OBX diff and slicks equals too much fun!!!!!

[turbovanman²]

Well, more boring stories for you guys.

Thursday after work, install my OBX LSD in my van, got to bed at 4 am, back at work for 8:45 am the next day.

Get to the track Friday after work, install slicks, boost is still set at 20 ish PSI from the other Friday night, van has been parked as my Jimmy needed some tlc. I put 20 litres of 94 oct Chevron in my empty tank and 1.5 gallons C16. Hit the burnout box and do a f*cking wicked burnout, but engine cutting out and chugging, clear out the engine and stage, bog off the line and it coughs and splutters the whole run, :mad: #$~!$$##%, run a 15.7@88.2 mph, 2.4 60ft. Its neat having both wheels spin in the bleach box.

I change out the custom cal chip and install Shel-Games chip. Make NO OTHER changes, do another wicked burnout-YES, I know, your not supposed to but I wanted to beat on my OBX and plus, its FUN-:D 2.37 60ft and rip a 14.4@94 mph, still at 20 ish boost.

Give the MBC 1 turn and go back out, pitted against a mint condition Datsun 510, its also eerily quiet!!!!!!!!! I bust a .564 time, him a .747, I get a 2.3 60 to his 2.9, I am ahead pretty good, not looking at my tach it starts to cough and splutter, sh*t, the lifters pumped up at 6200rpm, I pedal and float gas to try to let it catch, 510 boy goes by me 3/4 track, van comes alive and I catch and pass him just at the line, me-15.7@87 and him 16@66??????

No changes, but I am thinking of my crappy 60fts and how it bogs off the line than catches, I realize I need more boost off the line and now I have hot slicks, I can try it. I have been launching at roughly 6-7 psi.
Line back up with 510 again????? and off we go, another wicked burnout, I launch at 11 psi this time, me a .334, him .887, It launches pretty hard, I feel this could be a 13 sec run, cut a 2.14, him a 2.33, I rocket to a 14.1@93, him a 13.7@104-little bugger has a turbo hidden under the hood. I leaned out pretty good in 3rd gear on this run.

Turn up the fuel pressure 1 1/2 turns and go back out. Another wicked burnout and stage, I launch at 15ish psi and holy sh*t, it pulled out of the hole like a freight train, I cut a 2.009 60ft, racing a Ion supercharged Ecotec, he cut a 2.47, It was pulling hard then the valves pumped up again, Grrrrrrrrrrrrrrr, slowed down and ran a 16.7@67 to his 16.0@98.

All in all, had an awesome night, van again was the most popular vehicle there and learned alot, my old cal was the problem all along and now, just need to play some more and get on the dyno. BTW, if your thinking of drag racing, spend the money and get the Quaife or OBX, they friggin rock, :thumb:

A bud with his Rotary blew the turbo-first run, he had just had it rebuilt and on the way home, I was playing with a new Porche, he passed me so I pinned it and passed him, he wouldn't play though, :(

[DeckSetter]

dang, a turbo 510 would be a great sleeper... probably a 280ZXT motor swapped in. I just ALMOST put a turbo L28 in my 280ZX before I bought my van, but the ZX had too much underbody rust...

[looneytuner]

Sounds like the others had nightmares about you getting everything right. If participants are scarce next week, they might pay you to STAY AWAY>>>>

[turbovanman²]

Sounds like the others had nightmares about you getting everything right. If participants are scarce next week, they might pay you to STAY AWAY>>>>

One could only hope, :eyebrows: :nod:

[BIG PSI]

GOD I MISS MY MINI VANS !!!!!!!!!!!!!!!

I am glad to hear that you are getting VAN HELLAN sorted out. Next week the 13's will be there for you my friend. Keep at it.... I am lokking foward to meeting you in July.

Your Friend
Chuck

[ShelGame]

I change out the custom cal chip and install Shel-Games chip. Make NO OTHER changes, do another wicked burnout-YES, I know, your not supposed to but I wanted to beat on my OBX and plus, its FUN-:D 2.37 60ft and rip a 14.4@94 mph, still at 20 ish boost.


Glad to know it worked good for you...

