Well I finally worked the bugs/leaks etc out and put it on a dyno for tuning. I thought it would be more HP....and am looking for thoughts/ideas. I am running a 401CI with 218/224 at .050 on a 113LSA cam, AFR 195 heads. shorty header with 1 3/4 primaries. Super ram intake with the Edelbrock TPI base intake manifold. 58mm throttle body. Procharger P600b that hit 14lbs of boost thru a large intercooler. Sitting still on the dyno it was getting heat soaked as no moving air to the intercooler-hitting 190F IAT. I ended up with 424HP tops-I was going conservative on timing and AFR-AFR 11.5 was the goal and at 6000RPM up 12 degrees of timing, below that 16 to 17 degrees timing advance. No knock. Dizwiz24-I've seen your numbers-what intake are you running? I am stuck with Cali smog so the super ram is the best I can put on it wih an EO number. Would porting the hell out of the base and runners let it breathe up higher RPM? If I didn't have to smog it-it would have bigger cam/heads full lengh headers and a mini-ram, but it is what it is. I'd really appreciate thoughts on porting the hell out of the base and runners-or anything else I could get away with and still pass visual on the smog that would help. It does have a lot of Torque! If I could have hit high 400s HP I would have been happy. I really thought that boost would overcome that TPI choke point.

 

My car likes around 26 degrees of spark advance.

This pull was 478 whp (Dynojet) at maybe 9-10 psi in relatively hot air: https://datazap.me/u/tequilaboy/dyno...8&mark=443-439

Superram with unported TPIS base, 350, comp 503 cam (224/230), AFR 195, 3.12" blower pulley, Powerdyne BD-11a. Its a bit exhaust choked with 1 5/8 primaries into 2 1/4" duals x-pipe into old direct fit flowmaster 50 series I think.

 

Is the target AFR the actual AFR in your chart? I was going to try carefully adding in timing but ran out of time on the dyno. It looks like you have more cam, but my engine has more CI so you'd think they'd be similar. No knock with 26 degrees? Just looked again-nope no knock. My static CR is 8:1 but with cam specs dynamic CR is up there.Also I take it your maf air temp is in F? What RPM was your peak HP?

 

I've never had a WBO2 on the car. I trust my MAF calibration, so I've never had any real need for a WB. The Target AFR should be in the ballpark. AFR is scaled for E10 fuel ~14.12 stoich, so its a bit leaner than it looks relative to a 100% gasoline scale.

Static compression ratio is about 10:1 with flat-top pistons, 65 cc chambers and 0.028" thick head gasket. Small front mount intercooler. core length: 18" core height: 11.5" core thickness: 4".
inlet/outlet: 3"

Forgot to mention that I don't trust the knock sensor, so even if it does pickup knock counts, I don't pull much timing (if any). This pull was from 2012, so my tune has changed about a million times since then. It is only a reference point. I don't ever hear any audible knock.

You must be pushing that blower pretty hard to get 14 psi with 401 cubes. What is your impeller rpm, step-up ratio (3.05:1?) and pulley diameter?. You may be way out of its efficient range. With a stock 7.2" crank pulley, 3.12" blower pulley and 3.05:1 step-up ratio my impeller is only spinning 42,230 rpm at 6,000 engine rpm. Granted my impeller is biased a bit for lower rpm with its forward swept vane design (928 Motorsports billet impeller).

 

Thanks much for your info-I will be adding timing-hopefully that will pull the hp up where I expected it to be. It was running 16 to 17 degrees thru the pulls-in review the 12 degree was when the limiters were kicking in. So take out 4 degrees boost retard would put it at 21 degrees-I'll see how much diff that makes before I go any higher on the timing. On the impeller speed-procharger says max 60000rpm. My crank pulley is 7.75, SC pulley is 2.55 with a 3.05 ratio-the calc says 55617rpm at 6000 engine rpm., plus I'll be programming it to shift below 6000rpm based on the hp curve, so well within the limits. Who said that little P600b can't push some air?! I have the bracket and pulley from blowerworks so I get max wrap and have not had much belt slip if any. My intercooler is thru the hood with a hood scoop so no air thru it on the dyno with the hood up.

 

Paul's car has pretty similar tuning and is a bit closer to your configuration: https://datazap.me/u/tequilaboy/160-...9&mark=316-214

California car, low compression 383, superram, p600b blower. WB data is included in this one. I don't have any dyno data on this car but was told it made about 530 whp at some point. This is supported by the mass air flow readings approaching 475 gm/sec (about 63 lb/min) even though the calibration is a bit rich.

