my 360 WHP blower car with a nasty cam, 3.29 gears etc etc pulls almost 29 MPG on the highway....my bolt on L36 car got about 25....... also, there is absolutely ZERO lag with an M90 car....

 

I'm glad someone pointed both of these..um, points.
A properly set up and well tuned blower car will still get good gas mileage (I was seeing about 25hwy on my stock '04 s/c ss, but get around 28hwy on a bad day with a header/ic/rocker/gen5 setup).

If lag was an issue on an M90 car, then breaking input shafts certainly would not be an issue.

Yeah.

-Riggs.

 

Hence why I said "about". You cannot possibly say that everyone with an L36/L26 is going to dyno exactly 165whp stock, as there are FAR too many variables. Even discounting vehicle age and maintenance, vehicle power varies from engine to engine- these aren't hand built, they come off a production line which has to have tolerance ranges for fitment. Secondly, you have to consider where the car is dyno'd- temperature, humidity, and altitude all have an effect on the power made (unless you're comparing 'corrected' numbers). Lastly, you have to factor in the type of dyno- a Mustang dyno will show lower power numbers than a Dynojet dyno, which will show lower numbers than a wheel hub dyno.

I threw out the 160whp number based off the general assumption of whp being about 80% of bhp on these vehicles. That has never been proven to be exact (you are claiming 82.5%)- but rather just a general ballpark number to get an idea of "about" what the whp should be- hence why I used about, rather than exactly.

Doesn't that kinda prove my point? I'll admit it is lower than I expected; but you spent $2500 to get a dyno number about what a bone stock L67 will do (using your 82.5% figure from above, a L67 should dyno 198 whp and an L32 should dyno 215 whp)- even using my 80% ballpark figure- puts the L67 at ~192whp- just 1 whp less than your car, and you still have a 100% stock, factory warrantied car.

I don't see why any trans work would be necessary anyways- you're still about where stock L67's are from the factory running virtually the same transmission.

AFAIK, no one directly compares the torque numbers because there are too many variables that effect them- especially at the start of the run. From what I remember, it was something about the converter flashing when you nail it that can artificially inflate the number- and I'd assume with the looser converter on the L36 that it could be more pronounced.

I think this says it best:

IMO, comparing 0-40 racing is useless, especially the higher power level FWD cars. On crappy street tires on my old basic bolt on GTP, I couldn't go WOT until ~20mph- and its about the same, maybe a pinch higher on my GXP. On my monte, getting into boost at all anywhere in 1st creates wheel spin. Seems kinda silly to cut down the race length so short that the other car isn't even at WOT most of the time. I could see comparing 0-40 mph on cars that could actually hook- RWD with meaty tires, or AWD cars, but there is a reason why a lot of FWD people like to do roll racing- to avoid the crazy wheelspin from a dead stop and take that out of the equation to more equally compare the cars. Plus- how many races do you actually stop at 40 mph anyways?

Again, reiterating my point- now you're talking about an almost $3000 setup that is extremely labor intensive (ie pulling heads)- that still puts down little more than a bone stock L67 or L32. Also to reiterate a point from above- it seems to me like a cam is your last possible major mod without getting real crazy with custom pistons and crap- how much more power could you have had for the same money with a used turbo setup, or basic bolt on top swap setup?

I take it you've never driven a properly setup turbo car then. "LOTS of lag" is udder crap- maybe a non-BB T76 on an otherwise stock 3800. If you're starting from a stop, you can brake boost the car to get the turbo spooled up; and you can do the same from a roll too (albeit with much more brake wear). Also, at the very bottom rpm from a dead stop- you can't use all the extra power anyways.

If you're so worried about having full boost from a dead stop- I'm sure you could figure out a way to do a transbrake (didn't the GM ecotech drag car with the 4t65 have one?- and I know ZZP was working on one)- and doing a 2 step would be cake with an MSD setup- so you could literally leave on 100% full boost at WOT. The problem is- where are you going to get the traction to hook this kind of power? We're extremely limited on tire width due to being FWD and having to steer with the drive tires, and we have little extra space due to the body of the car. So the lack of full boost at lower rpm isn't hurting anything since we can't put that power down anyways.

My second issue with that is about turbo setups being thirsty. Obviously at WOT, it will consume more fuel- but under normal driving it should be no different than an NA car- as long as the wastegate is wide open and allowing exhaust to bypass the turbine, you aren't making boost- and the engine isn't operating any differently than stock. You're also the first person I've ever heard who says turbo setups have such terrible gas mileage- everything I've heard has said gas mileage is the same.

Secondly- compare apples to apples- a heavily built turbo setup to a heavily built SC or NA setup. The NA setup is going to have by far the most wild cam- with plenty of gas mileage killing valve overlap- unburned gas going straight out the tail pipe. Same to a certain extent with our biggest SC cams- many are very rough and aggressive, with a good bit of overlap. The turbo cams tend to be more mild in that aspect, and tend to get better gas mileage.

This is avoidable for the most part. I assume you're talking about the delay for the boost bypass valve to close, which understandably does slightly delay full boost. You can however bypass that feature (many fiero guys have)- so you always have the SC in the airflow loop. Even with the BBV operational- how much "lag" are you really talking about- virtually none before you're at FULL boost. If you're so concerned- brake boost it off the line; but even then, you can't leave the line at WOT anyways, so what difference does it really make having to wait an extra half second for full boost?

You are definitely WAY over exaggerating my saying "much lower". I looked up the original window sticker fuel economy for a 2000 L36 and L67 GTPs

L36: 20 city 29 hwy
L67: 18 city 28 hwy

So 1 MPG highway is MUCH lower? Even 2 mpg city is pretty small. If you're so concerned about gas mileage- the 3100 of the same year was rated at 30 hwy- so why not opt for that instead? I assume you also run on 87 octane since you're so worried about the fuel costs?