[turbovanman²]

It still doesn't pull very hard on the top end, this has me baffled. I am running the same time as my bone stock setup with a TIII turbo in 2003, I ran around 23psi then, around 20 psi now!!!!!!!!!!! hopefully I can get this thing in the 12's before summers end or I will die, :(

Oh, I am running the S1 cam, I am putting the stocker back in or the S2-thoughts? stock or S2?

[Birddog]

^^ I'd be a bit agravated too....
But keep the stories comin!

[turbovanman²]

But keep the stories comin!

You guys arent' bored by my stories yet?

[BIG PSI]

Simon,

I have an idea as to what may be your problem at the top end. Check your spark gap, maybe it is to far apart and the flame is getting blown out ???

Do you have a fuel pressure gauge hooked up to where you can see while you are going down the 1/4 mile or is the gauge just under the hood ?

Last but not least, what about your timing ???

Chuck

[turbovanman²]

Simon,

I have an idea as to what may be your problem at the top end. Check your spark gap, maybe it is to far apart and the flame is getting blown out ???

Do you have a fuel pressure gauge hooked up to where you can see while you are going down the 1/4 mile or is the gauge just under the hood ?

Last but not least, what about your timing ???

Chuck

Gap at .028 and a flame thrower of a coil

After I turned up the fuel pressure-yellow/green on the dawes and roughly 14-1500 EGT's, can't see all guages properly.

Timing at stock 12 deg. My old engine liked 15 when racing so I might play with that next time out.

[89acclaim]

You guys arent' bored by my stories yet?

How can stories of a drag racing tool shed ever be boring? :thumb:

Daniel Merrill

[ShelGame]

It still doesn't pull very hard on the top end, this has me baffled. I am running the same time as my bone stock setup with a TIII turbo in 2003, I ran around 23psi then, around 20 psi now!!!!!!!!!!! hopefully I can get this thing in the 12's before summers end or I will die, :(

Oh, I am running the S1 cam, I am putting the stocker back in or the S2-thoughts? stock or S2?

Where are you shifting at? I know my car has no top end at all. Just this afternoon, I lowered my shift light from 5900 to 5400 and picked up 0.300 et!. 2.5's just have NO top end what-so-ever unless you have a seriously ported head and big a$$ cam...

[turbovanman²]

Where are you shifting at? I know my car has no top end at all. Just this afternoon, I lowered my shift light from 5900 to 5400 and picked up 0.300 et!. 2.5's just have NO top end what-so-ever unless you have a seriously ported head and big a$$ cam...


Unfortuneatly, around 6 grand. I am going to lower my line pressure to lower the shift points a bit more.

[ShelGame]

Unfortuneatly, around 6 grand. I am going to lower my line pressure to lower the shift points a bit more.

You need a RMVB :)

[turbovanman²]

You need a RMVB :)


Hahhaaa, everyone keeps saying that but NO, if I go that route, going to put my 568 in. I refuse to shift an automatic on the street, just seems wrong, :eyebrows:

[Directconnection]

Simon, what do you mean by the valves "pumped up" ???

I'd seriously pull out everything non-stock except for the intercooler and turbo combo and start right from scratch. Proccess of elimination. Something still doesn't sound right.

[turbovanman²]

Simon, what do you mean by the valves "pumped up" ???

I'd seriously pull out everything non-stock except for the intercooler and turbo combo and start right from scratch. Proccess of elimination. Something still doesn't sound right.

The lifters or valve train pumped up, its never done that before at such low rpm, dropped the cylinders then had to wait for them to pump back up, then it stopped missing and back to life. Could be the conicals but others have had no issues at only 6000 rpm with them?

I know, something doesn't seem right but every drag night, find something else, :eyebrows:

[The S is Silent]

Have you thought about swapping out the conicals before next drag night to rule them out as the problem? All the data that is out there indicates that the stock valvetrain is adequate for how high the 2.5 will rev.

[turbovanman²]

Have you thought about swapping out the conicals before next drag night to rule them out as the problem? All the data that is out there indicates that the stock valvetrain is adequate for how high the 2.5 will rev.


That is something to think about but I am the only one that is having issues at such low rpm. I had them checked at the head shop said there perfect for this combo, seat and lift pressures are bang on, :thumb:

Again, for some reason, last friday night was the first time, I could rev it to 6700 before then it would pump up? I guess I could have damaged a spring or something?

[Clay]

when you say your valve trian pumps up, do you mean your valves are floating?

