|
Ok…what am I missing?? Should be much faster
Ok sooo I thought I would start a new thread since my last one was about asking about if I needed a gear change but I don’t think that’s the issue after talking with you guys….Please give me your input on my combo….I messaged a couple guys to help but as mentioned there are lots of guys on here with smaller heads and smaller cam running in the high 10’s …why am I so slow? Haha
Right now my times are high 11’s with my best at 11.7 at 115mph with a 1.79 60ft Here is my combo……As I said what am I missing??? Thank you guys Engine is 461 cubic inches 70' 400 block Forged Crank 4.250” stroke Ross pistons 4.155 bore Eagle 6.8” H beam connecting rods Clevite rod bearings, std. Sealed Power main bearings, std Edelbrock aluminum heads 85 cc combustion chambers 340 cfm Manley Springs 221432-16 installed @1.840” 175 lbs closed, 475 open Spring cups 42326-16 ~10.4 compression ratio Comp Cams hydraulic roller camshaft Duration @ .050 248 I 254 E 112 lobe speration Lift .619 I .638 E with 1.65 ratio rockers Cam degreed in at 108.75 degrees ICL RollMaster timing chain and gears BOP Viton dual lip one piece rear main seal Canton 7 quart oil pan and pick up Crank end play .006 Rod bearing clearance .0019 - .022 Main bearing clearance .0022 Rod side clearances .027 - .031 Northwind port matched intake 4L80e 3400 stall triple clutch 3.42 gears Currently leaving off idle Holley terminator X multiport with 1300cfm Wilson throttle body 32 degrees total timing Also have the heavy 17inch snowflakes on the car but am switching to 15inch SSR spike wheels 28inch tire bias plys |
What's the fuel system consist of? Do you have a fuel pressure gauge that you can see when making a pass?
|
Yes I can see it on the Holley it’s usually around 50psi i believe but I will check it….I can see the whole run in my data long ….what should it be at?
|
I would work on improving your 60’ time. You’re making good power running 115. Need to get it hooked up a little better.
|
Agree lots of room for improving 60ft & launching. But those heavy 17" wheels are not helping, tires probably arent good for drag racing either, if you plan to change wheels for drag use then use the 17's for street use, get a skinny front, like 4-5" wide & run a skinny front tire like a M/T sportsman or radial or other small radial guys use for front runners. Rear wheels can be 8" for best fitment in a 2nd gen TA with a good drag radial like M/T DOT drag radials or the newer pro bracket radials, 255/60 or 275/60, but the 255 will be shorter & help lower gear ratio some.
115mph still seems rather low for the power your engine should be making, I mentioned my car on your other thread, down 50-75-100 hp from yours or what it should be at, im at 525-550 max & run 121-123mph at 11.2-11.3.... something is off on the power level or how your shifting or doing the run, your engine combo should be at least in the 120's mph IMO. I also leave off idle due to having a very firm auto-x type suspension set up and have to "roll into" the throttle or the tires break free, 255/60 M/T drag radials with 3.23 gears. My fuel starvation with a dead head mech pump holds back my best times too, I would think your EFI system with electric pump wouldnt have a fuel issue. Reducing weight anywhere possible will help too, I remove the big heavy front sway bar for drag use, pretty easy to do when the car is jacked up to swap wheels. Also getting even some cheaper drag type shocks helps a lot vs normal street shocks, I use summit brand 3 way adjustable, fronts loosest setting & rears in the middle. Lower tire pressure to 18-20 on drag radials or street radials helps too. Besides all that just play with launch rpm/throttle and shift points... & dont use OD for drag racing if it shifting to OD. Also try to make up a adjustable pinion snubber if you dont have any other traction aids like cal tracs or traction bars. |
I agree something is off. For comparison what is the weight of your car? I would expect sub 1.6 60ft times and mph in the 125 range. If you have access to a dragstrip for tuning work on little changes at a time for increased power. I would just cover all the basics to see what is up..confirm ignition timing is correct or optimized and confirm fuel pressure is rock steady at full throttle. Also check for convertor slippage at higher rpms. A chassis dyno day would also benefit.
If you can also check what the DA was at the dragstrip with your runs would help. I've also seen "hurt" transmissions eat power up...my car for example lost almost a tenth in the 60 ft and was down 3 mph topend..even though the transmission felt fine..it was the cause of the performance loss. |
Like TA man says I would just cover all the basics first and practice, practice practice.