He's in Torrance. Its a white 86.

 

Almost 700ft LBs of torque to the tires on a California Legal build is crazy impressive. Great build!

 

Here is my ignition chart adjusted on the dyno.
3 deg more advance gave only 2-3 hp more, so it was not left.
Hp power is from the engine...

 

MrBigDee-Do you have a boost timing retard table? Or is that 21.4 degrees total/+ base of 5 that the engine actually sees? Just looked twice at your table-goes past 100 to 200 so direct numbers plugged in-so no boost retard table. But is the "base" timing on top of that?

 

That is a great build yes! It has been awhile but I did a super ram port (ported base too) and still have some pix. I didn't have access to a flow bench for numbers though.

 

I used to run a extrude honed SuperRam and Accel base when I had a 383. Ran low 11's with a 222 230 Crane hydraulic roller cam.

 

This is an awesome build ! Amazing data

690 rwTQ at 2100 RPM ?
wow ! That has to just light it up like a roots-style blower in street driving

I am amazed you were able to get 14 psi out of that.

i messed atound with a 2.xx? pulley / 7.362” 8 rib pulley and a gates RPM belt and couldnt get it over 12 PSI without it heating air up to 200+F , at which point it wouldnt generate more boost - just heat. That was with 100% methanol injection.

basicaly what I think is happening is, you have that blower in its sweet spot down lown (which the p600b is known for), but then it just heats the heck out of the air (and the Super Ram naturally falls off TQ)

You’d make 500+ with an lt1 intake, but at the expense of torque.

I would go into something like a d1-sc, or if engine is built for it, f1a-94 if you want more power up top bc the p600b blower isnt good for that (but im not ******* it, its doing awesome for you down low, that car has to be so fun to drive around town).

The -X blowers are more of a top end RPM blower . They are usually turds down low

that said who know what they’d do combined with the low end grunt of a superram intake.

everything is an experiment at this point.
thank you for sharing

 

Do you remember the cost to extrude hone the base and runners?

 

Thanks! What intake do you run with the combo in your sig-that's putting down 510rwhp? I'm just stuck with Kali smog on what I can run. It is fun with that TQ, but feel that I should be seeing more HP. My plan now is to continue the "experiment" without wasting any pistons. After more research I'm going to book another dyno session and increase timing by 2 degrees at a time under boost and see what the HP does-it looks like I should see significant gains going up from the current 16 degrees-but stop increasing when the gains are minimal and then back off a bit.

 

Thanks, just want more HP now!

 

Here i found this graph of boost (in kPA) vs. RPM on my old p600b max’d out with tiny 2.625” pulley (8 rib slotted) on super tight.

note that it destroyed a gates rpm (unforgiving ) belt with this combo

to answer your question.
lt1 ported intake (elliot portworks) and monoblade TB

 

Heres a photo (shoddy quality) during 3rd gear of a drag run of at least 209F - possibly higher , intake temp (measured in the tubing between p600b and TB) .

that was with 50/50 water/methanol spray (i correct myself earlier i said it was 100% methanol, its not, its 50%)

though my IAT sensor is only about an inch past the meth/water inj, so it may be cooler by the time it hits the intake manifold

I dont see near these intake tube temps with the d1-sc and likely now the f1a-94 that im just breaking in a new motor on. However I did also switch to 100% methanol so that may help also

 

I had it done over 20 years ago. Sorry, don't remember the cost.

 

I don't have it in use and I don't add "base" timing to it.
Yes, 21.4 degrees is total

And my car does not use more than 160kpa when I pull WOT.

 

I have a feeling that the power required to drive the blower is going up faster than the gains above 4500 rpm or so. I don't think the intake is the problem.

Might want to check the actual step-up ratio. Some say that the Corvette P600B blowers have a 3.36:1 ratio instead of 3.05:1.

3.36 – 74/ 22 T – P600B / M1 / P1R fine tooth – straight cut
3.05 – 55/ 18 T – P600B / M1 / P1R coarse tooth – straight cut

Old report attached. I assume that the P600B compressor is pretty similar to the one tested.

14 psi at the manifold is likely 18-19 psi at the blower. Assuming a flow rate ~70 lb/min and a power coefficient of around 8, driving the blower at 55,000 rpm could require about 150 hp.