Its not like the supercharger is constantly pressurizing air and drawing massive power- with the bypass valve open, total parasitic loss is barely more than the loss required to spin the rotors and drive.

If you're so concerned about fuel economy, none of us are coming out ahead- these wbodys are huge and fuel inefficient if you're trying to compare the big pictures. There are cars out there faster than ours with much better fuel economy (albeit smaller cars).

Also- keep going up the modding ranks a bit- keep doing more basic bolt ons to an L67 to keep up with the L36, and keep modding the L36 with available bolt ons (including a cam)- and I'd bet, at the same power level the stock cam, basic bolt on L67 gets better gas mileage than the cammed L36. That's not even getting into the money spent between the two to hit the same power level (which is much lower with the L67).

Expanding on this:

Saying you both drive the same mileage each year- and he is spending $141 extra a month on gas. Current national average for gas is $3.05 / gal (which actually is very high if you were comparing all of last year)- that means he used an extra 46.2 gallons per month.

Calculating this for all highway driving - saying your car gets 30 mpg now and you guys both drive the same 1416 miles each month- you would be using 47.2 gallons a month- add in his extra 46.2 gallons a month says he uses 93.4 gallons a month, and would be getting 15.1 MPG highway.

Computing this for the city- your car stock should be about 20 mpg- you would be using 70.8 gallons- add his extra 46.2 - thats 117 gallons per month, and 12.1 MPG city.

So you mean to tell me that his turbo car gets 12 MPG city / 15 MPG highway being driven exactly the same way you drive yours (ie neither person getting on it more than the other)? If this is true- something is SERIOUSLY wrong with your friend's setup.

Lets compare those numbers:
GP w/ turbo: 12 city / 15 hwy / 300-325 bhp?
2006 GTO manual: 17 city / 25 hwy / 400 bhp
2006 Lancer EVO: 19 city / 25 hwy / 287 bhp
2011 Mustang GT500: 15 city / 23 hwy / 550 bhp
2011 Chevy Camaro auto: 16 city / 25 hwy / 426 bhp
2010 Dodge Challenger 6.1L: 14 city / 22 hwy / 425 bhp
2009 Trailblazer SS LS2: 12 city / 16 hwy / 395 bhp

You mean to tell me that your friend really gets the same gas mileage as a 400 hp 4500#+ SUV (and that's with the lower, new EPA ratings- the old ones were 2 mpg higher on the TBSS for city and hwy)? Something is definitely screwy there...

That's also part of the point I was trying to make- you've done a lot of labor (ie removing heads) and spent a good chunk of money just to break even with a stock L67. What happens if the L67 person has mods? You're screwed NA, especially if you want to stick with the stock cam. Now I'm not saying some of the cammed NA setups couldn't hang with a basic bolt on L67- but can you really compare the WESXPRSS versus a basic bolt on L67 in terms of both costs and labor hours? What happens if the person has a cammed L67 or IC turbo kit- you simply cannot hang with an NA 3800.

I assume you will have to run E85 to do that on pump gas without killing timing? If so, the E85 will also lower your fuel economy. Even on normal gas, you'll need premium fuel- which also throws a wrench into your big fuel savings craze.

On top of that, you're talking about adding $2200 heads (plus shipping) for unported units; even with the high compression- will you be able to even come close to any of the heavily modded boosted power numbers? I think not, especially not on a stock cam.

And it will make as much power as a basic bolt on L67 that gets roughly the same MPG, with half the mod cost (or less), and only a fraction of the install labor- that's a no brainer?


My point this whole time has been making big power with these engines is very tough without boost. We have tiny displacement (231 cubic inches compared to 350's, 454's, etc that make decent NA power)- and heads that don't flow for crap (ie small, 2 valve), low stock compression and no real NA aftermarket (no intake manifolds, ultra high compression shelf stock pistons, small cam selection, etc).

Is it doable? Sure it is, but even with big money heads, a big cam, etc- what's the NA FWD record- just below 250 whp? Then when you get beat by an IC only M90 car (250 whp is doable on stock cam and stock heads with an IC), or a turbo car- then what? You can't throw more parts at it, because its almost completely maxed out.

I'm all for being different, but there is a reason why no one has pursued any NA 3800 power goals in a very long time...

 

wow^^^ lots of quotes. bumpin your math is far better than mine but you are correct thats very poor fuel mileage, and probably a mechanical or mathematical error. on having to run e85 with that compression. idk about that. with the aluminum heads he could probably get away with running 93 octane. im running iron heads on mine with almost 11:1 compression, aggressive timing, and im not pinging. i wouldnt go running regular though.

 

I'm assuming you're talking about on your LS4? I wonder how the flow of the zzp aluminum heads compares to the stock LS4 heads? I've heard the 3800 stock heads are worse even than LS1 heads as far as flow goes.

Which I would assume if he's worried about the 1-2 mpg lower fuel economy on the L67 that the extra 20-30 cents a gallon would also be a bad thing.

 

no not on the ls4. on my 406. iron heads, close to 11:1 compression, aggressive timing, no pinging on 93 octane. i dont think he would have to go as far as e85 with the compression hes talking about running with an aluminum head. i wouldnt run it on regular though, aluminum head or not. you can get away with running more compression with an aluminum head as opposed to an iron head. thats why i brought up my personal experience with my 80. im sure that you are correct that the stock ls1 head flows better than the stock 3800 head. i dont have any solid numbers on that, but just on the years the motors came out, aluminum vs iron, and the fact that the ls1 was a performance motor introduced in the corvette as opposed to the 3800.