kp

iTrader: (34)

Decided to hit a local 1/8 mile track yesterday and make a few blasts. It was fairly warm and humid abd the BARO was only 29.8 but it still ran pretty decent. Best 60' was a 1.544 and I think the little 8.6" wide ET streets are about at their limit. Still on the '01 Z06cam, stock valves in ported 98 heads, 98pcm/MAF, stock connecting rods (ARP bolts), wiseco pistons (9.5:1 compression). I am happy with the MPH at this track in this weather, ETs are a little off due to some tirespin.

Thats the good.

I am seeing very high IATs though, over 30 degree rise on a 1/8 mile pass, a good 55-60 degrees over ambient when I let off, around 145 degrees. That plus having the car on the dyno the other day and having a A&A car to compare it to I will say this 3" OBX just isnt up to the job. I was only showing a little over 11psi at 6600 rpm.

I think I am going to try to have Griffin make me an intercooler about the same dimensions with a 4" or so core and see what happens. The A&A kits I have worked with have never seen IATs like this and they use a Bell IC I believe. I may be throwing money away on a different IC but I'm pretty sure this one just isnt cutting it, done enough of these cars by now. I dynod right at 520rwhp with the TH400/9" and slicks so its not making a ton of power but this IC might just be too small.

here is a vid of a 6.80 pass, I couldnt hear my car with the mustang next to me and whacked the limiter pretty hard on the 1-2 and of course the only vid my wife took was the worst pass of the day, at least I beat the mustang though Ran 6.68, 6.69, 6.74 and 6.78 also, between 103.1 and 104.1.




Click here to see Video

PS: I'm just trying to kill these tires and thats why the John Force burnouts, these things just wont wear out and I wont throw them away until they are used up

onfire

iTrader: (17)

Man, a 6.6 at 104mph is impressive! Especially in the heat. I bet you'll pick up 2 psi with a better flowing IC. Congrats!

kp

iTrader: (34)

I think this flows OK, I just dont think it can handle the amount of air going through it. I should just take it off and run a pipe across and see where the boost is at. If I dumped the IC and ran meth I would lose 40lbs off the front probably and pick up 4psi with a straight shot right to the TB

SScam68

iTrader: (20)

hmmm, video is real choppy

It would be interesting to see the results from your intercooler test, even with just the meth.

Damn I love black WS6's, looks saweet!

kp

iTrader: (34)

I cant do anything about the video, it streams off LS1techs video site and may not look too good on a dialup.

We'll see on the IC in a couple weeks, I've spent more on stupider things

JZ 97 SS 1500

iTrader: (2)

The OBX units are not meant for high performance apps. We had a customer of ours that had the same heat rising issues as well. The IC is not very well designed. A temp. solution is , flip one of the tanks over, that dropped the IC temps down about 25 degs.

JZ

SSinNC

I was just curious , is your setup using pump gas only or are you using anything else ?

kp

iTrader: (34)

I have used some ICs woth the inlet/outlet lined up (spearco) on other turbo cars and I never seen anything like this. Maybe this core is aluminized steel or something - it sure weighs enough I wont invest any more in this, I would like to have the inlet/outlet opposed on this, would even like to do vertical flow even more but if I can get the temps down 20% with a better core I would be happy. May or may not work but I'm to lazy to redo the whole front of the car, just got it running.

toslowtosay, I was using 1/2 93 and 1/2 104 unleaded, it wouldnt do too well on straight 93 with these IATs. Going to a dragstrip on pump gas alone in 85+ degree weather with 9.5:1 compression and 10+ psi is asking for trouble., mine may run OK on 93 but why take a chance for 10.00 in gas.

PurEvl

iTrader: (2)

i used a 3" obx with 700hp and on several back to back wot my iats never went over 90...the obx works just fine for some of us. I will be putting a 4" obx on a t88 408 setup soon as well...I will keep an eye out for similiar issues you had...it would suck if I got heat issues too but so far i was lucky with the last one.

kp

iTrader: (34)

Well if it was 60 degrees when I was dynoing it probably would have gone to 90 as well But it was 90 in the shop and going to 135+ on a 6 second dyno pull. Dont let my 520rwhp deceive, it would be over 600 on a M6 car with a 12 bolt and turbo car would be higher with no loss from driving the blower. The OBX works, dont get me wrong, but I think I can find a air to air that works better. I may just try a 4" one, if I get 100.00 for this one it wont be so bad to just try and its zero fabrication to put it on.

Also there is a huge difference between driving down the highway and making a blast with the whole front of the car being cooled off and going to a dragstrip with your car baking in the 85+ degree sun, doing a burnout and letting it stage. I'm starting at 105-115 on the starting line on a 85 degree air temp day so adding another 30-40 degrees on a pass and thats getting up there in temps.

I'm not saying this OBX is no good, it works OK and to be fair they only rate it at 600bhp which I am over anyhow.

Here is a couple logs from the dyno a few days ago with the curser on the max temp (pic 1 and 2), first pull was 520, let it slow down and the second pull was 470, let it cool off for 15 minutes and it was at 515 again (IAt was the same as the first pull). Also another log (pic 3) of an 1/8 mile pass from friday, starting IAT was 109 and it was 85 out, dont mind the speedo, its hooked to the front wheel sensor and is 20% off, never got around to fixing it yet..