[Dave]

Ditch the computer. Go back to stock and give that a try. Your 60's aren't bad. 2.0's are workable, anything higher just sucks.

You should ATLEAST be mid 13's. What are you doing for an exhaust?

[ShelGame]

That is something to think about but I am the only one that is having issues at such low rpm. I had them checked at the head shop said there perfect for this combo, seat and lift pressures are bang on, :thumb:

Again, for some reason, last friday night was the first time, I could rev it to 6700 before then it would pump up? I guess I could have damaged a spring or something?


6700 is way too high for a 2.5. Seriously. There's no more power at 6700 than there is at 3000. So, you might as well be shifting at 3000. Shift at 5400-5600, and you'll find yourself going fast. Can't you manually shift your trans - eventhough it isn't a RVMB?

[turbovanman²]

Ditch the computer. Go back to stock and give that a try. Your 60's aren't bad. 2.0's are workable, anything higher just sucks.

You should ATLEAST be mid 13's. What are you doing for an exhaust?

See my setup on page 1, :p



6700 is way too high for a 2.5. Seriously. There's no more power at 6700 than there is at 3000. So, you might as well be shifting at 3000. Shift at 5400-5600, and you'll find yourself going fast. Can't you manually shift your trans - eventhough it isn't a RVMB?

That was 3 weeks ago trying to fix my governor, now it shifts at around 6000 rpm. Going to play with line pressure and tv cable to lower it more.


when you say your valve trian pumps up, do you mean your valves are floating?


Nope, there not floating, the lifters just pump up????? just started doing it. I swear I have a little gremlin living under my hood, :(

[Directconnection]

That is something to think about but I am the only one that is having issues at such low rpm. I had them checked at the head shop said there perfect for this combo, seat and lift pressures are bang on, :thumb:

Again, for some reason, last friday night was the first time, I could rev it to 6700 before then it would pump up? I guess I could have damaged a spring or something?


Not trying to be anti-pope... but the previous poster is correct.

Besides, with all the issues you are having, I'd go back to stock everything and then do one mod at a time. You are chasing your tail and making yourself lose hair I bet!

I'd put in the stock cam, lifters, cal and injectors. Even the darn coil and wires as well. That T3/T4 should be pulling much harder for 20+ psi even for your "tool shed" hehe... I like that. Maybe you should change your username to: "Turbotoolshed" Only if the wife would let me have one more TD..TM... well...a couple more ('86 GLHS and '89 CSX)

[Directconnection]

Ditch the computer. Go back to stock and give that a try. Your 60's aren't bad. 2.0's are workable, anything higher just sucks.

You should ATLEAST be mid 13's. What are you doing for an exhaust?

Forget about what his 60 ft is and his ET. MPH is indictive to what power he is making. 93mph in a minivan is great... but not with the setup he has stepped up to.

[SwiftTech]

you say they pump up, does that mean the valves are staying open all the time? Or do they bleed down and start ticking? Aren't you running the PT lifters too?

[fleckster]

The general concenus of trial and error has shown that unless you have a majorly worked head, the optimum shifting point for a 2.5L is only 5200 rpm. You can get a couple hundred more with the 2.2L. Any higher and you are just revving for nothing. This could also give you more mph at the traps too since you will be pulling closer to the peak torque after shifting. I would think with your set up, the slicks should be able to hold you launching at 15psi.

[turbovanman²]

Forget about what his 60 ft is and his ET. MPH is indictive to what power he is making. 93mph in a minivan is great... but not with the setup he has stepped up to.

93 mph sucks, I ran 95 on the stock setup. I am changing out the cam tonight as my fuel rail sprung a leak. I know I should change it back to stock but after reading for hours, the S2 is a good choice so thats going in. Bash me all you want, lol! I don't have the time or energy to put the stock springs back in so the Conicals have to stay. The lifters are going back to stock as you can't run PT's with a S2. Talking to my grinder, the S1 I had in there is no good for high boost, just a good RV cam so that would explain my lack of top end. Thanks for all the suggestions guys, I am getting them one by one and starting to have alot of fun. I am going to try launching at 20psi on Friday, if the weather stays dry, :thumb:

[89DaytonaTII]

Well I hope the S2 works then

[fleckster]

Simon, at the Mopar Nats last year, if I remember correctly James Reeves had an S2 cam in his GLH Turbo. He had tried it several times and at many different settings as far as timing with his adjustable cam sprocket. We swapped it in the pits between rounds and he put the stock '89 TBI cam back in and picked back up his 2mph plus he had lost on top end. It also launched harder with the stocker. I think the problem with most of the aftermarket cams is that they have a bit too much overlap which allows the boost to blow right through to the exhaust at higher rpms. Most company's blower cams, regardless of which engines (Chevy, Ford, etc.) are very near stock for overlap and in general don't run as aggressive duration either. I think the theory is to get more lift to allow the forced air in but try to minimize the times that the valves are open to keep the boost in the cylinder.

