno and REALLY KNOW how to tune!!

 

 

Stop right there! Dont keep going to different dynos to get the highest hp. As long as the dyno is repeatable then stick with it. You keep going to different machines and you will not know what changes did what. Just stay with that dyno and get the most hp you can on that dyno. Sure it may not tell you the numbers you want to see but you will have better results in the end.

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...