Maybe I'm just expecting too much out of a smallish air to air at the dragstrip, but I am just comparing this to dozens of logs I have from D1 A&A C5s and a couple twin turbo cars with Bell/Spearco ICs and mine are a bunch higher in similar conditions.

kp

iTrader: (34)

Also, thanks forcefed98 for noticing the giant air leak on my car in the video. I never really paid attention to it but he said it sounded like the bypass leaking so I watched the video a couple times and it sure did. Turns out the vortech mondo uses and O-ring to seal it and it blew off and was laying around the shaft. Fixed it today and picked up about 1/2PSI, thats 10hp so what the heck I have a feeling that o-ring blowing off is somewwhat common by the looks of how its made.

Slowhawk

iTrader: (12)

In this weather lately any intercooler will suck You will see higher intake temps and decrease in boost.Bring back a 40degree day and you'll gain 80-100hp

PurEvl

iTrader: (2)

great info kp, i notcied in your efi lives that the two hot iat's the car was 196 an 210 but when the car was 172 it was 90 on the iat. Are you sucking in too much engine temp as well?

frcefed98

iTrader: (16)

Your Welcome I'm quite in tune with the MONDO BYPASS and the noise it makes
I can even hear it bypassing while you are burning out....very distinct sound the MONDO makes. It should've only made its loud *** pSSSSSSSSHHH when you let off in the burnout box. Then when you went by the camera it was clearly the MONDO blowing your HP away.
Hope you can fix it with a new oring and maybe some glue in that groove you were telling me about.

J

kp

iTrader: (34)

I agree on the power loss at high temps but over the years I have noticed that you will get about the same amount of temp rise on a 1/4 mile pass on a 60 or 80 degree day, it just starts higher on the 80 degree day. I have logged D1 A&A cars at 2 more PSI of boost (bell) and a spearco core TT car and they only rise 15-20 degrees on a 1/8 mile pass on a 80-85 degree day (10* less then mine). On a 40 degree day I wouldnt be bitching but I wont be seeing one of those for a few months I'm not speculating, I have a ton of logs here from several cars from both the track and the dyno if anyone cares to look at them, I am fairly **** about keeping logs/notes when I tune a car - helps save time on the dyno when you get a similar combo.

PurEvl, My intercooler is nowhere near the radiator and neither is the IAT sensor so engine temp really shouldnt affect the IAT at the sensor, matter of fact my fastest 1/4 mile pass to date was coming right around after a pass and the ECT was 210 degrees. The IAt went from 89 (76 degree evening) to 127 at the end of the 1/4, where a couple cars I have logged with bigger coolers would only pick up 20 degrees at similar power levels. 38 degree rise is a lot on a 76 degree evening with only 11-12psi IMO. Dont mind the weird log jumping around, OBD cable was loose but here is that pass.

Anyhow, I'm not bashing on the OBX or trying to sell anyone on another brand, its working decent but I think I can do a little better with a little larger core from what I have observe/logged on the dyno and track with similar cars with different IC configs. Like I said the 3" OBX is only rated for 600 at the flywheel, I can t expect it to do any better. My main decision right now is to either have Griffin make me a cooler and redo the piping, or try a 4" OBX and just slap it right in. Honestly I am not going to push this thing much harder (stock connecting rods) then I am so I dont need a mega cooler, but if I could knock off 5-10 degrees of temp rise on a 1/4 mile pass on a 80 degree day for a few hundred bucks I would be happy, dont think thats asking a whole bunch

frcefed98

iTrader: (16)

Maybe the IC has a lot of oil build up on the inside as I had my overflow line running into the inlet hat and it can't ditch the heat as well....maybe

It worked well for me but then again I was making a lil less HP than you up here.
J

kp

iTrader: (34)

Its pretty clean inside, like I said though if its rated at 600bhp and I'm making 600 at the wheels (if I had an M6) it would seem to me I'm exceeding its limits a bit Honestly its a well made cooler and its hard to beat for the $$ no doubt. I may just try the 4" OBX since after coating all the piping, making nice little panels under the front to seal the IC to the big hole in the front and make everything and look nice I just dont feel like tearing it all apart again and starting over

I brought this car home and it was stock on march 6th so I think I can take a little break from working on it for a while, I need to work on the 60's a little more then I need another 20rwhp right now

PurEvl

iTrader: (2)

ya if its rated at 600 your definetly taxing it at this point

kp

iTrader: (34)

Oh well, didnt really want to invest too much more time or money into this setup since it has already done what I wanted it to do and its pretty much free waiting for cooler weather

But I ordered a 4" OBX since it will pretty much be a direct swap, we'll see what happens and it sure cant hurt. I may leave the front off and swap them right on the dyno and even put a thermocouple in the inlet since EFIlive has a direct K-type input and will log. Would be interesting to see the in/out temps.

Pro Stock John

iTrader: (34)

How many cfm is the 4" OBX rated for?