Then again I could be a total moron...let the audiance decide!

[BadAssPerformance]

Fleck is right on.

I also remember when Reeves was swapping it out... took off a couple tenths in the 1/4 with the swap too :thumb:

[WickedShelby88]

And a point is illustrated why aftermarket turbo cams dont last long. High lift and short duration equals steap ramps on the cams so there is a lot more pressure placed on the lobes by the followers. With the longer duration its like a shorter slope your trying to climb even though you might have the same lift. I like the 87 turbo and 88 tbi cam myself for stock choices.

[iTurbo]

Simon, IIRC you were running the cam timing advanced to aid in spool up correct? Have you tried different settings at the track? I think this would have a huge effect on trap speed.

I've been messing with the cam timing on my Shelby Lancer lately. I got it too far advanced today and it was actually bogging out and the RPMs would fall at WOT once I passed about 5000 RPM. Maybe this is what you are experiencing in the upper RPMs?

[turbovanman²]

And a point is illustrated why aftermarket turbo cams dont last long. High lift and short duration equals steap ramps on the cams so there is a lot more pressure placed on the lobes by the followers. With the longer duration its like a shorter slope your trying to climb even though you might have the same lift. I like the 87 turbo and 88 tbi cam myself for stock choices.

Its a roller so they don't wear out.



Simon, at the Mopar Nats last year, if I remember correctly James Reeves had an S2 cam in his GLH Turbo. He had tried it several times and at many different settings as far as timing with his adjustable cam sprocket. We swapped it in the pits between rounds and he put the stock '89 TBI cam back in and picked back up his 2mph plus he had lost on top end. It also launched harder with the stocker. I think the problem with most of the aftermarket cams is that they have a bit too much overlap which allows the boost to blow right through to the exhaust at higher rpms. Most company's blower cams, regardless of which engines (Chevy, Ford, etc.) are very near stock for overlap and in general don't run as aggressive duration either. I think the theory is to get more lift to allow the forced air in but try to minimize the times that the valves are open to keep the boost in the cylinder.

Then again I could be a total moron...let the audiance decide!

I know, I went over and over the cam thread on TD and the S2 put out more power all over the place over the 88 tbi cam. I could be wrong but driving home tonight, this cam rocks. It pulls like a mofo and hits boost instantly, this is with an auto. I probably burn't 5 gallons of gas, this cam is FUN, pulls to 5500 rpm, :thumb:



Simon, IIRC you were running the cam timing advanced to aid in spool up correct? Have you tried different settings at the track? I think this would have a huge effect on trap speed.

I've been messing with the cam timing on my Shelby Lancer lately. I got it too far advanced today and it was actually bogging out and the RPMs would fall at WOT once I passed about 5000 RPM. Maybe this is what you are experiencing in the upper RPMs?

I was, but now, cam is back to zero for now. The grinder suggested retarding the cam at the track as its ground 2 deg advanced. Like I said, driving home, this cam is fun. Its like a whole new van and the exaust sounds better, :thumb:

[Directconnection]

And a point is illustrated why aftermarket turbo cams dont last long. High lift and short duration equals steap ramps on the cams so there is a lot more pressure placed on the lobes by the followers. With the longer duration its like a shorter slope your trying to climb even though you might have the same lift. I like the 87 turbo and 88 tbi cam myself for stock choices.

Maybe this is Simon's problem? The steep ramp profile with the springs he is using?

[turbovanman²]

Maybe this is Simon's problem? The steep ramp profile with the springs he is using?

Maybe but last night, it pulled awesome. Guess if it doesn't rain on Friday night, we'll find out if it works, :thumb:

[LynX853]

go with the S-2 i say!