How many Vipers and Z06s I have seen could barely muster 13 seconds passes but they usually still get decent MPH. Your 115 does not reflect the heads nor the cam youre running. I know nothing about EFI so I cant chime on this. But If your engine puts out decent RWHP on a honest chassis dyno. I would say your converter may be the issue. Peter |
Quote:
What does you car weigh with you in it? Can you post a time slip? Stan |
1 Attachment(s)
Here is one from last week the DA was awful which happens a lot here in florida…..The 11.7 at 115 was a couple weeks ago after the hurricane sucked all humidity out of the air
Right now on my snowflake wheels I’m running MT Estreet R’s But I just got my Hoosier 28inch bias plys on 15 inch rims so I will be able to leave at alittle more rpm …..Also they are about 25lbs lighter per wheel! I haven’t been able to weigh the car but I am going to soon! |
With the OD transmission why now go to a 3.7 rear gear?
|
That is the plan actually…..I was even suggested 410’s would be ok with OD trans
|
Sounds like a really nice combo. With some very nice parts!
Just a few things I noticed about the combo. 1300cfm seems like a lot of overkill with that throttle body. On a small 461. Unless your crossing at high rpm. For reference I’m over 615+ cubic inches with cylinder heads that flow 550+ cfm I cross at 7500rpm,And I only have a 1050cfm carb. With a converter that slips at 10% at the stripe. And it dials in good air (600ft da) or bad air(4600ft da) In really really really good air you might get away with that big of a throttle body but in bad air/thin air it will struggle to produce enough air speed to make the motor happy. If you dyno’d the motor the more cfm on top of that intake will usually show bigger gains but set that sucker in motion on the track and you may not see a difference in acceleration. Shocks. Another thing I immediately I see is what shocks to you have? I would set your rears to full loose ext and comp and adjust the fronts to full tight on compression and play with the ext and start fairly tight and start loosening them up 2 clicks at a time. That will help plant that rear tire and keep it on the ground.I am a huge fan of double adjustable shocks in the front and rear. I think they are the most overlooked part of any combo. The gear change from the 3.42 to a 4.10 will pick you up about a tenth, but it’s a great all around gear and years down the road you may not vary much from that 4.10. Also converter. What does it flash to? That converter might be a bit too tight but I’m guessing with your 4L80 trans you drive it on the street a lot so I’m not sure how loose you want that converter. But my 2cents is in good air or bad air a loose converter is better and the looser the more consistent. Just remember carb/throttle body, converter, shocks, and tires is absolutely EVERYTHING for consistency. They all have to work together. Your combo is off to one bada$$ start!!!! Good luck! |
The 4l80 and triple clutch converter are costing you performance.
|
A lot of good advice given here! I'll add a couple things. You're car is probably heavier than you think. Weight loss is guaranteed to improve ET and MPH. ET should improve about a tenth for 100 lbs loss. You have a lot of room for improvement in your 60'. With 115 MPH, your 60' should be in the low 1.6 range. If you are spinning, the 15" wheels should help with that but in my experience bias tires are slower than radials if both have good traction. With good traction, leaving at a higher RPM should help your 60'. I would also try tuning your "accelerator pump" shot. As far as gear ratio, I think 4.10 would be ideal with a 4L80. In OD it would be like a 3.08.
|
Your mph now shows 11.40’s capability, u need to get the car moving, I would be looking at gears and conv to get it it out of the hole. I would try different launch techniques also,,if it’s not spinning it’s just slow to get going right now
|
Thank you all for your thoughts and info! Great advice!
I am definitely going to address the gears asap with the 410’s and do what I can to get it alittle lighter. Starting with the wheels! I also for sure think something is going on with the big throttle body getting enough air speed on the 461 like you said S/st Slowbird can you elaborate alittle more on the triple clutch? Absolutely have to get it moving better and aim for a 1.6! |
2 Attachment(s)
Quote:
|
Quote:
Dont get me wrong I know how much dedication and budget you've invested in your TA over the years and racing success is measured in small increments. But if the aftermarket industry used real life timeslips instead of "happy" dyno graphs, I dont think they would sell as many 3.73 gears, 310 cfm heads and big cams... anymore lol. Too many people think running fast times in the quarter is simply a matter of slapping HP parts together... You are the proof that its a labor of love. Peter. |
Quote:
|
TA man…..that’s pretty awesome! Thank you for the slips
What size carb are you running? I gotta get to the 1.5 60 range Also what do you guys suggest on total timing? Slowbird…..what would you suggest as an alternative? |
| All times are GMT -4. The time now is 08:06 PM. |